om manual for 500 mw gen-bhel

HARIDWAR

BHARAT HEAVY ELECTRICALS LIMITEDHeavy Electrical Equipment Plant

OPERATION & MAINTENANCE

MANUAL

FOR

500 MW TURBOGENERATORWITH

WATER COOLED STATOR WINDING &

DIRECT HYDROGEN COOLED ROTOR WINDING

Project :MEJIA TPS Stage -2 Unit- 1&2(500 MW)

Customer : DVC

BHEL Order no : 10555A12901 10556A12901

BHEL,Haridwar

Turbogenerators

General

Table of Contents

2.0-0010-10555/10609E

Cover Sheet 0.0-0000

GENERAL

Table of Contents . . . . . . . . . . . . . . . . . . 2.0-0010Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0-0030Notes on the Use of the Manual . . . . . . . . . 2.0-0040Operation Beyond Contract Commitment . . 2.0-0050Safe Disposal of Turbogenerator Items 2.0-0200

DESCRIPTION

Brief Description

Rating Plate Data . . . . . . . . . . . . . . . . . . . 2.1-1002Generator Cross Section . . . . . . . . . . . . 2.1-1050Generator Outline Diagram . . . . . . . . . . 2.1-1056Exciter Outline Diagram . . . . . . . . . . . . . 2.1-1058Design and Cooling System . . . . . . . . . 2.1-1100Generator Cooling Gas Circuit . . . . . . . 2.1-1150Stator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1210Stator Winding . . . . . . . . . . . . . . . . . . . . . 2.1-1230Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1300Hydrogen Cooler . . . . . . . . . . . . . . . . . . . 2.1-1440Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1450Shaft Seals . . . . . . . . . . . . . . . . . . . . . . . . 2.1-1460Oil Supply for Bearings and Shaft Seals . . 2.1-1510Seal Oil System (Simplified Diagram) 2.1-1511Gas System . . . . . . . . . . . . . . . . . . . . . . . 2.1-1520Gas System (Simplified Diagram) . . . . 2.1-1521Primary Water System . . . . . . . . . . . . . . 2.1-1530Primary Water System (Simplified Diagram) . 2.1-1531

Technical Data

General and Electrical Data . . . . . . . . . 2.1-1810Mechanical Data . . . . . . . . . . . . . . . . . . 2.1-1820Seal Oil System . . . . . . . . . . . . . . . . . . . 2.1-1825Gas System . . . . . . . . . . . . . . . . . . . . . . . 2.1-1826Primary Water System . . . . . . . . . . . . . . 2.1-1827Waste Gas System . . . . . . . . . . . . . . . . 2.1-1828Excitation System . . . . . . . . . . . . . . . . . . 2.1-1829Cooler Data . . . . . . . . . . . . . . . . . . . . . . . 2.1-1830Reactive Capability Curve . . . . . . . . . . . 2.1-1850Load Characteristic of pilot exciter . . . 2.1-1860Gas Specification . . . . . . . . . . . . . . . . . . 2.1-1883Primary Water Specification . . . . . . . . . 2.1-1885Specification for Ion Exchange Resins 2.1-1887Additive Specification for Alkalizer Unit 2.1-1888

Stator

Stator Frame . . . . . . . . . . . . . . . . . . . . . . 2.1-2100

Stator End Shields . . . . . . . . . . . . . . . . . 2.1-2150Generator Terminal Box . . . . . . . . . . . . 2.1-2170Hydraulic Testing and Anchoring of Stator 2.1-2190Anchoring of Generator on Foundation 2.1-2191Stator Core . . . . . . . . . . . . . . . . . . . . . . . . 2.1-2200Mounting of Stator Core in Stator Frame 2.1-2201Spring Support of Stator Core . . . . . . . . 2.1-2220Stator Winding . . . . . . . . . . . . . . . . . . . . . 2.1-2300Connection Diagram of Stator Winding 2.1-2301Stator Slot . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-2303Transposition of Stator Bars . . . . . . . . . 2.1-2305Micalastic High Voltage Insulation . . . . 2.1-2320Construction of High Voltage Insulation 2.1-2321Corona Protection . . . . . . . . . . . . . . . . . . 2.1-2330Coil and End Winding Support System 2.1-2340Stator End Winding. . . . . . . . . . . . . . . . . 2.1-2341Electrical Connection of Bars, Water Supply and Phase Connectors . . . 2.1-2350Electrical Bar Connections and Water Supply 2.1-2351Terminal Bushings. . . . . . . . . . . . . . . . . 2.1-2370PW Connection for Terminal Bushings and

Phase Connectors . . . . . . . . . . 2.1-2371Cooling of Terminal Bushings . . . . . . . 2.1-2372Components for Water Cooling of Stator

Winding . . . . . . . . . . . . . . . . . . 2.1-2380Grounding of Stator Cooling Water Manifold . . 2.1-2389

Rotor

Rotor Shaft . . . . . . . . . . . . . . . . . . . . . . . . 2.1-3000Cooing of Rotor Winding . . . . . . . . . . . . 2.1-3100Cooling Scheme of Rotor Winding . . . . 2.1-3101Rotor Winding. . . . . . . . . . . . . . . . . . . . . . 2.1-3300Rotor Slot . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-3301Rotor End Winding . . . . . . . . . . . . . . . . . 2.1-3310Rotor Retaining Ring . . . . . . . . . . . . . . . 2.1-3350Rotor Field Connections . . . . . . . . . . . . 2.1-3370Electrical and Mechanical Connection of EE

Coupling . . . . . . . . . . . . . . . . . 2.1-3373Rotor Fan . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-3600

Cooler

Hydrogen Cooler (Description) . . . . . . . 2.1-4000Hydrogen Cooler (Drawing) . . . . . . . . . 2.1-4001

Generator Bearings

Generator Bearing (Description) . . . . . 2.1-5000Generator Bearing (Drawing) . . . . . . . . 2.1-5001Measurement of Bearing Temperature 2.1-5003Generator Bearing Insulation . . . . . . . . 2.1-5005

2.0-0010-10555/20609E

Shaft Seal

Shaft Seal . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-6000Shaft Seal (Drawing) . . . . . . . . . . . . . . . 2.1-6001

Seal Oil System

Seal Oil System . . . . . . . . . . . . . . . . . . . 2.1-7100Differential pressure Valve A . . . . . . . . . 2.1-7101Differential Pressure Valve C . . . . . . . . 2.1-7103Pressure Equalizing Control Valve. . . 2.1-7104Seal Oil System Schematic Diagram . 2.1-7111List of Valves for Seal Oil System. . . . 2.1-7112Bearing Vapour Exhauster. . . . . . . . . . . 2.1-7120Seal Oil Pumps. . . . . . . . . . . . . . . . . . . . 2.1-7123Seal Oil Cooler and Seal Oil Filter. . . . 2.1-7130Seal oil Cooler (Drawing) . . . . . . . . . . . 2.1-7131Seal Oil Filter (Drawing) . . . . . . . . . . . . 2.1-7132Differential Pressure Meter Syste. . . . 2.1-7150

Gas System

Gas System. . . . . . . . . . . . . . . . . . . . . . . 2.1-7200Gas System Schematic Diagram. . . . 2.1-7211List of Valve for Gas System. . . . . . . . . 2.1-7212CO2 Vaporiser. . . . . . . . . . . . . . . . . . . . 2.1-7230Gas Dryer (Refrigeration type) . . . . . . 2.1-7270

Primary Water System

Primary Water System. . . . . . . . . . . . . . 2.1-7300Primary Water System Schematic Diagram. . 2.1-7311List of Valves for Primary Water System 2.1-7312Primary Water Pumps. . . . . . . . . . . . . . 2.1-7320Primary Water Cooler. . . . . . . . . . . . . . . 2.1-7330Primary Water Treatment System. . . . 2.1-7340Alkalizer Unit for Primary Water Circuit 2.1-7341Primary Water Filters. . . . . . . . . . . . . . . 2.1-7343Primary Water Main Filter. . . . . . . . . . . . 2.1-7344Primary Water Fine Filter. . . . . . . . . . . . 2.1-7345Protective Screens at Primary Water Inlet

and Outlet. . . . . . . . . . . . . . . . . 2.1-7349

Automatic Controls

Coolant Temperature Control. . . . . . . . 2.1-8010

Protective Devices

Safety Equipment for Hydrogen Operation. . 2.1-8310Waste Gas System. . . . . . . . . . . . . . . . . 2.1-8311List of Valves for Waste Gas System . 2.1-8312Generator Waste Fluid System . . . . . . 2.1-8315Generator Mechanical Equipment Protection. 2.1-8320Tripping Scheme for Generator Mechanical

Equipment Protection 2.1-8321Generator Mechanical Equipment Protection . 2.1-8323Generator Electrical Protection. . . . . . . 2.1-8330

Tripping Scheme for Generator Electrical Protection . . . . . . . . . . . . . 2.1-8331

Rotor Grounding System . . . . . . . . . . . 2.1-8350Arrangement of Brush Holders for Rotor

Grounding System. . . . . . . . . 2.1-8351

Measuring Devices and SupervisoryEquipment

Introduction. . . . . . . . . . . . . . . . . . . . . . . . 2.1-8400Temperature Transducers. . . . . . . . . . . 2.1-8410Supervision of Generator. . . . . . . . . . . . 2.1-8420Generator measuring points. . . . . . . . . 2.1-8422

Supervision of Bearings. . . . . . . . . . . . . 2.1-8440Supervision of Seal Oil System. . . . . . 2.1-8450Supervision of Gas System. . . . . . . . . 2.1-8460Supervision of Primary Water System 2.1-8470Supervision of Exciter. . . . . . . . . . . . . . 2.1-8490Exciter Measuring Points. . . . . . . . . . . 2.1-8491

Excitation System

Exciter . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1-9100Basic Arrangement of Brushless Excitation

System. . . . . . . . . . . . . . . 2.1-9101Rectifier Wheels. . . . . . . . . . . . . . . . . . . 2.1-9102Rectifier Wheels and Coupling. . . . . . 2.1-9103Permanent-Magnet Pilot Exciter Rotor & Fan 2.1-9104Exciter Cross Section. . . . . . . . . . . . . . 2.1-9110Exciter Cooling Air Circuit. . . . . . . . . . . 2.1-9120Stroboscope for Fuse Monitoring . . . . 2.1-9140Exciter Drying . . . . . . . . . . . . . . . . . . . . . 2.1-9150Ground Fault Detection System for Exciter

Field Circuit. . . . . . . . . . . . . 2.1-9180Arrangement of Bursh Holders for Ground

Fault Detection System . . 2.1-9181Brush Holders for Ground Fault Detection

System. . . . . . . . . . . . . . 2.1-9182

Operation

Operating and Setting Values-General 2.3-4000Gas Quantities. . . . . . . . . . . . . . . . . . . . 2.3-4010Measuring Point List of Generator . . . 2.3-4030Running Routine-General. . . . . . . . . . 2.3-4100Operating Log-Generator Supervision 2.3-4120Operating Log-Seal Oil System . . . . . 2.3-4150Operating Log-Gas System . . . . . . . . 2.3-4160Operating Log-Primary Water System 2.3-4170Operating Log-Exciter Supervision . . 2.3-4190

Start-up

Preparations for Starting-Introduction 2.3-5000Hints for Cooler Operation. . . . . . . . . . 2.3-5003Filling and Initial Operation of Air Side Seal

Oil Circuit. . . . . . . . . . . . . . . . . 2.3-5110

BHEL,Haridwar

Turbogenerators

General

2.0-0010-10555/30609E

Filling and Initial Operation of Hydrogen Side Seal Oil Circuit . . . 2.3-5120

Venting of Seal Oil Circuits. . . . . . . . . . 2.3-5130Setting of Seal Oil Pressures. . . . . . . 2.3-5150Setting of Operating Values for Seal Oil System 2.3-5160Measurement of Seal Oil Volume Flows 2.3-5163Functional Testing of Pumps and Exhausters 2.3-5180Startup of Air Side Seal Oil Circuit . . . 2.3-5210Startup of Hydrogen Side Seal Oil Circuit. . . . 2.3-5220Venting of Seal Oil Circuits and Checking of

Seal Oil Pressures . . 2.3-5230Checking Automatic Operation of Seal Oil

Pumps. . . . . . . . . . . . . . . . 2.3-5280Positions of Multi-Way Valves in Gas System 2.3-6107Scavenging the Electrical Gas Purity Meter

System . . . . . . . . . . . . . 2.3-6110Setting Electrical Zero of Electrical Gas Purity

Meter System . . . . . . . . 2.3-6120Purity Measurement During CO2 Filling 2.3-6130Purity Measurement During H2 Filling 2.3-6140Purity Measurement During H2 Operation 2.3-6150Gas Filling-Replacing Air With CO2. . . . . . 2.3-6310Gas Filling-Replacing CO2 With H2. . . . . . 2.3-6320N2 Purging After Filling of Primary Water

System . . . . . . . . . . . . . . . . . . 2.3-6810

Filling and Initial Operation of Primary WaterSystem-

Preparatory Work . . . . . . . . . . . . . . . . . . 2.3-7100Filling External Part of Primary Water Circuit 2.3-7110Filling the Water Treatment System . . 2.3-7120Filling the Terminal Bushings and Phase

Connectors . . . . . . . . . . . . . 2.3-7150Filling the Stator Winding . . . . . . . . . . . 2.3-7160Filling Primary Water Coolers on Cooling

Water Side . . . . . . . . . . . . . 2.3-7180Activating Primary Water System After a

Shutdown of Less Than 48 Hours 2.3-7210Activating Primary Water System After a

Shutdown of More Than 48 Hours 2.3-7220 Activating the Primary Water Conductivity

Meter System . . . . . . 2.3-7530Activating the Primary Water Volume Flow

Meter System . . . . . . . . . . . . . 2.3-7540Initial Operation of Primary Water System -

Checks Prior to Startup . . 2.3-7610Turning Gear Operation and Runup of

Generator . . . . . . . . . . . . . . . . . . . . . 2.3-8010Generator Startup Diagram . . . . . . . . . 2.3-8011Permissible Synchronizing Criteria . . 2.3-8081

On-Load Running

Permissible Load Limits of Generator 2.3-8170Permissible Loading at Rated PF During

Voltage and Frequency Deviations . . 2.3-8181

Generator Capability With Hydrogen Coolers out of Service on Water Side 2.3-8184

Unbalanced Load-Time Curve . . . . . . 2.3-8187Current Overload Capability . . . . . . . . . 2.3-8188Runback for loss of stator coolant . . 2.3-8190Unloading schedule for increased cooling

water inlet temperature . . 2.3-8191

Shutdown

Shutdown of Generator . . . . . . . . . . . . . 2.3-8310Generator Shutdown Diagram . . . . . . 2.3-8311

Supervision of Generator during Standstill

General . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-8400Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-8440Seal Oil System . . . . . . . . . . . . . . . . . . . 2.3-8500Shutdown of Seal Oil System . . . . . . . 2.3-8510Draining the air Side Seal Oil Circuit 2.3-8520Draining the Hydrogen Side Seal Oil Circuit 2.3-8521Draining the Seal Oil Signal Lines and Seal

Ring Relief Piping . . . . . 2.3-8522Gas System . . . . . . . . . . . . . . . . . . . . . . 2.3-8600Gas Removal-Lowering Hydrogen Gas

Pressure in Generator . . . . . . . 2.3-8610Gas Removal-Replacing H2 with CO2 2.3-8620Gas Removal-Replacing CO2 With Air 2.3-8630N2 Purging Before Draining of Primary

Water System . . . . . . . . . . 2.3-8650Primary Water System . . . . . . . . . . . . . 2.3-8700Shutdown of Primary Water System for Less

Than 48 Hours . . . . . . . . 2.3-8720Shutdown of Primary Water System for More

Than 48 Hours . . . . . . . . 2.3-8730Draining the Primary Water System- PW

Coolers (Cooling Water Side) . . . . 2.3-8732Draining the Primary Water System- Stator

Winding . . . . . . . . . . . . . . . . . 2.3-8734Draining the PW System-Terminal Bushings

and Phase Connectors 2.3-8738Draining the Primary Water System- Water

Treatment System . . . . . . . . 2.3-8746Draining the Primary Water System- External

Part of Primary Water Circuit 2.3-8748Exciter . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-8900

Fault Tracing

General . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9000Stator and Generator Supervisory Equipment 2.3-9200Coolant Temperature Control. . . . . . . 2.3-9280Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9310Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9440Bearings . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-9450Bearing Vapour Exhausters . . . . . . . . . 2.3-9521Seal Oil Pumps . . . . . . . . . . . . . . . . . . . 2.3-9523

2.0-0010-10555/40609E

Seal Oil Pressures and Temperatures 2.3-9531Relief Valves in Seal Oil System 2.3-9551Oil Level in Seal Oil System . . . . . . . . 2.3-9561Gas Pressures . . . . . . . . . . . . . . . . . . . 2.3-9640Gas Purity Meter System . . . . . . . . . . . 2.3-9680Primary Water Pumps . . . . . . . . . . . . . . 2.3-9720Water Pressures and Temperatures in

Primary Water System . . . . . . . . 2.3-9730Filters in Primary Water System . . . . . 2.3-9740Water Level in Primary Water Tank . . . 2.3-9760Conductivity in Primary Water System 2.3-9782Volume Flow Rates in Primary Water System 2.3-9784Alkalizer Unit for Primary Water System 2.3-9785Fuses on Rectifier Wheels . . . . . . . . . 2.3-9901Exciter Temperatures . . . . . . . . . . . . . . 2.3-9911Exciter Cooler . . . . . . . . . . . . . . . . . . . . . 2.3-9914Stroboscope . . . . . . . . . . . . . . . . . . . . . . 2.3-9941Exciter Drying System . . . . . . . . . . . . . 2.3-9955Ground Fault Detection System in Exciter

Field Circuit . . . . . . . . . . . . . 2.3-9980

Maintenance and supervision-

Introduction. . . . . . . . . . . . . . . . . . . . 2.4-4200Stator. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-4210Generator Coolers . . . . . . . . . . . . . . . . . 2.4-4240Bearings . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-4250Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-4310Seal Oil Pumps & Bearing Vapour Exhauster 2.4-4520Seal Oil Coolers . . . . . . . . . . . . . . . . . . . 2.4-4540Seal Oil Filters . . . . . . . . . . . . . . . . . . . . 2.4-4550Gas Consumption . . . . . . . . . . . . . . . . . 2.4-4610Primary Water Pumps . . . . . . . . . . . . . . 2.4-4720Primary Water Filters . . . . . . . . . . . . . . . 2.4-4740Primary Water Coolers. . . . . . . . . . . . . 2.4-4750Water Level in Primary Water Tank . . . 2.4-4760Concutivity Meter System. . . . . . . . . . . . 2.4-4780Alkalizer Unit . . . . . . . . . . . . . . . . . . . . . . 2.4-4785Fuses on Rectifier Wheels. . . . . . . . . . 2.4-4910Exciter Dryer . . . . . . . . . . . . . . . . . . . . . . 2.4-4925Ventilation and Make-Up Air Filters 2.4-4930Exciter Coolers . . . . . . . . . . . . . . . . . . . . 2.4-4940Ground Fault Detection System. . . . . . 2.4-4990

Inspection

Introduction. . . . . . . . . . . . . . . . . . . . . . . . 2.5-0010Determination of Dewpoint Temperature 2.5-0019Packing,Transport, Storage of Gen Rotors 2.5-0030Preventive Measures for Transport and

Storage of Generator Rotors . 2.5-0031Checking Desiccant in Gen Rotor Packing 2.5-0032Insulation Resistance Measurements on

Rotor and Exciter Windings. . . . 2.5-0033Preparation of Machinery Parts . . . . . . 2.5-0200Checking the Bearing and Seal Insulation . . 2.5-0300Test Norms During Overhaul . . . . . . . . 2.5-0305Leakage Tests of Generator and Gas System 2.5-0310Flushing the Oil Piping . . . . . . . . . . . . . 2.5-0320

Measures to Prevent Corrosion During Inspecitons . . . . . . . . . . . . . 2.5-1003

Preventive Measures to Avoid Stress Corrosion . . . . . . . . . . . . . . . 2.5-1005

Inspection Schedule-Foreword . . . . . . 2.5-1010Inspection Schedule-Stator . . . . . . . . . 2.5-1020Inspection Schedule-Rotor . . . . . . . . . 2.5-1030Inspection Schedule-Coolers . . . . . . . 2.5-1040Inspection Schedule-Bearings . . . . . . 2.5-1050Inspection Schedule-Shaft Seals . . . . 2.5-1060Inspection Schedule-Seal Oil System 2.5-1071Inspection Schedule-Gas System . . . 2.5-1072Inspection Schedule-Primary Water System 2.5-1073Inspection Schedule-Generator Supervisory

Equipment. . . . . . . . . . 2.5-1080Inspection Schedule-Excitation System 2.5-1090Measures for Preservation of Generator

During Standstill. . . . . . . . . . . . . . . . . 2.5-1100Stator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5-2000Cementing the Joints of Profiled Gaskets. . 2.5-2120Sealing Generator End Shield Joints . 2.5-2160IR Measurements on Stator Winding 2.5-2300Procedure for carrying out Tan delta test with

End Winding Vibration probes in position 2.5-2305Drying the Windings . . . . . . . . . . . . . . . 2.5-2310Test Instruction for Stator Slot Support System

With Top Ripple Springs . . 2.5-2340Stator Slot Support System-Radial Wedge

Movements-Test Record . . 2.5-2341Test Equipment for Stator Slot Support System 2.5-2342Instructions for Checking the Stator Slot

Support System. . . . . . . . . . . . . 2.5-2343Rewedging of Stator Winding. . . . . . . . 2.5-2345Cementing Stator Slot End Wedges at Turbine

and Exciter Ends. . . . . . 2.5-2346Treatment of Bolted Contact Surfaces 2.5-2350Rotor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5-3000Insulation Resistance Measurements on Rotor

and Exciter Windings 2.5-3300Ultrasonic Examination of Rotor Retaining

Rings at Power Plant . . . 2.5-3357Hydrogen Coolers. . . . . . . . . . . . . . . . . . 2.5-4000Insertion and Removal of Hydrogen Coolers 2.5-4100Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . 2.5-5000Shaft Seals. . . . . . . . . . . . . . . . . . . . . . . . 2.5-6000Seal Oil System. . . . . . . . . . . . . . . . . . . . 2.5-7100Seal Oil Pumps & Bearing Vapour Exhausters 2.5-7120Seal Oil Coolers. . . . . . . . . . . . . . . . . . . 2.5-7130Gas System. . . . . . . . . . . . . . . . . . . . . . . 2.5-7200Primary Water System. . . . . . . . . . . . . . 2.5-7300Primary Water Pump. . . . . . . . . . . . . . . . 2.5-7320Primary Water Coolers . . . . . . . . . . . . . 2.5-7330Treatment and Cleaning of Pipes in Primary

Water Circuit . . . . . . . . . 2.5-7381Flushing External Part of Primary Water Circuit2.5-7382Leakage Test of External Primary Water Circuit2.5-7384Excitation System-Exciter . . . . . . . . . . . 2.5-9000Checking the Insulation Resistance of Heat

Sink Insulation . . . . . . . . . . 2.5-9010Checking the Insulation at Rectifier Wheels 2.5-9011

BHEL,Haridwar

Turbogenerators

GeneralPreface

2.0-0030-0500/10609E

This manual contains informat ion onoperation and maintenance of Turbogeneratorand its auxillary systems.

The information has been prepared on theassumpt ion that the operat ing andmaintenance personnel have a basicknowledge of power plant engineering andoperation. It is an essential prerequisite forsatisfactory operation and maintenance of theturbogenerator that the operat ing and

maintenance personnel are fully familiar withthe design of the turbogenerator plant andhave aquired thorough training in operationand maintaining the unit.

The manual is subdevided into followingmain sections

-General-Description-Operation-Maintenance-Inspection

BHEL,Haridwar

Turbogenerators

GeneralNotes on the Use of the Mannual

2.0-0040-0500/10609E

The turbogenerator instruction manual consistsof the following manual sections:

2.0 General2.1 Description2.3 Operation2.4 Maintenanceand Supervision2.5 Inspection

Each sect ion contains a number of separateinstructions.

The manual contains a Table of Contents togetherwith a List of Effective Pages. Please check yourmanual against this list and advise if there are anyomissions.

Identification Number

The identification number consists of the abovementioned section number, supplemented by a four-digit code number. It is indicated in the bottom mostline of the pages.

For the user of the manual, the identif icationnumber is a suff ic ient reference for locat ing aparticular instruction number must be indicated.

Instruction Number

The instruction number consists of the manualsection number, the identification number, the variantnumber, the page number, and the date with thelanguage symbol.

2.0 - 0040 - 0009 / 11205 E

Manual section number

Identification number

Variant number

Page number

Language (English)

Date (mm yy)

BHEL,Haridwar

Turbogenerators

General

Operation Beyond ContractCommitment

2.0-0050-0500/10609E

The Turbogenerator set has been designed andmanufactured to meet the contract commitment asregards to the capability for the continuous operationor variable load operation below maximum continuousrating with an aim to achieve objective of securinglong life and trouble free operation.

Because of the margin provided in the design, itmay be possible to operate the turbogenerator atoverloads for the time specified in the manual.However, such operations although possible for theshort time will encroach upon the design margin builtinto the generator.

The Turbogenerator is designed to operate withinthe temperature rise in accordance with EC standard.Operating the generator in excess of the capabilitycurves which are part of this O & M Manual will cause

increase in Copper temperature, thermal expansionand higher insulation stresses. Such operation is notpermitted by the manufacturer.

Continued operation of unit without recommendedscheduled maintenance will eventually result inincreased maintenance and reduction in the usefullife of the machine. BHEL cannot be responsible forany malfunctioning occurring as a result of operationbeyond the contract limits and operation of machinewithout carrying out scheduled maintenance/inspection. Such operation if undertaken by the usermust be at his own risk.

BHEL reserves the right of changing the operationand maintenance instructions based on experiencegained.

BHEL,Haridwar

Turbogenerators

General

Safe Disposal of Turbogenerator Items

In line with ISO 14001 requirements HEEP-BHEL,Haridwar has adopted an Environmental policy andhas pledged to fulfil its responsibility of protectingand conserving the environment around itself.

The materials, which are scrapped duringinspections and capital overhaul after consumption oftheir useful life, are disposed in an environment friendlymanner to protect our natural resources and controlenvironment pollution.

Guidelines given in the following paragraphs cango a long way in planning the activity of scrapping thehazardous material effectively in an echo friendlymanner.

A proper system of waste disposal should also beevolved and its compliance ensured and necessaryprecautions as published from time to time adhered towhile disposing hazardous material.

Generator is manufactured mainly from threetypes of items namely,

1. Metals:

Structured steel, Cast steel, Forged steel, brass,bronze etc.

2. Non Metals:

Rubber, insulation, plastics, glass etc.

3. Lubricating oil and Greases.

Disposal of Generator wastes:1. Metals:

May be disposed as scrap metal for recycling andreuse.

2. Non- Metals:

a) Rubber:

Residue of fluoro-elastomer products, obtained by

exposure of fluoro-elastomers like O-rings, rubbers etc.at very high temperature above 400 degree C, in extremecase of fire etc, should be disposed with great care, suchas very high incineration.

b) Insulation:

Insulation material should be disposed by very highincineration.

c) Plastics and glass:

May be disposed as scrap material for recycling andreuse.

3. Lubricating Oil and Grease:

These items can be disposed/recycled/ reused asfollows:

a) Lubricating Oil :

To be recycled after cleaning as far as possible. Afterit has become unserviceable, it may be disposed asfollows:

Send the discarded oil to registered refiners whohave facilities to reclaim the oil by

- physio-chemical treatment for further use in noncritical applications.

- send the used oil to parties who are licensed to handle and dispose used lubricating oil.

- burn off the discarded oil in boiler furnace by mixing with fuel oil.

b) Grease:

I t may be disposed for reuse as low-gradelubrication.

2.0-0200-0500/10609E

BHEL,Haridwar

Turbogenerators

General

Project name: MEJIA TPS Stage-II Unit-1 10555A12901

Unit-2 10556A12901

Rating Plate Data for Generator

2.1-1002-10555/10609E

BHARAT HEAVY ELECTRICALS LTD

KW : 500,000

Gas Pressure : 3.5 Kg/cm2 (g)

P.F. 0.85 Lag

R.P.M : 3000

Insulation : Class F

KVA : 588,000 Hz : 50

Type: THDF 115/59

StatorVolts 21000

Amps 16166

Phase 3

Conn. Y Y

Spec. IS: 5422I I

RotorAmps 4040

Volts 340 Coolant: Hydrogen & Water

DIV : HaridwarMADE IN INDIA

IEC: 34

BHEL,Haridwar

Turbogenerators

General

Generator Cross Section

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BHEL,Haridwar

Turbogenerators

General

General Outline Drawing

2.1-1056-0500/10609E

BHEL,Haridwar

Turbogenerators

General

Weights:Total Weight 39 300 kgRotor 7 550 kgCoolers (without water) 1 860 kg

Exciter Outline DrawingELR 70/90-30/6-20ELR 50/42-30/16

2.1-1058-0500/10609 E

BHEL,Haridwar

Turbogenerators

General

General Design Features

Design and Cooling System

2.1-1100-0500/10609 E

1. General

The two-pole generator uses direct water coolingfor the stator winding, phase connectors and bushingsand direct hydrogen cooling for the rotor winding. Thelosses in the remaining generator components, such asiron losses, windage losses and stray losses, are alsodissipated through hydrogen.

The generator frame is pressure-resistant and gastight and equipped with one stator end shield on eachside. The hydrogen coolers are arranged vertically insidethe turbine end stator end shield.

The generator consists of the following components :

• StatorStator frameEnd shieldsStator coreStator windingHydrogen coolers

• RotorRotor shaftRotor windingRotor retaining ringsField connections

• BearingsShaft seals

The following additional auxiliaries are required forgenerator operation :

• Oil system• Gas system• Primary water system• Excitation system

2 Cooling System

The heat losses arising in the generator interior aredissipated to the secondary coolant (raw water,condensate etc.) through hydrogen and primary water.

Direct cooling essentially eliminates hot spots anddifferential temperatures between adjacent componentswhich could result in mechanical stresses, particularlyto the copper conductors, insulation, rotor body andstator core.

3. Hydrogen Cooling Circuit

The hydrogen is circulated in the generator interiorin a closed circuit by one multi-stage axial-flow fanarranged on the rotor at the turbine end. Hot gas is drawn

by the fan from the air gap and delivered to the coolers,where it is re-cooled and then divided into three flowpaths after each cooler.

Flow path I is directed into the rotor at the turbineend below the fan hub for cooling of the turbine end halfof the rotor.

Flow path II is directed from the coolers to theindividual frame compartments for cooling of the statorcore.

Flow path III is directed to the stator end windingspace at the excitor end through guide ducts in the framefor cooling of the exciter end half of the rotor and of thecore end portions.

The three flows mix in the air gap. The gas is thenreturned to the coolers via the axial-flow fan.

The cooling water flow through the hydrogencoolers should be automatically controlled to maintain auniform generator temperature level for various loadsand cold water temperatures.

4. Cooling of Rotor

For direct cooling of the rotor winding, cold gas isdirected to the rotor end windings at the turbine andexcitor ends. The rotor winding is symmetrical relativeto the generator center line and pole axis. Each coilquarter is divided into two cooling zones. The first coolingzone consists of the rotor end winding and the secondone of the winding portion between the rotor body endand the mid-point of the rotor. Cold gas is directed toeach cooling zone through separate openings directlybefore the rotor body end. The hydrogen flows througheach individual conductor in closed cooling ducts. Theheat removal capacity is selected such thatapproximately identical temperatures are obtained forall conductors. The gas of the first cooling zone isdischarged from the coils at the pole center into acollecting compartment within the pole area below theend winding. From there the hot gas passes into the airgap through pole face slots at the end of the rotor body.The hot gas of the second cooling zone is dischargedinto the air gap at mid-length of the rotor body throughradial openings in the hollow conductors and wedges.

5. Cooling of Stator Core

For cooling of the stator core, cold gas is admittedto the individual frame compartments via separatecooling gas ducts.

From these frame compartments the gas then flowsinto the air gap through slots in the core where it absorbs

2.1-1100-0500/2 0609E

the heat from the core. To dissipate the higher losses inthe core ends, the cooling gas slots are closely spacedin the core end sections to ensure effective cooling.These ventilating ducts are supplied with cooling gasdirectly from the end winding space. Another flow pathis directed from the stator end winding space past theclamping fingers between the pressure plate and coreend section into the air gap. A further flow path passesinto the air gap along either side of the flux shield.

All the flows mix in the air gap and cool the rotorbody and stator bore surfaces. The gas is then returnedto the coolers via the axial-flow fan. To ensure that thecold gas directed to the exciter end cannot be directlydischarged into the air gap, an air gap choke is arrangedwithin the range of the stator end winding cover and therotor retaining ring at the exciter end.

6. Primary Cooling water Circuit in the Generator

The treated water used for cooling of the statorwinding phase connectors and bushings is designatedas primary water in order to distinguish it from thesecondary coolant (raw water, condensate, etc.). Theprimary water is circulated in a closed circuit anddissipates the absorbed heat to the secondary coolingwater in the primary water cooler. The pump is suppliedwith hot primary water from the primary water tank anddelivers the water to the generator via the coolers. The

cooled water flow is divided into two flow paths asdescribed in the following paragraphs.

Flow path 1 cools the stator windings. This flowpath first passes to a water manifold on the excitor endof the generator and from there to the stator bars viainsulated hoses. Each individual bar is connected to themanifold by a separate hose. Inside the bars the coolingwater flows through hollow strands. At the turbine end,the water is passed through similar hoses to anotherwater manifold and then returned to the primary watertank. Since a single pass water flow through the statoris used, only a minimum temperature rise is obtained forboth the coolant and the bars. Relative movements dueto different thermal expansions between the top andbottom bars are thus minimized.

Flow path 2 cools the phase connectors andbushings. The bushings and phase connectors consistof thick-walled copper tubes through which the coolingwater is circulated. The six bushings and the phaseconnectors arranged in a circle around the stator endwinding are hydraulically interconnected so that threeparallel flow paths are obtained. The primary water entersthree bushings and exits from the three remainingbushings.

The secondary water flow through the primary watercooler should be controlled automatically to maintain auniform generator temperature level for various loadsand cold water temperatures.

BHEL,Haridwar

Turbogenerators

General

Generator Cooling Gas Circuit

2.1-1150-0500/10609 E

Note: The cross section may not match with the generator described in this manual

Section A-B

Section E-F

BHEL,Haridwar

Turbogenerators

General


Stator

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1. Stator Frame

The stator frame consists of a cylindrical sectionbody and two end shields which make the stator gas-tight and pressure-resistant.

The stator end shields are joined and sealed tothe stator frame with an O-ring and bolted flangeconnection. The stator frame accommodates theelectricity active parts of the stator, i.e., the stator coreand the stator windings. Both the gas ducts and alarge number of welded circular ribs provide for therigidity of the stator frame. Ring-shaped supports forresilient core suspension are arranged between thecircular ribs. The generator cooler is subdivided intocooler sections arranged vertically in the turbine sidestator end shield. In addition, the stator end shieldscontain the shaft seal and bearing components. Feetare welded to the stator frame and end shields tosupport the stator on the foundation. The stator isfirmly connected to the foundation with anchor boltsthrough the feet.

2. Stator Core

The stator core is s tacked f rom insulatedelectrical sheet-steel laminations and mounted insupporting rings over insulated dovetailed guide bars.Axial compression of the stator core is obtained byclamping fingers, pressure plates, and non-magneticthrough-type clamping bolts, which are insulated fromthe core. The supporting rings form part of an innerframe cage. This cage is suspended in the outer frameby a large number of separate flat springs distributedover the entire core length. The flat springs aretangentially arranged on the circumference in setswith three springs each, i.e. two vertical supportingsprings on both sides of the core and one horizontalstabilizing spring below the core. The springs are soarranged and tuned that forced vibrations of the coreresulting from the magnetic field will not be transmittedto the frame and foundation.

The pressure plates and end portions of thestator core are effectively shielded against straymagnetic fields. The flux shields are cooled by flowof hydrogen gas directly over the assembly.

BHEL,Haridwar

Turbogenerators

General


Stator Winding

2.1-1230-0500/10609 E

1. Construction

Stator bars, phase connectors and bushings aredesigned for direct water cooling. In order to minimizethe stray losses, the bars are composed of separatelyinsulated strands which are transposed by 540° in theslot portion and bending, the end turns are likewisebonded together with baked synthetic resin fillers.

The bars consist of hollow and solid strandsdistributed over the entire bar cross-section so thatgood heat dissipation is ensured. At the bar ends, allthe solid strands are jointly brazed into a connectingsleeve and the hollow strands into a water box fromwhich the cooling water enters and exits via tefloninsulating connection between top and bottom barsis made by a bolted connection at the connectingsleeve.

The water manifolds are insulated from the statorframe, permitting the insulation resistance of thewater-filled winding to be measured. During operation,the water manifolds are grounded.

2. Micalastic High-Voltage Insulation

High-voltage insulation is provided according tothe proven Micalastic system. With this insulatingsystem, several half-overlapped continuous layers ofmica tape are applied to the bars. The mica tape isbuilt up from large area mica splittings which aresandwiched between two polyester backed fabriclayers with epoxy as an adhesive. The number oflayers, i.e., the thickness of the insulation dependson the machine voltage. The bars are dried undervacuum and impregnated with epoxy resin which hasvery good penetrat ion propert ies due to i ts lowviscosity. After impregnation under vacuum, the barsare subjected to pressure, with nitrogen being used

as pressur iz ing medium (VPI process) . Theimpregnated bars are formed to the required shapein molds and cured in an oven at high temperature.The high-voltage insulation obtained is nearly void-free and is characterized by its excellent electrical,mechanical and thermal properties in addition to beingfully waterproof and oil-resistant. To minimize coronadischarges between the insulation and the slot wall,a final coat of semiconducting varnish is applied tothe surfaces of all bars within the slot range. Inaddition, all bars are provided with an end coronaprotection, to control the electric field at the transitionfrom the slot to the end winding and to prevent theformation of creepage spark concentrations.

3. Bar Support System

To protect the stator winding against the effectsof magnet ic forces due to load and to ensurepermanent firm seating of the bars in the slots duringoperation, the bars are inserted with a top ripple springlocated beneath the slot wedge. The gaps betweenthe bars in the stator end windings are completelyfilled with insulating material which in turn is fullysupported by the frame. Hot-curing conforming fillersarranged between the stator bars and the support ringensure a firm support of each individual bar againstthe support ring. The bars are clamped to the supportring with pressure plates held by clamping bolts madefrom a high-strength insulating material. The supportring is free to move axially within the stator frame sothat movements of the winding due to thermalexpansions are not restricted.

The stator winding connections are brought outto six bushings located in a compartment of weldednon-magnetic steel below the generator at the exciterend. Current transformers for metering and relayingpurposes can be mounted on the bushings.

BHEL,Haridwar

Turbogenerators

General


Rotor

2.1-1300-0500/10609E

1. Rotor Shaft

The rotor shaft is a single-piece solid forgingmanufactured from a vacuum casting. Slots for insertionof the field winding are milled into the rotor body. Thelongitudinal slots poles are obtained. The rotor poles aredesigned with transverse slots to reduce twice systemfrequency rotor vibrations caused by deflections in thedirection of the pole and neutral axis.

To ensure that only high-quality forging is used,strength tests, material analysis and ultrasonic tests areperformed during manufacture of the rotor.

After completion, the rotor is balanced in variousplanes at different speeds and then subjected to anoverspeed test at 120% of rated for two minutes.

2. Rotor Winding

The rotor winding consists of several coils whichare inserted into the slots and series connected suchthat two coil groups form one pole. Each coil consists ofseveral series connected turns, each of which consistsof two half turns which are connected by brazing in theend section.

The rotor winding consists of si lver-bearingdeoxidized copper hollow conductors with two lateralcooling ducts. L-shaped strips of laminated epoxy glassfiber fabric with Nomex filler are used for slot insulation.

The slot wedges are made of high-conductivity materialand extend below the shrunk seat of the retaining ring.The seat of the retaining ring is silver-plated to ensure agood electrical contact between the slot wedges androtor retaining rings. This system has long proved to bea good damper winding.

3. Retaining Rings

The centrifugal forces of the rotor end windings arecontained by single-piece rotor retaining rings. Theretaining rings are made of non-magnetic high-strengthsteel in order to reduce stray losses. Each retaining ringwith its shrink-fitted insert ring is shrunk onto the rotorbody in an overhung position. The retaining ring issecured in the axial position by a snap ring.

4. Field Connections

The field current is supplied to the rotor windingthrough radial terminal bolts and two semicircularconductors located in the hollow bores of the exciter androtor shafts. The field current leads are connected tothe exciter leads at the exciter coupling withmulticontact plug-in contact which allow forunobstructed thermal expansion of the field currentleads.

BHEL,Haridwar

Turbogenerators

General

The hydrogen cooler is a shell and tube type heatexchanger which cools the hydrogen gas in thegenerator. The heat removed from the hydrogen isdissipated through the cooling water. The cooling waterflows through the tubes, while the hydrogen is passedaround the finned tubes.

The hydrogen cooler is subdivided into identicalsections which are vertically mounted in the turbine-endstator end shield. The cooler sections are solidly boltedto the upper half stator end shield, while the attachmentat the lower water channel permits them to move freelyto allow for expansion.

The cooler sections are parallel-connected on theirwater sides. Shut-off valves are installed in the linesbefore and after the cooler sections. The required coolingwater flow depends on the generator output and it isadjusted by control valves on the hot water side.Controlling the cooling water flow on the outlet sideensures an uninterrupted water flow through the coolersections so that proper cooler performance will not-beimpaired.


Hydrogen Cooler

2.1-1440-0500/1 0609E

1 Cooler2 Stator end shield

Fig.1 Arrangement of Hydrogen Cooler

1 2

BHEL,Haridwar

Turbogenerators

General


Bearings

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1 Connection for shaft lift oil2 Thermocouple3 Bearing sleeve

Fig.1 Bearing

The sleeve bearings are provided with hydraulicshaft lift oil during start-up and turning gear operation.To eliminate shaft currents, all bearings are insulatedfrom the stator and base plate, respectively. Thetemperature of the bear ings is moni tored wi ththermocouples embedded in the lower bearing sleeveso that the measuring points are located directly belowthe babbitt. Measurement and any required recordingof the temperatures are performed in conjunction withthe turbine supervision. The bearings have provisionsfor f i t t ing v ibrat ion p ickups to moni tor bear ingvibrations.

1 2 3

BHEL,Haridwar

Turbogenerators

General

The points where the rotor shaft passes throughthe stator casing are provided with a radial seal ring.The seal ring is guided in the seal ring carrier which isbolted to the seal ring carrier flange and insulated toprevent the flow of shaft currents. The seal ring is linedwith babbitt on the shaft journal side. The gap betweenthe seal ring and the shaft is sealed withseal oil onhydrogen side and air side. The hydrogen side seal oilis supplied to the seal ring via an annular groove in theseal guide. This seal oil is fed to the hydrogen sideannular groove in the seal ring and from there to thesealing gap via several bores uniformly distributed onthe circumference. The air side seal oil is supplied to


Shaft Seals

2.1-1460-0500/10609E

13 Annular groove for air side seal oil14 Babbit15 Seal ring16 Annular groove for pressure oil17 Oil wiper ring (air side)18 Seal oil groove

the sealing gap from the seal ring chamber via radialbores and the air side annular groove in the seal ring.To ensure effective sealing, the seal oil pressures in theannular gap are maintained at a higher level than thegas pressures within the generator casing. The air sideseal oil pressure is set at slightly higher than thehydrogen side seal oil pressure. The hydrogen side sealoil is returned to the seal oil system through ducts belowthe bearing compartments. The oil drained on the airside is returned to the seal oil storage tank together withthe bearing oil.

On the air side, pressure oil is supplied laterally tothe seal ring via an annular groove. This ensures freemovement of the seal ring in the radial direction.

Fig.1 Shaft Seal

1 Seal ring carrier flange2 Seal3 Insulation4 Seal ring chamber5 Inner labyrinth ring6 Seal strip

7 Rotor shaft8 Oil wiper ring (H2 side)9 Seal ring carrier10 Annular groove for hydrogen side seal oil11 Seal oil inlet bore (H2 side)12 Annular groove for hydrogen side seal oil

BHEL,Haridwar

Turbogenerators

General

1 Bearing Oil System

The generator and exciter bearings are connectedto the turbine lube oil supply.

2 Seal Oil System

2.1 ConstructionThe shaft seals are supplied with seal oil from two

seal oil circuits which consist of the following principalcomponents.

Hydrogen Side Seal Oil Circuit :

Seal oil tankSeal oil pumpOil cooler 1Oil cooler 2Seal oil filterDifferential pressure valve CPressure equalizing valve TEPressure equalizing valve EE.

Air Side Seal Oil Circuit :

Seal oil storage tankSeal oil pump 1Seal oil pump 2Standby seal oil pumpOil cooler 1Oil cooler 2Seal oil filterDifferential pressure valve A1Differential pressure valve A2

2.2 Hydrogen Side Seal Oil CircuitThe seal oil drained towards the hydrogen side is

collected in the seal oil tank. The associated seal oilpump returns the oil to the shaft seals via a cooler andfilter. The hydrogen side seal oil pressure requireddownstream of the pump is controlled by differentialpressure valve C according to the preset reference value,i.e. the preset difference between air side and hydrogenside seal oil pressures.


Oil supply for Bearings and Shaft Seals

2.1-1510-0500/10609E

The hydrogen side seal oil pressure required at theseals is controlled separately for each shaft seals byrespective pressure equalizing valves, according to thepreset pressure difference between the hydrogen sideand air side seal oil.

Oil drained from the hydrogen side is returned tothe seal oil tank via the generator pre-chambers. Twofloat-operated valves keep the oil level at apredetermined level, thus preventing gas from enteringthe suction pipe of the seal oil pump (hydrogen side).The low level float-operated valve compensates for thelow oil level in the tank by admitting oil from the air sideseal oil circuit. The high level float-operated valve drainsexcess oil into the seal oil storage tank. The hydrogenentrapped in the seal oil comes out of the oil in the sealoil storage tank and is extracted by the bearing vaporexhauster for being vented to the atmosphere above thepower house roof. During normal operation, the high levelfloat-operated drain valve is usually open to return theexcess air side seal oil, which flowed to the hydrogenside via the annular gaps of the shaft seals, to the airside seal oil circuit.

2.3 Air Side Seal Oil CircuitThe air side seal oil is drawn from the seal oil

storage tank and delivered to the seals via a cooler andfilter by seal oil pump 1. In the event of its failure, sealoil pump 2 automatically takes over the seal oil supply.Upon failure of seal oil pump 2, the standby seal oil pumpis automatically started and takes over the seal oil supplyto the shaft seals. In the event of a failure of the seal oilpump of the hydrogen side seal oil circuit, the seal oil istaken from the air side seal oil circuit.

The air side seal oil pressure required at the sealsis controlled by differential pressures valve A1 accordingto the preset value, i.e. the required pressure differencebetween seal oil pressure and hydrogen pressure. In theevent of a failure, i.e. when the seal oil for the seals isobtained from the standby seal oil pump, differentialpressure valve A2 takes over this automatic controlfunction.

The seal oil drained from the air side of the shaftseals is directly returned to the seal oil storage tank.

BHEL,Haridwar

Turbogenerators

General

Seal Oil System

(Simplified Diagram)

2.1-1511-0500/10609 E

Hydrogen side seal oil

Air side seal oil

Pressure oil for seal ring relief

Hydrogen

Hydrogen side seal oil circuit

7 Generator Prechamber 8 Pressure equalizing control valve 9 Seal oil tank10 Seal oil filter11 “C” valve12 Seal oil cooler13 Seal oil pump

Air side seal oil circuit

1 Seal ring2 Seal oil storage tank3 Seal oil pump4 “A” valve5 Seal oil cooler6 Seal oil filter

BHEL,Haridwar

Turbogenerators

General

1 General

The gas system conta ins a l l equipmentnecessary for filling the generator with CO2, hydrogenor air and removal of these media, and for operationof the generator filled with hydrogen. In addition, thegas system includes a nitrogen (N2) supply. The gassystem consists of :

• H2 supply

• CO2 supply

• N2 supply

• Pressure reducers

• Pressure gauges

• Miscellaneous shutoff valves

• Purity metering equipment

• Gas dryer

• CO2 flash evaporator

• Flowmeters

2 Hydrogen (H2) Supply

2.1 Generator CasingThe heat losses arising in the generator are

dissipated through hydrogen. The heat dissipatingcapacity of hydrogen is eight times higher than thatof air. For more effective cooling, the hydrogen in thegenerator is pressurized.

2.2 Primary Water TankA nitrogen environment is maintained above the

primary water in the pr imary water tank for the


Gas System

2.1-1520-0500/10609E

following reasons.

• To prevent the formation of a vacuum due todifferent thermal expansions of the primary water& tank.

• To ensure that the primary water in the pumpsuction line is at a pressure above atmosphericpressure so as to avoid pump cavitation.

• To ensure that the primary water circuit is at apressure above atmospheric pressure so as toavoid the ingress of air on occurrence of a leak.

3 Carbon Dioxide (CO2) Supply

As a precaution against explosive hydrogen airmixtures, the generator must be filled with an inertgas (CO2) prior to H2 filling and H2 removal.

The generator must be filled with CO2 until it ispositively ensured that no explosive mixture will formduring the subsequent filling or emptying procedures.

4 Compressed Air Supply

To remove CO2 from the generator, compressedair is to be admitted into the generator.

The compressed air must be clean and dry. Forthis reason, a compressed air filter is installed in thefilter line.

5 Nitrogen (N2) Supply

Nitrogen is required for removing the hydrogenor air during primary water f i l l ing and emptyingprocedures.

BHEL,Haridwar

Turbogenerators

General

Gas System

Simplified Diagram

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1 H2 bottle2 H2 pressure reducer3 N2 bottle4 N2 pressure reducer5 Primary water tank6 Pressure controller7 Upper generator gas header8 Lower generator gas header9 Gas drier heater

10 Gas drier fan11 Gas drier chamber12 CO2/H2 purity transmitter13 Dehydrating filter for measuring gas14 Pressure reducer for measuring gas15 Compressed air hose16 Compressed air filter17 CO2 flash evaporator18 CO2 bottle

BHEL,Haridwar

Turbogenerators

General

1 General

The pr imary water requi red for cool ing iscirculated in a closed circuit by a separate pump. Toensure uninterrupted generator operation, two full-capacity pumps are provided. In the event of a failureof one pump, the standby pump is immediately readyfor service and cuts in automatically. Each pump isdriven by a separate motor.

All valves, pipes and instruments coming intocontact with the primary water are made from stainlesssteel material.

The pr imary water system consis ts of thefollowing principal components :

• Primary water tank

• Primary water pumps

• Cooler

• Primary water filter

• Fine filter

• Ion exchanger

• Alkalyser unit

As i l lustrated in the diagram, the primary wateradmitted to the pump from the tank is first passed viathe cooler and fine filter to the water manifold in thegenerator interior and then to the bushings. Afterhaving performed its cooling function, the water is



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returned to the primary water tank. The gas pressureabove the water level in the primary water tank ismaintained constant by a pressure regulator.

2 Primary Water Tank

The primary water tank is located on top of thestator frame on an elastic support, thus forming thehighest point of the entire primary water circuit interms of static head.

3 Primary Water Treatment System

The direct contact between the primary water andthe high-voltage windings calls for a low conductivityof the primary water. During operation, the electricalconductivity should be maintained below a value ofapproximately 1 µmho/cm. In order to maintain sucha low conductivity i t is necessary to provide forcontinuous water treatment. During operation, a smallquantity of the primary water flow should thereforebe continuously passed through the ion exchangerlocated in the bypass of the main cooling circuit. Theion exchanger resin material required replacementduring operation of the generator, since with the watertreatment system out of service, the conductivity willrise very slowly.

BHEL,Haridwar

Turbogenerators

General


(Simplified Diagram)

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Primary water circuit, generalCoolant flow : stator windingCoolant flow : main bushings and phase connectorsWater treatmentWaste gasHydrogen

7 Bypass line8 Cooling water for stator winding9 Ion exchanger10 Cooling water for main bushings and phase connectors11 Teflon hose12 Cooling water manifold13 Alkaliser unit

1 Primary water tank2 Pressure regulator3 Waste gas to atmosphere4 Pump5 Cooler6 Filter

BHEL,Haridwar

Turbogenerators

Description

Technical Data

General and Electrical Data

2.1-1810-10555/10609E

Project name MEJIA TPS Stage II Unit-1 & 2

Generator Type THDF 115/59

Main Exciter Type ELR 70/90-30/6-20

Pilot exciter Type ELP 50/42-30/16

Year of manufacture 2008-09

Rated Data and Outputs Turbogenerator Main Exciter Pilot ExcitorApparent power 588MVA - 65 kVAActive power 500 MW 3780 kW -Current 16.166 kA 6300 A 195 AVoltage 21 kV + 1.05 kV 600 V 220 V + 22 VSpeed 50s-1 50s-1 50 s-1

Frequency 50 Hz - 400 HzPower factor 0.85 (lag) - -Inner connection of stator winding YY - -H2 pressure 3.5 bar (g) - -Cont. perm. unbalanced Load 8% - -Rated field current for rated output 4040 A - -Rated field voltage 340 V - -The machines are designed in conformity with IEC-34 and should be operated according to these specifications.The field current is no criterion of the load carrying capacity of the turbogenerator.

Resistance in Ohms at 25°C Turbogenerator Main Excitor Pilot ExcitorU-X 0.0014747 ohms U-0 0.002579 ohms

Stator Winding V-Y 0.0014747 ohms F1-F2 0.6036 ohms V-0 0.002579 ohmsW-Z 0.0014747 ohms W-0 0.002579 ohms

U-V 0.000469 ohmsRotor Winding F1-F2 0.067873 ohms U-W 0.000469 ohms

V-W 0.000469 ohms

Rectifier WheelNumber of fuses 30per rectifier wheel (800 V, 800 A)

-

Fuse, resistance approx. 150 μ ohms -Number of diodesper rectifier wheel 60

-

Action Required:Number of fuses blown per 2 fuses Switch off field forcingbridge arm and rectifier wheel 3 fuses Shutdown turbine-generator, replace

fuses and diodes.

General

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Mechanical Data

2.1-1820-10555/10609 E

Torques, Critical Speed etc. Torques and UnitsSpeeds

Maximum short-circuit torque of stator atline-to-line single-phase short-circuit 14585 kpm

Moment of inertia of generator rotor shaft 10000 kgm2

ηk1 864Critical speed (calculated) ηk2 2388 RPM(Generator + Exciter coupled) ηk3 4680

Generator Volume and Filling Quantities Volume UnitsGenerator volume (gas volume) 80 m3

CO2 filling quantity*** 160 m3 (s.t.p.)*H2 filling quantity (to 3.5 bar)** 480 m3 (s.t.p.)*

Weights Weight unitsStator with end shields and coolers 360000 kgShipping weight of stator 265000 kgStator end shield, upper part TE 22066 kgStator end shield, upper part EE 6665 kgStator end shield, lower part, TE 24200 kgStator end shield, lower part, EE 9950 kgRotor 68000 kgH2 cooler section, including water channels 1770 kgGas dryer 950 kgOne seal oil cooler (air side) 320 kgOne seal oil cooler (H2 side) 250 kgOne primary water cooler 90 kgExciter rotor 7550 kg

Component Material Component Material

Rotor shaft 26NiCrMoV145 Electrical sheet-steel 1.5 W/Kg at 1 Tesla 0.5 mm TK

Rotor copper CuAg0.1PF25 Stator copper E-Cu58F20Rotor wedges CuCoBeZr Bearing babbitt Babbitt V 738Retaining rings X8CrMnN1818K Seal rings babbitt Babbitt V 738Damper wedges CuAg0.1F25

* s.t.p. = Standard temperature and pressure, 0oC and 1.013 bar to DIN 1343

** Volume required with unit at standstill. With the unit on the turning gear, the volume will be higher.

*** CO2 quantity kept on stock must always be sufficient for removal of the existing hydrogen filling.All values are approximate.

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Seal Oil System

2.1-1825-10555/10609E

Seal oil pumps -1,2 (Air Side) MKW 11 AP 001 andMKW 21 AP 001

Kind of pumpTypeCapacityDischarge pressurePump motorRatingVoltage/ frequencyCurrentSpeedType of enclosureNos.

Seal oil pump -3 ( Air side) MKW 31 AP 001Kind of pumpTypeCapacityDischarge pressurePump motorRatingVoltageCurrent ArmatureSpeedType of enclosureNos.

Seal oil pump (H2 side) MKW 13 AP 001Kind of pumpTypeCapacityDischarge pressurePump motorRatingVoltage/ frequencyCurrentSpeedType of enclosureNos.

Seal oil filters MKW 51 BT 001, MKW 51 BT 002,MKW 53 BT 001 & MKW 53 BT 002

Kind of filterTypeVolumetric flow rateDegree of filtrationPressure drop across filterNos. for air sideNos. for H2 side

Three Screw pumpT3S - 52/54258 LPM12Kg/Cm2

CGL, ND132M7.5 KW415V, 3 Ph AC 50Hz14.5 A1500 RPM (Syn.)TEFC, IP552x100% capacity

Three Screw pumpT3S - 52/54258 LPM12 Kg/cm2

CGL, AFS 225L8.5 KW220 V DC67 A1450 RPMTEFC , IP551x100% capacity

Three Screw pumpT3S - 52/46130 LPM12 kg/cm2

CGL, ND 132M4 KW415V, 3 Ph AC 50Hz9.3 A940 RPMTEFC, IP551x100% capacity

Strainer-type filterBFD (M/s Boll & Kirch)12 m 3/hr100 microns0.3 bar with clean filter *2x100% capacity2x100% capacity

* 1.2 bar with 100% blockage

Design Data

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Gas System

2.1-1826-10555/10609E

CO2 vapouriser MKG 51 AH 001RatingVoltageHeat transfer liquidVolume of heat transfer liquidHole in orificeRelief valve on high-pressure sideRelief valve on low-pressure sideNos.

Refrigeration type gas drierRating and parameters

Compressed air filter MGK 25 BT 001

Volume of activated carbonService hoursThroughputNos.

18 kW415V, 3 Ph AC 50HzHYTHERM 500 (M/s HPCL)25 dM3

2.8 mm175 bar8 bar1x100% capacity

As per sub-supplier’s manual

3 dm3

approx. 1500 hr to 2000 hr80 m

3/hr at 8 bar

1x100% capacity

Design Data

BHEL,Haridwar

Turbogenerators

Description

Technical Data


2.1-1827-10555/10609E

Design Data

Primary water pumps MKF12AP001 and MKF22AP001Kind of pump Centrifugal pumpType CPK-CM 65-250 (S) M/s KSB makeSpeed 2950 RPMCapacity 70 m3/HrDischarge head 80 mPump motor ND225 M (M/s Crompton Greaves Ltd)Rating 37KWVoltage 415V, 3 Ph AC 50HzFrequency 50 HzSpeed 2950 RPMType of enclosure TEFCNos. 1x100% capacity

Main filters MKF 52 BT 001 and MKF 52 BT 002Kind of filter Strainer-type filter with magnet barsType 1.53.1 (M/s Boll & Kirch)Volumetric flow rate 25 dm3/s max.Degree of filtration 150 mmPressure drop across filter 0.1 bar with clean filter

1.2 bar with 100% foulingNos. 2x100% capacity

Fine filter MKF 60 BT 001Kind of filter 1 plug. 1 cartridgeType 1.55.1 (M/s Boll & Kirch)Volumetric flow rate 0.42 dm3/s max.Pressure drop across filter 0.15 bar with clean filter

1.2 bar with 100% foulingNos. 1x100% capacity

Ion exchanger MKF 60 BT 001Volume 83 litresResin LewatitResin volume 56 litres (45 kg)Nos. 1x100% capacity

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Waste Gas System

2.1-1828-10555/10609 E

Bearing vapor exhausters MKC 31 AN 001 and MKQ 32 AN 001

Moter RatingVoltage/frequencyCurrentSpeedType of enclosureType of exhaustersNos.

Design Data

0.75kW415V, 3 Ph AC 50Hz1.8A2780 RPMIP 55Radial-flow2x100% capacity

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Excitation System

2.1-1829-10555/10609 E

A-wheel (negative polarity)No./Type of diodesNo./Type of fusesResistance/voltage/current per fuseNo. of RC networks

B-wheel (positive polarity)No./Type of diodesNo./Type of fusesResistance/voltage/current per fuseNo. of RC networks

StroboscopeTypeVoltageFrequencyNo. of stroboscope

Exciter air dryerTypeRatingVoltageFrequencyAdsorption air flow rateRegeneration air flow rateNo. of dryer

60 Nos./BHdL 1220 (BHEL EDN,Bangalore make)30 Nos./3NC 9 538approx. 150 μΩ, 800 V, 800 A6 Nos.

60 Nos./BHdL 1320(BHEL EDN,Bangalore make)30 Nos./3NC 9 538approx. 150 μΩ, 800 V, 800 A6 Nos.

LX5-30/36-2240 V50/60 Hz1 No.

BA-1.5 A (M/S BRYAIR MAKE)4,6 kW230 V50 Hz120 m3/h35 m3/h1 No.

Design Data

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Cooler Data

2.1-1830-10555/10609 E

Materials and PressuresUnits

Design Data for One Seal Oil Cooler (H2 Side)Drg. No. 0-165-03-70005 C (1 x100% )

Materials and Pressures

Note: The specified cooler data refer to max. cooling water inlet temperatures. During operation the operatingvalues of the coolers may deviate from above design data.

Units

3.5 Bar (g)

33 m3/s

4640 kW

44 °C

72 °C

700 Pa

540 m3/hr

38 °C

45.4 °C

3.0 MWC

Design Data for the H2 Cooler,Drg. No. 0-166-01-70006C(4 x 25% each)

MaterialsFins CopperTubes 90/10 Cu-NiTubesheets Carbon steelWater channels Carbon steel

Pressures (Tube Side)Design pressure 10 kg/cm2

Test pressure 15 kg/cm2

Hydrogen pressure

Gas flow (Total)

Heat dissipating capacity (Rated)

Cold gas temperature

Hot gas temperature (max.)

Gas pressure drop (approx.)

Cooling water flow (Total for 4 sections)

Cooling water inlet temperature (design)

Water outlet temperature

Water pressure drop

Design Data for One Seal Oil Cooler (Air Side)Drg. No. 0-165-03-70006 C (1 x 100% )

Units Materials and Pressures

Oil flow


Oil inlet temperature

Oil Outlet temperature

Oil pressure drop (approximate)

Cooling water flow



Water pressure drop (approximate)*

4.16 dm3/s

140 kW

70 °C

50 °C

0.833 Bar

35 m3/hr

38 °C

41.4 °C

6.8 MWC

MaterialsTubes Admiralty BrassTubesheets Carbon steelWater channels Carbon steel

Cooling water PressuresOperating pressure 16 kg/cm2


Oil Side PressuresOperating pressure 16 kg/cm2


Oil flow


Oil inlet temperature

Oil outlet temperature

Oil pressure drop (approximate)

Cooling water flow



Water pressure drop (approximate)*

2.17 dm3/s

90 kW

70 °C

50 °C

0.85 bar

22 m3/hr

38 °C

41.5 °C

7.1 mWC

MaterialsTubes Admiralty BrassTubesheets Carbon steelWater channels Carbon steel

Cooling Water PressuresDesign pressure 16 kg/cm2


Oil Side PressuresDesign pressure 16 kg/cm2


2.1-1830-10555/20609E


18.06 dm3/s

1715 kW

71.7 °C

49 °C

1160 mbar

250 m3/hr

38 °C

43.9 °C

2.0 MWC

Design Data for the Primary WaterCooler, Drg. No. 0-165-41-70013 C(2 x 100% )

MaterialsShell SSTubes SSTubesheets SSWater channels Carbon Steel

Primary Water Side PressuresDesign pressure 10 kg/cm2


Cooling Water Side PressuresDesign pressure 10 kg/cm2


Primary water flow


Primary water inlet temperature

Primary water outlet temperature

Primary water pressure drop

Cooling water flow

Maximum cooling water inlet temperature

Cooling water outlet temperature

Water pressure drop*

* Flange to flange of equipment only


1 Bar (g)

15.5 m3/s

500 kW

45 °C

74 °C

700 Pa

200 m3/hr

38 °C

40.2 °C

3.0 MWC

Design Data for the Exciter Air Cooler,Drg. No. 0-166-05-70003C(2 x 50% each)

MaterialsFins CopperTubes 90/10 Cu-NiTubesheets Carbon steelWater channels Carbon steel

Pressures (Tube Side)Design pressure 10 kg/cm2


Hydrogen pressure

Gas flow (Total)


Cold gas temperature

Hot gas temperature (max.)

Gas pressure drop (approx.)

Cooling water flow (Total for 4 sections)



Water pressure drop*

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Reactive Capability Curve

2.1-1850-10555/10609E

BHEL,Haridwar

Turbogenerators

Description

Technical Data

Load Characteristic of Pilot Exciter

2.1-1860-10555/10609E

PMG Pilot Exciter Characteristic

200

205

210

215

220

225

230

235

240

0 50 100 150 200 250

PMG field current (amps)

PM

G V

olta

ge(v

olts

)

BHEL,Haridwar

Turbogenerators

Description

1) s.t.p. = standard temperature and pressure. 00C and 1.013 bar to DIN 1343.The gauge pressures and temperatures indicated are those at the inlets of the generator gas supply units.

Gas Specification

2.1-1883-10555/10609E

1. Compressed Air

The compressed air shall be free of-

corrosive contaminants andhazardous gases, flammable or toxic.

The maximum total oil or hydrocarbon content,exclusive of non-condensables, shall be as closeto zero (0) w/w or v/v as possible, and under nocircumstances shall it exceed one (1) ppm w/w orv/v under normal operating conditions.The compressed air shall be practically free of dust.The maximum particle size in the air stream shall befive (5) micrometers.The oxygen content of the expanded air shall bebetween 20 and 21% v/v.The dew point at line pressure shall be at least 15 Kbelow the minimum possible generator temperature.In no case should the dew point at line pressureexceed 10 °C.The compressed air shall be available at a gaugepressure between 6 and 9 bar.Volumetric flow rate: 144 to 216 m3/h.

2. Carbon Dioxide (CO2)

Carbon dioxide shall be made available with a purity ≥99.9 % v/v. The remaining 0.1 % v/v shall be free ofcorrosive contaminants: traces of ammonia (NH3) andsulphur dioxide (SO2) shall not be detectable byanalysis.

If obtained from a central bulk supply, the gas shall bemade available at the following conditions:

Gauge pressure : 1 to 2.5 barTemperature : 20 to 30 0CVolumetric flow rate : 144 to 216 m3/h.

3 Hydrogen (H2)

The hydrogen gas shall be made available with a purity99.9% v/v. The remaining 0.1 % v/v shall be free ofcorrosive contaminants: traces of ammonia (NH3) andsulphur dioxide (SO2) shall not be detectable byanalysis.If obtained from a central bulk supply, the hydrogengas shall be made available at the following conditions:

Gauge pressure : 8 to 9 barVolumetric flow rate : 144 to 216 m3/h.

4 Nitrogen (N2)

The nitrogen gas shall be made available with a purityof 99.99 % v/v.

Contaminants (O2, H2O): not applicable

The remaining 0.01% v/v shall be free of corrosivecontaminants; traces of ammonia (NH3) and sulphurdioxide (SO2) shall not be detectable by analysis.

BHEL,Haridwar

Turbogenerators

Description

2.1-1885-10555/10609E

Primary Water Specification

The water used must not contain any contaminantsthat might have a harmful effect on the materials used inthe primary water circuit. For this reason, the water musthave the following quality criteria :

Conductivity : < 10 μ mho/cm. preferably0.5 μ mho/cm

pH : 6 - 8Dissolved O2 : Minimum, preferably less than 100 ppbDissolved CO2 : Minimum, permissible conductivityChlorides : after a strongly acidic cation

exchangerOther anions : < 0.2 μ mho/cmAmmonia : Minimum, test with Nessler’s solution

as a regent shall not cause a changein color.

Cu, dissolved/undissolved : Less than 20 ppb

Fe, dissolved/Undissolved : Less than 20 ppb

Dissolved solids : The water shall not contain chemicalsfrom treatment processes, such ashydrazine, morpholine, levoxine, phos-phate, etc.

If the water to be used does not meet these qualitycriteria, BHEL Haridwar must be informed for their evalua-tion and approval.

BHEL,Haridwar

Turbogenerators

Description

2.1-1887-10555/10609E

Specification forIon Exchange Resins

1. General

The primary water must have a low condictivity since itcomes into direct contact with the high-voltage winding.To maintain a low conductivity the primary water requirescontinuous treatment. This is achieved by continuouslypassing a small primary water volume flow through a mixedbed ion exchanger arranged in the bypass of the maincooling circuit. The ion exchange resins must be replacedat certain intervals. The resins may be replaced while thegenerator is in operation, since with the water treatmentsystem out of service the conductivity will continue to riseonly very slowly.

2. Resin Specification

The resins should contain no impurities or soluble

substances having a detrimental effect on the materialsused in the primary water circuit and thus on the availabilityof the generator.

Our recommendation to use Lewatit ion exchangeresins is based on many years of service experience andthe close cooperation between the resin supplier and manypower plant operators as well as the high quality standardof the resins.

The initial charge of the mixed-bed ion exchangerconsists of the following types of resins.

Lewatit S 100 KR/H/chloride-freeLewatit M 500 KR/OH/chloride-free

When replacing the resins, use either the above typesor resins available from other manufacturers which mustcomply with the specification below.

Cation exchanger Anion exchanger(Lewatit S100KR/H/chloride-free) (Lewatit M500 KR/OH/chloride-free)

Functional group Strongly acidic Very strongly basic

Grain shape Beads Beads

Particle size (0.3 - 1.25) mm (0.3 - 1.25) mm

Bulk density of swollen resin (800 - 900) g/dm3 (670 - 750) g/dm3

Resin form H-ions OH-ions

Specific load up to 40 dm3/h × dm3 40 dm3/h × dm3

Total capacity of swollen resin (1.9 - 2.2) mol/dm3 (1.1 - 1.6) mol/dm3

Useful capacity min. 50 gCaO/dm3 16 gCaO/dm3

Chloride content up to 50 mg/dm3 50 mg/dm3

Thermal stability up to 1200C 700C

Stability in pH range Unlimited Unlimited

Shelf life min.(in original packing 5 years 3 yearsat temperatures of +1oC to +40oC

BHEL,Haridwar

Turbogenerators

Description

2.1-1888-10555 /10609 E

Additive Specificaitonfor Alkalizer Unit

Also refer to the following information[1] 2.1-7341 Alkalizer Unit for Primary Water Circuit[2] 2.1-1885 Primary Water Specification

Despite the use of oxygen-poor water, corrosion ofcopper in the primary water circuits of water-cooledwindings, cannot be completely avoided, and in isolatedcases the corrosion products can reduce the cross-sectional flow area of the water distribution system.

The sever i ty of the corrosion at tack can besubstantially reduced by alkalizing the oxygen-poor water.In addition, the system becomes less susceptible todisturbances resulting from air in-leakage.

Operating the generator with alkaline water at pH 8 to9 will improve the reliability and availability of the turbinegenerator.

For operation of the alkalizer unit [1], dilute sodiumhydroxide for continuous injection into the primary watercircuit and lime are required.

1 Sodium Hydroxide SolutionThe sodium hydroxide solution should have a

concentration of 10 to 20 g of NaOH per dm3.

Sodium hydroxide solution should be prepared from :

Caustic Soda [NaOH] of P.A. quality, containing.NaOH : > 98%Carbonates [Na2CO3] : < 1%

Water in conformity with the primary waterspecification [2].

2 LimeA lime filter to be provided in the NaOH tank vent serves

to bind the carbon dioxide (CO2) contained in the inlet air inorder to prevent the formation of carbonates in the sodiumhydroxide solution.

The lime filter consists of equal parts of sodiumhydroxide (NaOH) and calcium hydroxide (Ca(OH)2 ). Thismixture is commercially available and known as soda lime.

BHEL,Haridwar

Turbogenerators

Description

2.1-2100-0500/10609 E

Stator Frame

To facilitate manufacture, erection and transport, thestator consists of the following main components:

Stator frameEnd shieldsBushing compartment

The stator frame with flexible core suspensioncomponents, core, and stator winding is the heaviestcomponent of the entire generator. A rigid frame isrequired due to the forces and torques arising duringoperation. In addition, the use of hydrogen for thegenerator cooling requires the frame to be pressure-resistant up to an internal pressure of approximately 10bar (130 psi g).

The welded stator frame consists of the cylindricalframe housing, two flanged rings and axial and radialribs. Housing and ribs within the range of the phaseconnectors of the stator winding are made of non-magnetic steel to prevent eddy current losses, while theremaining frame parts are fabricated from structuralsteel.

1 2 3 4

1 Stator End shield 2 Bushing compartment3 Frame housing 4 Stator foot

Fig:1 Stator frame

The arrangement and dimensionally of the ribs aredetermined by the cooling gas passages and the requiredmechanical strength and stiffness. Diminishing is alsodictated by vibrational considerations, resulting partly ingreater wall thickness then required, from the point ofview of mechanical strength. The natural frequency ofthe frame does not correspond to any exciting frequency.

Two lateral supports for flexible core suspension inthe frame are located directly adjacent to the pointswhere the frame is supported on the foundation. Due tothe rigid design of the supports and foot portion, theforces due to weight and short-circuits will not result inany over-stressing of the frame.

Manifolds are arranged inside the stator frame at thebottom and top for filling the generator with CO2 and H2

. The connections of the manifolds are located side byside in the lower part of the frame housing.

Additional openings in the housing, which are sealedgastight by pressure-resistant covers, afford access tothe core clamping flanges of the flexible core suspensionsystem and permit the lower portion of the core to beinspected. Access to the end winding compartments ispossible through manholes in the end shields.

In the lower part of the frame at the exciter end anopening is provided for bringing out the winding ends.The generator terminal box is flanged to this opening.

1 2 3 4

1 Frame housing2 Clamp3 Supporting ring4 Dovetail bar

Fig.2 Stator Frame Interior

BHEL,Haridwar

Turbogenerators

Description

2.1-2150-0500/10609 E

Stator End shields

The ends of the stator frame are closed by pressurecontaining end shields. The end shields feature a highstiffness and accommodate the generator bearings, shaftseals and hydrogen coolers. The end shields arehorizontally split to allow for assembly.

The end shields contain the generator bearings. Thisresults in a minimum distance between bearings andpermits the overall axial length of the TE end shields to beutilized for accommodation of the hydrogen cooler sections.Cooler wells are provided in the end shield on both sidesof the bearing compartment for this purpose. One manholein both the upper and lower half end shield provided.

Inside the bearing compartment the bearing saddle ismounted and insulated from the lower half end shield. Thebearing saddle supports the spherical bearing sleeve andinsulates it from ground to prevent flow of shaft currents.

The bearing oil is supplied to the bearing via a pipepermanently installed in the end shield and is then passedon to the lubricating gap via ducts in the lower bearingsleeve. The bearing drain oil is collected in the bearingcompartment and discharged from the lower half ofthe end shields via a pipe.

Fig.1 TE Stator End Shield

The bearing compartment is seated on the air sidewith labyrinth rings. On the hydrogen side the bearingcompartment is closed by the shaft seal and labyrinthr ings. The oi l for the shaft seal is admitted viaintegrally welded pipes. The seal oil drained towardsthe air side is drained together with the bearing oil.The seal oil drained towards the hydrogen side is firstcollected in a gas and oil tight chamber below thebearing compartment for defoaming and then passedvia a siphon to the seal oil tank of the hydrogen sideseal oil circuit.

The static and dynamic bearing forces are directlytransmitted to the foundation via lateral feet attachedto the lower half end shield. The feet can be detachedfrom the end shield, since the end shields must belowered into the foundation opening for rotor insertion.

Fig. 2 EE Stator End Shield

BHEL,Haridwar

Turbogenerators

Description

2.1-2170-0500/10609 E

Generator Terminal Box

The phase and neutral leads of the three-phasestator windings are brought out of the generatorthrough s ix bushings located in the generatorterminal box at the exciter end of the generator.

The terminal box is a welded construction of non-

magnetic steel plate. This material reduces straylosses due to eddy currents.

Welded ribs are provided for the rigidity of theterminal box. Six manholes in the terminal box provideaccess to the bushings dur ing assembly andoverhauling.

1 2 3

1 Generator terminal box2 Manhole3 Flange for bushing

Fig.2 Terminal Box Interior

1 Flange for terminal box2 Phase connector3 Connection to bushing

Fig.1 Phase Connector

1 2 3

BHEL,Haridwar

Turbogenerators

Description

2.1-2190-0500/10609 E

Hydraulic Testing and Anchoringof Stator Frame

sealed with elastically deformed O-ring packings.Each O-ring packing is inserted into a groove ofrectangular cross-section and compressed by theflanges. The elastic deformation of the O-ring packingprovides for a sufficient sealing force.

3 Anchoring and Aligning the Stator Frame andEnd Shields to the Foundation

The stator frame is anchored to the foundation withanchor bolts in conjunction with aligning elements andsole plates set in grout on the foundation.

Fig.3 Feet at Stator Frame

The levelling screws are screwed into the supportfoot of the frame and permit a rapid and exacta l ignment of the stator. To ensure a uni formtransmiss ion of forces these are arrangedsymmetrically about the anchor bolts. The sphericalportions of the levell ing screws ensure completecontact and thus a rigid connection between statorand foundation.

The stator end shields are aligned on the machinesole plates with shims.

Different thermal expansion of the stator and thefoundation result in differential movements betweenthe frame and machine sole plates. The stator istherefore fixed in position in a manner allowing forexpansion while retaining al ignment. Fixed keyslocated at the feet in the middle of the stator framesecure the frame axially in a central position.

1 Hydraulic Testing of Stator Frame

The empty stator frame with attached end shieldsand terminal box is subjected to hydraulic test at 10bar to ensure that it will be capable of withstandingmaximum explosion pressures. The water pressureis increased in steps with pressure being reduced toatmospheric pressure after each step, to allow formeasurement of any permanent deformation.This test also checks for leakage at the weld seams.In addition, the welded structure is subjected to anair pressure test to check its gas tightness.

Fig.1 Hydraulic Testing of Stator Frame

Fig.2 Sealing of bolted flange joints

2 Sealing the Bolted Flange Joints

The bolted flange joints which must be gas tight(e.g., end shields, terminal box, manhole covers) are

BHEL,Haridwar

Turbogenerators

DescriptionAnchoring of Generator On Foundation

2.1-2191-0500/10609 E

1St

ator

foot

4 Le

velli

ng s

crew

7 Hy

drau

lic ja

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Shi

ms

2An

chor

bol

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eat

3So

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lat e

6 Sp

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al w

ashe

r8

End

shie

ld f o

ot10

. Fou

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ion

skid

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ele

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ing

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t at o

r

BHEL,Haridwar

Turbogenerators

Description

2.1-2200-0500/10609 E

Stator Core

In order to minimize the hysteresis and eddy currentlosses of the rotating magnetic flux which interacts withthe core, the entire core is built up of thin laminations.Each lamination layer is made up from a number ofindividual segments.

Fig.1 Segment with Spacers

The segments are punched in one operation from0.5 mm (0.02 in.) thick electrical sheet-streetlaminations having a high silicon content, carefullydebarred and then coated with insulating varnish onboth sides. The stator frame is turned on end while thecore is stacked with lamination segments in individuallayers. The segments are staggered from layer to layerso that a core of high mechanical strength and uniformpermeability to magnetic flux is obtained. On the outercircumference the segments are stacked on insulateddovetail bars which hold them in position. One dovetailbar is not insulated to provide for grounding of thelaminated core. Stacking guides inserted into thewinding slots during stacking provide smooth slot walls.

To obtain the maximum compression and eliminateundue setling during operation, the laminations arehydraulically compressed and heated during thestacking procedure when certain heights of stack arereached. The complete stack is kept under pressureand located in the frame by means of clamping boltsand pressure plates.

The clamping bolts running through the core made

of non-magnetic steel and are insulated from the coreand the pressure plates to prevent the claiming boltsfrom short-circuiting the laminations and allowing the flowof eddy currents.

1 Clamping finger2 Stator Slow3 Pressure Plate4 Stator core tooth5 Clamping bolt6 Shield

Fig.2 Stator Core After Compression

The pressure is transmitted from the pressure platesto the core by clamping fingers. The clamping extend upto the ends of the teeth, thus ensuring a firm compressionin the area of the teeth. The stepped arrangement of thelaminations at the core ends provides for an efficientsupport of the tooth portion and, in addition, contributesto a reduction of eddy current losses and local heatingin this area. The clamping fingers are made of non-magnetic steel to avoid eddy current losses.

For protection against the effects of the stray flux inthe coil ends, the pressure plates and core end portionsare shielded by gas-cooled rings of insulation-bondedelectrical sheet-steel.

To remove the heat, space segments, placed atintervals along the bore length, divide the core intosections to provide radial passages for cooling gas flow.In the core end portions, the cooling ducts are wider andspaced more closely to account for the higher lossesand to ensure more intensive cooling of the narrow coresections.

12

34

5

6

BHEL,Haridwar

Turbogenerators

Description

Mounting of Stator Core in StatorFrame

2.1-2201-0500/10609 E

1 Stator frame2 Flat spring3 Cage4 Flux shied

1

2

3

4

5

6

7

8

3

2

1

5 Insulated through bolt6 Pressure plate7 Clamping finger8 Core

BHEL,Haridwar

Turbogenerators

Description

Spring Support of Stator Core

2.1-2220-0500/10609 E

1

2

3

4

5

6

The revolving magnetic field exerts a pull on thecore, resulting in a revolving and nearly ellipticaldeformat ion of the core which sets up a statorvibration at twice the system frequency. To reduce thetransmission of these dynamic vibrat ions to thefoundation, the generator core is spring mounted inthe stator frame. The core is supported in several setsof rings. Each ring set consists of two supporting ringsand two core clamping rings. The structural membersto which the insulated dovetail bars are bolted areuniformly positioned around to supporting ring interiorto support the core and to take up the torque actingon the core.

For firm coupling of the ring sets to the core, thesupporting ring is solidly pressed against the core by

the clamping ring. The clamping ring consists of twoparts which are held together by two c lamps.Tightening the clamps reduces the gap between thering segments so that the supporting ring is linked tothe frame by three flat springs. The core is supportedin the frame via two vertical springs in the vicinity ofthe generator feet. The lower spring prevents a lateraldeflection of the core. The flat spring are resilient toradial movements of the core suspension points andwill largely resist transmission of double frequencyvibration to the frame. In the tangential direction theyare however, sufficiently rigid to take up the short-circuit torque of the unit. The entire vibration systemis tuned so as to avoid resonance with vibrations atsystem frequency or twice the system frequency.

1 Clamp2 Stator frame3 Rib

4 Flat spring5 Cage6 Insert sleeve

BHEL,Haridwar

Turbogenerators

DescriptionStator Winding

2.1-2300-0500/10609 E

properties and resistance to magnetically induced forces.The bars afford maximum operating reliability, since eachcoil consists of only main insulation identical.

2. Conductor Construction

The bar consists of a large number of separatelyinsulated strands which are transposed to reduce the skineffect losses.

The strands of small rectangular cross-section areprovided with a braided glass insulation and arranged sideby side over the slot width. The individual layers are insulatedfrom each other by a vertical separator. In the straight slotportion the strands are transposed by 5400.

The transposition provides for a mutual neutralizationof the voltages induced in the individual strands due to theslot cross-field and end winding flux leakage and ensuresthat minimum circulation currents exist. The current flowingthrough the conductor is thus uniformly distributed over theentire bar cross-section so that the current-dependent losseswill be reduced.

The alternate arrangement of one hollow strand and twosolid strand ensure optimum heat removal capacity andminimum losses.

At the Roebel crossover points the insulation isreinforced with insulating strip inserts.

To ensure that the strands are firmly bonded togetherare to give dimensional stability in the slot portion, the barsare cured in an electrically heated press. Prior to applyingthe bar insulation, The bar ends are bent with a special careto ensure a uniform spacing of the bars over the entire lengthof the end turns after installation.

Contacts sleeves for electrical connection of the barsand the water boxes with cooling water connections arebrazed to the bar ends.

In the course of manufacture, the bars are subjected tonumerous electrical and leakage tests for quality control.

1. General, Connection

The three-phase stator winding is a fractional-pitch two-layer type consisting of individual bars. Each stator slotaccommodates two bars.

τp=pole pitch

Fig.1 Lap type Winding

The slot bottom bar and top bars are displaced fromeach other by one winding pitch and connected at their endsto from coil groups.

The coil groups are connected together with phaseconnectors inside the stator frame shown in the connectiondiagram.

This arrangement and the shape of the bars at the endsresult in a cone shaped winding having particularlyfavourable characteristics both in respect of its electrical

BHEL,Haridwar

Turbogenerators

DescriptionConnection Diagram of Stator Winding

2.1-2301-0500/10609 E

BHEL,Haridwar

Turbogenerators

Description

Stator Slot

2.1-2303-0500/10609 E

1 Stator core 2 Slot wedge 3 Top strip 4 Top ripple spring 5 Side strip 6 Semiconducting wrapper 7 Vertical separating strip 8 Top bar 9 Center filler10 Bottom bar11 Solid strand12 Hollow strand13 Insulation14 Semiconducting side ripple spring15 Equallising strip

1

2

34

5

6

7

8

9

1011

12

1314

15

BHEL,Haridwar

Turbogenerators

Description

Transposition of Stator Bars

2.1-2305-0500/10609 E

In slot portion: 540o transposition of strandsIn end winding portion: transposition, bar ends short circuit

At the bar end all strands arebrazed into a contact sleeveand thus short-circuited.

BHEL,Haridwar

Turbogenerators

Description

2.1-2320-0500/10609 E

Micalastic High Voltage Insulation

High-quality mica, selected epoxy resins and amatching vacuum pressure impregnation (VPI)process are the character is t ic features of theMicalastic insulation for large turbogenerators. Aconsistent development has led to a high-qualityinsulation system, the reliability of which is ensuredby continuous quality control.Method of Insulationand Impregnation

For insulation with Micalastic , the conductorstrands as well as the ventilating ducts are arrangedtogether to form a compact assembly and set to therequired shape. This assembly is then baked with

epoxy resin to give it the mechanical strength requiredfor further processing.

Following this, several layers of mica tape areapplied continuously, half-overlapped, upto the endportions of the bar. The mica tape consists of a thinhigh-strength backing material to which the mica isbonded by synthetic resin. The number of layers, i.e.,the thickness of insulation, is determined by thevoltage of the machine. The taped bars are then driedunder vacuum and impregnated with epoxy resinwhich, by reason of its low viscosity penetrates theinsulation thoroughly and eliminates all voids. After

2.1-2320-0501/2

impegnatioin under vacuum, the bars are subjectedto pressure, with nitrogen being used as pressurizingmedium (VPI process).

For d i rect cooled windings, the ind iv idualimpregnated bars are brought to the requi reddimensions in processing moulds and cured in anoven at high temperature. With indirectly cooledwindings, up to 20 stator bars are placed in moldswith by insulation for impregnation and curing. Fig.2shows a mold loaded with bars ready for impregnationprior to insertion into the impregnating plant.

To minimize corona discharges between theinsulation and the wall of the slot, the insulation inthe slot sect ion is then provided with a coat ofconductive varnish.

For end corona protection at voltages above 6kV, a semiconductive coating is also added on theslot-end sections to control the electric field andprevent the formation of creepage sparks during high-voltage tests.

The bars are now ready for insertion into the slots.In case of indirectly or direct gas-cooled stator bars,the connecting bus bars and phase connectors arealso provided with an insulat ion bonded with athermosetting synthetic resin. Dependent on theirgeometr ica l conf igurat ion and d imensions, theconnect ions are prov ided wi th mica tapes andinsulating caps.

Tests

After insulation and curing, the insulation of eachstator bar is subjected to a high- voltage test at 150%of the winding test voltage (UP= 2 ×UN + 1 kV) forquality control. For assessment of the quality of theslot insulation, the dielectic dissipatin factor tanδδδδδ ismeasured as a function of the voltage. The dielectricdissipation factor/test voltage curve of a typical stator

Fig. 4 Cumulative frequency of Maximum increase inDielectric Dissipation Factor of Bars in a 21 KVwinding with Micalastic insulation

ΣΣΣΣ Σ in

%

Fig. 2 Impregnating and Curing Mould for 20 stator Bars in Front of Impregnating Tank

5

10

20

30×10–3

tan δδδδ δ

0.2 0.4 0.6 0.8 1.0 1.2 1.4Rated Voltage

Fig.3 Dielectric Dissipation Factor of a Stator Bar withMicalastic Insulation for 21 KV as a Function of theVoltage

BHEL,Haridwar

Turbogenerators

Description

2.1-2320-0500/30609 E

bar with Micalastic insulation is shown in Fig. 3.

Fig.4 shows the fluctuations due to manufacturing ofthe maximum increase in the dielectric dissipationfactor up to rated voltage for the bars of a 21 kVwinding. The method of impregnation, which is exactlymatched to the insulation, and the use of a specialimpregnating resin enable the maximum increase indielectric dissipation factor to be reduced considerablybelow the limits specified in section 33 of VDE 0530.

During insertion of the stator bars, high-voltagetests of one minute duration are performed as follows:115% UP after installation and blocking of bottom bars110% UP after installation and blocking of top bars105% UP after completion of winding,100% UP after run of generator.

The Properties of MicalasticMicalstic is an extremely dependable winding

insulat ion system developed for h igh-vol tageturbogenerators. The insulation is applied from endto ened on the stator gbars providing effedt ivepeotection against over voltages arising during normaloperation and against the high stresses that mayoccur at the slot ends when high test voltages areappl ied. In this manner is is possible to isulatewindings for voltages of over 30 kV efficiently andreliably.

Micalastic has a long e lecter ica l l i fe asdetermined on hunndreds of experimental bars andsubstantiated on numerous full-size bars (Fig. 5).

Mcalastic is a good conductor of heat by reasonof the high mica content and the void free syntheticresin. Efficient heat transfer is particularly importantin machines that require a thick insulation becauseof the high voltages, especially if these machines arenot designed with direct conductor cooling.

Micalastic is highly resistant to high temperaturesand temperature chages. The composition of theinsulation and synthetic resin impregnation permitsthe machine to be operated cont inuously underconditions corresponding to those for insulation classF.

Micalastic insulation shows only an insignificantincrease in the dielectr ic dissipation factor withinceasing temperature.(Fig.6)

The e last ic i ty o f Mica last ic enables i t toaccomodate thermo-mechanical stesses. Studies onmodels have provided information on the on theperformance of Micalastic insulation under the effectof alternating thermal stresses. Heat cycles with largedifferences in temperature are generated by thealternate application of heating and colling. The result;there is no displacement between the Micalst icinsulationand the copper conductor, even after 5000heat cycles, with 1000 cycles between 40oC and160oC.

Micalastic owes its insesitivity to high temperatureand temperature changes to the cured synthetic resin.This favourable performance under thermal stress isparticularly advantageous for machines subject tofrequent load changes, e.g., generators driven by gasturbines or peak-load generators in steam powerplants.

Micalastic does not burn. The flammability is solow that even on arcing it does not continue to burnonce the arc is ext inguished. Fire ext inguishing

Fig.6 Dielectric Dissipation Factor of 27 kV MicalasticInsulation as a Function of the Temperature

Fig.5 Dielectric Dissipation Factor of 27 kV Micalastic Insulation as a Function of the Temperature

systems, such as CO2 systems, are therefore notnecessaryfor machines insulated with Micalastic.

Micalastic provides protection against moisturedue to its impregnation with synthetic resin which sealthe winding completely.

Micalastic is highly resistant to chemical action.Corrosive gases, vapours, lubrication oil and weakacids or alkalies, to which the windings of air-cooledmachines may be exposed under unfavourablecondi t ions, do not a t tack the insulat ion; theimpersonat ing res in behaves neutra l ly towardschemicals.

Micalastic retains its outstanding properties, evenafter years of operation. Evidence of its unchangingquality has been provided by repeated test carriedout on machines over an operating period of severalyears.

Micalastic owes its insesitivity to high temperatureand temperature changes to the cured synthetic resin.This favourable performance under thermal stress isparticularly advantageous for machines subject tofrequent load changes, e.g., generators driven by gasturbines or peak-load generators in steam powerplants.

2.1-2320-0501/4

BHEL,Haridwar

Turbogenerators

Description

2.1-2321-0500/10609 E

Construction of High Voltage Insulation

Item No. Component Insulant, semiconductive material1 Strand insulation Braided glass fiber insulation2 Strand bonding Epoxy resin3 Crossover insulation Micanite4 Profiled strip Profiled micanite5 Internal potential grading wrapper Semiconductive wrapping6 Insulation Mica tape, vacuum impergnated with epoxy resin7 Outer corona protection Semiconductive varnish

Note: The number of conductors shown does not necessarily correspond to the number of conductors of the generator .

BHEL,Haridwar

Turbogenerators

Description

2.1-2330-0500/10609 E

Stator WindingCorona Protection

To prevent potential differences and possible coronadischarges between the insulation and the slot wall, theslot sections of the bars are provided will an outercorona protection. This protection consist of a wear-resistant, highly flexible coating of conductive alkydvarnish containing graphite.

1 Stator bar (slot end)2 High-voltage insulation3 Outer corona protection4 Transition coating5 End corona protection6 Glass tape-epoxy protective layer7 Stator bar (end winding)

Fig.1 Typical Buildup of Corona Protection

At the transition from the slot to the end windingportion of the stator bars a semi-conductive coating isapplied. On top of this, several layers of semi conductiveand corona protection coating are applied in varyinglength. This ensures uniform control of the electric field

and prevents the formation of corona discharge duringoperation and during performance of high voltage tests.

A final wrapping of glass fabric tapes impregnatedwith epoxy resin serves as surface protection.

Fig.2 Application of Graded End CoronaProtection

1 2 3 4 5 6 7

BHEL,Haridwar

Turbogenerators

Description

2.1-2340-0500/10609 E

Coil and End Winding Support System

The stator windings are placed in rectangular slotswhich are uniformly distributed around thecircumference of the stator core. The location of thebars in the slots is illustrated in a separate drawing [1].

The bars are protected by a cemented graphitizepaper wrapper over the slot portion of the bar. The barsfit tightly in the slots. Manufacturing tolerances arecompensated with semi-conducting filler strips alongthe bar sides which ensure good contact between theouter corona protection and the slot wall.

Radial positioning of the bar is done with slotwedges. Below the longitudinally divided slot wedgesa top ripple spring of high-strength, fiber glass fabric isarranged between the filler and slide strip which pressesthe bar against the slot bottom with a specif icpreloading. An equalizing strip is inserted at the slotbottom to compensate any unevenness in the bar shapeand slot bottom surface during bar insertion. The stripis cured after insertion of the bars. These measuresprevent vibrations. The specified preloading is checkedat each slot wedge.

With the windings placed in the slots, the bar endsform a cone-shaped end winding. A small cone taper is

used to keep the stray losses at a minimum. The designand construction of the end windings are illustrated in aseparate drawing [2].

Any gaps in the end winding due to the design ormanufacturing are filled with curable plastic fillers,ensuring solid support of the cone-shaped top andbottom layers.

The two bar layers are braced with clamping bolts ofhigh-strength fibre glass fabric against a rigid, taperedsupporting ring of insulating material. Tight seating isensured by plastic filters on both sides of the bars whichare cured on completion of winding assembly.

Each end winding thus forms compact, self-supporting arches of high rigidity which prevents barvibrations during operation and can withstand short-circuit forces.

In addition, the end turn covering provides goodprotection against external damage. The supporting ringsrest on supporting brackets which are capable of movingin the axial direction. This allows for a differentialmovement between the end winding and the core as aresult of different thermal expansions.

Also refer to the following information[1]. 2.1-2303 Stator slot[2]. 2.1- 2341 Stator End Winding

1 Slot wedge2 End turn covering

Fig.1 Stator with Complete Stator Winding

1 2

1 21 End turn covering2 Clamping bolt

Fig.2 Covering and Locating the End Winding

BHEL,Haridwar

Turbogenerators

DescriptionStator End Winding

2.1-2341-0500/10609 E

1 Teflon hose 8 Flux Shield2 Water manifold 9 Support ring3 Stator frame 10 Clamping bolt4 Core 11 Bottom bar5 Clamping 12 Top bar6 Pressure plate for core 13 Pressure plate for stator bars7 Insulated through bolt 14 Water box

14 13 12 11 10 9 8 7 6 5 4

3

1 2

BHEL,Haridwar

Turbogenerators

Description

2.1-2350-0500/10609 E

Electrical Connection of BarsWater Supply and Phase Connectors

boxes. The cooling water is then discharged from thegenerator via the hoses and the ring header.

During manufacturing of the stator bars, various checksare performed to ensure water tightness and unobstructedwater passages.

The flow check ensures that no reduction in the crosssectional area of the strand ducts has occurred, and thatall strands are passed by identical water flows. Afterbrazing of the upper part of the water box, all brazed jointsare subjected to a helium leakage test followed by athermal shock treatment.

The tangential air clearance between the water boxesand bar connections within a coil group and the axialclearance relative to the inner shield, which is at groundpotential, is so dimensioned that additional insulation isnot required. For the spaces between the individual phasesinsulating caps, which enclose both the connecting sleevesand the water boxes, are connected to the stator bars.

3 Phase Connectors

The phase connector interconnect the coil groups andlink the beginning and ends of the winding to the bushings.They consist of thick-walled copper tubes. The stator barends coupled to the phase connectors are provided withconnecting fittings which are joined to the cylindricalcontact surface with Belleville washers on the bolts tomaintain a uniform and constant contact pressure.

The phase connectors are provided with a Micalasticinsulation. In addition, a grounded outer corona protectionconsisting of a semiconducting coating is applied over theentire length. At the beginnings and ends of the phaseconnectors several layers of semi-conductive and coronaprotection is applied in varying lengths.

The phase connectors are mounted on end windingsupporting ring over supporting brackets. Neighbouringphase connectors are separated with spacers and tiedsecurely in position. This ensures a high short-circuitstrength and differential movements between phaseconnectors and end windings are thus precluded.

1 Electrical Connection of Bars

The electrical connection between the top and bottombars is by a bolted contact surface.

At their ends the strands are brazed into a connectingsleeve, the strand rows being separated from each otherby spaces. The contact surfaces of the connectingsleeves for the top and bottom bars are pressed againsteach other

Fig.1 Electrical Bar Connections and WaterSupply

by non-magnetic clamping bolts. Special care is takento obtain flat and parallel contact surfaces. In order toprevent an any reduction in contact pressure or anyplastic deformations due to excessive contact pressure,Belleville washers are arranged on the clamping boltswhich ensure a uniform and constant contact pressure.

2 Water Supply

The water connection at the stator bar is separatefrom the electrical connection. As a result no electricalforces can act on the water connection.

While the solid strands of the stator bars terminateat the connecting sleeve, the hollow strands are brazedinto water boxes, with solid spencers inserted tocompensate for the solid strands. Each water box consistof two parts, i.e. the sleeve-shaped lower part enclosingthe hollow strands and the cover-type upper part. Thestrand rows are separated from each other by splicers.

Each water box is provided with a pipe connectionof non-magnetic stainless steel for connection of thehose.

The exciter-end water boxes serve for wateradmission and distribute the cooling water uniformly tothe hollow strands of the bar. The hot water is collectedon leaving the hollow strands in the turbine-end water Fig.2 Phase Connector Ends

BHEL,Haridwar

Turbogenerators

Description

Electrical Bar Connectionand Water Supply

2.1-2351-0500/10609 E

* Contact surface

1 2 3 4 5 6 7 9 10 11 12

14

15

1 Teflon Hose2 Crimping sleeve3 Cap nut4 Pipe connection5 Water box

6 Clamping bolt 7 Connecting sleeve 8 Clamping plate with through bore 9 Intermediate member10 Clamping plate with threaded bore

11 Bottom bar12 Top bar13 Belleville washer14 Spring washer15 O-ring

BHEL,Haridwar

Turbogenerators

Description

2.1-2370-0500/10609 E

Terminal Bushings

1 Arrangement of Terminal Bushings

The beginnings and ends of the three phase windingsare brought out from the stator frame through terminalbushings which provide for high-voltage insulation andseal against hydrogen leakage.

The bushings are bolted to the bottom plate of thegenerator terminal box by the mounting flanges.

The generator terminal box located beneath the statorframe at the exciter end is made from non-magnetic steelto avoid eddy-current losses resulting temperature rises.

Bushing-type generator current transformers, formetering and relaying are mounted on the bushingsoutside the generator terminal box. The customer's busis connected to the air side connection flange of thebushings via terminal connectors.

2 Construction of Bushings

The cylindrical bushing conductor consists of high-conductivity copper with a central bore for direct primarywater cooling.

The insulator is wound directly over the conductor. Itconsists of impregnated capacitor paper with conductingfillers for equalization of the electrical direct-axis andquadrature-axis fields.

The shrunk-on mounting sleeve consists of a gastightcasting of nonmagnetic steel with a mounting flange anda sleeve-type extension extruding over entire height ofthe current transformers.

The cylindrical connection ends of the terminalbushing conductors are silver-plated and designed toaccommodate bottle two-part cast terminal connectors.

Connection to the beginning and end each phaseinside the terminal box and to the external bus in bymeans of flexible connectors. To maintain a uniform andconstant contact pressure Belleville washers are usedfor all bolted connections.

Covers with brazed sockets for connection to thewater supply are flanged to the ends of the terminal

1 Phase connector2 Teflon hose3 Flexible connector4 Manhole5 Terminal bushing

Fig.1 Flexible Connection Between Bushing andPhase Connector

1

2

3

4

5

BHEL,Haridwar

Turbogenerators

Description

PW Connection for TerminalBushings and Phase Connectors

2.1-2371-0500/10609 E

1 Phase connector2 H.V. terminal box3 Flexible connector4 PTFE insulating hose5 Water-cooled bushing

Note: If required, the H.V. terminal box may be turned through 180 deg. Mounting position of phase connectors andneutral connection may be changed as well.

1

2

3

4

5

Primary water inlet

ConventionalNeutral connection

BHEL,Haridwar

Turbogenerators

Description

2.1-2372-0500/10609 E

Cooling of Terminal Bushing

Primary waterinlet

Primary wateroutlet

BHEL,Haridwar

Turbogenerators

Description

2.1-2380-0500/10609 E

Components for Water Coolingof Stator Windings

1 General

The separate water cooling circuits are used forthe stator windings and phase connectors and thebushings.

All water connections between ungrounded partsand the distribution manifolds and water manifolds ofthe cooling circuits are insulated with teflon hoses.The water connections are equipped with O-rings ofViton and Belliville washers to prevent loosening ofthe connect ion. The f i t t ings are made f romnonmagnetic stainless steel.

2 Winding Cooling Circuit

The end windings are enclosed by an annularwater manifold to which all stator bars are connectedthrough hoses. The water manifold is mounted on theholding plates of the end winding support ring andconnected to the primary water supply pipe. Thispermits the insulation resistance of the water-filledstator winding to be measured. The water manifold isgrounded during operation. For measurement of theinsulat ion res is tance, e .g. dur ing inspect ions,grounding is removed by opening the circuit outsidethe stator frame.

The hoses, one side of which is connected toground, consists of a metallic section to which themeasuring potential is applied for measurement of theinsulation resistance of the water-filled stator winding.

The cooling water is admitted to three terminalbushings via a distr ibution water manifold f lowsthrough the attached phase connectors and is thenpassed to the distribution water manifold for outlet

via the terminal bushings on the opposite side.The parallel-connected cooling circuit are checked

for uniform water flows by a flow measurement systemcovering all three phase.

The cooling primary water flows through the statorbars, which are hydraulically connected in parallel,f rom the exc i ter and to the turb ine end of thegenerator. This ensures a minimum temperature riseof the stator bars, a minimum water velocity, and aminimum head loss. Moreover, the thermalexpansions of the stator bars are completely uniform.

3 Phase Connector Cooling Circuit

Phase connectors and terminal bushing suppliedwith cooling water through pipes arranged outside thegenerator at the terminal bushing and generatorterminal box and connected to the cooling water inletsand outlet of the cooling circuit through teflon hoses.The flexible expansion joints and the hydraulicallyser ies-connected phase connector sect ions areconnected by teflon hoses.

The hoses, one side of which is connected toground, consist of a metallic section to which themeasuring potential is applied for measurement of theinsulation resistance of the water-filled stator winding.

The cooling water is admitted to three terminalbushings via a distr ibution water manifold f lowsthrough the attached phase connectors and is thenpassed to the distribution water manifold for wateroutlet via the terminal bushings on the opposite side.

The parallel-connected cooling circuit are checkedfor uniform water flows by a flow measurement systemcovering all three phase.

BHEL,Haridwar

Turbogenerators

Description

Grounding of the Stator CoolingWater Manifold

2.1-2389-0500/10609 E

Primary water outlet

Primary water inlet

1

2

3

4

5

7

6

8

4

1 Primary water inlet / outlet2 Compensator3 Insulation4 Stator frame5 Water manifold6 Insulated ground connection7 Water manifold ground connection8 Stator frame ground connection

BHEL,Haridwar

Turbogenerators

Description

2.1-3000-0500/1 0609E

Rotor Shaft

The high mechanical stresses resulting from thecentrifugal forces and short-circuit torques call for high-quality heat-treated steel. Therefore, the rotor shaft isforged from a vacuum cast steel ingot. Comprehensivetests ensure adherence to the specified mechanical andmagnetic properties as well as a homogeneous forging.

The root shaft consists of an electrically activeportion the so-called rotor body, and the two shaftjournals. Integrally forged flange couplings to connectthe rotor to the turbine and exciter are located outboardof the bearings. Approximately two-thirds of the rotorbody circumference is provided with longitudinal slotswhich hold the field winding. Slot pitch is selected so

that two solid poles are displaced by 1800.Due to the non-uniform slot distribution on the

circumference, different moments of inertia are obtainedin the main axis of the rotor. This in turn causesoscil lat ing shaft deflections at twice the systemfrequency. To reduce these vibrations, the deflection inthe direction of the pole axis and the neutral axis arecompensated by transverse slotting of the pole.

The solid poles are also provided with additionallongitudinal slots to hold the copper bars of the damperwinding. The rotor wedges act as a damper winding inthe area of the winding slots.

1 Shaft journal 4 Transverse slot in pole2 Rotor slot 5 Retaining ring seat3 Pole 6 Rotor tooth

Fig.1 Rotor Shaft

Note:Shaft and slots may vary from actual design.

1 2 3 4 5 6

BHEL,Haridwar

Turbogenerators

Description

2.1-3100-0500/10609 E

Cooling of Rotor Winding

Each turn is subdivided into eight parallel coolingzones. One cooling zone includes the slots from thecentre to the end of the rotor body, while anothercovers half the end winding.

The cooling gas for the slot portion is admittedinto the hollow conductors through milled openingsdirectly before the end of the rotor body and flows

1 2 3 4

1 End winding2 Gas inlet (cooling zone: slot portion)3 Gas inlet (cooling zone: end winding)4 Rotor toothFig.1 Gas Inlets at End Winding

through the hollow conductors to the centre of therotor body. The hot gas is then discharged into theair gap between the rotor body and the stator corethrough radial openings in the conductors and therotor slot wedges. The cooling gas passages arearranged at d i f ferent levels in the conductorassembly so that each hollow conductor has its own

cooling gas outlet.The cooling gas for the end windings is admitted

into the hollow conductors at the ends of the rotorbody. It flows through the conductors approximatelyup to the pole centre for being directed into acollecting compartment and is then discharged intothe air gap via slots.

1 2 3 4 5 6 71 Rotor winding2 Gas outlet in orator slot wedge3 Top strip4 Rotor tooth5 Rotor slot wedge6 Damper bar7 Rotor body

Fig.2 Gas Outlets in Slot Portion

At the end winding, one hollow conductor passageof each bar is completely closed by a brazed copperfil ler section. The enlargement of the conductorcross-section results in both a reduction of lossesand increased conductor rigidity.

BHEL,Haridwar

Turbogenerators

Description

2.1-3101-0500/10609 E

Cooling Scheme of Rotor Winding

8 Pa

ralle

l coo

ling

zone

s pe

rtu

rn

Coo

ling

zone

: End

win

ding

Coo

ling

zone

: Sl

ot p

ortio

n

BHEL,Haridwar

Turbogenerators

Description

2.1-3300-0500/10609 E

Rotor Winding

1. Rotor Winding

1.1 ConstructionThe f ie ld winding consists of several coi ls

inserted into the longitudinal slots of the rotor body.The coils are wound around the poles so that onenorth and one south magnetic pole are obtained.

The hollow conductors have a trapezoidal cross-section and are provided with two cooling ducts ofapprox imate ly semi-c i rcu lar cross-sect ion Al lconductors have identical copper and cooling ductcross-sections.

The individual conductors are bent to obtain halfturns. After insertion into the rotor slots, these turnsare combined to form full turns, the series-connectedturns of one slot constituting one coil. The individualcoi ls of the rotor winding are electr ic i ty ser ies-connected.

1.2 Conductor MaterialThe conductors are made of copper with a silver

content of approximately 0.1%. As compared toelectrolytic copper, silver-alloyed copper features highstrength properties at higher temperatures so that coildeformations due to thermal stresses are eliminated.

1.3 InsulationThe insulation between the individual turns is

made of layers of glass fibre laminate. The coils areinsulated from the rotor body with L-shaped strips ofglass fibre laminate with Nomex filler.

To obtain the required creepage paths betweenthe coil and the frame, thick top strips of glass fibrelaminate are inserted below the slot wedges.

2. Location of Parts in the Rotor Winding

2.1 Rotor Slot WedgesTo protect the winding against the effects of the

centrifugal force, the winding is secured in the slotswith wedges. The slot wedges are made from a

copper-nickel-silicon alloy featuring high strength andgood electrical conductivity, and are used as damperwinding bar. The slot wedges extend below the shrinkseats of the retaining rings. The rings act as short-c i rcui t r ings to induced currents in the damperwindings.

2.2 End Winding BracingThe spaces between the individual coils in the

end winding are filled with insulating members whichprevent coil movement. Fig. 1 shows a typical rotorend winding with the fillers inserted.

1 Rotor shaft2 Rotor slot wedge3 Filler4 Gas outlet5 Rotor end winding

Fig. 1 Rotor End Winding With Filler

1 2 3 4 5

BHEL,Haridwar

Turbogenerators

Description

Rotor Slot

2.1-3301-0500/10609 E

1 Rotor slot wedge 6 Slot liner2 Top strip 7 Radial cooling gas outlet3 Hollow conductor 8 Cooling gas bore4 Cooling gas duct 9 Rotor shaft5 Winding insulation

Note: The number of conductors shown does not necessarily correspond to the number of conductors of the generator described.

2

3

4

5

6

7 8 9 1

BHEL,Haridwar

Turbogenerators

Description1

2

3

4

5

6

7

8

Rotor End Winding

2.1-3310-0500/10609 E

1R

otor

bod

y5

End

win

ding

ins

ulat

ion

2S

nap

ring

6F

iller

3R

etai

ning

rni

g7

End

rin

g4

Rot

or w

indi

ng8

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anci

ng s

lot

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ors

of th

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tor d

escr

ibed

.

BHEL,Haridwar

Turbogenerators

Description

2.1-3350-0500/10609 E

Rotor Retaining Ring

The rotor retaining rings contain the centrifugalforces due to the end windings. One end of each ringis shrunk on the rotor body, while the other end of thering overhangs the end windings without contactingthe shaf t . This ensures an unobstructed shaf tdeflection at the end windings.

The shrunk on end ring at the free end of theretaining ring serves to reinforce the retaining ringand secures the end winding in the axial direction atthe same time.

A snap ring is provided for additional protection

against axial displacement of the retaining ring.To reduce the stray losses and retain strength, the

r ings are made of non-magnet ic , co ld-workedmaterial.

Comprehensive tests , such as u l t rasonicexamination and liquid penetrant examination, ensureadherence to the specified mechanical properties.

The retaining ring shrink-fit areas act as short-circuit rings to induce currents in the damper system.To ensure low contact resistance, the shrink seats ofthe retaining rings are coated with nickel, aluminiumand silver by a three-step flame spraying process.

BHEL,Haridwar

Turbogenerators

Description

Rotor Field Connections

2.1-3370-0500/10609 E

The f ie ld connect ions provide the electr ical ,connection between the rotor winding and the exciterand consists of:

Field current lead at end windingRadial boltsField current lead in shaft bore

1. Field Current lead at End Winding

The field current lead at the end winding consistsof hol low rectangular conductors. The hol lowconductors are inserted into shaft slots and insulated.That are secured against the effects of centrifugalforce by steel wedges. One end of each field currentlead is brazed to the rotor winding and the other endis screwed to a radial bolt. Cooling hydrogen isadmitted into the hollow conductors via radial bolts.The hot gas is discharged into the air gap togetherwith the gas used to cool the end winding.

2. Radial Bolts

The field current leads located in the shaft bore areconnected to the conductors inserted in the shaft slotsthrough radial bolts which are secured in position withslot wedges. Contact pressure is maintained with atension bolt and an expanding cone in each radial bolt.Contact pressures increase due to centrifugal forceduring operation. All contact surfaces are silver-platedto attain a low contact resistance. The radial bolt is madefrom forged electrolytic copper.

3. Field Current Lead in Shaft Bore

The leads are run in the axial direction from the radialbolt to the exciter coupling. These consist of two semi-circular conductors insulated from each other and fromthe shaft by a tube. The field current leads are connectedto the exciter leads at the coupling with multicontactplug-in contact which allow for unobstructed thermalexpansion of the field current leads.

BHEL,Haridwar

Turbogenerators

Description

2.1-3373-0500/10609 E

Electrical and MechanicalConnection of EE Coupling

1 Generator rotor 7 Exciter rotor2 Coupling bolt 8 Insulation3 Shear bush 9 Insulation4 H2 seal between half couplings 10 Field current lead in exciter rotor shaft5 Multicontact plug-in socket strip 11 Insulation6 Multicontact plug-in bolt 12 Field current lead in generator rotor shaft

1 2 3 4 5 6 7 8

9

10

11

12

BHEL,Haridwar

Turbogenerators

Description

Rotor Fan

2.1-3600-0500/10609 E

Note: Depending on generator size the rotor fan may be of three or five stages.

The generator cooling gas is circulated by oneaxial- f low fan located on the turbine-end shaftjournal. To augment the cooling of the rotor winding,the pressure establ ished by the fan works in

conjunction with the gas expelled from the dischargeports along the rotor.

The moving blades of the fan are inserted into T-shaped grooves in the fan hubs. The fan hubs areshrink-fitted to the shaft journal spider.

1 Rotor shaft journal2 Balancing weight3 Gas inlet to rotor winding

4 Fan Hub5 Fan blade6 Rotor retaining ring (Covered)

1 2 3 4 5 6

BHEL,Haridwar

Turbogenerators

Description

Hydrogen Cooler

2.1-4000-0500/10609 E

The hydrogen cooler is shell and tube type heatexchanger which cools the hydrogen gas in thegenerator. The heat removed from the hydrogen isdissipated through the cooling water. The coolingwater flows through the tubes. While the hydrogenis passed around the finned tubes.

The cooler consists of individual sections forvertical mounting. This arrangement permits thecoolers to be mounted without an increase in theoverall generator axial length or cross-sectional areaof the stator frame.

The hydrogen flows through the coolers in ahorizontal direction. The cold cooling water flowsfrom the bottom to the top of the cooler on the coldgas side and, after reversal in the return waterchannel, the heated water flows downwards on thehot gas side. This cooling water flow passage isobtained through a partition in the inlet/outlet waterchannel.

Each cooler consists of the tube bundle, theupper and lower tube-sheets, the return waterchannel and the inlet/outlet water channel. The tubeshave copper fins to obtain a larger heat transfersurface, the fins being joined to the tubes by tinning.The ends of the tubes are expanded into the upperand lower tube-sheets.

The two side walls of structural steel base thecooler and direct the hydrogen flow. They are solidlybolted to the upper tube-sheet. While the attachmentto the lower tubesheet permits them to move freelyto allow for expansion of the tube bundle.

Flexible seal strips bolted to the side walls sealthe gap between the cooler and the cooler well inthe cooler assembly, thus preventing uncooledhydrogen from flowing past the cooler.

The upper tubesheet is larger than the cooler wellopening and is used to fix the cooler. Gastight sealingof this tubesheet is done by a packing.

The return water channel is bolted to the uppertubesheet over a f lat gasket. This arrangementpermits the return water channel to be detached forcleaning, even when the generator is in operationand filled with hydrogen.

The lower tubesheet is f reely movable andcapable of fo l lowing the di f ferent ial movementbetween stator frame and cooler due to the differentthermal expansion resul t ing f rom the di f ferentmaterials and temperature.

Attached to the lower tubesheet is the inlet/outlet

water channel with its cooling water inlet and outletpipes.

A seal cap is bolted over the inlet/outlet waterchannel. The seal cap has opening for bringing outthe cooling water pipes.

Gastight sealing is done by a gland type seal whichis s imul taneously pressed against the outercircumference of the tubesheet and against thesealing face of the seal cap by a compression ring.

The cooler are parallel-connected on their watersides shut off valves are installed in the lines beforeand after each cooler. The required cooling watervolumetric flow depend on the generator output andis adjusted by a control valves on the heated waterside. Controlling the cooling water flow on the outletside ensures an uninterrupted water flow through thecoolers, with proper cooler performance not beingimpaired

Fig.1 Hydrogen Cooler Removed

BHEL,Haridwar

Turbogenerators

Description

2.1-4001-0500/10609 E

Hydrogen Cooler

1

2

3

4

5

6

1 Return water channel2 End shield3 Finned tube bundle

4 Cooling water connection5 Protective chamber6 Hydrogen seal

BHEL, Haridwar

Turbogenerators

Description

Generator Bearings

2.1-5000-0500/10609 E

The rotor shaft is supported in sleeve bearingshaving forced-oil lubrication. The bearings are locatedin the stator end shields. The oil required for bearinglubrication and cooling is obtained from the turbine oilsupply system and supplied to the lubricating gap viapipes permanently installed inside the lower half of thestator end shield and via grooves in the bearing saddleand lower bearing sleeve.

The lower bearing sleeve rests on the bearingsaddle via three brackets with spherical support seat forself-alignment of the bearing. The bearing saddle isinsulated from the stator end shield and the bearingbrackets are insulated from the bearing sleeve to preventthe flow of shaft currents and to provide for doubleinsulation of the generator bearing from ground. A radiallocator serves to locate the bearing in the verticaldirection and is bolted to the upper half of the stator endshield. The locator is adjusted to maintain the requiredclearance between the bearing sleeve and the insulationof the radial locator.

A tangential locator is located at the bearing sleevejoint to prevent the bearing from turning in the saddle.

The tangential locator is supported on the bearingsaddleover a piece of insulating material.

The inner surface of the cast bearing sleeve bodyis provided with spiral dovetail grooves which firmly holdthe babbitt liner to the bearing sleeve body. The lowerbearing sleeve has a groove to admit the bearing oil tothe bearing surface. The upper sleeve has a wideoverflow groove through which the oil is distributed overthe shaft journal and fed to the lubricating gap. The oil isdrained laterally from the lubricating gap, caught bybaffles and returned to the turbine oil tank.

All generator bearings are provided with a hydraulicshaft lift oil system to reduce bearing friction duringstartup. High pressure oil is forced between the bearingsurface and the shaft journal, lifting the rotor shaft toallow the formation of a lubricating oil film.

The bearing temperature is monitored with onedouble element thermocouple located approximately inthe plane of maximum oil f i lm pressure. Thethermocouples are screwed in position on both sides ofthe lower bearing sleeve from outside with the detectorsextending to the babbitt liner.

1 2 3 4 5 6 7

1 Stator End shield2 Shaft Seal3 Lower Bearing sleeve

4 Pressurised oil inlet for Hydraulic shaft lift oil system5 OIl Baffle6 Bearing oil inlet7 Outer labyrinth ring

Fig.1 Generator Bearing

BHEL, Haridwar

Turbogenerators

DescriptionGenerator Bearing (Insulation)

2.1-5001-0500/10609 E

14

13

12

11

10

98

76

5

432

1

1 End shield, lower half 2 Bearing oil drain 3 Bearing insulation 4 Bearing saddle 5 Connections for jacking oil 6 Rotor shaft 7 Bearing oil wiper 8 Outer labyrinth ring 9 Bearing sleeve10 Tangential locator11 Radial locator12 Bearing cover13 End shield Upper half14 Shaft seal

BHEL, Haridwar

Turbogenerators

Description

2.1-5003-0500/10609 E

Measuring of Bearing Temperature

Direction ofShaft rotation

1 End Shield2 Thermocouple lead3 Thermocouple4 Bearing Sleeve

4

1

2

3

4

BHEL, Haridwar

Turbogenerators

Description

2.1-5005-0500/10609 E

Generator Bearing Insulation

Insulation

1 End shield or Bearing bracket2 Half Bearing ring3 Bearing sleeve4 Bearing oil wiper5 Bearing oil drain6 Bearing oil inlet7 Tangential locator

5

6

8

7

2

1

6

4

3

BHEL, Haridwar

Turbogenerators

DescriptionShaft Seal

2.1-6000-0500/10609 E

The rotor shaft ends are brought out of thegastight enclosure through double-flow shaft seals.

With th is type of shaft seal , the escape ofhydrogen between the rotating shaft and the housingis prevented by maintaining a continuous film of oilbetween the shaft and a non-rotating floating sealring. To accomplish this, seal oil from two separatecircuits, i.e. the air side and the hydrogen side sealoil circuit, is fed to the seal ring at a pressure slightlyhigher than the hydrogen pressure. In addit ion,higher pressure air side oil is supplied to the shaftseal for thrust load compensation of the seal ring.

1

2

1 Seal ring housing2 Seal ring

Hydrogen side seal oilAir side seal oilRing relief oil

Fig.1 Interchange of Oil in Annular Groove of Shaft Seal

The double-flow shaft seal is characterized by itsshor t ax ia l length, i ts independence f rom therespective axial and radial position of the shaft, andlow hydrogen losses due to absorption by the sealoil.

The two halves of the babbited seal ring float onthe shaft journal with a small clearance and areguided in the axial direction by a seal ring housingresistant to distortion and bending. The seal ring is

relatively free to move in the radial direction, but isrestrained from rotating by use of a pin. The seal ringhousing, bolted to the end shield, is insulated toprevent the flow of shaft currents. The oil is suppliedto the shaft seal at three different pressures (air sideseal oil pressures, hydrogen side seal oil pressuresand higher pressure oil for ring relief) over pipes andthe mounting flange of the seal ring housing. The airside and hydrogen side seal oil is admitted into theai r s ide and hydrogen s ide annular grooves,respectively, of the seal ring via passage in the sealring housing and seal ring. A continuous film of oil ismaintained between the shaft and the seal ring. Theclearance between shaft and seal ring is such thatfr ict ion losses are minimized and an oi l f i lm ofsuff ic ient th ickness is mainta ined wi thoutunnecessarily large oil flow. Temperature rise of theseal oil is therefore small which contributes to reliablesealing. The babbit lining of the seal ring ensure highreliability even in the event of boundary friction.

The air side seal oil pump delivers the oil at apressure maintained at >1.4 bar above the generatorhydrogen gas pressure at the shaft seal by means ofa differential pressure valve ("A" valve)

On the hydrogen side, the hydrogen-saturated sealo i l is c i rculated in a c losed c i rcui t . A pressureequalizing valve maintains the oil pressure on thehydrogen side slightly below that on the air side, thuskeeping the interchange of oil between the air andhydrogen sides to a very small value.

Air side seal oil for ring relief is fed to the annulargroove in the air side seal ring carrier and forcedbetween the seal ring and the seal ring housing. Inthis way the oil and gas pressure acting on the sealring are balanced, and the friction between the sealand seal ring housing is reduced. The seal ring is thusfree to adjust its radial position, which is importantduring the starting and shutdown period. The seal ringwill adjust its position according to the shaft positionas dictated by the oil film thickness and the vibratorycondition.

The seal ring need to allow axial displacement ofthe generator shaft, which is primarily caused byturbine expansion. This permits the shaft to slidethrough the seal ring without impairing the sealingeffect.

Hyd

roge

nsi

de

Air

side

BHEL,Haridwar 2.1-6001-0500/10609 E

Turbogenerators

GeneralShaft Seal

1 End shield 2 Packing 3 Insulation 4 Seal ring chamber 5 Seal oil inlet bore 6 Pressure oil groove 7 Seal oil groove

8 Inner labyrinth ring 9 Seal strip10 Rotor shaft11 Oil wiper ring (H2 side)12 Seal ring carrier13 Seal oil groove (H2 side)14 Seal oil groove (H2 side)

15 Seal oil groove (Air side)16 Babbit17 Seal ring18 Oil wiper ring (Air side)19 Seal oil inlet bore (air side)20 Pin

Section G-H

Section A-B Section E-F

Air

Hydrogen

Air side seal oil

H2 side seal oil

Pressure oil for seal ring relief

H2 side Air side

1

2

3

4

5

6

7 8

9

10

19 11 9 12 13 14 15 16 17 18 Section C-D

20

BHEL, Haridwar

Turbogenerators

Description

2.1-7100-0500/10609 E

Seal Oil System

Shaft seals supplied with pressurized seal oil areprovided to prevent hydrogen losses at the shaft andthe ingress of air into the hydrogen-cooled generator.

Details of the shaft seal are given in a separatedescription in this manual.

As long as the seal oil pressure in the annular gapexceeds the gas pressure in the generator, no hydrogenwill escape from the generator housing. The shaft sealis supplied with seal oil by a separate system consistingof a hydrogen side seal oil circuit and an air side sealoil circuit. The oil in the seal oil system is the same asthat used in the turbine-generator journal shown.

1 Air Side Seal Oil Circuit

During normal operation, the air side seal oil pump(AC) draws the seal oil from the seal oil storage tankand feeds it to the shaft seals via coolers and filters.The seal oil supplied to the shaft seals which drainstowards the air side through the annular gaps betweenthe shaft and seal rings is returned to the seal oil storagetank.

For the air side seal oil circuit, three seal oil pumpsare provided with one of the three pumps always inoperation. In the event of a failure of the pump in service

due to a mechanical or electrical failure, the secondpump automatically takes over. If both pumps fail, theseal oil supply is taken over by the stand-by pumpwithout any interruption.

2 Hydrogen Side Seal Oil Circuit

During normal operation, the hydrogen side pumpdraws the seal oil from the seal oil storage tank andfeeds it to the shaft seal via coolers and filters. Theseal oil supplied to the shaft seals which drainstowards the hydrogen side through the annular gapsbetween the shaft and the seal rings is first collectedin the generator pre-chambers and then returned tothe seal oil tank.

By dividing the seal oil system into two separatecircuits, the hydrogen losses at the seals are kept toa minimum. Since the hydrogen side seal oil comesinto contact with only the hydrogen gas, it is saturatedwith hydrogen and contains no air. Vacuum treatmentof the seal oil and the resulting continuous hydrogenlosses are thus avoided. The air side seal oil, whichis only in contact with air, becomes saturated with air.By separating the two seal oil circuits, entry of air tothe hydrogen compartment is kept to a minimum

1 Seal ring

Air side seal oil circuit 2 Seal oil storage tank 3 Seal oil pump 4 DPR-A valve 5 Oil cooler 6 Seal oil filter

Hydrogen side seal oil circuit 7 Generator prechamber 8 Pressure equalising valve 9 Seal oil tank10 Seal oil filter11 DPR-C Valve12 Oil cooler13 Seal oil pump

Air side seal oil

Hydrogen side seal oil

Pressure oil for Seal oil ring relief

Hydrogen

Fig-1: Seal oil diagram (Simplified)

2.1-7100-0500/20609 E

thereby maintaining good hydrogen purity.One seal oil pump is used for oil circulation in the

hydrogen side oil circuit. In the event of a failure ofthis pump, the seal oil to the hydrogen side annularderived from the air side oil supply circuit.

When operat ing is th is manner, a s lowdeterioration of the hydrogen purity in the generatorwill take place, since the oil f lowing towards thehydrogen side will introduce air, which will come outof the oil in the hydrogen atmosphere due to thechange in pressures. In case of prolonged operation,it may eventually become necessary to improve thehydrogen purity by gas scavenging.

3 Seal Oil Pressure Regulation

The air side and the hydrogen side seal oil circuitsare, however, in contact in the annular gaps betweenthe shaft seal. The seal oil pressures at the shaft sealare set so that the air side seal oil pressure is slightlyhigher than the hydrogen side seal oil pressure.Accordingly, a very small quantity of oil flows fromthe air side to the hydrogen side in the annular gapresulting in a gradual increase in the amount of oil inthe hydrogen side oil circuit. A float valve in seal oiltank returns the excess oil to the seal oil storage tank.The interchange of oil between the two circuit is sosmall that the aforementioned advantages of twoseparate circuit are not impaired.

Oil pressures which exceed the generator gaspressure are required to ensure proper sealing of thegenerator. With the seal oil pumps in operation, theseal oil pressure is controlled by differential pressurevalves "A" ("A" valve). The first "A" valve controls theseal oil pressure after two equal-priority ac air sideseal oil pumps. The pressure after the stand-by sealoil pump is separately controlled by the second "A"valve. Depending on the valve setting and the impulseoil pressure prevailing (seal oil pressure and hydrogencasing pressure), a larger or smaller amount of oil isreturned to the suction pipe so that the required sealoil pressures is established at the shaft seals.

The function of the "A" valves is illustrated in theattached diagram. Since the gas pressure and theimpulse oil pressure act in opposite directions, thevalve stem is moved upwards or downwards whenthese pressure become unbalanced. The valve coneis arranged so that the valve closes further for adownward movement of the valve stem (occurs atrising gas pressure or falling seal oil pressure). Thisoil flow throttling results in a rise of the air side sealoil pressure at the shaft seals. Setting of the desireddifferential pressure (set valve) to be maintained bythe valve is done by a corresponding pre-loading ofthe main bellows. The pre-loading is adjusted with acompression spring, the upper end of which is rigidlyconnected to the valve yoke, while its lower end is

linked to the valve stem by means of an adjusting nut.As may be seen on the at tached d iagram,

differential pressure valve "C" ("C" valve) serves tocontrol the seal oil pressure in the hydrogen side sealoil circuit and operates on the same principle, withthe only difference being that the air side seal oilpressures are used as impulse.

The constant differential pressure between the airs ide and the hydrogen side oi l is control led byseparate pressure equalizing control valves for eachshaft seal. The function of the pressure equalizingcontrol valve is illustrated in the attached diagram.Due to the fact that the air side and hydrogen sideseal oil pressures act in opposite directions, the valvestem is moved upwards or downwards when thesepressures are unbalanced. The valve opens furtherwith a downward movement of the valve stem (occursat rising air side seal oil pressure), resulting in a raiseof the hydrogen side seal oil pressure. Setting of thedesired differential pressure to be maintained by thevalve is done by a corresponding pre-loading of thecontrol piston.

4 Seal Oil Drains

The oil drains from the air side of the shaft sealsdischarges to the generator bearing space and isreturned to the turbine oil tank via the seal oil storagetank together with the bearing oil.

The oil drained from the hydrogen side of the shaftseals is discharged into the generator pre-chambers.The pre-chambers reduce the oil flow which permitsthe escape of entrapped gas bubbles and de-foamingof the oil. Down-stream of the pre-chambers, the oilflows are combined and returned into the seal oil tank.Float valves keep the oi l level in the tank at apredetermined level. If an excessive amount of oil issupplied to the seal oil tank, a float valve allows someoil to return to the seal oil storage tank.

The small amount of hydrogen escaping from thegenerator together with the oil does not present adanger to the generator surrounding since the oildrained on the hydrogen side is returned to the turbineoil tank only via the seal oil storage tank where themajority of the entrapped hydrogen is removed. Theseal oil storage tank is connected to the bearingvapour-exhausters which also vent the generator pre-chambers.

5 Seal Ring Relief

To ensure free movement of the seal ring, the shaftseals are provide with pressure oil for ring relief. Theoil supply for ring relief is obtained from the air sideoil circuit. The required pressure setting for each shaftseal is accomplished separately.

BHEL, Haridwar

Turbogenerators

Description

2.1-7101-0500/10609 E

Differential Pressure Valve A

Hydrogen

Seal oil

**

*

4

5

*

6

7

8 910

11

12

13

14

15

1

2

3

1 Connection for gas signal pipe2 Connection for oil signal pipe3 Oil inlet4 Valve head5 Main Bellow6 Upper sealing bellows7 Valve stem8 Compression spring9 Adjusting nut10 Lock nut11 Yoke12 Lower sealing bellows13 Valve Housing14 Valve cone15 Oil inlet

* Vent connection

** Screw plug

BHEL, Haridwar

Turbogenerators

Description

2.1-7103-0500/10609 E

Differential Pressure Valve C

1 Connection for air side seal oil signal

2 Connection for hydrogen side seal oil signal3 Hydrogen side seal oil inlet4 Valve head5 Main Bellow6 Upper sealing bellows7 Valve stem8 Compression spring9 Adjusting nut10 Lock nut11 Yoke12 Lower sealing bellows13 Valve Housing14 Valve cone15 Hydrogen side seal oil inlet

* Vent connection

** Screw plug

*

4

5

*

6

7

8

910

11

12

13

14

15

1

2

3

BHEL, Haridwar

Turbogenerators

Description

2.1-7104-0500/10609E

Pressure Equalizing Control Valve

2

3

4

5

6

7

8

9

10

11

1

17

16

15

14

13

12

1 Connection for air side signal pressure 2 Cap 3 Lock nut 4 Threaded spindle 5 Compression spring 6 Piston housing 7 Oil outlet 8 Compression spring 9 Threaded spindle10 Lock nut11 Cap12 Valve cone13 Oil inlet14 Valve housing15 Connection for Hydrogen side signal pressure16 Valve cone stem17 Control piston

BHEL, Haridwar

Turbogenerators

DescriptionList of Valves for Seal oil System

2.1-7112-10555/10609 E

1 MAV 72 NEEDLE VALVE 15 2.5 CS SC SHUT OFF VALVE IN U LOOP DRAIN PIPE LINEAA 513

2 MKW 01 GATE VALVE 80 2.5 CS FL SHUT OFF TO SEAL OIL PUMPS PIPE LINEAA 503

3 MKW 01 NEEDLE VALVE 15 2.5 CS SC SHUT OFF VALVE FOR SOST DRAIN PIPE LINEAA 504

4 MKW 03 FLOAT VALVE 50 1.6 CS FL FLOAT VALVE FOR SOST DRAIN SEAL OIL UNITAA 001

5 MKW 03 FLOAT VALVE 50 1.6 CS FL FLOAT VALVE FOR SOT SEAL OIL UNITAA 002 SUPPLY FROM AIR SIDE CIRCUIT

6 MKW 03 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE IN DRAIN LINE SEAL OIL UNITAA 501 OF SOT CIRCUIT

7 MKW 03 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE FOR SEAL OIL SEAL OIL UNITAA 502 SUPPLY TO SOT

8 MKW 03 NEEDLE VALVE 15 2.5 CS SC DRAIN VALVE FOR H2 SIDE SEAL PIPE LINEAA 503 OIL DRAIN LOOP

9 MKW 03 GLOBE VALVE 50 4.0 CS FL SHUT OFF VALVE IN DRAIN BYPASS SEAL OIL UNITAA 504 AT SOT

10 MKW 03 GLOBE VALVE 20 2.5 CS FL SHUTOFF VALVE FOR OIL LEVEL SEAL OIL UNITAA 505 INDICATOR FOR SEAL OIL TANK

11 MKW 03 GLOBE VALVE 20 2.5 CS FL SHUT OFF VALVE FOR OIL LEVEL SEAL OIL UNITAA 506 INDICATOR ,BOTTOM

12 MKW 11 RELIEF VALVE 20 2.5 CS FL RELIEF VLV FOR AC SOP-1(AIR SIDE) SOP UNITAA 001

13 MKW 11 DPR VALVE 25 1.6 CS FL FOR MAINTAINING CONSTANT PRESS SEAL OIL UNITAA 002 DIFFERENCE

14 MKW 11 CHECK VALVE 50 4.0 CS FL CHECK VALVE AFTER AC SOP-1 SEAL OIL UNITAA 003 AIR SIDE

15 MKW 11 SHUT OFF VALVE 50 2.5 CS FL NR SHUT OFF VALVE AFTER AIR SEAL OIL UNITAA 004 SIDE SOP-1&2

16 MKW 11 GATE VALVE 80 4.0 CS FL INLET TO SOP-1 AIR SIDE SEAL OIL UNITAA 501

17 MKW 11 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE BEFORE DPRV SEAL OIL UNITAA 504

18 MKW 11 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE AFTER DPRV SEAL OIL UNITAA 505

19 MKW 11 GLOBE VALVE 10 2.5 CS BW SHUT OFF VALVE IN OIL IMPULSE SEAL OIL UNITAA 506 LINE OF DPRV

20 MKW 11 GLOBE VALVE 8 2.5 CS BW SEAL OIL IMPULSE OF DPRV SEAL OIL UNITAA 507

21 MKW 11 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE IN BYEPASS LINE SEAL OIL UNITAA 508

22 MKW 13 RELIEF VALVE 20 2.5 CS FL BLOW OFF OF OIL FOR SOP(H2 SIDE) SEAL OIL UNITAA 001

23 MKW 13 DPR VALVE 25 1.6 CS FL FOR MAINTAINING CP DIFFERENCE SEAL OIL UNITAA 002

24 MKW 13 CHECK VALVE 50 4.0 CS FL CHECK VALVE AFTER H2 SIDE SOP SEAL OIL UNITAA 003

SL. VLV TYPE OF VALVE NB NP BODY END FUNCTION LOCATIOINNO. DESG MM MPA MAT CONN

2.1-7112-10555/20609 E

25 MKW 13 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE BEFORE H2 SIDE SEAL OIL UNITAA 501 SEAL OIL PUMP

26 MKW 13 GATE VALVE 50 4.0 CS FL SHUT OFF VALVE FOR SEAL OIL SEAL OIL UNITAA 503 BEFORE H2 SIDE COOLERS

27 MKW 13 GLOBE VALVE 50 4.0 CS FL SHUT OFF VALVE IN AIR SIDE SEAL OIL UNITAA 505 IMPULSE LINE

28 MKW 13 GLOBE VALVE 10 2.5 CS BW SHUT OFF VALVE IN H2 SIDE SEAL OIL UNITAA 506 IMPULSE LINE

29 MKW 13 GLOBE VALVE 10 2.5 CS BW EQUALISING VALVE IN BYE PASS OF SEAL OIL UNITAA 507 IMPULSE LINE

30 MKW 13 NEEDLE VALVE 8 2.5 CS BW SEAL OIL VENT VALVE AT DPRV SEAL OIL UNITAA 508 AIR SIDE

31 MKW 13 GLOBE VALVE 8 2.5 CS BW SEAL OIL VENT VLV AT DPRV H2 SIDE SEAL OIL UNITAA 509

32 MKW 13 GATE VALVE 25 4.0 CS FL SHUT OFF VLV IN H2 SIDE DPRV SEAL OIL UNITAA 510 BY PASS LINE TO SOT

33 MKW 13 GLOBE VALVE 50 4.0 CS FL SHUT OFF VALVE IN H2 SIDE SEAL SEAL OIL UNITAA 511 OIL DRAIN LINE

34 MKW 21 RELIEF VALVE 20 0.0 CS FL RELIEF VLV FOR AC SOP-2(AIR SIDE) SOP UNITAA 001

35 MKW 21 CHECK VALVE 50 4.0 CS FL CHECK VLV AFTER AIR SIDE SOP-2 SEAL OIL UNITAA 002

36 MKW 21 GATE VALVE 80 4.0 CS FL INLET TO SOP-2(AIR SIDE) SOP UNITAA 501

37 MKW 21 GATE VALVE 50 4.0 CS FL AIR SIDE & H2 SIDE OIL INTERCONN SEAL OIL UNITAA 503

38 MKW 23 GLOBE VALVE 8 25.0 CS SC H2 IMPULSE TO DPRV SEAL OIL UNITAA 503

39 MKW 23 GLOBE VALVE 8 25.0 CS SC H2 IMPULSE TO DPRV SEAL OIL UNITAA 504

40 MKW 31 RELIEF VALVE 20 2.5 CS FL RELIEF VLV FOR SOP-3 (AIR SIDE) SOP UNITAA 001

41 MKW 31 DPR VALVE 25 1.6 CS FL FOR MAINTAINING CP DIFFERENCE SEAL OIL UNITAA 002

42 MKW 31 CHECK VALVE 50 4.0 CS FL CHECK VLV AFTER SOP-3(AIR SIDE) SEAL OIL UNITAA 003

43 MKW 31 NR SHUT OFF 50 2.5 CS FL NON RETURN SHUT OFF VLV AFTER SEAL OIL UNITAA 004 VALVE AIR SIDE SEAL OIL PUMP

44 MKW 31 GATE VALVE 80 4.0 CS FL INLET TO SOP-3(AIR SIDE) SEAL OIL UNITAA 501

45 MKW 31 GATE VALVE 50 4.0 CS FL SHUT OFF VLV BEFORE DPRV SEAL OIL UNITAA 504

46 MKW 31 GATE VALVE 50 4.0 CS FL SHUT OFF VLV AFTER DPRV SEAL OIL UNITAA 505

47 MKW 31 GLOBE VALVE 10 2.5 CS BW SHUT OFF VLV IN OIL IMPULSE LINE SEAL OIL UNITAA 506 OF DPRV

48 MKW 31 GLOBE VALVE 8 2.5 CS BW SEAL OIL IMPULSE VENT OF DPRV SEAL OIL UNITAA 507

49 MKW 51 DOUBLE CHANGE 50 1.6 CS FL 3-WAY CHANGE OVER VLV AT SEAL SEAL OIL UNITAA 501 OVER VALVE OIL COOLER (AIR SIDE)

50 MKW 51 DOUBLE CHANGE 50 1.6 CS FL 3-WAY CHANGE OVER VLV AT SEAL SEAL OIL UNITAA 502 OVER VALVE OIL COOLER (AIR SIDE)


BHEL, Haridwar

Turbogenerators

DescriptionList of Valves for Seal oil System

2.1-7112-10555/30609E

51 MKW 51 GLOBE VALVE 8 2.5 CS BW FILLER VLV FOR AIR SIDE S.O.COOLER SEAL OIL UNITAA 503

52 MKW 51 GLOBE VALVE 8 2.5 CS BW S.O.DRAIN VLV AT AIR SIDE COOLER-2 SEAL OIL UNITAA 504

53 MKW 51 GLOBE VALVE 8 2.5 CS BW S.O.DRAIN VLV AT AIR SIDE COOLER-1 SEAL OIL UNITAA 505

54 MKW 51 GLOBE VALVE 8 2.5 CS BW COOLING WATER DRAIN VLV AT SEAL OIL UNITAA 506 COOLER-2 AIR SIDE

55 MKW 51 GLOBE VALVE 8 2.5 CS BW COOLING WATER DRAIN VLV AT SEAL OIL UNITAA 507 COOLER-1(AIR SIDE)

56 MKW 51 GLOBE VALVE 8 2.5 CS BW COOLING WATER VENT VLV AT SEAL OIL UNITAA 508 COOLER-2 (AIR SIDE)


58 MKW 51 GLOBE VALVE 8 2.5 CS BW SEAL OIL VENT VLV INLET AT SEAL OIL UNITAA 510 COOLER-2(AIR SIDE)

59 MKW 51 GLOBE VALVE 8 2.5 CS BW SEAL OIL VENT VLV FROM SEAL OIL UNITAA 511 COOLER-1 (AIR SIDE)

60 MKW 51 DOUBLE CHANGE 50 1.6 CS FL CHANGE OVER VALVE FOR SEAL OIL SEAL OIL UNITAA 512 OVER VALVE FILTER-1 (AIR SIDE) WITH FILTER

61 MKW 51 DOUBLE CHANGE 50 1.6 CS FL CHANGE OVER VALVE FOR SEAL OIL SEAL OIL UNITAA 513 OVER VALVE FILTER-2 (AIR SIDE) WITH FILTER

62 MKW 53 DOUBLE CHANGE 50 1.6 CS FL CHANGE OVER VALVE AT SEAL OIL SEAL OIL UNITAA 501 OVER VALVE COOLER (H2 SIDE)

63 MKW 53 DOUBLE CHANGE 50 1.6 CS FL CHANGE OVER VALVE AT SEAL OIL SEAL OIL UNITAA 502 OVER VALVE COOLER (H2 SIDE)

64 MKW 53 GLOBE VALVE 8 2.5 CS BW FILLER VLV FOR H2 SIDE S.O.COOLER SEAL OIL UNITAA 503

65 MKW 53 GLOBE VALVE 8 2.5 CS BW SEAL OIL DRAIN VALVE AT H2 SIDE SEAL OIL UNITAA 504 COOLER-2

66 MKW 53 GLOBE VALVE 8 2.5 CS BW SEAL OIL DRAIN VALVE AT H2 SIDE SEAL OIL UNITAA 505 COOLER-1

67 MKW 53 NEEDLE VALVE 8 2.5 CS BW COOLING WATER DRAIN VLV AT SEAL OIL UNITAA 506 COOLER-2(H2 SIDE)

68 MKW 53 GLOBE VALVE 8 2.5 CS BW COOLING WATER DRAIN VLV AT SEAL OIL UNITAA 507 COOLER-1(H2 SIDE)


70 MKW 53 GLOBE VALVE 8 2.5 CS BW COOLING WATER VENT VLV AT SEAL OIL UNITAA 509 COOLER-1(H2 SIDE)

71 MKW 53 GLOBE VALVE 8 2.5 CS BW SEAL OIL VENT VALVE AT COOLER-2 SEAL OIL UNITAA 510 (H2 SIDE)

72 MKW 53 GLOBE VALVE 8 2.5 CS BW SEAL OIL VENT VALVE AT COOLER-1 SEAL OIL UNITAA 511 (H2 SIDE)

73 MKW 53 DOUBLE CAHNGE 50 1.6 CS FL CHANGE OVER VLV AT SEAL OIL SEAL OIL UNITAA 512 OVER VALVE FILETR-1(H2 SIDE)

74 MKW 53 DOUBLE CHANGE 50 1.6 CS FL CHANGE OVER VLV FOR SEAL OIL SEAL OIL UNITAA 513 OVER VALVE FILTER-2(H2 SIDE) WITH FILTER


2.1-7112-10555/40609 E

75 MKW 71 3-WAY VALVE 50 1.6 CS FL 3-WAY VLV TE(AIR SIDE) SOV RACKAA 511

76 MKW 71 GATE VALVE 50 4.0 CS FL SHUT OFF VLV FOR SEAL OIL,TE SOV RACKAA 512 (AIR SIDE)

77 MKW 71 GLOBE VALVE 10 2.5 CS BW SHUT OFF VLV IN SEAL OIL IMPULSE SOV RACKAA 513 LINE,TE (AIR SIDE)

78 MKW 71 GLOBE VALVE 8 2.5 CS BW VENT FOR EQUALISING VLV TE SOV RACKAA 514 (AIR SIDE)

79 MKW 71 3-WAY VALVE 50 1.6 CS FL 3-WAY VLV,EE (AIR SIDE) SOV RACKAA 521

80 MKW 71 GATE VALVE 50 4.0 CS FL SHUT OFF VLV FOR SEAL OIL,EE SOV RACKAA 522 (AIR SIDE)

81 MKW 71 GLOBE VALVE 10 2.5 CS BW SHUT OFF VLV IN SEAL OIL IMPULSE SOV RACKAA 523 LINE,EE (AIR SIDE)

82 MKW 71 GLOBE VALVE 8 2.5 CS BW VENT FOR EQUALISING VLV EE SOV RACKAA 524 (AIR SIDE)

83 MKW 71 NEEDLE VALVE 15 2.5 CS SC FIRST SHUT OFF VLV FOR PR. PIPE LINEAA 551 MEASUREMENT BEF.AIR SIDE MANIFOLD

84 MKW 71 NEEDLE VALVE 15 2.5 CS SC FIRST SHUT OFF VLV FOR AIR SIDE. PIPE LINEAA 552 S.O.PRESSURE MEASUREMENT,TE

85 MKW 71 NEEDLE VALVE 15 2.5 CS SC FIRST SHUT OFF VLV FOR AIR SIDE. PIPE LINEAA 553 S.O.PRESSURE MEASUREMENT,EE

86 MKW 73 EQUALISING 50 2.5 CS FL EQUALISING VLV FOR S.O.PRESSURE SOV RACKAA 011 VALVE TE (H2 SIDE)

87 MKW 73 EQUALISING 50 2.5 CS FL EQUALISING VLV FOR S.O.PRESSURE SOV RACKAA 021 VALVE EE (H2 SIDE)

88 MKW 73 3-WAY VALVE 50 1.6 CS FL 3-WAY VLV TE (H2 SIDE) SOV RACKAA 511

89 MKW 73 GATE VALVE 50 4.0 CS FL SHUT OFF VLV FOR SEAL OIL IMPULSE SOV RACKAA 512 LINE, TE (H2 SIDE)

90 MKW 73 GLOBE VALVE 10 2.5 CS BW SHUT OFF VLV FOR SEAL OIL IMPULSE SOV RACKAA 513 LINE, TE (H2 SIDE)

91 MKW 73 GLOBE VALVE 8 2.5 CS BW VENT FOR EQUALISING VALVE SOV RACKAA 514 TE (H2 SIDE)

92 MKW 73 3-WAY VALVE 50 1.6 CS FL 3-WAY VLV,EE (H2 SIDE) SOV RACKAA 521

93 MKW 73 GATE VALVE 50 4.0 CS FL SHUT OFF VLV FOR SEAL OIL SOV RACKAA 522 EE (H2 SIDE)

94 MKW 73 GLOBE VALVE 10 2.5 CS BW SHUTOFF VALVE IN SEAL OIL IMPULSE SOV RACKAA 523 LINE,EE (H2 SIDE)

95 MKW 73 GLOBE VALVE 8 2.5 CS BW VENT FOR EQUALISING VALVE SOV RACKAA 524 EE (H2 SIDE)

96 MKW 76 GATE VALVE 25 1.6 CS FL MULTIWAY SHUT OFF VALVE FOR SOV RACKAA 511 R.R.FLOW METERS (TE)

97 MKW 76 GATE VALVE 25 4.0 CS FL SHUT OFF VALVE AFTER R.R.FLOW SOV RACKAA 512 METER (TE)

98 MKW 76 REGULATING 25 4.0 CS FL REGULATING VALVE FOR RING RELIEF SOV RACKAA 513 OIL,TE

99 MKW 76 GATE VALVE 25 1.6 CS FL MULTIWAY SHUT OFF VALVE FOR PIPE LINEAA 521 R.R.FLOW METERS (EE)


BHEL, Haridwar

Turbogenerators

Description

2.1-7112-10555/50609E

List of Valves for Seal oil System

100 MKW 76 GATE VALVE 25 4.0 CS FL SHUT OFF VALVE AFTER R.R.FLOW PIPE LINEAA 522 METER (EE)

101MKW 76 REGULATING 25 4.0 CS FL REGULATING VALVE FOR RING RELIEF PIPE LINEAA 523 VALVE OIL,TE

102 PGB 51 3-WAY VALVE 65 1.6 CS FL 3-WAY VLV FOR COOLING WATER SEAL OIL UNITAA 501 INLET (H2 SIDE)

103 PGB 52 REGULATING 65 1.6 CS FL REGULATING VALVE AFTER SEAL OIL SEAL OIL UNITAA 501 VALVE COOLER-1, H2 SIDE

104 PGB 52 REGULATING 65 1.6 CS FL REGULATING VALVE AFTER SEAL OIL SEAL OIL UNITAA 502 VALVE COOLER-2,H2 SIDE

105 PGB 61 3-WAY VALVE 65 1.6 CS FL 3-WAY VLV FOR COOLING WATER SEAL OIL UNITAA 501 INLET (AIR SIDE)

106 PGB 62 REGULATING 65 1.6 CS FL REGULATING VALVE AFTER SEAL OIL SEAL OIL UNITAA 501 VALVE COOLER-1,AIR SIDE

107 PGB 62 REGULATING 65 1.6 CS FL REGULATING VALVE AFTER SEAL OIL SEAL OIL UNITAA 502 VALVE COOLER-2,AIR SIDE


FL = FlangedSC = ScrewedCS = Carbon SteelCR = Cromium SteelGM = Gun Metal

RT = Room Temperature

Legend

VALVES FOR EMERGENCY SEAL OIL SUPPLY FROM LUB OIL SYSTEM

108 MKW 23 GLOBE VALVE 8 2.5 CS BW IMPULSE LINE TO DPR PIPE LINEAA 505

109 MKW 31 GATE VALVE 50 4.0 CS FL CONN. FOR EMERGENCY SO SUPPLY PIPE LINEAA 005

110 MKW 31 DPR 50 4.0 CS FL DIFFERENTIAL PRESSURE PIPE LINEAA 006 REGULATOR.

111 MKW 31 NRV 50 4.0 CS FL NON RETURN VALVE AFTER DPR PIPE LINEAA 007

112 MKW 31 GLOBE VALVE 8 2.5 CS BW IMPULSE LINE TO DPR PIPE LINEAA 008

113 MKW 31 GLOBE VALVE 50 4.0 CS FL VENT VALVE BEFORE DPR PIPE LINEAA 009

BHEL, Haridwar

Turbogenerators

Description

2.1-7120-0500/10609 E

Bearing Vopour Exhauster

The bearing vapour exhauster establishes avacuum in the generator bearing compartmentswhich prevents the escape of oil from the bearingcompartments along the shaft . In addit ion, thebearing vapour exhausted draws off any hydrogengas which may be admit ted in to the bear ingcompartments in the event of a shaft seal failure.

The bearing vapour exhauster embodies optimumsafeguards permitting it to be used for extractinghydrogen gas from the bearing compartments.

The exhauster is driven by a three-phase motorattached perpendicular to the exhauster housing.Flanged connections are provided for the suction anddelivery pipes.

The fan impeller is directly mounted on the motorshaft. The shaft is sealed with a double-actinggrease-lubricated axial seal which works via apacking washer which is forced in the axial directionagainst the seal collar. A spring provides for a highlyflexible seal.

1 Drive motor2 Regressing device3 Suction branch4 Delivery branch

Fig.1 Bearing Vapour Exhauster

1 Packing washer2 Seal collar3 Motor shaft4 Motor flange5 Regressing device6 Exhauster housing7 Fan Impeller

Fig.2 Bearing Vapour Exhauster

6

4 5 7

3 2 1

1 2 3

4

BHEL, Haridwar

Turbogenerators

Description

2.1-7123-0500/10609 E

Seal Oil Pumps

1 General

Oil lubricated radial seals at the rotor shaft endsprevent the hydrogen gas from escaping from thegenerator to the atmosphere.

Seal oil pumps are used to supply the seal oil to theshaft seals in a closed circuit.

2 Construction and Mode of Operation

The seal oil pumps are three-screw pumps. Onedouble-thread driving rotor and two driven idler screwdare closely meshed and run with a close clearance inthe casing insert. The pump casing accommodates thecasing insert and is closed off by covers at the driveend and nondriver end.

The crew pump is suitable for rigorous service and,due to the absence of control parts sensitive to dirt,allows for relatively large variations of seal oil viscosity.

High speeds are readily attainable because all movingparts perform rotary movements only.

The main components of the pump are illustrated inthe sectional view of a screw pump.

By internalising, the helical passages in the rotorsare divided into compartments completely sealed which,while rotating progress completely uniformly and withoutundue stressing from the suction to the discharge end,thus acting like a piston. Dummy pistons compensatefor the axial thrust on the thread flank faces at thedischarge end. Axial thrust on the deep-groove ballbearing is thus eliminated.

The idler screw are hydraulically driven due tosuitable screw dimensions. The thread flanks transmitonly the torque resulting from fluid friction, which ensuresvery quiet running.

The screw pumps are driven by electric motorsthrough a coupling. The motor speed and rating arematched to the expected delivery flow and heads.

1 Idler screw2 Driving rotor3 Dummy pastor4 Shaft seal (sliding ring gland)

Fig.1 Screw Pump With Relief Valve

1 2 3 4

BHEL, Haridwar

Turbogenerators

Description

2.1-7130-0500/10609 E

Seal Oil Cooler and Seal Oil Filter

1 Seal Oil Coolers

The air side and hydrogen side oil coolers are eachfull-capacity coolers. One is always in operation, whilethe second one serves as a stand-by. The seal oil flowcan be changed over from one cooler to the other bymeans of two interlocked three-way rotary transfervalves.

2 Seal Oil Filters

The seal oil filters are arranged directly after theseal oil coolers. The filters have a fine mesh screenwhich serves to prevent damage to the shaft seals byforeign particles entrained in the oil. By connectingtwo separate filters in series, one of the two filterscan always be maintained in operation, supplyingfiltered oil to the shaft seals. The change-over valveassembly at the filters allows one filter to be out ofservice for cleaning without interruption of the oil flow.

1 Valve assembly 5 Transfer valve assembly2 Position indicator 6 Valve lever3 Pressure equalizing valve 7 Filter housing4 Differential pressure indicator 8 Oil outlet flange

Fig.1 Seal Oil Filter

1234

5

6

7

8

BHEL, Haridwar

Turbogenerators

Description

2.1-7131-0500/10609 E

Seal Oil Cooler

1. Upper tubesheet2. Support plate3. Return water channel4. Partition ring5. Inspection port6. Tube bundle7. Cooler shell

8. Cooling water connection9. Cooler base10. Water channel11. Lower tubesheet12. Oil outlet13. Oil inlet

BHEL, Haridwar

Turbogenerators

DescriptionSeal Oil Filter

2.1-7132-0500/10609 E

1 Position indicator 8 Drain plug2 Eyebolt 9 Changeover valve assembly3 Filter valve 10 Oil outlet flange4 Strainer 11 Valve lever5 Filter housing 12 Oil inlet flange6 Support 13 Signal line for differential7 Vent plug pressure

7 8 9 10 11 12

1 2

3

4

5

6

BHEL, Haridwar

Turbogenerators

DescriptionDifferential Pressure Meter System

2.1-7150-0500/10609 E

1. General

The pressures of the hydrogen side and air sideseal oil circuits are applied to differential pressuremeasurement devices. A complete system formeasurement of the seal oil differential pressuresconsists of the following components.

Differential pressure transmission linesEqualizing valve assemblyDifferential pressure gauges

The seal oi l pressures are transmitted to thediaphragms of the pressure gauges v ia the

transmission lines and equalizing valve assembly.Vents are provided at the pressure gauges.

2. Dif ferent ial Pressure Meters for DirectIndication

The two input pressures to be compared act onthe diaphragms on both sides, With the force set upby the differential pressure producing a deflection ofthe e last ic body. The resul t ing movement istransmit ted to the pointer mechanism for directindication of the differential pressure. The point hasa deflection of 270 degrees.

BHEL, Haridwar

Turbogenerators

Description

Gas System

2.1-7200-0500/10609 E

1. GeneralThe gas system consists of the following components:

CO2 bottle rackH2 bottle rackN2 bottle rackGas dryerGas valve rack

The design of the gas system complies with the safetyregulations according to VDE 0530. Part 3 and with theGerman pressure vessel code.

2. Hydrogen Supply

The hydrogen for the generator is supplied from ahydrogen bottle rack. The hydrogen should have a minimumpurity of 99.7%.

2.1 H2 Bottle RackThe H2 bottles are connected to the manifold on the

bottle rack. Valves on the bottles and valves on the manifoldallow replacement of individual bottles during operation.The hydrogen is stored in the steel bottles at a very highpressure. The hydrogen gas available in the manifold atbottle pressure is passed to two parallel-connectedpressure reducers for expansion to the requiredintermediate pressure and is then passed to pressurereducers on the gas valve rack for expansion to thepressure required for generator operation. Relief valveson the low-pressure sides of all pressure reducers areconnected to an outlet pipe system through which anyexcess hydrogen is passed to the atmosphere. All pressurereducers are of identical design. Single-stage constructionof the pressure reducers ensures a constant pressure,even under low or no flow conditions, and allows largevolume flow quantities of hydrogen to be reduced inpressure during the hydrogen filling procedure.

3. Carbon Dioxide Supply

As a precaution against explosive mixtures, air mustnever be directly replaced with hydrogen during generatorfilling not the hydrogen replaced directly with air during theemptying procedure. In both cases, the generator must bescavenged or purged with an inert gas, carbon dioxide(CO2) being used for this purpose.

3.1 CO2 Bottle RackThe carbon dioxide is supplied in steel bottles in the

liquid state. The bottles should be provided with risers toensure complete emptying. The arrangement of the CO2

bottle rack corresponds to that of the H2 bottle rack. Theliquid CO2, which is stored under pressure, is fed to thegas valve rack via a shutoff valve.

3.2 CO2 VaporiserAt the gas valve rack the liquid CO2 is evaporated and

expanded in a CO2 vapouriser. The heat for vaporization issupplied to the vapouriser electrically. A temperature controlis provided so that freezing of the flash evaporator isprevented, and the CO2 is admitted into the generator atthe proper temperature. One safety valve each on the high-pressure and low-pressure sides protects the pipe systemagainst inadmissible high pressure.

4 Compressed air Supply

To remove the CO2 from the generator, a compressedair supply with compressed air filter is connected to thegeneral air system of the power plant.

Under all operating conditions, except for CO2purging, the compressed air hose between the filter andthe generator pipe system should be disconnected. Thisvisible break is to ensure that no air can be admitted into ahydrogen-filled generator.

5. Gas Valve Rack and Gas Monitoring Equipment

5.1 Gas Valve RackTo aid in operation of the gas system, the gas valve

rack is furnished with a mini diagram on the face of thepanel.

The valves used in the gas system have rubber/metal-sealed valve seats to ensure gas tightness.

5.2 Casing Pressure MeasurementFor measuring and checking the gas pressure in the

generator, the gas rack is provided with a pressuretransmitter and pressure gauges for local measurement.For safety, the pressure transmitter is of an explosion proofdesign.

5.3 Electrical Purity meter SystemThe transmitter for the CO2 / H2 purity meter system on

the gas valve rack is also of an explosion proof design.The meter system operates on the thermal conductivitymethod. The meter system measures the H2 content of thegas in the generator as well as the composition of gasmixtures (CO2 / air and H2 / CO2) during filling and emptying

2.1-7200-0500/20609 E

of the generator.

5.4 Mechanical Purity Meter SystemThe second purity meter system is a mechanical type

and uses the physical relationships between the hydrogenpressure, the speed of the generator fan, and the specificgravity of the medium. This meter system, therefore,functions only at rated speed.

5.5 Gas AnalysisIn addition, facilities are provided for gas sampling for

chemical analysis of the gas in the generator.

6. Gas Dryer

A small amount of the hydrogen circulating in thegenerator for cooling is passed through a gas drier. Thegas inlet and gas outlet pipes of the gas dryer are connectedat points of the generator with different staticheads(differential fan pressure), so that the gas is forcedthrough the dryer by the differential pressure only.

7. Nitrogen (N2 ) Supply

On a water-cooled turbine generator an additional

nitrogen supply is required for:

Removing the air above the water level in theprimary water tank during initial operation of theprimary water system.Removing the oxygen dissolved in the primary waterduring filling of the primary water system.Removing the hydrogen gas above the water levelin the primary water tank during shutdown of theprimary water systemRemoving the hydrogen gas dissolved in the primarywater during shutdown of the primary watersystem.

The N2 purge during initial operation ensures acomplete removal of the oxygen from the primary watercircuit, thus eliminating the risk of corrosion attack.

The N2 purge during shutdown prevents theformation of an explosive hydrogen-air mixture Duringoperation hydrogen may enter into the primary watertank by diffusion at the insulating hoses.

The nitrogen available from a bottle is passed to apressure reducer for expansion and admitted into theprimary water tank via the N2 supply line.

BHEL, Haridwar

Turbogenerators

DescriptionList of Valves for Gas System

2.1-7212-10555/10609E

1 MKG 05 GLOBE VALVE 8 25 CS SC SHUTOFF AT INLET TO GAC PIPE LINEAA 501 FROM GENERATOR

2 MKG 11 PR.REDUCER 8 0.0 CS SC H2 PR.REDUCER(STAGE-1) H2 DISTRIBUTORAA 001

3 MKG 11 GLOBE VALVE 8 25 CS SC SHUTOFF AT H2 CYLINDER H2 CYLINDERAA 501

4 MKG 11 MANIFOLD VLV 8 25 CR SC H2 DISTRIBUTER MANIFOLD H2 DISTRIBUTORAA 531

5 MKG 11 GLOBE VALVE 8 25 CR SC SHUT OFF AT INLET TO H2 DISTRIBUTORAA 561 MKG 11/ AA 001

6 MKG 12 PR.REDUCER 8 25 CS SC H2 PR.REDUCER(STAGE-1) H2 DISTRIBUTORAA 001

7 MKG 12 GLOBE VALVE 8 25 CR SC SHUT OFF AT INLET TO H2 DISTRIBUTORAA 501 MKG 12/ AA 001

8 MKG 15 GLOBE VALVE 25 2.5 CR SC SHUT OFF AT OUTLET FROM H2 DISTRIBUTORAA 501 MKG 11/ AA 001

9 MKG 15 GLOBE VALVE 25 2.5 CS SC SHUT OFF AT INLET TO GAS UNITAA 502 MKG 19/ AA 001

10 MKG 15 GLOBE VALVE 25 2.5 CS SC FOR CONNECTING H2 GAS UNITAA 504 DISTRIBUTOR TO GAS UNIT

11 MKG 16 GLOBE VALVE 25 2.5 CR SC SHUT OFF AT OUTLET FROM H2 DISTRIBUTORAA 501 MKG 12/ AA 001

12 MKG 17 GLOBE VALVE 25 2.5 CS SC FOR CONNECTING GAS UNIT GAS UNITAA 504 TO STATION H2 PLANT

13 MKG 17 GLOBE VALVE 25 2.5 CS SC SHUT OFF AT INLET TO GAS UNITAA 505 MKG 19/ AA 002

14 MKG 19 PR.REDUCER 25 2.5 CS SC H2 PR.REDUCER(STAGE-2) GAS UNITAA 001

15 MKG 19 PR.REDUCER 25 2.5 CS SC H2.PR.REDUCER(STAGE-2) H2 UNITAA 002

16 MKG 19 GLOBE VALVE 50 2.5 CS FL SHUT OFF AT OUTLET FROM GAS UNITAA 501 MKG 19/ AA 001

17 MKG 19 GLOBE VALVE 50 2.5 CS FL SHUT OFF AT OUTLET FROM GAS UNITAA 502 MKG 19/ AA 002

18 MKG 25 GLOBE VALVE 8 25 CR SC VALVE AT INLET TO GAS PIPELINEAA 021 ANALYSER CABINET

19 MKG 25 GLOBE VALVE 8 25 CR SC VALVE AT INLET OF GAC PIPELINEAA 022 FROM GENERATOR

20 MKG 25 GLOBE VALVE 25 2.5 CS SC SHUT OFF AT INLET TO AF GAS UNITAA 501

21 MKG 25 GLOBE VALVE 50 2.5 CS FL EXHAUST GAS UNITAA 502

22 MKG 25 3-WAY VALVE 12 1.6 CR SC FOR CALIBRATION OF GAS GAS UNITAA 507 ANALYSER

23 MKG 25 GLOBE VALVE 25 2.5 CS SC SHUT OFF AT OUTLET TO AF GAS UNITAA 509

24 MKG 25 GLOBE VALVE 8 25 CR SC SHUT OFF AT INLET TO GAS GAS UNITAA 511 ANALYSER CABINET

SL. VLV TYPE OF VALVE NB NP BODY END FUNCTION LOCATIOINNO. DESG MM MPA MATL CONN

2.1-7212-10555/20609 E

FL = FlangedSC = ScrewedCS = Carbon Steel

CR = Cromium SteelGM = Gun Metal


Legend

25 MKG 25 GLOBE VALVE 8 25 CR SC FOR TAKING SAMPLE OF GAS UNITAA 512 GAS FOR PURITY ANALYSIS

26 MKG 25 THREE WAY 50 1.6 CR FL SHUT OFF CO2 SUPPLY TO GAS UNITAA 518 VALVE EXHAUST FROM TG

27 MKG 25 3-WAY VALVE 50 1.6 CS FL SHUT OFF TO H2 SUPPLY TO GAS UNITAA 519 GENERATOR

28 MKG 31 PRESSURE 8 15 CS SC N2 PRESSURE REGULATION N2 DISTRIBUTORAA 001 REGULATOR

29 MKG 31 GLOBE VALVE 8 CS SC SHUTOFF VALVE AT N2 N2 CYLINDERAA 501 CYLINDER

30 MKG 31 GLOBE VALVE 8 25 CR SC N2 DISTRIBUTER MANIFOLD N2 DISTRIBUTORAA 502

31 MKG 31 GATE VALVE 8 25 CR SC INLET TO PRESSURE N2 DISTRIBUTORAA 503 REGULATOR

32 MKG 35 GLOBE VALVE 8 25 CR SC OUTLET OF PRESSURE N2 DISTRIBUTORAA 501 REGULATOR

33 MKG 51 SAFETY RELIEF 6 17.5 CS SC TO RELEASE EXCESS CO2 CO2 VAPOURISERAA 001 VALVE PR. AT INL TO CO2 VAP.

34 MKG 51 GLOBE VALVE 8 CS SC SHUTOFF AT CO2 CYLINDER CO2 CYLINDERAA 501

35 MKG 51 MANIFOLD 8 25 CR SC CO2 DISTRIBUTER MANIFOLD CO2 DISTRIBUTORAA 531 VALVE VALVES

36 MKG 51 GLOBE VALVE 10 26 CR SC SHUT OFF AT INLET TO CO2 CO2 VAPOURISERAA 561 VAPORISER

37 MKG 59 SAFETY RELIEF 32 0.6 CS FL TO RELEASE EXCESS CO2 CO2 DISTRIBUTORAA 001 VALVE PR. ATCO2 VAP. OUTL

38 MKG 59 GLOBE VALVE 50 CR SC OUTLET CO2 PRESSURE PIPELINEAA 507 REGULATOR

39 MKG 69 GAS VALVE 50 1.6 CS FL SHUT OFF AT INLET TO REF. PIPE LINEAA 502 GAS DRIER-1

40 MKG 69 GAS VALVE 15 1.6 CS SC SHUT OFF IN OIL TRAP DRAIN PIPE LINEAA 502

41 MKG 69 GAS VALVE 50 1.6 CS FL SHUT OFF AT OUTLET TO PIPE LINEAA 503 REF.GAS DRIER-1

42 MKG 69 GAS VALVE 50 1.6 CS FL SHUT OFF AT INLET TO OIL PIPE LINEAA 505 TRAP IN GAS DRIER INL.

43 MKG 69 GLOBE VALVE 8 1.6 CS SC INLET OF DEW POINT METER PIPE LINEAA 506 FROM GAS DRIER OUTLET

44 MKG 69 GLOBE VALVE 8 1.6 CS SC INLET OF DEW POINT METER PIPE LINEAA 507 FROM CASING GAS

45 MKG 69 GAS VALVE 50 1.6 CS FL SHUT OFF AT INLET TO REF. PIPE LINEAA 509 GAS DRIER-2

46 MKG 69 GAS VALVE 50 1.6 CS FL SHUT OFF AT OUTLET TO PIPE LINEAA 510 REF.GAS DRIER-2

SL. VLV TYPE OF VALVE NB NP BODY END FUNCTION LOCATIOINNO. DESG MM MPA MATL CONN

BHEL, Haridwar

Turbogenerators

Description

Primary Water Pumps

2.1-7320-0500/10609 E

Design Features of Primary Water Pumps

The primary water for cooling the stator winding,phase connectors and terminal bushings is circulated in aclosed system. To insure uninterrupted generatoroperation, two full-capacity primary water pump setsare provided. Either pump can be in service with otheracting as the stand-by. The standby pump is ready forservice and is automatically started without interruptingthe primary water circulation if the operating pump fails.

The primary water pumps are of a single-stagecentrifugal type with spiral casing and overhung impeller.

The pump suction is arranged axially, while the

discharge is directed radially upwards. The spiral casingis flanged to the bearing housing. The pump impeller isprovided with relief holes close to the hub so that no axialthrust is carried by the bearings. The point where the pumpshaft passes through the pump casing is sealed by meansof a water-cooler sliding-ring gland. The cooling water issupplied to the sliding-ring gland through a bypass linefrom the pump discharge. The pump shaft is supported inoil-lubricated anti-friction bearings. The oil level in thebearing housing can be checked at an oil sight glass. Thepump is connected to the three-phase AC motor by a flexiblecoupling covered by a coupling guard.

BHEL, Haridwar

Turbogenerators

Description

2.1-7230-0500/10609 E

CO2 Vaporiser

Fig.1 CO2 Vaporiser

1 GeneralCO2 is used to displace air from the generator

before hydrogen filling and to displace hydrogen fromthe generator before filling the generator with air.

Since the CO2 is available in the liquid state, itmust be expanded into a gas before use. The CO2 isexpanded in a CO2 vaporiser located on the gas valverack.To prevent icing of the vaporiser it is electricallyheated.

2 Design features and mode of operation

The CO2 vaporiser consists of a tubular housingclosed by flanges at both ends. One flange carrieselectrical heating elements which are connected toterminals in the terminal box mounted external to theflange. The opposite flange contains the inlet and

outlet to the cooled copper pipe of the evaporator.The horizontally arranged housing isfilled with heat transmitting liquid to ensure a betterheat transfer to the copper pipe coil and thus to theCO2 flowing through the pipe coil.

The heat transfer l iquid is f i l led into the CO2

vaporiser through the expansion vessel mounted ontop of the housing. For protection against excessivepressures in the CO2 line, one relief valve is arrangedbefore and after the CO2 flash evaporator.

The orifice at the CO2 out let of the expansionvessel provides for an expansion of the CO2 obtainedfrom the bottles to a pressure of 25 to 7 psig. Heatingof the CO2 in the copper pipe coil is sufficient toprevent icing of the expansion device at the prevailingflow velocities.

1 2 3 4 5 6

12 11 10 9 8 7

1 Vent for heat transmitting liquid 2 Copper pipe coil 3 Insulation 4 Expansion vessel 5 Relief valve before CO2 vaporiser 6 Shutoff valve before CO2 vaporiser

7 CO2 inlet 8 CO2 outlet 9 Housing10 Heating element11 Drain for heat transfer liquid12 Terminal box

BHEL, Haridwar

Turbogenerators

Description

2.1-7270-10555/10609 E

Gas Dryer (RefrigerationType)

For hydrogen gas drying, 2 nos. Refrigeration gas driersare available. Either of these two can be selected for thegas drying operation, by suitably operating the followingvalves, to bring in circuit either drier-1 or drier-2:

MKG69 AA501 At inlet of Refrigeration gas drier-1MKG69 AA504 At outlet of Refrigeration gas drier-1

MKG69 AA 506 At inlet of Refrigeration gas drier-2MKG69 AA507 At outlet of Refrigeration gas drier-2

The Refrigeration gas drier is to be operated for a totalperiod of 8 hours in 24 hours duration. This can besuitably selected on the timer available on the drier.

After the operation of the Refrigeration drier, thecondensate gets collected in the condensate chamber,which can be observed through the glass window.Drain the condensate chamber once every 24 hours.For draining, first open the upper valve and let thecondensate flow from the condensate chamber andcollect in the pipe. Then close this upper valve andopen the lower valve to drain the condensate. This isdone to ensure that no hydrogen leakage takes placefrom the generator system.

For fu r ther de ta i l s , re fer O&M manua l fo r theRefrigeration gas drier

BHEL, Haridwar

Turbogenerators

Description


2.1-7300-0500/10609 E

1 GeneralThe losses occurring in the stator windings ,

terminal bushings and phase connectors aredissipated through direct water cooling. Since thecooling water is the primary coolant to dissipate thelosses, it is designated as primary water.

The primary water system basically consists of thefollowing components:

-Primary water supply unit-Primary water coolers-Primary water valve rack-Primary water tank

The primary water supply unit combines thefollowing components for primary water supply to thegenerator:

Primary water pumpsPrimary water filtersConductivity transmitterWater treatment systemFlow, pressure and temperature transmitters.

2 Primary Water QualityThe primary water system may be filled with oxygen-

free, mechanically clean-distilled water-fully de-mineralised water from boiler feed water

treatment plant-condensateSince the primary water comes into direct contact

with the high-voltage stator winding, it must have anelectrical conductivity below a value of 2 µmho/cm. Thewater in the primary water circuit is therefore treated in awater treatment system. Fully de-mineralised water fromthe boiler feed water treatment plant and condensate mayonly be used if no chemicals, such as ammonia,hydrazine, phosphate, etc. were added to the water orcondensate.

3 Primary Water CircuitFig. 1 shows a simplified schematic of the primary

water system. Note that the diagram shows that theexternal portion of the system may be operated througha bypass line, with no primary water flowing through thewater-cooled generator components.

The primary water is circulated by one of the twopumps on the primary water supply unit. Both primarywater pumps are of full-capacity type. The electric control

Primary water circuit-GeneralCoolant flow: Stator windingCoolant flow: Main bushingsand phase connectorsWater treatmentWaste gas

1 Primary water tank 2 Pressure regulator 3 Waste gas to atmosphere 4 Pump 5 Cooler 6 Filter 7 Bypass line 8 Cooling water for stator winding 9 Ion exchanger10 Cooling water for main bushings and phase connector11 Teflon hose12 Cooling water manifold

12 1 2 3

11

8

12

9

45

6

11 7 2 10

Fig.1 Simplified schematic of the primary water system

2.1-7300-0500/20609 E

circuit of the pumps is arranged so that either pump maybe selected for normal service.

The primary water is drawn from the primary watertank and passes to a primary water manifold (inlet) viacoolers and filters and from there to the stator bars viateflon hoses. The primary water leaving the statorwinding is passed through similar teflon hoses to anotherprimary water manifold (outlet) and is then returned tothe primary water tank. A separate flow path from a pointbefore the stator winding inlet cools the bushings andphase connectors.

4 Primary Water TankThe primary water tank is mounted on the stator

frame on anti-vibration pads and is covered by thegenerator lagging. The purpose of primary water tank isto remove the hydrogen in the primary water after it

leaves the stator winding. The hydrogen occurs in theprimary water due to diffusion through the teflon hoseswhich connect the stator winding to inlet and outletmanifolds.

Since the primary water tank is the lowest pressurepoint in the system, has a relatively high watertemperature, a large water surface and sufficientretention time, intensive de-gassing of the primary wateris ensured. The hydrogen gas in the primary water tankis vented to atmosphere via the primary water valve rackand a pressure regulator. The pressure regulator can beadjusted to set the gas pressure in the primary watertank.

The water level in the primary water tank can be readat a water level gauge. Additionally, a capacitance typemeasuring system is provide for activating an alarm atminimum and maximum water level.

Turbogenerators

Description

BHEL, Haridwar

SL VALVE TYPE OF VALVE NB mm BODY mat FUNCTION LOCATIOINNO. DESIG NP MPA END conn

List of Valves for Primary Water System

2.1-7312-10555/10609 E

1 MKF 12 N- R VALVE 100 SS NON RETURN AT OUTLET OF STATOR P&F UNITAA 001 1.6 FL WATER PUMP-1

2 MKF 12 GLOBE VALVE 100 SS INLET TO STATOR WATER PUMP-1 MKF P&F UNITAA 501 2.5 FL 12/AP001

3 MKF 12 NEEDLE VALVE 10 SS DRAIN VALVE BEFORE PUMP-1 P&F UNITAA502 2.5 SC

4 MKF 12 GLOBE VALVE 100 SS OUTLET OF STATOR WATER PUMP-1 P&F UNITAA 504 2.5 FL

5 MKF 22 N- R VALVE 100 SS NON RETURN AT OUTLET OF STATOR P&F UNITAA001 1.6 FL WATER PUMP-1

6 MKF 22 GLOBE VALVE 100 SS INLET TO STATOR WATER PUMP-1 MKF P&F UNITAA 501 2.5 FL 12/AP001

7 MKF 22 NEEDLE VALVE 10 SS DRAIN VALVE BEFORE PUMP-2 P&F UNITAA502 2.5 SC

8 MKF 22 GLOBE VALVE 100 SS OUTLET OF STATOR WATER PUMP-1 P&F UNITAA 504 2.5 FL

9 MKF 36 DOZING VALVE 25 SS FEED VALVE AFTER DOSING PUMP ALK. UNITAA 488 1.6 FL

10 MKF 36 GLOBE VALVE 25 SS SHUTOFF VALVE FOR ALKALISER UNIT PIPE LINEAA 495 1.6 FL

11 MKF 36 NEEDLE VALVE 15 SS VENT VALVE AT ALKALISER UNIT PIPE LINEAA 497 2.5 SC

12 MKF 52 GLOBE VALVE 100 SS PRIMARY WATER SHUT OFF VALVE BEF PIPE LINEAA501 2.5 FL ORE COOLER-1

13 MKF 52 GLOBE VALVE 100 SS PRIMARY WATER SHUT OFF VALVE BEF PIPE LINEAA502 2.5 FL ORE COOLER-2

14 MKF 52 GLOBE VALVE 100 SS PRIMARY WATER SHUT OFF VALVE AFT PIPE LINEAA511 2.5 FL ER COOLER-1

15 MKF 52 GLOBE VALVE 100 SS PRIMARY WATER SHUT OFF VALVE AFT PIPE LINEAA512 2.5 FL ER COOLER-2

16 MKF 52 NEEDLE VALVE 15 SS PRIMARY WATER DRAIN VALVE FOR CO PIPE LINEAA521 2.5 SC OLER-1

17 MKF 52 NEEDLE VALVE 15 SS PRIMARY WATER DRAIN VALVE FOR CO PIPE LINEAA 522 2.5 SC OLER-2

18 MKF 52 NEEDLE VALVE 10 SS PRIMARY WATER VENT VALVE FOR COO PIPE LINEAA 531 2.5 SC LER-1

19 MKF 52 NEEDLE VALVE 10 SS PRIMARY WATER VENT VALVE FOR COO PIPE LINEAA 532 2.5 SC LER-2

20 MKF 52 NEEDLE VALVE 15 SS PRIMARY WATER VENT VALVE BEFORE PIPE LINEAA 541 2.5 SC COOLERS

21 MKF 52 NEEDLE VALVE 15 SS PRIMARY WATER DRAIN VALVE (MANIF PIPE LINEAA544 2.5 SC OLD)

22 MKF 52 NEEDLE VALVE 10 SS PRIMARY WATER VENT VALVE (MANIFO PIPE LINEAA 545 2.5 SC LD)

23 MKF 52 NEEDLE VALVE 15 SS COOLING WATER DRAIN VALVE AT COO PIPE LINEAA 551 2.5 SC LER-1


2.1-7312-10555/20609 E

24 MKF 52 NEEDLE VALVE 15 SS COOLING WATER DRAIN VALVE AT COO PIPE LINEAA 552 25.0 SC LER-2

25 MKF 52 NEEDLE VALVE 10 SS COOLING WATER VENT VALVE AT COOL PIPE LINEAA 561 2.5 SC ER-1

26 MKF 52 NEEDLE VALVE 10 SS COOLING WATER VENT VALVE AT COOL PIPE LINEAA 562 2.5 SC ER-2

27 MKF 52 NEEDLE VALVE 15 SS VENT VALVE AFTER PW COOLERS PIPE LINEAA 578 2.5 SC

28 MKF 52 GLOBE VALVE 100 SS INLET TO WATER FILTER-1 P&F UNITAA 580 2.5 FL

29 MKF 52 NEEDLE VALVE 15 SS DRAIN VALVE AT FILTER-1 P&F UNITAA 581 2.5 SC

30 MKF 52 NEEDLE VALVE 10 SS VENT VALVE AT FILTER-1 P&F UNITAA 582 2.5 SC

31 MKF 52 GLOBE VALVE 100 SS OUTLET FROM WATER FILTER-1 P&F UNITAA 583 2.5 FL

32 MKF 52 GLOBE VALVE 100 SS INLET TO WATER FILTER-2 P&F UNITAA 590 2.5 FL

33 MKF 52 NEEDLE VALVE 15 SS DRAIN VALVE AT FILTER-2 P&F UNITAA 591 2.5 SC

34 MKF 52 NEEDLE VALVE 10 SS VENT VALVE AT FILTER-2 P&F UNITAA 592 2.5 SC

35 MKF 52 GLOBE VALVE 100 SS OUTLET FROM WATER FILTER-2 P&F UNITAA 593 2.5 FL

36 MKF 60 RELIEF VALVE 25 SS RELIEF VALVE IN MAKE UP LINE P&F UNITAA 001 2.5 FL

37 MKF 60 N- R VALVE 25 SS CHECK VALVE IN MAKE UP LINE P&F UNITAA 003 1.6 FL

38 MKF 60 REG. VALVE 25 SS MAKE UP INLET VALVE PIPE LINEAA 501 2.5 FL

39 MKF 60 GLOBE VALVE 25 SS MAKE UP DRAIN VALVE PIPE LINEAA 201 2.5 FL

40 MKF 60 REG. VALVE 25 SS CONTROL VALVE FOR WATER TREATMEN P&F UNITAA 502 2.5 FL T SYSTEM

41 MKF 60 NEEDLE VALVE 10 SS VENT VALVE BEFORE ION-EXCHANGER P&F UNITAA 503 2.5 SC

42 MKF 60 GLOBE VALVE 25 SS SHUT OFF VALVE IN MAKE UP LINE P&F UNITAA 506 2.5 FL

43 MKF 60 GLOBE VALVE 25 SS SHUT OFF VALVE AFTER ION-EXCHANG P&F UNITAA 509 2.5 FL ER

44 MKF 60 NEEDLE VALVE 10 SS DRAIN VALVE AFTER ION-EXCHANGER P&F UNITAA 510 2.5 SC

45 MKF 60 NEEDLE VALVE 10 SS DRAIN VALVE AT FINE FILTER P&F UNITAA 511 2.5 SC

46 MKF 60 NEEDLE VALVE 10 SS VENT VALVE AT FINE FILTER P&F UNITAA 512 2.5 SC

47 MKF 60 GLOBE VALVE 25 SS SHUT OFF VALVE AFTER FINE FILTER P&F UNITAA 513 2.5 FL

48 MKF 60 NEEDLE VALVE 10 SS DRAIN VALVE FOR WATER TREATMENT P&F UNITAA 517 2.5 SC SYSTEM

Turbogenerators

Description

BHEL, Haridwar



2.1-7312-10555/30609 E

49 MKF 60 GLOBE VALVE 25 SS SHUT OFF VALVE AFTER WATER TREAT P&F UNITAA 519 2.5 FL MENT SYSTEM

50 MKF 60 GLOBE VALVE 25 SS BY PASS VALVE IN MAKE UP LINE P&F UNITAA 520 2.5 FL

51 MKF 60 NEEDLE VALVE 10 SS DRAIN PRIMARY WATER MAKE UP LINE P&F UNITAA 522 2.5 SC

52 MKF 80 GLOBE VALVE 100 SS SHUT OFF AT INLET TO GEN. P.W.TANKAA 121 2.5 FL

53 MKF 80 GLOBE VALVE 100 SS SHUT OFF IN MAIN CIRCUIT DISCHAR P.W.TANKAA 503 2.5 FL GELINE

54 MKF 80 GLOBE VALVE 100 SS SHUT OFF VALVE FOR GEN. BY PASS P.W.TANKAA 504 2.5 FL

55 MKF 01 WATER VALVE 20 SS SHUT OFF VALVE BEFORE WATER LEVE P.W.TANKAA 321 1.6 FL L GAUGE,TOP

56 MKF 01 WATER VALVE 20 SS SHUT OFF VALVE BEFORE WATER LEVE P.W.TANKAA 311 1.6 FL L GAUGE,BOTTOM

57 MKF 01 WATER VALVE 20 SS SHUT OFF VALVE BEFORE LEVEL TRAN P.W.TANKAA 326 1.6 FL SMITTER,TOP

58 MKF 01 WATER VALVE 20 SS SHUT OFF VALVE BEFORE LEVEL TRAN P.W.TANKAA 316 1.6 FL SMITTER,BOTTOM

59 MKF 01 GLOBE VALVE 10 SS DRAIN VALVE AT LEVEL TRANSMITTER P.W.TANKAA 210 2.5 SC

60 MKF 01 WATER VALVE 20 SS VENT VALVE AT LEVEL TRANSMITTER P.W.TANKAA 251 1.6 FL

61 MKF 01 WATER VALVE 20 SS SHUT OFF VALVE FOR INLET TO P.W.TANKAA 306 1.6 FL LEVEL TRANSMITTER

62 MKF 01 WATER VALVE 20 SS SHUT OFF FOR OUTLET FROM LEVEL P.W.TANKAA 301 1.6 FL TRANSMITTER

63 MKF 81 REG. VALVE 20 SS FOR NITROGEN FILLING P.W.TANKAA 502 1.6 FL

64 MKF 82 GLOBE VALVE 100 SS SHUT OFF VALVE IN PRIMARY WATER P.W.TANKAA 001 1.6 FL OUTLET OF STATOR WDG

65 MKF 82 REG. VALVE 100 SS REGULATING VALVE BEFORE STATOR PIPE LINEAA 501 1.6 FL WINDING

66 MKF 82 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA 504 2.5 SC MITTER AT STATOR OUT

67 MKF 82 NEEDLE VALVE 10 SS DRAIN VALVE BEFORE MKF82/AA501 PIPE LINEAA 502 2.5 SC

68 MKF 82 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA 505 2.5 SC ITTER AT STATOR OUT

69 MKF 82 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA 507 2.5 SC ITTER AT STATOR OUT

70 MKF 82 NEEDLE VALVE 15 SS SHUT OFF VALVE FOR PRESS. MEAS PIPE LINEAA 508 2.5 SC BEFORE STATOR WDG

71 MKF 82 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA 509 2.5 SC MITTER AT STATOR OUT


2.1-7312-10555/40609 E

72 MKF 82 NEEDLE VALVE 15 SS SHUTR OFF VALVE AFTER FLOW TRANS PIPE LINEAA 510 2.5 SC MITTER AT STATOR OUT

73 MKF 82 NEEDLE VALVE 10 SS ISOLATION VALVE FOR D.P.GAUGE GEN.AA 512 2.5 SC

74 MKF 82 NEEDLE VALVE 10 SS ISOLATION VALVE FOR D.P.GAUGE GEN.AA 513 2.5 SC

75 MKF 83 REG. VALVE 40 SS REGULATING VALVE BEFORE BUSHING PIPE LINEAA 501 1.6 FL

76 MKF 83 GLOBE VALVE 40 SS SHUT OFF VALVE AFTER BUSHING PIPE LINEAA 502 1.6 FL

77 MKF 83 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA 503 2.5 SC MITTER MKF83/CF001A

78 MKF 83 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA 504 2.5 SC ITTER MKF83/CF001A


80 MKF 83 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA 506 2.5 SC ITTER MKF83/011A



83 MKF 83 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA 513 2.5 SC MITTER MKF83/CF001B

84 MKF 83 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA 514 2.5 SC ITTER MKF83/CF001B





89 PGB 71 GATE VALVE 250 CS COOLING WATER INLET OF COOLER-1 PIPE LINEAA 501 1.6 FL

90 PGB 71 GATE VALVE 250 CS COLING WATER INLET OF COOLER-2 PIPE LINEAA 502 1.6 FL

91 PGB 72 GATE VALVE 250 CS COOLING WATER OUTLET OF COOLER-1 PIPE LINEAA 501 1.6 FL

92 PGB 72 GATE VALVE 250 CS COOLING WATER OUTLET OF COOLER-2 PIPE LINEAA 502 1.6 FL

93 MKF83 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA519 2.5 SC MITTER MKF83/CF001A


95 MKF83 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA521 2.5 SC MITTER MKF83/CF011B

96 MKF83 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA522 2.5 SC ITTER MKF83/011A

Turbogenerators

Description

BHEL, Haridwar


2.1-7312-10555/50609E


97 MKF83 NEEDLE VALVE 15 SS SHUT OFF VALVE BEFORE FLOW TRANS PIPE LINEAA523 2.5 SC MITTER MKF83/CF021B

98 MKF83 NEEDLE VALVE 15 SS SHUT OFF VALVE AFTER FLOW TRANSM PIPE LINEAA524 2.5 SC ITTER MKF83/CF021A

99 MKF 82 NEEDLE VALVE 10 SS ISOLATION VALVE FOR WDG. INLET PIPE LINEAA 514 2.5 SC PR.TRANSMITTER

Legend

FL = FlangedSC = ScrewedCS = Carbon SteelCR = Cromium SteelGM = Gun Metal


BHEL, Haridwar

Turbogenerators

Description

Primary Water Pumps

2.1-7320-10555/10609 E

Design Features of Primary Water Pumps

The primary water for cooling the stator winding,phase connectors and terminal bushings is circulated in aclosed system. To insure uninterrupted generatoroperation, two full-capacity primary water pump setsare provided. Either pump can be in service with otheracting as the stand-by. The standby pump is ready forservice and is automatically started without interruptingthe primary water circulation if the operating pump fails.

The primary water pumps are of a single-stagecentrifugal type with spiral casing and overhung impeller.

The pump suction is arranged axially, while the

discharge is directed radially upwards. The spiral casingis flanged to the bearing housing. The pump impeller isprovided with relief holes close to the hub so that no axialthrust is carried by the bearings. The point where the pumpshaft passes through the pump casing is sealed by meansof a water-cooler sliding-ring gland. The cooling water issupplied to the sliding-ring gland through a bypass linefrom the pump discharge. The pump shaft is supported inoil-lubricated anti-friction bearings. The oil level in thebearing housing can be checked at an oil sight glass. Thepump is connected to the three-phase AC motor by a flexiblecoupling covered by a coupling guard.

BHEL, Haridwar

Turbogenerators

Description

2.1-7330-10555/10609E

Primary Water Cooler

The primary water cooler is of a straight tube type.One tubesheet is stationary, while the other tubesheetis a floating type. The floating tubesheet is sealed byO-Ring.

Tube bundle is free to move in response totemperature change.

The water channel at glands can be removedwithout draining the primary water.

The tube bundle consists of round tubes expandedinto the tubesheets. Baffles installed on the tubebundle result in a transverse flow of cooling wateracross the tubes. This achieves a more efficient heat

exchange and protects the tubes from vibrations andbending.

The cooler shell is stainless steel with weldedflanges for connection to the flanges on the waterchannels. The pipe nozzles for the primary water inletand outlet are welded to the shell. Each cooler shellhas vent and drain connection.

To vent and drain the tube side of the primary watercoolers, the water channels are equipped with ventand drain connections.

Tube bundle, cooler shell and water channels arebolted together. The larger tubesheet is mountedbetween the shell flange and the water channel.

The p r imary wate r coo le r sec t ions a reinterconnected on their primary water sides via valves.

BHEL, Haridwar

Turbogenerators

DescriptionPrimary Water Treatment System

2.1-7340-0500/10609 E

The water treatment system serves to maintain alow electrical conductivity of the primary water. The watertreatment system is connected in parallel to main circuitand contains a mixed-bed ion exchanger with seriesconnected fine filter, an integrating flow meter and aconductivity transmitter.

1. Mixed-Bed Ion Exchanger

The mixed-bed ion exchanger consists of a tankfilled with anion and cation exchanger tank prevent theescape of the resins into the piping system. A fine filterafter the ion exchanger retains any resin particles. Analarm is initiated when the filter is contaminated.

The water flow passing through the ion exchangeris measured by means of an integrating flow meter afterthe filter. After the ion exchanger part of the flow ispassed through a conductivity transmitter for checkingthe resin activity.

2. Ion Exchanger Resins

The ion exchangers consist of chemically and highlyactive synthetic resins.

The base substances of the exchanger resins arepolymers. The polymer in the cation exchanger containshighly acid groups, while the polymer in the anionexchanger is composed of highly basic groups.

The exchanger resins are thus capable of acceptingions from the primary water while simultaneouslyreleasing equivalent amounts of other ions (hydrogenions from the cation exchanger and hydroxyl ions fromthe exchanger) to the primary water. This process takesplace through the ion exchanger.

The combination of highly acid cation exchangersand highly basic cation exchangers forms a multitude ofsmall demineralization units, resulting in a high-puritydeionate.

The capacity of the mixed- bed of the ion exchangeris limited by the number of ion it can exchange. Thiscapacity is primarily determined by the type of exchangerused, but also depends on the quantity of reactivatingagent, the rate of flow and the water temperature.

When the resins are exhausted, they must bereplaced by new resins.

After removal from the primary water treatmentsystem, the resins can be reactivated.

3. Adding Make-up Water to the Primary WaterCircuit

Any loss of primary water in the total circuit can becompensated for by introducing make-up water upstreamof the mixed-bed ion exchanger. The quantity of make -up water is totaled at a volumetric water meter and isindicative of the tightness of the primary water system.

BHEL, Haridwar

Turbogenerators

Description

Alkalizer Unitfor Primary Water Circuit

2.1-7341-0500/10609 E

1 General

Even with the use of oxygen-poor water, coppercorrosion in the primary water circuit of water-cooledwindings cannot be completely avoided; in isolatedcases the corrosion products reduce the cross-sectional flow area of the water distribution system.Besides, the formation of conductive deposits canoccur in the rotating water inlet and outlet hoses ofwater-cooled rotor windings.

The severity of the corrosion attack can be largelyreduced by alkalizing the oxygen-poor water. Also, thesystem becomes less susceptible to disturbancesresulting from air in-leakage.

Operating the generator with alkaline water at pH8 to 9 improves its reliability land availability.

Operation at alkaline pH is ensured by a self-regulating alkalizer unit for feeding dilute sodiumhydroxide solution (NaOH).

2 Mode of Operation

Dilute sodium hydroxide solution is injected intothe low-conductivity primary water circuit where itremains as dissolved, dissociated sodium hydroxidesolution. OH – ion concentration determines the pHvalue.

The ion exchanger in the water treatment system,i.e. mixed bed filters with H+ cation exchangers andOH – anion exchangers, remains in serv icecontinuously. It removes all copper, iron, chlorine,

carbon dioxide ions, etc. from the water, However, italso removes the Na+ ions from the sodium hydroxidesolut ion. This e l iminat ion of sodium, which isproportional both to the volumetric flow rate throughthe ion exchanger and the NaOH concentration, mustbe compensated by continuous feeding of di lutesodium hydroxide solution.

The alkalizer unit is arranged in the treatmentcircuit Sodium hydroxide solution is injected into thetreatment circuit where it is mixed with the water inthe treatment circuit and raises its conductivity. Thewater has the h ighest pur i ty a t the feed pointdownstream of the ion exchangers. The conductivityof the mixed water is only determined by theconcentration of the sodium hydroxide solution andprovides a reference quantity for the pH valve. Therelationship between pH and conductivity under idealconditions is illustrated in Fig.1

Following the admission on alkaline water, theconductivity in the treatment circuit is monitored.Conductivity must be maintained constant as requiredfor obtaining the specified alkalinity. Conductivity inprimary water circuit likewise approaches a constantvalue after several hours.

3 Hydraulic Circuit

The hydraul ic circuit of the alkal izer units isillustrated in Fig.2

The diaphragm pump extracts the NaOH solution

Fig. 1 Conductivity as a function of pH in water at 18oC

1 Diaphragm pump 4 Level detector2 NaOH tank 5 Soda lime filter in tank vent3 Feed valve 6 Vent

(check valve) 7 Treatment circuit

Fig.2 Schematic Diagram of Alkalizer Unit

2.1-7341-0500/20609 E

from the NaOH tank and delivers it to the treatment circuitvia a spring-loaded feed valve. The treatment circuit andespecially the fine filter down steam of the treatmentcircuit homogenize the concentration of the solutioninjected into the circuit by shot feeding. The volume flowmeter in the treatment circuit stops the diaphragm pumpvia a limit switch when the volumetric flow rate dropsbelow a predetermined limit value. A vent on thediaphragm pump enables starting without back pressure

and venting of the unit for activation. Low NaOH level inthe tank is sensed with a level detector to activate analarm. A soda lime filter in the tank vent binds the carbondioxide contained in the inlet air and prevents theformation of carbonates in the NaOH solution.

The tank has a capacity to store the sodium hydroxidesolution required for a service period of several months.

4 Control and MonitoringAn interlock using the volumetric flow rate in the

treatment circuit as a criterion prevents starting of thediaphragm pump and NaOH feeding into the treatmentcircuit under no-flow or empty conditions. The feed rateof the diaphragm pump is controlled by changing thestroking rate dependent on the conductivity in thetreatment circuit using a controller and stroking ratetransducer.

The diaphragm pump is stopped as soon as theconductivity in treatment circuit or conductivity in primarywater circuit exceeds a predetermined maximum valve,or as soon as the conductivity in treatment circuit orvolumetric flow rate in treatment circuit drops below aminimum valve.

This avoids over feeding due to faults or incorrectoperation of the alkalizer unit. After the pump has beenstopped the conductivity of the water is promptlydecreased by ion exchanger in the mixed-bed filter.

The alkalizer unit provides warning limits forlow conductivity in primary water circuitlow conductivity in leakage water circuitlow level in NaOH tank.

which are displayed in the control cabinet.Via potential-isolated contacts the following alarm

conditions can be signalled to the control room either assingle alarm or as group alarm:

low conductivity in leakage water circuitlow conductivity in primary water circuitlow NaOH level in tankloss of supply voltage.

1. NaOH tank2. NaOH tank cap3. Diaphragm pump4. NaOH tank vent with lime filter5. Feed valve (check valve)

Fig. 3 Alkalyser Unit

1

2

3

4

5

BHEL, Haridwar

Turbogenerators

Description

2.1-7343-0500/10206 E

Primary Water Filters

1 Main Filter

The primary water system includes a strainer-typemain filter with magnet bars. The filter screen of thestrainer has a mesh size of 75 mm (3 mils) and issupported by a perforated sheet-metal cylinder. Themagnet bars consist of a magnet carrier and a numberof permanent magnets. The high-grade permanentmagnets have an unlimited useful service life. Themagnet bars are arranged so that a strong magneticfield is set up between them. The primary water mustpass through this magnetic field so that all iron particlescome within the range of the magnetic bars, and arethus attracted and retained. The magnet bar areprotected by stainless steel sleeves. On contaminationof the strainer-type filter, which is indicated by an alarminitiated at excessive differential pressure, the filtershould be cleaned.

2 Fine Filter

A fine filed with one-way filter element giving a degreeof filtration of 5 mm (0.2 mils) is installed after the mixed-bed ion exchanger in the primary water treatment system.

The filter element consists of cellulose fibres bondedwith synthetic resin to achieve stability. The fibres aredistributed in the element in such a way that their porosityis highest on the outer circumference of the element anddecreases continuously towards the filer interior.Therefore, filtration takes place in depth, and the solidmatter is held in the entire volume of the element. Thecoarser particles are removed at the highly porous outersurface, while the smaller particles are arrested in theelement body at varying depth, depending on their size.On contamination of the filter, which is indicated by analarm initiated at excessive differential pressure, the filterelement should be removed and replaced with new one.

BHEL, Haridwar

Turbogenerators

Description

2.1-7344-0500/10206 E

Primary Water Main Filter

Primarywateroutlet

Primarywaterinlet

13

12

11

1

23

4

5

6

7

8

9

10

1 Connection for vent pipe 2 Filter cover 3 O-ring 4 Compression spring 5 Clamping bolt (adjustablea0 6 Connections for differential pressure indicator 7 Supporting cylinder (inner) 8 Filter screen 9 Supporting cylinder (outer)10 Filter housing11 Connection for drain pipe12 Tension bolt13 Magnet bar

Note: Internal details shown here are typical and may varyfrom actual supply.

BHEL, Haridwar

Turbogenerators

Description

2.1-7345-0500/10206 E

Primary Water Fine Filter

1

2

3

4

5

6

4

7

8

9

10

11

12

1 Connection for vent pipe 2 Differential pressure indicator 3 Filter cover 4 O-ring 5 Impulse pipe for differential pressure indicator 6 Support plate 7 Upper seating ring 8 Filter housing 9 Filter element10 Clamping bolt11 Bottom seating ring12 Connections for drain pipe

Primarywater inlet

Primarywater outlet

Note: Internal details shown here are typical and may varyfrom actual supply.

BHEL, Haridwar

Turbogenerators

Description

2.1-7349-0500/10206 E

Protective Screens at Primary Water Inletand Outlet

Primary water outlet

Primary water inlet

Section A-B

Detail-Y

Detail-X

BHEL, Haridwar

Turbogenerators

Description

Coolant Temperature Control

2.1-8010-0500/10609 E

Due to load variations during operation and the resultingthermal expansions and contractions, the generator issubjected to stresses.

In order to reduce these stresses, the hydrogen coolingcircuit and the primary water cooling are each provided witha temperature control system to control the cooling gas andprimary water temperatures so that the active generatorcomponents are maintained at the proper temperature level.

The requirements for the temperature control systems aredescribed below :

ϑcold = Cold gas temperature or cold primary watertemperature

ϑhot = Hot gas temperature or hot primary watertemperature

ϑmean = Mean temperature of hot and cold gas or ofhot and cold primary water

∆ϑ = ϑhot

- ϑcold with generator carrying full load.

The temperature rise ∆ϑ at full load is the temperaturedifference between the hot and cold hydrogen gas as givenin the hydrogen cooler design data or between the hot andcold primary water as given in the design data of the primarywater cooler.

After start-up and run-up to rated speed, the cooling watersupply to the hydrogen coolers should be opened only whenthe temperature of the hydrogen gas has reached the presetcold gas reference. The temperature difference between coldgas and hot gas is determined by the no-load losses.

The cooling water supply to the primary water coolers

should be opened only when the generator is carrying load,since only then current-dependent heat losses will have tobe dissipated.

The temperature control systems are cold coolanttemperature control schemes with variable set point as afunction of the stator current. Set point adjustment is selectablebetween I and I2 or with an exponent between one and two.With rising stator current, the set point is reduced, so that themean value (ϑmean) of hot and cold coolant temperaturesassumes a nearly constant value, as shown in Fig. 1.

The difference between the setting values of the two setpoints corresponds to half the temperature rise of thehydrogen cooling gas at no-load, with 5-10 K (9-180F) to betaken as a guiding value.

In order to maintain a low temperature level in thegenerator, the reference should be set at the lowest possiblevalue, ensuring that the cold coolant temperature will not dropbelow the minimum level of 100C (500F) even when thegenerator is carrying the full load.

Parallel shifting of the curves shown in Fig. 1 is possibleby adjustment of the cold gas reference. The temperature ofcold primary water must, however, always be higher than coldhydrogen cooling gas over the entire load range of thegenerator in order to avoid any condensation of moisturecontained in the gas on the generator components carryingprimary water.

The control valve must be absolutely tight when in theclosed position to ensure that the cooling gas temperaturewill not drop while the generator is being shut down.

Fig. 1 Coolant temperature as a Function of Generator load

Roomtemperature

t(0F)

Generator load l/lN (%)

BHEL, Haridwar

Turbogenerators

Description

Safety Equipment

for Hydrogen Operation

2.1-8310-0500/10609 E

The use of hydrogen as coolant in the generatorcalls for special safety equipment to ensure thathazardous operating conditions which might endangerpersonnel or the plant will not occur.

The safety and protective measures provided forthe generator are described in detail in this section.The required measuring and alarm equipment isdiscussed elsewhere in this manual [1].

During normal operation, leaks may develop whichresult in a continuous escape of hydrogen. Long timeexperience has shown that no operational restrictionsare required as long as the hydrogen losses do notexceed 12 m

3 (s.t.p.) during any 24 hour period. The

surroundings of the generator and the hydrogensupply system should not be endangered i fengineering principles were followed in plant designand provision is made for ample ventilation of theseareas so that the formation of localized hydrogenpockets or explos ive hydrogen-a i r mixtures isprecluded.

Particular precautions are taken with respect to afa i lure of the seal o i l system. A specia l vaporexhauster creates a slight vacuum in the generatorbearing compartments to prevent the escape of oilvapor from the bearing compartments along the shaft.Any hydrogen collecting in the bearing compartmentwill be drawn off by the exhauster and vented.

Operation of the exhauster is monitored by a flowtransmitter with limit switch. If the exhauster fails, thesecond exhauster on standby is automatically started.

To prevent the hydrogen which enters the bearingcompartment from escaping via the oil drain pipes,the drain oil is returned to the turbine oil tank via theseal oil storage tank and a loop seal. This loop sealis permanently filled with oil to prevent the escape ofgas. The loop is designed to withstand momentarypressure surges.

The bearing oil circuit and the seal oil circuit are

separated from each other.The seal o i l dra ined f rom the seal o i l tank

(hydrogen side circuit) passes into the seal oil storagetank. After remaining in this tank for a predeterminedtime, the degassed oil is admitted to the turbine oiltank together with the bearing oil via a loop seal.

The measures outlined above have the followingeffects:

The bearing compartments and the oil drain pipesare ventilated continuously so that no explosivehazard will arise during normal operation.

During normal operation, practically no hydrogenwill enter the turbine lube oil tank via the loop sealtogether with the seal oil drained from the shaftseals, since the hydrogen is already extracted inthe seal oil storage tank.

The isolating action of the loop seal prevents thehydrogen escaping due to small leakages fromflowing into the turbine through the only partly filledoil drain pipe.

The seal oil storage tank is continuously ventedvia the vapor exhauster provided for the bearingcompartments. The exhauster creates a slight vacuumin the seal oil storage tank so that the oil saturatedwith hydrogen is degassed. After remaining in this tankfor a predetermined time, the degassed oil is admittedto the turbine oil tank together with the bearing oil viaa loop seal.

This continuous ventilation of the seal oil storagetank prevents the format ion of any explos ivehydrogen-air-mixture.

To avoid any danger to the unit to the hydrogensupply, only two hydrogen bottles should be openedif the bottle supply is used.

Also refer to the following section[1] 2.1-8400 Measuring devices and supervisory equipment

BHEL, Haridwar

Turbogenerators

Description

List of Valves

For Waste Gas System

2.1-8312-10555/10609 E

Legend

FL = FlangedSC = ScrewedCS = Carbon SteelCR = Cromium SteelGM = Gun MetalRT = Room Temperature

SL. VLV TYPE OF VALVE NOM. NOM BODY END FUNCTION LOCATION REMARKSNO. DESG BORE PRESS MATL CONN

1 MKF 91 Safety Valve 6 2.5 CS SC Shut Off at PW Tank Pipe LineAA 003

2 MKF 91 Globe Valve 20 2.5 CS SC PW Tank Gas Exhaust Pipe LineAA 506



5 MKQ 31 Disphragm valve 80 2.5 GM FL Shut Off at inlet of Pipe LineAA 501 Vapour Exhauster

6 MKQ 32 Disphragm valve 80 2.5 GM FL Shut Off at inlet of Pipe LineAA 501 Vapour Exhauster

7 MKQ 31 Non-Return valve 80 2.5 CS FL Shut Off at Outlet of Pipe LineAA 001 Vapour Exhauster

8 MKQ 32 Non-Return valve 80 2.5 CS FL Shut Off at Outlet of Pipe LineAA 001 Vapour Exhauster

BHEL, Haridwar

Turbogenerators

Description

Generator Waste Fluid System

2.1-8315-10555/10609 E

The Waste f luid system serves for control leddischarge of fluid to be drained from the

• seal oil system• generator liquid level detection system• waste gas system

as a result of venting or minor leaks.

In addition, the fluids to be drained for carryingout repair or maintenance work in the above areas

are discharged to the waste fluid system.Any waste fluid collected is discharged to the

waste fluid system either directly or via collectingvessels that are integrated in the respective systems.

In the waste fluid system, the fluid is collected ina pipe section of large nominal size. This pipe sectionis fitted with a shutoff valve for fluid draining and alevel detector for activating a high level alarm. Thefluid drained should be transferred to the waste oiltank of the power station for controlled waste disposal.

MKX81 CL011 Level detector for waste fluidMKX81 AA211 Drain valve for waste fluidFig. 1 Generator Waste Fluid System

BHEL, Haridwar

Turbogenerators

Description

Generator Mechanical Equipment

Protection

2.1-8320-0500/10609 E

1 Tripping Criteria

Turbogenerators require comprehensive safety andsupervisory devices to prevent damage and long forcedoutages.

The protective equipment detects dangerousoperation conditions at an early stage and prevents themfrom developing into damaging condit ions. Theprotection relieves the operating personnel from makingthe necessary fast decisions.

The following criteria are sensed by the generatormechanical equipment protection and processed by thegenerator protection circuits:

1.1 High Cold Gas Temperature in Generator

1.2 Liquid in Generator Terminal Box

1.3 High Hot Air Temperature in Exciter Unit

1.4 High Seal Oil Inlet Temperatures

1.5 High Primary Water Inlet Temperature

1.6 Low Primary Water Flow Rate at Sector Outlet

1.7 Low Primary Water Flow Rate at Bushing Outlets

Each of these criteria activates a turbine trip. Thegenerator is disconnected from the system and de-excited through the two-channel reverse power relay.

2 Protection Circuits

2.1 Generators Protection Against Overheating byHigh Cold Gas TemperatureThe protection circuit covering criterion 1.1 prevents

insufficient cooling and thus overheating of the hydrogen-cooled components in case of high cooling gastemperature.

2.2 G enerator Protection Against Internal GroundFault or Terminal Short-CircuitThe generator may be damaged by leaks in

components through which primary or secondary coolingwater or seal oil flows inside the generator.

Primary water flows through the stator winding,

terminal bushing and phase connectors. Secondarycooling water flows through the hydrogen coolers locatedin the stator end shields. Generator operation will onlybe endangered by these coolants in the event of largeleakages. As a result of the high hydrogen pressure.Little water will emerge from a small leak. Hydrogen will,however, enter into the water circuit. The hydrogen losscan be derived from the hydrogen consumption of thegenerator.

Operation of the generator wil l be seriouslyendangered in the event of a major ingress of water whichwill collect in the generator terminal box. Due to therestricted volume of the compartment the liquid can risequickly, resulting in a terminal short-circuit or groundfault. In order to prevent such a failure, two leveldetectors are connected to the generator terminal boxto activate the generator mechanical equipmentprotection before a critical level is reached.

2.3 Exciter Unit Protection Against OverheatingThe protection circuit covering criterion 1.3 prevents

overheating of the exciter in case of insufficient cooling(failure of exciter coolers).

2.4 Shaft Seal protection Against High Seal Oil InletTemperatureHigh seal oil inlet temperature endangers proper

sealing performance of the shaft seals. High seal oiltemperature, as may, for instance, be experienced onfailure of the seal oil coolers, results in a reduction of oilviscosity. The gas may penetrate the seal oil film at theshaft seal contact face and allow the hydrogen to enterthe bearing compartment.

2.5 Protecting of Water-Cooled Components AgainstOverheatingThe protection circuit covering criteria 1.5 prevents

insufficient cooling and thus overheating of the water-cooled components in case of high primary water inlettemperature.

2.6/2.7 Protection of Water-Cooled ComponentsAgainst Insufficient primary Water Supply

The protection circuits covering criteria 1.6 to 1.7prevent overheating and damage to the stator winding,phase connectors and bushing in case of insufficientprimary water supply.

BHEL, Haridwar

Turbogenerators

Description

Tripping Scheme for Generator

Mechanical Equipment Protection

2.1-8321-0500/10609 E

Liquid in generator terminal box

High cold gas temperature

High hot air temperaturein main exciter

High seal oil temperaturedownstream of cooler

High primary water flow rateat stator outlet

High primary water flow rateat stator outlet

Low primary water flow rateat bushing outlet

TT = Turbine tripGCB = Generator Circuit breakerFB = Field breakerA = Alarm

Alarm is initiated when the electrical generator protection system is tripped. Individual alarms for each criterion are provided.

Tripout without reverse power protection (Short time initiation)

TT GCB FB A

BHEL, Haridwar

Turbogenerators

Description

2.1-8323-0500/10609 E

Generator Mechanical Equipemtn ProtectionTwo-out-of-Two Protection CircuitWith Functional Test

Plantenable

CSA11 = non coincidence moduleCSF11 = functional test moduleCSV11 = logic moduleCSZ11 = pulse generator

GS = limit value monitorK1 = relayMU = transducer

BHEL, Haridwar

Turbogenerators

DescriptionGenerator Electrical Protection

2.1-8330-0500/10609 E

Generators are high-quality machines for securingthe best possible continuity of power supply. Inaddition to a suitable technical design and responsiblemode of operation, provision must therefore be madefor automatic protection facilities. This protection mustensure a fast and selective detection of any faults inorder to minimize their dangerous effects.

The protective equipment must be designed sothat any serious fault wil l result in an immediatedisconnection and de-excitation of the generator.Faults which do not cause any direct damage mustbe brought to the attention of the operating staff,enabling them to operate the unit outside the criticalrange or to take precautionary measures for shutdown.

Generators may be endangered by short-circuits,ground faults, overvoltages, under-excitation andexcessive thermal stresses.

The fo l lowing protect ive equipment isrecommended:

1 Differential protectionBreakdown of insulation between different stator

phase windings results in an internal short-circuit. Thefault is detected by a differential relay which initiatesimmediate isolation and de-excitation of the generator.In order to obtain a high sensitivity, the protected areashould include the generator only.

Operating value: 0.2-0.4/NRelay time: < 60 ms

In certain cases, the generator may also beincluded in the differential protection for the maintransformer and station service feeder. Generatorfaults are then detected by two differential protectiondevices.

2 Stator Ground Fault ProtectionBreakdown of insulat ion between the stator

winding and frame results in a stator ground fault. Ifpossible, the stator ground fault protection shouldcover the complete winding, including the neutral pointof the generator. The protect ion is to in i t ia teimmediate isolation and de-excitation of the generator.

Relay time: <1 s

The load resistance of a found transformer andany required boost to raise the neutral point potentialshould be selected so that ground current due to afault will amount to less than 15 A.

3 Rotor Ground Fault Protection

Rapid fault detection is required for the followingreasons:

An interruption of the field circuit with arcingreleases high amounts of energy in the form ofheat which may cause severe burning.A one-line-to-ground fault may develop to a doubleground fault, resulting in dangerous magneticunbalances, especially on four-pole generators.

To minimize the consequent ial damage, i t isrecommended to provide two pole and four-polegenerators with a protection circuit featuring a delayedresponse. In the core of four-pole generators, the rotorground fault protection must always operate of avoidthe hazard of sudden, extremely high vibrations dueto magnetic unbalances.

Relay time: approximately 1 s

4 Under-excitation ProtectionFailure of the voltage regulator, mal-operation of

the generator or transformer control system andgenerator operation in a system with capacitive loadmay result in a reduction of the excitation required toensure system stabi l i ty below a predeterminedminimum value. Short-circuits or interruptions in thefield circuit result in a complete loss of field and thusin instability of the generator. This causes highertemperature rises in the rotor and core end portions,rotor overvol tage, system swims and tors ionalvibrations of the shaft.

A momentary excursion beyond the steady-statestability limit must not necessarily result in a loss ofstability. Therefore it is advisable to design the under-excitation protection so that a warning will be givenwhen the steady-state stability limit is reached. Thegenerator will be shut down after a few seconds only.

The protection must operate instantaneously if aloss of field occurs when the steady-state stability limitis reached.

If the loss of field cannot be detected directly (e.g.exciters with rotating diodes), it is recommended tointroduce a second stator criterion covering the rangeof the permeance values 1/xd and 1/x’d and to providefor instantaneous tr ipping when this cr i ter ion isexceeded.

5 Over current ProtectionSystem faults may result in inadmissible thermal

stressing of the generator. For this reason, an overcurrent protection should be provided which operates

2.1-8330-0500/2

on failure of the system protection.A definite-time delay over current relay may be used

for this purpose, however, its relay time should longerthan that of the system protection.

Operating value: 1.3/NRelay time: 6-8 s maximum

To avoid long relay times, it is recommended to equiplarge generators with an inverse-time-delay (impedancerelay. This relay is energized by over current andoperates with long or short-time setting, dependent onthe location of the short-circuit.

If connected to the generator neutral point, the over-current protection serves as backup protection for thedifferential protection.

6 Load Unbalance ProtectionGenerators operating in an interconnected system

are normally subjected to small load unbalances only.However, all one and two line-to-ground faults occurringin the system, phase breakages or circuit breaker failuresare in fact load unbalances which may result in undulyhigh thermal stressing of the rotor.

It is recommended to provide a two-stage loadunbalance protection. When the continuously permissibleload unbalance is reached, an alarm is given, whereasa time-dependent isolation from the system occurs whenthis value is exceeded.

In case of large units, it is recommended to providea protection with unbalanced load/time characteristic.Operating value and relay time should be matched tothe load unbalanced/time characteristic applicable to theparticular generator.

7 Rise-in-voltage ProtectionRejection of partial or complete system loads causes

a voltage rise, followed by an increase in the prime moverspeed. This may result in the generator and theapparatus connected to it being endangered by undulyhigh voltages. Mal-operation during manual voltageregulation of the generator may also result ininadmissible voltage stressing of these devices. Due tothe sudden voltage variations resulting from switchingoperations, it is advisable, at least in the case of largeunits, to provide a two-stage rise-in voltage protection,i.e.:

with high (1.45 × UN) operating value andinstantaneous tripping;with low (1.2 × UN) operating value and delayedtripping.

8 Under-Frequency ProtectionMajor disturbances in an interconnected system may

result in operation of the generator at under-frequency.At rated voltage, the generator can be continuouslyoperated at rated k VA up to 95% of rated frequency.

To avoid excessive magnetic and thermal stressing,it is recommended to provide an under-frequencyprotection.

Since the frequency deviation due to a systemdisturbance is normally accompanied by a voltagedeviation, the protection should be designed on the basisof the permissible load characteristic of the generatoron frequency and voltage deviations.

9 Reverse Power ProtectionA rise in system frequency for any reason whatsoever

result in closing of the control valves, and the turbine isdriven by the motoring generator. Since the turbine isthen no longer supplied with cooling steam, the unit mustbe disconnected from the system. The relay must beprovided with a time delay of approximately 20s toprevent undesired response to system swings (long timesetting).

Specific faults in the turbine-generator interior initiateemergency tripping. The steam supply to the turbine isinterrupted. A reliable criterion of perfectly tight closureof the emergency stop valves is the flow of power fromthe system back into the generator.

Disconnection of the unit from the system by thegenerator circuit breaker with a time delay of 4s is onlypermissible after the reverse power has been drawn bythe generator (short-time setting).

Operating value: about 50-80% of reverse powerRelay time: longtime setting: approximately 20 s

short-time setting: approximately 4s

10 Overvoltage ProtectionThe use of surge inverters on the high-voltage side

of the unit transformer is considered sufficient forprotecting the generator against atmospheric overvoltage and switching surges in the system.

With a view to a possible flashover from the high-voltage winding to the low-voltage winding in the unittransformer, it is, however, advisable to provide surgediverters for the generator too, which should beconnected between the phases and ground.

Normally, the surge diverters are installed in the directvicinity of the unit transformer. It is assumed thatswitching surges due to a load isolator or circuit breakerconnected between the generator and transformer willnot endanger the generator.

Care should be taken to provide explosion-proofsurge diverters or suitable constructional measures inorder to avoid danger to persons or nearby components.

Design principle:Reseal voltage: approximately 1.2-1.4 × UN

(allowing for power-frequencyovervoltage on load rejection)

Power-frequencyspark-over voltage: approximately 2 × UN

(<test voltage for stator winding,e.g. VDE 0530,UP = 2 UN + 1 kV)

Impulse spark-overvoltage <4 × UN

BHEL, Haridwar

Turbogenerators

Description

Tripping Scheme for

Generator Electrical Protection

2.1-8331-0500/10609 E

Alarm is initiated when the electrical power protection system is tripped. Individual alarms for each criterion are provided.

Differential protection

Stator ground fault protection

Rotor ground fault protection

Underexcitation protectionwithout loss of fieldwith loss of field

Over current protection

Unbalance load protection

Rise-in-voltage protection

Under-frequency protection

Reverse powerLong timeshort time (operates uonly at TT) TT has been

activated

Initiation of

TT GCB FB

TT = Turbine tripGCB = Generator circuit breakerFB = Field breaker

BHEL, Haridwar

Turbogenerators

Description

2.1-8350-0500/10609 E

Rotor Grounding System

Grounding brushes are fitted to the turbine-end sta-tor end shield to remove the static charges of the shafts.

The brush holders are arranged with 900 displace-ment, which ensures that at least one brush will makecontact with the rotating shaft journal.

Fig.1 Arrangement of Brush Holders

1. Stator end shield 3. Rotor shaft2. Brush holder 4. Turbine bearing

1

2

3

4

BHEL, Haridwar

Turbogenerators

Description

Arrangement of Brush Holders for

Rotor Grounding System

2.1-8351-0500/10609 E

1 2 4 5 3 6

8

7

2

3

1 Brush holder2 Grounding brush (Design A)3 Grounding brush (Design B)4 Brush spindle

5 Insulation6 Roror shaft7 Labyrinth ring8 End shield

BHEL, Haridwar

Turbogenerators

Operation

Measuring Devices and SupervisoryEquipmentIntroduction

2.1-8400-0500/10609 E

The supervisory equipment consists of alarms andmeasuring devices. The measuring devices give avisual indication of the system parameters, the alarmdevices initiate visual or audible signals in the eventof a controlled quantity falling below or exceeding thepredetermined l imit values. In many cases, the

measuring and alarm devices are combined to formone supervisory.

Closely associated with the supervisory equipmentare regulat ing systems, automat ic controls andprotective devices which provide for a reduction ofthe manual supervisory work.

BHEL, Haridwar

Turbogenerators

Operation

Temperature TranducersResistance Temperature Detectorsand Thermocouples

2.1-8410-0500/10609 E

1 Resistance Temperature Detectors (RTD’s)

RTD’s are used for temperature measurements on thegenerator, e.g. to measure the slot temperatures and thecold gas and hot gas temperatures.

When making measurements with RTD’s the resistanceelement is exposed to the temperature to be measured.The RTD works on the change in electrical resistance of aconductor by the following formula:

R = R0 (1+ α α α α α T)where

R0 = reference resistance at 00Cααααα = temperature coefficient, andT = temperature in 0C

Fig. 1: Resistance Characteristics of Platinum RTD’s 100 Ω

The standard reference resistance of the platinumresistance element is 100 ohms. The temperaturecoefficient amounts to ααααα =3.85×10-3 degC-1 this being themean value for the range 0 -100 0C.

1.1 Circuit ConnectionsThe two-wire connections so far commonly used involves

errors in case of leads. Long leads are exposed to differenttemperatures, and the lead resistances then reach values inthe order of the resistance of the RTD element.

1.1.1 Three wire ConnectionsIf a third lead is connected to the element in addition to

the two element leads, automatic compensation for leadwire resistance including its changes can be achieved byresistance of the two leads forming the pair to the elementare always the same.

1.1.2 Four-Wire ConnectionIf the two element leads are not alike or if the three-

wire method of compensation would be too costly a four-wire circuit should be used. Fig.2 shows the circuit diagramof the four-wire method.

Fig. 2: Four-wire ConnectionLeads RL1 and RL2 form the pair of lead wires to the

RTD Pt 100, while the other set of lead wires RL3 and RL4

from the RTD are connected to amplifier V. Being a normaldifferential amplifier, it amplifies only the voltage drop acrossthe RTD to the required output voltage level.

Due to the mostly very high input resistance of amplifierV, the resistance of lead wires RL3 and RL4 from the RTDto the amplifier is negligible, even if it would be substantiallyincreased be the provision of a safety barrier (explosionprotection).

2 Thermocouples

Thermocouples are used for temperaturemeasurements on generator, e.g. to measure the generatorand exciter bearing temperatures. Thermocouples aremainly employed where small time constants require fasttemperature indication.

2.1 PrincipleTemperature measurement with thermocouples is

carried out as follows:Two conductors of dissimilar materials, i.e. the

positive and the negative conductor (thermoelectricelements) are joined at one end (hot junction) so as toproduce an electromotive force (emf), i .e. athermoelectric emf (in mV). The magnitude of the emf isdependent upon the temperature difference between thetemperature to be measured and that of the other twoends of the conductors.

To use the thermoelectric emf for temperaturemeasurement, the free ends of the conductors are exposedto a constant temperature (cold junction temperature) andconnected to a milli-voltmeter calibrated in 0C.

2.1-8410-0500/20609 E

Fig.4: Voltage-temperature function for standardised thermocouples

2.2 Compensating LeadsThe compensating leads serve to extend the

thermocouple up to the cold junction. When exposed toa temperature up to 200 0C they produce the samethermoelectric emf as the associated thermocouple. SeeDIN 43710 for calibration data and limits of error ofcompensating leads.

The compensating leads used for the differentthermocouples are identified by colors:

Cu-CuNi brownFe-CuNi blueNiCr-Ni greenPtRh-Pt whiteNiCr-Constantan redThe insulating sleeve of the positive lead is provided

withe a red mark in addition to the color code.

2.3 Cold JunctionFor measuring a temperature by means of a

thermocouple, the cold junction temperature must beknown. A cold junction at a temperature of 00C can bevery easily produced by melting ice. The use ofthermostats with reference junction temperature of 200C and 500C is also possible. Note that in these casescertain corrections must be added to the calibration figureof the particular thermocouple which are referred to 00C.To do this, add the thermoelectric emf due to the coldjunction temperature to the measured thermoelectric emfand read measuring point temperature to obtain the totalthermoelectric emf .

The cold junction can, however, also be implementedby using a Pt100 RTD for determination of the actualtemperature. The temperature is referred to thecalibration figure for 0oC by electronic means. Theelectronic cold junction also avoids the temperature errordue to the junction between the compensating leads andthe copper leads.

To obtain a simpler circuit, the large number ofthermocouples used on the generator can be connectedto a double pole measuring point selector switch enablingthe respective thermocouple to be connected to acompensator for measurement.

1 Hot junction 4 Cold junction correction2 Thermocouple 5 Connecting cables3 Compensating lead 6 Milli volt meter

7 Compensating resister

1 Compensator2 Genenerator3 Double pole double throw switch

Fig.: 5 Circuit arrangement for connection of several thermocouples

NiCr-Const.

Cu-CuNiFe-CuNi

NiCr-Ni

PtRh-Pt

Fig. 3: Thermocouples

Thermocouple Temperature limits Max. continuous Parameter Colour codes Indicator oC oC Neg. pole Pos.pole

Cu - NiCu -200 - +600 400 ~4.3 mV/100 deg C Red Brown Fe - NiCu -200 - +900 700 ~5.3 mV/100 deg C Red Blue Moving Ni Cr - Ni ± 0 - +1200 1000 ~4.1 mV/100 deg C Red Green coil Pt Rh - Pt ± 0 - +1600 1300 ~0.6 mV/100 deg C Red White Ni Cr- Constantan ± 0 - +1000 400 ~6.3 mV/100 deg C Red Purple

60

50

40

30

20

10

0Ther

moe

lect

ric v

olta

ge U

ther

m in

mV

BHEL, Haridwar

Turbogenerators

Operation

Supervision of Generator

2.1-8420-0500/10609 E

The most essential measuring and supervisorydevices at the generator serve for:

-temperature monitoring-detection of liquid in generator interior.

1 Temperature Monitoring

1.1 Stator Slot MonitoringThe slot temperatures are measured with resistance

temperature detectors (RTD’S). This platinum measuringwire is embedded in a molded plastic body whichprovides for insulation and pressure relief.

The RTD’S are embedded directly in the stator slotsbetween the bottom and top bars at points where thehighest temperature are expected.

The RTD’S are characterized by a constanttemperature vs. resistance characteristic, highmechanical strength and insensitivity to electrical andmagnetic fields.

1 Top bar2 Resistance temperature detector3 Separator4 Bottom bar5 Stator core

Fig. 1 Stator slot resistance temperature detector

1.2 Cold and Hot Gas TemperaturesThe temperature of the hot and cold gases are

measured by RTD’S upstream and downstream of thehydrogen coolers, and the limit values are senseddownsteam of the coolers for use with the hydrogentemperature control system.

Temperature detectors located in the generatorinterior are mounted in gas tight protective tubes weldedto the stator frame.

1.3 Primary Water TemperaturesThe temperature of the hot primary water in the

turbine-end water manifold of the stator winding ismeasured withe manifold of the stator winding ismeasured with resistance temperature detectors. Thetemperature detectors are mounted in the water manifoldin thermowell exposed to the primary water.

2 Stator Liquid DetectionLiquid (cooling water from hydrogen coolers, primary

water or seal oil) entering the generator housing issensed by level detectors assembled in gas tight housinglocated on the seal oil valve rack. See Figs.2 and 3.

Fig. 2 Level detector

When pipes from several low-level points of the generatorare connected to a common level detector, sight glassesare provided in the inlet pipe to identify the source of theliquid.

The generator terminal box has two leakage detectionpipes acting on the generator protectors. The two pipesextend serval inches above the bottom of the generatorterminal box and are interconnected so that bothdetectors will respond if the box should be in an inclinedposition.

These detectors are utilized as tripping criteria forthe generator mechanical equipment protection, whereasall other detectors initiate only alarms.

1 Shutoff valve before level detector2 Level detector3 Sight glass4 Shut off valve after level detector

Fig. 3 Combined arrangement of Level detectors in Seal oil valve rack

1

23

4

5

1

2

3

4

BHEL, Haridwar

Turbogenerators

Operation

Supervision of Bearings

2.1-8440-0500/10609 E

1 Generator Bearing Temperatures

The generator bearing temperatures are measuredwith thermocouples located in the bearing lowerhalves. The actual measuring point is located at thebabbitt/sleeve interface. Measurement and recordingof the temperatures are performed in conjunction withthe turbine supervision. The overall turbine protectionis tripped when the maximum permissible temperatureis exceeded.

2 Vibration Monitoring

The generator and exciter rotors are manufacturedwith high precision and carefully balanced.

The unavoidable residual unbalance will, however,resul t in v ibrat ions dur ing operat ion, which aretransmitted to the stator frame and foundation via thebearings.

To permit a reliable assessment of the runningcondi t ion, v ibrat ion p ickups are located at thebear ings. Measurement and record ing of thevibrations are performed in conjunction with theturbine supervision. The overall turbine protection istripped when a predetermined amplitude is exceeded.

1 Rotor shaft2 Babbitt3 Thermocouple4 Bearing sleeve

Fig. 1 Bearing temperature measurement

1

23

4

BHEL, Haridwar

Turbogenerators

Operation

Supervision of Seal Oil System

2.1-8450-0500/10609 E

The location of the transmitters of the measuringand supervisory equipment in the seal oil system isshown in the seal oil diagram [1].

The most essential measuring and supervisorydevices in the seal oil are:

Level detectorsPressure and differential pressure gaugesTemperature detectorsVolume flow measuring devices

1 Level DetectorsWithin the seal oil system-

the oil levels in the TE and EE prechambersthe oil levels in the seal oil tankthe oil levels in the seal oil storage tank

are supervised.A high oil level in the generator prechambers, due

to an increase in the amount of seal oil on the hydrogenside of the shaft seal, results in an alarm to be initiatedwhen the probe is immersed in oil.

A low oil level in the seal oil tank is monitored suchthat an alarm takes place when the probe is no longercovered with oil. This prevents dry running of thehydrogen side seal oil pump.

A low oil level in the seal oil storage tank-onlyfeasible during the start-up phase- results in an alarmfor protection of the air side pumps. The alarm is initiatedwhen the probe is no longer covered with oil.

2 Pressure and Differential Pressure Gauges

The following pressure measuring points areprovided:

Pressure downstream of air side seal oil pump-1

On failure of seal oil pump-1, a pressure switchactivates air side seal oil pump-2, If the later is not readyfor operation, air side oil pump 3 is automatically started.

Local indication is required for pressure setting ofthe A1 valve and for visual examination.

Pressure downstream of air side seal oil pump 2

On failure of seal oil pump-2, a pressure switchactivates air side seal oil pump-1. If the later is not readyfor operation, air side seal oil pump 3 is automatically

started.Local indication is required for pressure setting of

the A1 valve and for visual examination.

Pressure downstream of air side seal oil pump 3

A pressure switch signals the takeover of the sealoil supply by seal oil pump 3.

Local indication is required for pressure setting ofthe A2 valve and for visual examination.

Pressure downstream of air side seal oil pumps

Readings from this pressure gauge are required forpressure setting of the A1 and A2 valves.

H2 casing pressure

This pressure gauge reading is required for settingthe pressure differential between the air side seal oilpressure and the H2 casing pressure.

Seal oil pressure downstream of oil orifice

At this pressure gauge the seal oil pressure, set bymeans of the control orifice, can be observed.

Seal oil pump 3 is activated via a differentialpressure transducer, which detects the pressuredifferential between the generator casing pressure andthe air side seal oil, and a pressure switch when pressurefalls below the preset set point value. An additionalpressure switch initiates miscellaneous alarms and isused for Off control of the hydrogen side seal oil pump.

TE and EE ring relief pressure

The pressure gauges indicate the relief pressure sitby means of the manual control valves.

In addition, pressure transmitters are provided forfurther processing of the pressure signals.

Pressure downstream of hydrogen side seal oilpump

A pressure switch signals a failure of the oil supply.The reading is required for setting of the C valve

and for visual examination.

Pressure in hydrogen side seal oil circuit ofshaft seal

This pressure gauge serves for local observation of

2.1-8450-0500/20406 E

Also refer to the following section[1] 2.1-7111 Seal Oil Diagram

the set seal oil pressure at the shaft seal.

Pressure differentials are sensed at the following points:

Pressure differential between the air side seal oilbefore TE and EE shaft seals and the generator casingpressure is sensed by transducers which initiate an alarmon falling pressure differential, Local indication is providefor manual adjustment of the pressure regulating valvesand for visual examination.Differential Pressure Indication at Air - CooledHydrogen Side Seal Oil Filters

The indicators display the degree of f i l tercontamination and activate an alarm at preset pressuredifferentials.

3. Temperature Detectors

The following temperatures are measured locallywith thermometers :

Seal oil temperature upstream and downstream ofair side seal oil coolers.Seal oil temperature upstream and downstream ofhydrogen side seal oil coolers.Cooling water temperature upstream and

downstream of air side and hydrogen side seal oilcoolers.

In addition, the following temperatures are measuredby means of resistance temperature detectors for remoteindication :

Seal oil temperature in hydrogen side seal oil drain,TE and EE.Seal oil temperature upstream and downstream ofair side and hydrogen side seal oil coolers.Seal oil temperature downstream of air side andhydrogen side seal oil coolers.

4. Volume Flow Meter System

The following volume flows are measured forcomparison measurements :

Volume flow of EE seal ring relief oilVolume flow of TE seal ring relief oilVolume flow of air side seal oil, EEVolume flow of air side seal oil, TEVolume flow of hydrogen side seal oil, EEVolume flow of hydrogen side seal oil, TE

BHEL, Haridwar

Turbogenerators

OperationSupervision of Gas System

2.1-8460-0500/10609 E

The location of the transmitters of the measuring andsupervisory equipment in the gas system is shown in theGas Diagram [1].

The essential measuring and supervisory devices inthe gas system are :

Purity meter systemsVolume flow meter systemPressure gaugeTemperature detectors

1 Gas Purity Meter System

The gas purity meter system measures the purity ofthe hydrogen gas in the generator as well as thecomposition of the gas mixtures (CO2/ air and H2/ CO2)during filling of the generator. The gas purity meter systemis also used when removing the hydrogen from thegenerator, where the hydrogen is replaced with carbondioxide and the carbon dioxide in turn with air. The gasrequired for the measurement is taken from the generatoror from the filling lines, respectively, and, on completion ofthe measurement, is discharged to the atmosphere througha vent line.

For details on the gas purity meter system, referOperation and maintenance manual of the Gas analysercabinet [2].

The gas purity meter system is equipped with a limitswitch which provides a signal to initiate an alarm whenthe purity drops below a preset value.

2 Volume Flow System

Measuring gas volume flow

For comparison measurement, a precisely definedmeasuring gas flow must be admitted to the gas purity metersystem. The measuring gas volume flow can be read locallyat the flow meter.

3 Pressure Gauges

The following measuring points are provided :

CO2 bottle pressure

The bottle pressure during CO2 filling can be observedat a local pressure gauge.

H2 bottle pressure

The bottle pressure can be read at the pressure gauge.The pressure switch activates a signal at low H2 pressure.

In addition, the pressure is sensed with a pressuretransmitter, the electrical signal being used for remotecontrol and supervision.

N2 bottle pressure

The bottle pressure can be read at a local pressuregauge.

H2 pressure at pressure reducers.

For observation of the pressure settings.

H2 casing pressure

The pressure is sensed by pressure transmitters, theelectrical signal of one pressure transmitter being used forremote control and supervision. The signals of theremaining two transmitters are converted into alarm andcontrol signals.

The H2 casing pressure can be read at a local pressuregauge.

4 Temperature detectors

Within the gas system, temperature detectors are usedfor supervision of CO2 flash evaporator.

The temperatures of the heat transfer liquid in CO2 flashevaporator is detected by means of RTD and used forcontrol functions. In addition, the temperature of heattransfer liquid in the CO2 flash evaporator is indicated locallyby a thermometer.

Als refer to the following sections[1] 2.1-7211 Gas Diagram[2] refer Operation and maintenance manual of the Gas

analyser cabinet

BHEL, Haridwar

Turbogenerators

OperationSupervision of Primary Water System

2.1-8470-0500/10609 E

The location of the transmitters of the measuringand supervisory equipment in the primary water systemis shown in the Primary Water diagram [1].

The essential measuring and supervisory devicesin the primary water system are:

Conductivity meter systemLevel monitoring systemVolume flow metersPressure gaugesTemperature detectors

1 Conductivity Meter System

The conductivity of the primary water is monitored:

Downstream of ion exchangerUpstream of primary water inlet of generator

The measuring point downstream of the ionexchanger checks the ion exchanger for properperformance.

The measuring point in the primary water inlet ofthe generator permits the conductivity of the entirecooling system to be assessed.

Both measuring devices are equipped for indicationand alarm.

2 Level Monitoring System

The water level in the primary water tank is sensedby capacitive method, a high or low water level initiatingan alarm.

A local water level gauge is located in parallel tothe electrical monitoring system.

3 Volume Flow Meter System

The primary water volume flows of the statorwinding and bushings are measured andindicated by a differential pressure flow meter system. Ifthe flow falls below a minimum value, an alarm isactivated. If the flow continues to fall, the generatormechanical equipment protection is tripped.

The amount of primary water flowing though the ionexchanger is monitored by a local flow meter. The amountof water added to the system during operation isdetermined by a water meter.

4 Pressure Gauges

Pressure or pressure differentials are sensed at thefollowing measuring point in the primary water coolingcircuit:

Pressure downstream of primary water pump 1

Pressure downstream of primary water pump 2

The two pressure measuring points are equippedwith pressure switches and are required for automaticcontrol of the two primary water pumps.

In addit ion, a pressure gauge is provideddownstream of each pump for local observation of thepressure.

Pressure upstream of stator winding

This pressure measuring point is equipped withpressure switches and a local pressure gauge. Thepressure switches initiate an alarm at rising primary waterpressure.

The pressure gauge is provided for localobservation.

Gas pressure in primary water tank

A pressure switch activates an alarm at rising gaspressure in the primary water tank.

In addition, a pressure gauge is provided for localobservation of the tank gas pressure.

Differential pressure across main filterDifferential pressure across fine filter

Differential pressure transmitters are providedacross both these filters for indication of differentialpressure and also for initiating alarm.

5 Temperature Detectors

The following temperatures are measured locally bymeans of thermometers:

Primary water temperature downstream ofcoolers

Cooling water temperature upstream anddownstream of coolers

Primary water temperature downstream ofbushings

Resistance temperature detectors are used tomeasure the followings temperatures for furtherprocessing according to different methods:

Primary water temperature upstream anddownstream of coolers

Primary water temperature downstream ofstator winding

Primary water temperature downstream ofbushings

Primary water temperature downstream ofcoolers

Also refer to the following section[1] 2.1-7311 Primary Water Diagram

BHEL, Haridwar

Turbogenerators

OperationSupervision of Exciter

2.1-8490-0500/10609 E

The most essential measuring and supervisorydevices at the exciter are:

Temperature monitoring systemFuse monitoring systemGround fault detection systemExcitation current measuring device

1 Temperature Monitoring System

The exciter is provided with devices for monitoringthe temperatures of the cold air after the exciter coolerand the hot air leaving the rectifier wheels and hot airleaving the rectifier wheels and main exciter.

2 Fuse Monitoring System

The indicator flags of the fuses on the rectifier

wheels may be checked during operation with the built-in stroboscope.

3 Ground Fault Detection System

Two sliprings are installed on the shaft between themain exciter and bearing. One is connected to the starpoint of the three-phase winding of the main exciter andthe other to the frame. These sliprings permit groundfault detection.

4 Excitation Current Measuring Device

The excitation current is measured indirectlythrough a coil arranged between two poles of the mainexciter. The voltage induced in this coil is proportionalto the excitation current thus enabling a determinationof the excitation current.

BHEL, Haridwar

Turbogenerators

Description

Exciter

2.1-9100-0500/10609 E

1 Design FeatureThe exciter consists of

-Rectifier wheels-Three-phase pilot exciter-Cooler-Metering and supervisory equipment

1 Automatic voltage regulator

2 Permanent magnet pilot exciter

3 Sliprings for field ground fault detection

4 Quadrature-axis measuring coil

5 Three-phase main exciter

6 Diode rectifier set

7 Three-phase lead

8 Multicontact connector

9 Rotor winding of turbogenerator

10 Stator winding of tubogenerator

Fig. 1 Basic Arrangement of Brushless Excitation SystemWith Rotating Diodes

Fig. 1 shows the basic arrangement of the exciter.The three-phase pilot exciter has a revolving field with

permanent magnet poles. The three-phase AC generatedby the permanent-magnet pilot exciter is rectified andcontrolled by the AVR to provide a variable DC currentfor exciting the main exciter. The three-phase AC isinduced in the rotor of the main exciter. This three-phaseAC induced in the rotor of the main exciter is rectified bythe rotating rectifier bridge and fed to the field windingof the generator rotor through the DC leads in the rotorshaft.

Fig. 2 Exciter Rotor

The exciter rotor shown in fig. 2 corresponds to thebasic arrangement described above. A common shaftcarries the rectifier wheels, the rotor of the main exciterand the permanent-magnet rotor of the pilot exciter. Theshaft is rigidly coupled to the generator rotor. The excitershaft is supported on a bearing between the main andpilot exciter. The generator and exciter rotors are thussupported on total of three bearings.

Mechanical coupling of the two shaft assembliesresults in simultaneous coupling of the dc leads in thecentral shaft bore through the Multicontact electricalcontact system consisting of plug-in bolts and sockets.This contact system is also designed to compensate forlength variations of the leads due to thermal expansion.

2 Rectifier Wheels

The main-components of the rectifier wheels are thesilicon diodes which are arranged in the rectifier wheelsin a three-phase bridge circuit. The contact pressure forthe silicon wafer is produced by a plate spring assembly.The arrangement of the diodes is such that this contactpressure is increased by the centrifugal force duringrotation.

Fig. 3 shows additional components contained in therectifier wheels. Two diodes each are mounted in eachaluminum alloy heat sink and thus connected in parallel.

2

3

45

6

7

8

9

10

1

1 Coupling2 Rectifier wheel3 Rotor of main exciter4 Fan5 Permanent magnet rotor

5 4 3 2 1

2.1-9100-0500/2

Associated with each heat sink is a fuse which serves toswitch off the two diodes if one diodes fails (loss ofreverse blocking capability).

For suppression of the momentary voltage peaksarising from commutation, each wheel is provided withsix RC network consisting of a capacitor and a dampingresistor each, which are combined in a single resin-encapsulated unit.

The insulated and shrunken rectifier wheels serveas DC buses for the negative and positive side of therectif ier bridge. This arrangement ensures goodaccessibility to all components and a minimum of circuitconnections. The two wheels are identical in theirmechanical design and differ only in the forwarddirections of the diodes.

The direct current from the rectifier wheels is fed toDC leads arranged in the center bore of the shaft viaradial bolts.

The three-phase alternating currents is obtained viacopper conductors arranged on the shaft circumferencebetween the rectifier wheels and the three-phase mainexciter. The conductors are attached by means ofbanding clips and equipped with screw-on lugs for theinternal diode connections.

3 Three-Phase Main Exciter

The three-phase main exciter is a six-pole revolving-armature unit. Arranged in the stator frame are the poleswith the field and damper winding. The field winding isarranged on the laminated magnetic poles. At the poleshoe bars are provided. Their ends being connected soas to form a damper winding Between two poles aquadrature-axis coil is fitted for inductive measurementof the exciter current.

The armature rotor consists of stacked laminations,which are compressed by through bolts over

compression rings. The three-phase winding is insertedin the slots of the laminated armature rotor. The windingconductors are transposed within the core length, andthe end turns of the rotor winding are secured with stealbands. The connections are made on the side facing therectifier wheels. The winding ends are run to a bus ringsystem to which the three-phase leads to the rectifierwheels are also connected. After full impregnation withsynthetic resin and curing, the complete armature rotoris shrunk onto the shaft. A journal bearing is arrangedbetween main exciter and pilot exciter and has forcedoil lubrication from the turbine oil supply.

4 Three-Phase Pilot Exciter

The three-phase p i lo t exc i ter is a 16 polerevolving-field unit. The frame accommodates the

Fig. 3 Rectifier Wheel

Fig. 4 Main Exciter

1. Diode 2. Fuse3. Diode Rectifier Wheel

3. Diode Rectifier Wheel 4. Exciter armature5. Wound armature 6. Exciter main stator

6 5 3 4 1 2 3

3. Stator4. Amature Rotor7. Sliprings for ground fault detection8. Bearing housing

7 8 3 4

BHEL, Haridwar

Turbogenerators

Description

2.1-9100-0500/30609 E

Exciter

laminated core with the three-phase winding. Therotor consists of a hub with mounted poles. Each poleconsists of 12 separate permanent magnets which arehoused in a non-magnetic metallic enclosure. Themagnets are braced between the hub and the externalpole shoe with bolts. The magnet hub is shrunk ontothe free shaft end.

5 Cooling of Exciter

The exciter is air cooled. The cooling air is circulated

in a closed circuit and cooled in two cooler sectionsarranged alongside the exciter.

The complete exciter is housed in an enclosure drawthe cool air in at both ends and expel the warned air tothe compartment beneath the base plate.

The main exciter enclosure receives cool air fromthe fan after it passes over the pilot exciter. The air entersthe main exciter from both ends and is passed into ductsbelow the rotor body and discharged through radial slotsin the rotor core to the lower compartment. The warmair is then returned to the main enclosure via the coolersections.

6 Replacement of Air Inside Exciter Enclosure

When the generator is filled with hydrogen (operationor standstill) an adequate replacement of the air insidethe exciter enclosure must be ensured. The air volumeinside the exciter enclosure requires an air change rateof 125 m3/h.

While the generator is running, the air leaving theexciter enclosure via the bearing vapor exhaust systemand the leakage air outlet in the foundation provides fora pull-through system. The volume of air extracted fromthe cooling air circuit is replaced via the filters locatedat the top of the enclosure.

When the generator is at rest, the air dryer of theexciter unit discharges dry air inside the exciterenclosure. The air leaves the exciter enclosure via theleakage air filter and the leakage air outlet at the shaftas well as via the bearing vapor exhaust system if thissystem is in service.

Fig. 5 Permanent-Magnet Pilot Exciter

1 2 3

1 Stator2 Pilot exciter Stator winding3 Permanent magnet rotor

BHEL, Haridwar

Turbogenerators

Description

Basic Arrangement of BrushlessExcitation System

2.1-9101-0500/10609 E

1 Automatic voltage regulator2 Permanent magnet pilot exciter3 Sliprings for field ground fault detection4 Quadrature-axis measuring coil5 Three-phase main exciter

6 Diode rectifier set7 Three-phase lead8 Multicontact connector9 Rotor winding of turbogenerator10 Stator winding of tubogenerator

2

3

4

5

6

7

8

9

10

1

BHEL, Haridwar

Turbogenerators

Description

2.1-9102-0500/10609 E

Rectifier Wheels

1

2

34

5

6

78

9

43

2

10

1 AC lead 2 Fuse 3 Heat sink 4 Diode 5 Rectifier wheel (+ve polarity)

6 Hot air outlet 7 Tension bolt 8 Terminal bolt 9 Rectifier wheel (-ve polarity)10 DC lead

Current path

- +

~

+ _

BHEL, Haridwar

Turbogenerators

Description

2.1-9103-0500/10609 E

Rectifier Wheels and Coupling

Exciter coupling without Contact pin Exciter coupling with Contact pin 5 6 7 7 8

1

2

3

4

1 Balancing Weight2 Fuse3 Rectifier wheels4 Diode5 Multi Contact band6 DC lead7 Coupling8 Contact pin

BHEL, Haridwar

Turbogenerators

Description

2.1-9104-0500/10609 E

Permanent-Magnet

Pilot Exciter Rotor and Fan

1 Permanent magnet pole2 Fan3 Sliprings of field ground earth fault detection4 Rotor of main exciter

1 2 3 4

4 5

BHEL,Haridwar

Turbogenerators

General

2.1-9110-0500/10807 E

Exciter Cross Section

1 2 3 4 5 6 7 8 9 10 11 12 13 14

20 19 18 17 16 15

1 Coupling with connector2 Fuse3 Heat sink4 Rectifier wheels5 Diode

6 Magnetic pole of main exciter 7 Main exciter rotor 8 Main exciter stator 9 Sliprings for ground fault detection10 Bearing

11 Radial flow fan12 Pilot exciter stator13 Pilot exciter rotor14 Exciter enclosure15 Foundation

16 Cooler17 Armature balancing ring18 Air housing19 Base frame20 DC lead

BHEL, Haridwar

Turbogenerators

Description

Exciter cooling Air circuit

During operation

2.1-9120-0500/10609 E

Col

d ai

r

Hot

air

Leak

age

air

and

mak

eup

air

to b

earin

g va

pour

exh

aust

er

Sect

ion

C-D

Se

ctio

n A-

B

A

C

BHEL, Haridwar

Turbogenerators

Description

2.1-9140-0500/10609 E

Stroboscope for Fuse Monitoring

1 2 3 4 5 6 7 8 9 10

1 Flash tube 1 (A wheel)2 Control unit3 Pushbutton for flash tube 14 Pushbutton for flash tube 2

5 Feed pushbutton6 Pilot lamp for control voltage7 Return pushbutton

8 On pushbutton9 Off pushbutton10 Flash tube 2 (B wheel)

Fig.1 Components and Operating Elements of Stroboscope

The fuses on the rectifier wheels may be checkedduring operation with the stroboscope. A separate flashtube is provided for each wheel (A and B). The tubes,which are supplied through a common control unit, arepermanently installed in the rectifier wheel enclosure.This permits easy monitoring without any adjustmentoutside the exciter enclosure being required.

Fig. 1 shows the basic arrangement of a fullytransistorized stroboscope The electronics required forcontrol of the light signals are contained in the controlunit and in the tubular lamps. The tubular lamps areconnected to the control unit by cables.

The stroboscope is located in the rectifier wheel andexciter enclosure so that the fuses may be observed fromoutside the exciter enclosure while controlling thestroboscope.

To synchronize the sequence of flashes with thegenerator rotation, the system frequency is utilized toactivate the flashes. A double synchronous motor,controlled through two push-button and connected to twopotentiometers and IC's, causes the flash to be timedso that a slow-motion observation of the fuse becomespossible.

The Observation period for one full revolution of therectifier wheel (3600) is approximately 25 seconds. Atapproximately 4500, the flash is reset to its initial rate,and the observation can be repeated. The continuous

sequence of flashes can be interrupted at any time byactuating the Feed or Return push-button. Followingthis, a stationary image is obtained which ensuresaccurate checking of a single fuse. After approximatelytwo minutes, the stroboscope is automatically switchedoff. If this period should not be sufficient for fusechecking, switching on the stroboscope for another twominutes without delay can be repeated for any desirednumber of times by depressing the On push-button.

The stroboscope contains four plug-in printed circuitboards which can be readily replaced in order to remedyany faults.

The capacitor and high-voltage transformer requiredto produce the firing pulses for the flash tubes are locatedon a printed circuit board which is accommodated in thehandle of the flash lamp.

The operating elements are located on the front panelof the control unit for ease of operation. A depressedpush-button is indicated by an illuminated dot in the push-button head.

The line connector, the two connectors for the flashlamps and the fuse are located on the back of the controlunit.

All connectors have a mechanical lock and areprotected against dust and splash water. The cables arerun in flexible metal hoses for protection againstmechanical damage.

BHEL, Haridwar

Turbogenerators

DescriptionExciter Drying System

2.1-9150-0500/10609 E

1 General

A dryer (dehumidifier) and an anti-condensation heatingsystem are provided to avoid the formation of moisturecondensate inside the exciter with the turbine-generator atrest or on turning gear.

2 Mode of Operation

The dryer dehumidifies the air within the exciterenclosure. The dryer wheel is made of a nonflammablematerial. On its inlet side, the wheel is provided with asystem of tubular ducts, the surfaces of which areimpregnated with a highly hygroscopic material.

The tubular ducts are dimensioned so that a laminarflow with low pressure loss is obtained even at high airvelocity.

The moisture absorbed by the dryer wheel is removedin a regeneration section by a stream of hot air directedthrough the wheel in the opposite direction of the inlet airand then discharged to the atmosphere.

After regeneration, the dryer wheel material is againcapable of absorbing moisture.

The adsorption of moisture and regeneration of thedryer wheel material take place simultaneously, usingseparate air streams, which ensures a continuous dryingof the air.

2.1 Operating Principle of Adsorption DryerThe dehumidification takes place in a slowly rotating

dryer wheel (approximately 7 revolutions per hour). Thehoneycomb dryer wheel consists of a magnesium silicaalloy containing crystalline lithium chloride. The inlet sideof the dryer wheel is subdivided so that 1/4 is available forregeneration and 3/4 for the adsorption section.

2.1.1 Adsorption SectionThe air to be dehumidified passes through the

adsorption section of the dryer wheel, with part of themoisture contained in the air being removed by theadsorbent material, i.e. lithium chloride. The moisture is

1 2 3 4 5

5 4 6 7

Fig. 1 Schematic Diagram of Dryer

removed as a result of the partial pressure drop existingbetween the air and the adsorbent material.

2.1.2 Regeneration SectionIn the regeneration section of the dryer wheel, the

accumulated moisture is removed from the dryer wheel bythe heated regeneration air.

Continuous rotation of the dryer wheel ensurescontinuous dehumidification of the air within the exciter.

3 Anti-condensation Heating SystemAn Anti-condensation heating system to support the

dryer is installed in the exciter base frame. The heatersare rated and arranged so that the temperature in the exciterinterior.

1 Regeneration air outlet2 Dryer wheel3 Heater4 Ventilator5 Filter6 Shutoff valve7 Dry air outlet

BHEL, Haridwar

Turbogenerators

DescriptionGround Fault Detection Systemfor Exciter Field Circuit

2.1-9180-0500/10609 E

The field ground fault detection system detects high-resistance and low-resistance ground faults in the exciterfield circuit. It is very important for safe operation of agenerator, because a double fault causes magneticunbalances with very high currents flowing through thefaulted part, resulting in its destruction within a very shorttime. It is therefore an essential requirement that evensimple ground faults should activate an alarm andprotective measures be initiated, if possible, before thefault can fully develop. For this reason, the field ground

fault detection system consists of two stages andoperates continuously.

If the field ground fault detection system detects aground fault, an alarm is activated at RE < 80 kΩ (1ststage). If the insulation resistance between the exciterfield circuit and ground either suddenly or slowly dropsto RE < 5 kΩ the generator electrical protection is tripped(2nd stage).

The generator is thus automatically disconected fromthe system and de-excited.

BHEL, Haridwar

Turbogenerators

Description

2.1-9181-0500/10609 E

Arrangement of Bursh Holders for

Ground Fault Detection System

1

2

3

4

5

6

A B

7

1 Measuring sliprings2 Measuring brush3 Mounting plate4 Brush carrier segment5 Plug-in brush holder6 Measuring rod7 Measuring leads

Section A-B

BHEL, Haridwar

Turbogenerators

Description

2.1-9182-0500/10609E

Brush Holders for Ground Fault

Detection System

1

2

3

4

5

6

1 Handle2 Bayonet sleeve3 Brush contact pressure adjustment4 Compression spring5 Brush pigtail6 Measuring brush

BHEL, Haridwar

Turbogenerators

Operation

Operating and Setting Values

General

2.3-4000-0500/10609 E

Strict observance of the operating and settingvalues is a prerequisite for reliable operation of theTurbogenerators.

Separate tables are provided for the variousdesign groups of the generator and its auxiliaries.They show the transmitters activating the controls andalarms as well as the transmitters acting on thegenerator protection circuits.

The Remark co lumn conta ins addi t ionalinformation on controls, temperatures and pressures.

All operating and setting values refer to ratedoutput of generator and maximum cooling watertemperatures under steady-state conditions.

The operat ing and set t ing va lues in i t ia l lyspecified in this manual are based on experienceunder due consideration of the specific site conditions,such as static head in case of pressure measuringpoints or thermal character is t ics in case oftemperature measuring points. These calculatedvalues are intended as guiding values for making thepreliminary settings during initial commissioning of theunit.

These settings require certain corrections toaccount for the actual conditions. The final settingsobtained after startup and initial load operation are tobe entered in the Operating Value column.

BHEL, Haridwar

Turbogenerators

Operation Gas Quantities

2.3-4010-0500/10609 E

CO2

H2

Air

N2

Replacement of air inGenerator housing*:V1 = 2.V

Replacement of CO2 ingenerator housing*:V1 = 2.5 VFilling to operatingpressure : V2 = pe.V

Not required

Reduction of O2

content of Primarywater:50 m3 (s.t.p.)

Replacement of H2 inGenerator housing*: V1 = 2.V

Not required

Replacement of CO2

in generator housing* :V1 = 3.V

Reduction of H2

content of Primarywater to be drained:10 m3 (s.t.p.)

Not permitted

Compensation for H2losses : 0.5 m3/hr (s.t.p.)+ consumption**

Not permitted

Reduction of O2

content of Primarywater introduced bymakeup warer:6 m3 (s.t.p.)/addition

Startup :3. V1

During operation :2. V1

2.( V1 + V2)

Supply of 40-60 dm3 /s(s.t.p.) compressed airfrom air system mustbe ensured

100 m3 (s.t.p.)

Gas Startup Shutdown Operation Recommended Stock

* It is assumed that generator is at rest during gas filling and removal. Filling during turning gear operation will resultin a higher gas consumption. Due to the whirling motion between the medium to be displaced and medium admitted,the purity deteriorates so that more gas is required for scavenging.

** Consumption: H2 purity measurement : 20 dm3/hr (s.t.p.)Primary water leakage monitoring system : 120 dm3/hr (s.t.p.)Primary water purging gas system : 100 - 300 dm3/hr (s.t.p.)

s.t.p. = Standard temperature and pressure, 0oC and 1.013 bar

2.3-4010-0500/2

In the following, an example is given to illustratethe calculation of the amounts of CO2, H2 and air requiredfor filling. In the example one given generator volumeand one given operating pressure are assumed. Thevalues for other generator sizes, operating pressures andgas bottle sizes will vary accordingly.

1 Example

Pe = Operating pressure, e.g. 4 barV = Generator volume, e.g. 85 m3

V1 = Amount of gas to fill or purge generatorV2 = Amount of gas to fill generator to operating

pressureV3 = H2 bottle volume, e.g. 6 M3 (s.t.p.)V4 = CO2 bottle volume, e.g. 15 M3 (s.t.p.)Z = Number of bottles required

1.1 Filling

Amount of CO2 required for removing air fromgenerator (2 generator volumes)

V1 = 2 . 85 m3 = 170 m3 (s.t.p.)

V1 170 m3 (s.t.p.)Z = ---- = -------------------- ~ 12 CO2 bottles

V4 15 m3 (s.t.p.)

Amount of H2 required for removing CO2 fromgenerator (2.5 generator volumes)

V1 = 2.5 . V = 2.5 . 85 m3 (s.t.p.)

V1 213 m3 (s.t.p.)Z = ---- = -------------------- ~ 35 H2 bottles

V3 6 m3 (s.t.p.)

Amount of H2 required to fill generator to operatingpressure (operating pressure in bar x generator volume)

V2 = Pe . V = 4 . 85 m3 = 340 m3 (s.t.p.)

V2 340 m3 (s.t.p.)Z = ---- = -------------------- ~ 57 H2 bottles

V3 6 m3 (s.t.p.)

1.2 PurgingAmount of CO2 required for removing H2 (2

generator volumes)

V1 = 2 . V = 2 . 85 m3 = 170 m3 (s.t.p.)

V1 170 m3 (s.t.p.)Z = ---- = ----------------- ~ 12 CO2 bottles

V4 15 m3 (s.t.p.)

Amount of compressed air required for removingCO2 (3 generator volumes)

V1 = 3 . V = 3 . 85 m3 = 255 m3 (s.t.p.)

1.3 Bottle Volume

H2 bottle 40 Liters at 150 bar = 6 m3 (s.t.p.)H2 bottle 50 Liters at 200 bar = 10 m3 (s.t.p.)

CO2 bottle : 40 Liters = 15 m3 (s.t.p.)45 = 1766.7 = 25.2

It should be taken into consideration that the bottlecontents cannot be completely used up. For H2 bottles itis assumed that the contents can be expanded to apressure of approximately 1 bar above the operationpressure. This means approximately 3% of the bottlecontents at a final pressure of 4 bar will remain followinga fill to 3 bar.

* For reasons of safety, a sufficient number of full CO2 bottlesmust be available prior to starting with any generator fillingoperations.

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS ---------- -------- --------------- -------------- --------- ---------- PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 1 MKA 06 CL001 OIL LEVEL IN PRECHAMBER (TE) - LS - X >MAX <MAX LVL BELOW CASING C.LINE 0-149-00-01213 - COC COMMON ANN. WITH MKA07CL001 ATRS 2 MKA 06 CP501 SO DIFF.(TE) -50+50 dPG 10-20 - - - - 0-149-00-01213 mBAR - 3 MKA 07 CL001 OIL LEVEL IN PRECHAMBER (EE) - LS - X >MAX <MAX LVL BELOW CASING C.LINE 0-149-00-01213 - COC COMMON ANN. WITH MKA06CL001

ATRS 4 MKA 07 CP501 SO DIFF. (EE) -50+50 DPG 10-20 - - - 0-149-00-01213 mBAR - 5 MKA 11 CT001 TEMP. STATOR CORE (TE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 6 MKA 11 CT002 TEMP. STATOR CORE (TE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCUNi 7 MKA 11 CT003 TEMP. STATOR CORE (TE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 8 MKA 11 CT004 TEMP. STATOR CORE (TE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 9 MKA 11 CT005 TEMP. STATOR CORE (TE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 10 MKA 11 CT006 TEMP. STATOR CORE (TE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 11 MKA 11 CT007 TEMP. STATOR CORE (TE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 12 MKA 11 CT008 TEMP. STATOR CORE (TE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 13 MKA 11 CT009 TEMP. STATOR CORE (TE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 14 MKA 11 CT010 TEMP. STATOR CORE (TE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 15 MKA 11 CT011 TEMP. STATOR CORE (TE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORETEMP.(TE+EE)

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS ---------- -------- --------------- -------------- --------- ---------- PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 16 MKA 11 CT012 TEMP. STATOR CORE (TE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 17 MKA 12 CT001 TEMP. STATOR SLOT -01 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 18 MKA 12 CT002 TEMP. STATOR SLOT -01 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 19 MKA 12 CT003 TEMP. STATOR SLOT -04 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 20 MKA 12 CT004 TEMP. STATOR SLOT -04 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 21 MKA 12 CT005 TEMP. STATOR SLOT -09 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 22 MKA 12 CT006 TEMP. STATOR SLOT -09 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 23 MKA 12 CT007 TEMP. STATOR SLOT -12 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 24 MKA 12 CT008 TEMP. STATOR SLOT -12 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 25 MKA 12 CT009 TEMP. STATOR SLOT -17 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 26 MKA 12 CT010 TEMP. STATOR SLOT -17 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 27 MKA 12 CT011 TEMP. STATOR SLOT -20 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 28 MKA 12 CT012 TEMP. STATOR SLOT -20 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 29 MKA 12 CT013 TEMP. STATOR SLOT -25 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 30 MKA 12 CT014 TEMP. STATOR SLOT -25 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS ---------- -------- --------------- -------------- --------- ---------- PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 31 MKA 12 CT015 TEMP. STATOR SLOT -28 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 32 MKA 12 CT016 TEMP. STATOR SLOT -28 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 33 MKA 12 CT017 TEMP. STATOR SLOT -33 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 34 MKA 12 CT018 TEMP. STATOR SLOT -33 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 35 MKA 12 CT019 TEMP. STATOR SLOT -36 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 36 MKA 12 CT020 TEMP. STATOR SLOT -36 0-100 RTD <80 C - - -

0-139-00-01260 DEG.C Pt 100 37 MKA 12 CT021 TEMP. STATOR SLOT -41 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 38 MKA 12 CT022 TEMP. STATOR SLOT -41 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 39 MKA 12 CT023 TEMP. STATOR SLOT -44 0-100 RTD <80 C X >80 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C Pt 100 STATOR CORE TEMP.HIGH 40 MKA 12 CT024 TEMP. STATOR SLOT -44 0-100 RTD <80 C - - - 0-139-00-01260 DEG.C Pt 100 41 MKA 13 CT001 TEMP. STATOR CORE (EE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 42 MKA 13 CT002 TEMP. STATOR CORE (EE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 43 MKA 13 CT003 TEMP. STATOR CORE (EE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 44 MKA 13 CT004 TEMP. STATOR CORE (EE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 45 MKA 13 CT005 TEMP. STATOR CORE (EE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE)

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS ---------- -------- --------------- -------------- --------- ---------- PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 46 MKA 13 CT006 TEMP. STATOR CORE (EE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 47 MKA 13 CT007 TEMP. STATOR CORE (EE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 48 MKA 13 CT008 TEMP. STATOR CORE (EE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 49 MKA 13 CT009 TEMP. STATOR CORE (EE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 50 MKA 13 CT010 TEMP. STATOR CORE (EE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 51 MKA 13 CT011 TEMP. STATOR CORE (EE) 0-150 TC <90 C X >90 C - COMMON ANNUNCIATION FOR 0-139-00-01260 DEG.C CuCuNi STATOR CORE TEMP.(TE+EE) 52 MKA 13 CT012 TEMP. STATOR CORE (EE) 0-150 TC <90 C - - - 0-139-00-01260 DEG.C CuCuNi 53 MKA 21 CL001 LIQUID IN GEN. (TE) - LS <MAX X >MAX <MAX COMMON ANNUN. & ATRS 0-139-00-01260 MM COC 54 MKA 22 CL001 LIQUID IN GEN.(CENTRE) - LS - X >MAX <MAX COMMON ANNUN. & ATRS 0-139-00-01260 MM COC 55 MKA 23 CL001 LIQUID AT LEADS BOTTOM - LS - X >MAX <MAX COMMON ANNUN. & ATRS 0-139-00-01260 MM COC 56 MKA 23 CL011 LIQUID AT LEADS BOTTOM - LS - X >MAX <MAX COMMON ANNUN. & ATRS 0-139-00-01260 MM COC 57 MKA 23 CP501 GAS IMPULS TO DPR(H2 PRESS.) 0-10 PG - - - - - 0-149-00-01213 KG/CM2 - 58 MKA 24 CL001 LIQUID AT LEADS TOP - LS - X >MAX >MAX 2V3 (1) PROTN., COMMON ANN. 0-139-00-01260 MM COC LVL ABOVE BOTTOM OF CASING 59 MKA 24 CL011 LIQUID AT LEADS TOP - LS - X >MAX >MAX 2V3 (1) PROTN., COMMON ANN. 0-139-00-01260 MM COC LVL ABOVE BOTTOM OF CASING 60 MKA 24 CL021 LIQUID AT LEADS TOP - LS - X >MAX >MAX 2V3 (1) PROTN., COMMON ANN. 0-139-00-01260 MM COC LVL ABOVE BOTTOM OF CASING

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS ---------- -------- --------------- -------------- --------- ---------- PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 61 MKA 61 CT001A TEMP. PW O/L MANIFOLD 0-100 RTD <75 C X >80 C - C. ANN. WITH MKA61CT002A, 0-139-00-01260 DEG.C Pt 100 MKA61CT003A & MKF82CT001A 62 MKA 61 CT001B TEMP. PW O/L MANIFOLD 0-100 RTD <75 C - - - SPARE 0-139-00-01260 DEG.C Pt 100 63 MKA 61 CT002A TEMP. PW O/L MANIFOLD 0-100 RTD <75 C X >80 C - C.ANN. WITH MKA61CT001A, 0-139-00-01260 DEG.C Pt 100 MKA61CT003A & MKF82CT001A 64 MKA 61 CT002B TEMP. PW O/L MANIFOLD 0-100 RTD <75 C - - - SPARE 0-139-00-01260 DEG.C Pt 100

65 MKA 61 CT003A TEMP. PW O/L MANIFOLD 0-100 RTD <75 C X >80 C - C. ANN. WITH MKA61CT001A, 0-139-00-01260 DEG.C Pt 100 MKA61CT002A & MKF82CT001A 66 MKA 61 CT003B TEMP. PW O/L MANIFOLD 0-100 RTD <75 C - - - SPARE 0-139-00-01260 DEG.C Pt 100 67 MKA 71 CT002A TEMP. HOT GAS CLRS A & B 0-100 RTD 65-72 X >80 C - C. ANN WITH MKA71CT002A,3A,4A & 0-139-00-01260 DEG.C Pt 100 MKA72CT002A,3A,4A & C. IND OF CLR A&B AND FOR FAST F/B TO C.V. 68 MKA 71 CT002B TEMP. HO T GAS CLRS A & B 0-100 RTD 65-72 - - - SPARE 0-139-00-01260 DEG.C Pt 100 69 MKA 71 CT003A TEMP. HOT GAS CLRS A & B 0-100 RTD 65-72 X >80 C - C. ANN WITH MKA71CT002A,3A,4A & 0-139-00-01260 DEG.C Pt 100 MKA72CT002A,3A,4A & C. IND OF CLR A&B 70 MKA 71 CT003B TEMP. HOT GAS CLRS A & B 0-100 RTD 65-72 - - - SPARE 0-139-00-01260 DEG.C Pt 100 71 MKA 71 CT004A TEMP. HOT GAS CLRS A & B 0-100 RTD 65-72 X >80 C - C. ANN WITH MKA71CT002A,3A,4A & 0-139-00-01260 DEG.C Pt 100 MKA72CT002A,3A,4A & C. IND OF CLR A&B 72 MKA 71 CT004B TEMP. HOT GAS CLRS A & B 0-100 RTD 65-72 - - - SPARE 0-139-00-01260 DEG.C Pt 100 73 MKA 72 CT002A TEMP. HOT GAS CLRS C & D 0-100 RTD 65-72 X >80 C - C. ANN WITH MKA71CT002A,3A,4A & 0-139-00-01260 DEG.C Pt 100 MKA72CT002A,3A,4A & C. IND OF CLR C&D AND FOR FAST F/B TO C.V. 74 MKA 72 CT002B TEMP. HOT GAS CLRS C & D 0-100 RTD 65-72 - - - SPARE 0-139-00-01260 DEG.C Pt 100 75 MKA 72 CT003A TEMP. HOT GAS CLRS C & D 0-100 RTD 65-72 X >80 C - C. ANN WITH MKA71CT002A,3A,4A & 0-139-00-01260 DEG.C Pt 100 MKA72CT002A,3A,4A & C. IND CLR C&D

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 76 MKA 72 CT003B TEMP. HOT GAS CLRS C & D 0-100 RTD 65-72 - - - SPARE 0-139-00-01260 DEG.C Pt 100 77 MKA 72 CT004A TEMP. HOT GAS CLRS C & D 0-100 RTD 65-72 X >80 C - C. ANN WITH MKA71CT002A,3A,4A & 0-139-00-01260 DEG.C Pt 100 MKA72CT002A,3A,4A & C. IND CLR C&D 78 MKA 72 CT004B TEMP. HOT GAS CLRS C & D 0-100 RTD 65-72 - - - SPARE 0-139-00-01260 DEG.C Pt 100 79 MKA 75 CT002A TEMP. COLD CLRS A & B 0-100 RTD 51-44 X >55 C >60 C 2V3 (2) & MEAN VALUE INDICATION 0-139-00-01260 DEG.C Pt 100 >60 C <45 C WITH MKA75CT003A & 4A AND ATRS 80 MKA 75 CT002B TEMP. COLD CLRS A & B 0-100 RTD 51-44 - SPARE 0-139-00-01260 DEG.C Pt 100 81 MKA 75 CT003A TEMP. COLD CLRS A & B 0-100 RTD 51-44 X >55 C >60 C 2V3 (2) & MEAN VALUE INDICATION 0-139-00-01260 DEG.C Pt 100 >60 C WITH MKA75CT002A & 4A 82 MKA 75 CT003B TEMP. COLD CLRS A & B 0-100 RTD 51-44 - SPARE 0-139-00-01260 DEG.C Pt 100 83 MKA 75 CT004A TEMP. COLD CLRS A & B 0-100 RTD 51-44 X >55 C >60 C 2V3 (2) & MEAN VALUE INDICATION 0-139-00-01260 DEG.C Pt 100 >60 C WITH MKA75CT002A & 3A 84 MKA 75 CT004B TEMP. COLD CLRS A & B 0-100 RTD 51-44 - - - SPARE 0-139-00-01260 DEG.C Pt 100 - 85 MKA 75 CT005A TEMP. COLD (LEFT) 0-100 RTD 51-44 X >55 C >55C DIFF TEMP PW/H2 "LOW & V. LOW 0-139-00-01260 DEG.C Pt 100 WITH MKF80CT003A 86 MKA 75 CT005B TEMP. COLD (LEFT) 0-100 RTD 51-44 - - - SPARE 0-139-00-01260 DEG.C Pt 100 87 MKA 78 CT002A TEMP. COLD CLRS C & D 0-100 RTD <50 C X >55 C >60 C 2V3 (3) & MEAN VALUE INDICATION 0-139-00-01260 DEG.C Pt 100 >60 C <45 C WITH MKA78CT003A & 4A AND ATRS 88 MKA 78 CT002B TEMP. COLD CLRS C & D 0-100 RTD <50 C X - - SPARE 0-139-00-01260 DEG.C Pt 100 - 89 MKA 78 CT003A TEMP. COLD CLRS C & D 0-100 RTD <50 C X >55 C >60 C 2V3 3) & MEAN VALUE 0-139-00-01260 DEG.C Pt 100 >60 C WITH MKA78CT002A & 4A 90 MKA 78 CT003B TEMP. COLD CLRS C & D 0-100 RTD <50 C - - - SPARE 0-139-00-01260 DEG.C PT 100 -

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 91 MKA 78 CT004A TEMP. COLD CLRS C & D 0-100 RTD <50 C X >55 C >60 C 2V3 3) & MEAN VALUE 0-139-00-01260 DEG.C Pt 100 >60 C WITH MKA78CT002A & 3A 92 MKA 78 CT004B TEMP. COLD CLRS C & D 0-100 RTD <50 C - - - SPARE 0-139-00-01260 DEG.C PT 100 - 93 MKA 78 CT005A TEMP. COLD (RIGHT) 0-100 RTD <45 C X >55 C >55 C DIFF TEMP PW/H2 "LOW & V. LOW 0-139-00-01260 DEG.C Pt 100 WITH MKF80CT004A 94 MKA 78 CT005B TEMP. COLD (RIGHT) 0-100 RTD <45 C - - - SPARE 0-139-00-01260 DEG.C Pt 100 - 95 MKC 21 CE001 QUAD. AXIS MEAS. COIL-1 0-8000 COL - X >110 C - ROTOR TEMP PROCESSING WITH 2-145-00-01026 A VOLT NON LINAR CURVE(SEE NOTE 7) FIELD CURRENT MEAS. BY EDN 96 MKC 21 CE002 QUAD. AXIS MEAS. COIL-2 0-8000 COL - - - - SPARE 2-145-00-01026 A VOLT 97 MKC 41 CU001 STROBO. FOR FUSE CHECKING - - - - - - VISUAL CHECKING OF FUSES 2-145-00-01026 - - 98 MKC 80 CT012A TEMP. COLD AIR MAIN EXCITER 0-100 RTD 45C X >45C <45C,>50 SWITCHING ON/OFF EXCITER 2-145-00-01026 DEG.C Pt 100 <43 SHUNT DOWN HTR. / AIR DRIER ATRS 99 MKC 80 CT012B TEMP. COLD AIR MAIN EXCITER 0-100 RTD 45C - - - SPARE 2-145-00-01026 DEG.C Pt 100 100 MKC 80 CT014A TEMP. COLD AIR MAIN EXCITER 0-100 RTD 45C X >45C >90 SWITCHING ON/OFF EXCITER 2-145-00-01026 DEG.C Pt 100 SHUNT DOWN HEATER/AIRDRIER, PROT.ALSO 101 MKC 80 CT014B TEMP. COLD AIR MAIN EXCITER 0-100 RTD 45C - - - SPARE 2-145-00-01026 DEG.C Pt 100 102 MKC 82 CT001A TEMP. HOT AIR MAIN EXCITER 0-140 RTD 75C X >75 C, >80 C 2V3 (4) & MEAN VALUE INDICATION 2-145-00-01026 DEG.C Pt 100 >80 C WITH MKC82CT002A & 3A 103 MKC 82 CT001B TEMP. HOT AIR MAIN EXCITER 0-140 RTD 75C - - - SPARE 2-145-00-01026 DEG.C Pt 100 104 MKC 82 CT002A TEMP. HOT AIR MAIN EXCITER 0-100 RTD 75C X >75 C, >80 C 2V3 (4) & MEAN VALUE INDICATION 2-145-00-01026 DEG.C Pt 100 >80 C WITH MKC82CT001A & 3A 105 MKC 82 CT002B TEMP. HOT AIR MAIN EXCITER 0-100 RTD 75C - - - SPARE 2-145-00-01026 DEG.C Pt 100

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SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 106 MKC 82 CT003A TEMP. HOT AIR MAIN EXCITER 0-140 RTD 75C X >75 C, >80 C 2V3 (4) & MEAN VALUE INDICATION 2-145-00-01026 DEG.C Pt 100 >80 C WITH MKC82CT001A & 2A 107 MKC 82 CT003B TEMP. HOT AIR MAIN EXCITER 0-140 RTD 75C - - - SPARE 2-145-00-01026 DEG.C Pt 100 108 MKC 84 CT002A TEMP.HOT AIR RECT.WHEEL 0-100 RTD 75C X >75 C - 2-145-00-01026 DEG.C Pt 100 109 MKC 84 CT002B TEMP.HOT AIR RECT.WHEEL 0-100 RTD 75C - - - SPARE 2-145-00-01026 DEG.C Pt 100 110 MKD 11 CT014A TEMP.METAL (TE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD11CT014B/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 111 MKD 11 CT014B TEMP. METAL (TE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD11CT014A/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 112 MKD 11 CT014C TEMP. METAL (TE) 0-150 TC <75 C - >MAX* >130 C 2V3 WITH MKD11CT014A/B 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 113 MKD 11 CT018A TEMP. METAL (TE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD11CT018B/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 114 MKD 11 CT018B TEMP. METAL (TE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD11CT018A/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 115 MKD 11 CT018C TEMP. METAL (TE) 0-150 TC <75 C - >MAX* >130 C 2V3 WITH MKD11CT014A/B 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 116 MKD 12 CT014A TEMP. METAL (EE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD12CT014B/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 117 MKD 12 CT014B TEMP.METAL (EE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD12CT014A/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 118 MKD 12 CT014C TEMP METAL (EE) 0-150 TC <75 C - >MAX* >130 C 2V3 WITH MKD12CT014A/B 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 119 MKD 12 CT018A TEMP. METAL (EE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD12CT018B/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 120 MKD 12 CT018B TEMP. METAL (EE) 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD12CT018A/C 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10

2.3-4030-10555/11 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 121 MKD 12 CT018C TEMP. METAL (EE) 0-150 TC <75 C - >MAX* >130 C 2V3 WITH MKD12CT018A/B 0-139-00-01260 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 122 MKD 15 CT014A TEMP. EXCITER BEARING 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD15CT014B/C 2-145-00-01026 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 123 MKD 15 CT014B TEMP. EXCITER BEARING 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD15CT014A/C 2-145-00-01026 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 124 MKD 15 CT014C TEMP. EXCITER BEARING 0-150 TC <75 C - >MAX* >130 C 2V3 WITH MKD15CT014A/B 2-145-00-01026 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 125 MKD 15 CT018A TEMP. EXCITER BEARING 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD15CT018B/C 2-145-00-01026 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 126 MKD 15 CT018B TEMP. EXCITER BEARING 0-150 TC <75 C X >MAX* >130 C 2V3 WITH MKD15CT018A/C 2-145-00-01026 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 127 MKD 15 CT018C TEMP. EXCITER BEARING 0-150 TC <75 C - >MAX* >130 C 2V3 WITH MKD15CT014A/B 2-145-00-01026 DEG.C NiCrNi >130C TRIPPING MYA01EZ.10 128 MKF 01 CL001 LEVEL PW - 0-470 LT 195-255 X >255, >155 LVL ABOVE BOTTOM PERMISSIVE 0-153-00-01069 MM 4-20mA <195,<100 FOR SWITCHING ON OF SLC & ATRS 129 MKF 01 CL501 LEVEL PW - 0-470 LG 195-255 - - - - 0-153-00-01069 MM - 130 MKF 12 CP001 PRESS. AFTER PUMP 1 0.5-16 PS 8-9 X <5 >5, COMMON ANN. WITH 0-153-00-01069 Kg/CM2 COC <5 MKF22CP001 & ATRS 131 MKF 12 CP501 PRESS. AFTER PUMP 1 0.5-16 PG 8-9 - - - - 0-153-00-01069 Kg/CM2 - 132 MKF 22 CP001 PRESS. AFTER PUMP 2 0.5-16 PS 8-9 X <5 >5, COMMON ANN. WITH 0-153-00-01069 Kg/CM2 COC <5 MKF12CP001 & ATRS 133 MKF 22 CP501 PRESS. AFTER PUMP 2 0.5-16 PG 8-9 - - - - 0-153-00-01069 Kg/CM2 - 134 MKF 36 CL001 NaOH TANK - - LS - - - < MIN STOP OF DOSING PUMP ON LOW 0-153-00-01069 - COC LEVEL ( INBUILT IN PUMP CKT.) 135 MKF 52 CP001 DIFF PRESS MAIN FILTER 1 0-1.6 DPT <0.9 X >0.9 - COMMON ANN. WITH 0-153-00-01069 Kg/CM2 4-20mA MKF52CP002

2.3-4030-10555/12 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 136 MKF 52 CP002 DIFF PRESS. MAIN FILTER 2 0-1.6 DPT <0.9 X >0.9 - COMMON ANN. WITH 0-153-00-01069 Kg/CM2 4-20mA MKF52CP001 137 MKF 52 CT001A TEMP. AFTER PUMP 1&2 0-100 RTD 61-77C X >80 C - - 0-153-00-01069 DEG.C Pt 100 138 MKF 52 CT001B TEMP. AFTER PUMP 1&2 0-100 RTD 61-77C - - - SPARE 0-153-00-01069 DEG.C Pt 100 139 MKF 52 CT501 TEMP. AFTER PUMP 1&2 0-100 TG 61-77C - - - - 0-153-00-01069 DEG.C - 140 MKF 52 CT506 TEMP. AFTER PW CLR 0-100 TG 61-77C - - - - 0-153-00-01069 DEG.C - 141 MKF 60 CF002 FLOW OF WATER 6-60 FM 30-36 X < MIN <MIN, CONTROL OF DOSING PUMP 0-153-00-01069 LPM - >MIN FLOW METER USED WITH CNTCT 142 MKF 60 CF501 FLOW OF TOP UP WATER 0-7 FG - - - - - 0-153-00-01069 M3/HR - 143 MKF 60 CP001 DIFF PRESS MESH FILTER 0-1.6 DPT <0.9 X >0.9 - - 0-153-00-01069 Kg/CM2 4-20mA 144 MKF 60 CQ001 COND. AFTER ION EXCHANGER 0-5 CC 1.8 X <1.0 <1.0, SWITCHING 'ON' & 'OFF' OF 0-153-00-01069 uS/CM 4-20mA >3.0 >3.0 DOSING PUMP. 145 MKF 80 CQ001 COND. AFTER MAIN FILTER 0-5 CC 3-4.8 X >3.0 >2.5 SWITCHING 'OFF' OF 0-153-00-01069 uS/CM 4-20mA >4.0 >4.0 DOSING PMP. ON COND>4.0us/cm FLUSHING OF DM WATER RECOM. 146 MKF 80 CT002A TEMP. OF PW AT INLET 0-100 RTD 61-49C X >55,>60C >60C 2V3 (8) & MEAN VAL. IND. 0-153-00-01069 DEG.C Pt 100 <50C, WITH MKF80CT003A&4A. PW TMP

CONT VLV & ATRS. 147 MKF 80 CT002B TEMP. OF PW AT INLET 0-100 RTD 61-49C - - SPARE 0-153-00-01069 DEG.C Pt 100 148 MKF 80 CT003A TEMP. OF PW AT INLET 0-100 RTD 61-49C X >55,>60C >60C 2V3 (8) & M.V. IND WITH MKF80CT 0-153-00-01069 DEG.C Pt 100 <3K,<1K >3 K 002A& 4A. PW TMP CONT VLV & PW/H2 DT ANN WITH MKA75CT005A 149 MKF 80 CT003B TEMP. OF PW AT INLET 0-100 RTD 61-49C - - SPARE 0-153-00-01069 DEG.C Pt 100 150 MKF 80 CT004A TEMP. OF PW AT INLET 0-100 RTD dt -5C X >55,>60C >60C 2V3 (8) & M.V. IND WITH MKF80CT 0-153-00-01069 DEG.C Pt 100 <3K,<1K >3 K 002A& 3A. PW TMP CONT VLV & PW/H2 DT ANN WITH MKA78CT005A

2.3-4030-10555/13 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 151 MKF 80 CT004B TEMP. OF PW AT INLET 0-100 RTD dt -5C - - SPARE 0-153-00-01069 DEG.C Pt 100 152 MKF 80 CT501 TEMP. OF PW AFTER CLR 0-100 TG 61-49C - - - - 0-153-00-01069 DEG.C - 153 MKF 82 CF001 FLOW STATORWINDING O/L 0-250 DP - - 0-153-00-01069 mBar - ORIFICE FOR FLOW 0-72M3/HR 154 MKF 82 CF001A FLOW STATOR WINDING O/L 0-72 DPT 60 X <54,<48 <48, 2V3 (9) DELAY OF 1MIN &

0-153-00-01069 M.VAL IND m3/hr 4-20mA >54 WITH MKF82CF001B & 01C. ATRS ORIFICE PLT. OF 0-250 mbar. 155 MKF 82 CF001B FLOW STATOR WINDING O/L 0-72 DPT 60 X <54,<48 <48 2V3 (9) DELAY OF 1MIN & M.VAL IND 0-153-00-01069 m3/hr 4-20mA WITH MKF82CF001A & 01C. ORIFICE PLT. OF 0-250 mbar. 156 MKF 82 CF001C FLOW STATORWINDING O/L 0-72 DPT 60 X <54,<48 <48 2V3 (9) DELAY OF 1MIN & M.VAL IND 0-153-00-01069 m3/hr 4-20mA WITH MKF82CF001A & 01B. ORIFICE PLT. OF 0-250 mbar. 157 MKF 82 CP003 PRESS. WINDING I/L 0-10 PT 2.6 X <3.0 - - 0-153-00-01069 Kg/Cm2 4-20mA >3.8 158 MKF 82 CP005 DIFF PRESS STATOR WINDING 0-2.5 DPT 1.1 X >MAX - - 0-153-00-01069 Kg/Cm2 4-20mA 159 MKF 82 CP501 PRESS.WINDING I/L 0-10 PG 2.6 - - - - 0-153-00-01069 Kg/Cm2 - 160 MKF 82 CQ001 PW AT GEN O/L 0-5 CC 3-4.8 X >3.0 - - 0-153-00-01069 uS/CM 4-20mA 161 MKF 82 CT001A TEMP. STATOR INDING O/L 0-100 RTD 61-77C X >80 C - C.ANN.WITH MKA61CT001A, 0-153-00-01069 DEG.C Pt 100 2A,3A. FOR FAST FEED BACK PW TEMP CV 162 MKF 82 CT001B TEMP. STATOR WINDING O/L 0-100 RTD 61-77C - - - SPARE 0-153-00-01069 DEG.C Pt 100 163 MKF 82 CT002 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND

164 MKF 82 CT003 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 165 MKF 82 CT004 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND

2.3-4030-10555/14 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 166 MKF 82 CT005 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 167 MKF 82 CT006 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 168 MKF 82 CT007 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 169 MKF 82 CT008 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 170 MKF 82 CT009 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 171 MKF 82 CT010 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 172 MKF 82 CT011 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 173 MKF 82 CT012 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 174 MKF 82 CT013 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 175 MKF 82 CT014 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 176 MKF 82 CT015 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 177 MKF 82 CT016 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 178 MKF 82 CT017 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 179 MKF 82 CT018 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 180 MKF 82 CT019 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND

2.3-4030-10555/15 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 181 MKF 82 CT020 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 182 MKF 82 CT021 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 183 MKF 82 CT022 TEMP. UPPER W O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 184 MKF 82 CT023 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 185 MKF 82 CT024 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 186 MKF 82 CT025 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 187 MKF 82 CT026 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 188 MKF 82 CT027 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 189 MKF 82 CT028 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 190 MKF 82 CT029 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 191 MKF 82 CT030 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 192 MKF 82 CT031 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 193 MKF 82 CT032 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 194 MKF 82 CT033 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 195 MKF 82 CT034 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND

2.3-4030-10555/16 0609E


2.3-4030-10555/17 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 211 MKF 82 CT050 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 212 MKF 82 CT051 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 213 MKF 82 CT052 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 214 MKF 82 CT053 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 215 MKF 82 CT054 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 216 MKF 82 CT055 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 217 MKF 82 CT056 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 218 MKF 82 CT057 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 219 MKF 82 CT058 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 220 MKF 82 CT059 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 221 MKF 82 CT060 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 222 MKF 82 CT061 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 223 MKF 82 CT062 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 224 MKF 82 CT063 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 225 MKF 82 CT064 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND

2.3-4030-10555/18 0609E


2.3-4030-10555/19 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 241 MKF 82 CT080 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 242 MKF 82 CT081 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 243 MKF 82 CT082 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 244 MKF 82 CT083 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 245 MKF 82 CT084 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 246 MKF 82 CT085 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 247 MKF 82 CT086 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 248 MKF 82 CT087 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 249 MKF 82 CT088 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 250 MKF 82 CT089 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 251 MKF 82 CT090 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 252 MKF 82 CT091 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 253 MKF 82 CT092 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 254 MKF 82 CT093 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 255 MKF 82 CT094 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND

2.3-4030-10555/20 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 256 MKF 82 CT095 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 257 MKF 82 CT096 TEMP. UPPER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 258 MKF 82 CT097 TEMP. LOWER PW O/L 0-100 RTD 61-77C - * - ON LINE W. TEMP MTG 0-139-00-01260 DEG.C Pt 100 IN BAR (NOTE 10),*... AS PER SITE COND 259 MKF 82 CT501 TEMP. STATOR WINDING O/L 0-100 TG 61-77C - - - - 0-153-00-01069 DEG.C - 260 MKF 83 CF001 FLOW MAIN BUSHING 'R' 0-250 DP - ORIFICE FOR FLOW 0-153-00-01069 mBar - 0-1.8M3/HR 261 MKF 83 CF001A FLOW MAIN BUSHING 'R' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33, 2V3 (10) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA >1.4 WITH MKF83CF001B & 01C. ATRS ORIFICE PLT. OF 0-250 mbar. 262 MKF 83 CF001B FLOW MAIN BUSHING 'R' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33 2V3 (10) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA WITH MKF83CF001A & 01C. ORIFICE PLT. OF 0-250 mbar. 263 MKF 83 CF001C FLOW MAIN BUSHING 'R' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33 2V3 (10) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA WITH MKF83CF001A & 01B. ORIFICE PLT. OF 0-250 mbar. 264 MKF 83 CF011 FLOW MAIN BUSHING 'S' 0-250 DP - ORIFICE FOR FLOW 0-153-00-01069 mBar - 0-1.8M3/HR 265 MKF 83 CF011A FLOW MAINBUSHING 'S' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33, 2V3 (11) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA >1.4 WITH MKF83CF011B & 11C. ATRS ORIFICE PLT. OF 0-250 mbar. 266 MKF 83 CF011B FLOW MAIN BUSHING 'S' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33 2V3 (11) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA WITH MKF83CF011A & 11C. ORIFICE PLT. OF 0-250 mbar. 267 MKF 83 CF011C FLOW MAIN BUSHING 'S' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33 2V3 (11) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA WITH MKF83CF011A & 11B. ORIFICE PLT. OF 0-250 mbar. 268 MKF 83 CF021 FLOW MAIN BUSHING 'T' 0-250 DP - ORIFICE FOR FLOW 0-153-00-01069 mBar - 0-1.8M3/HR 269 MKF 83 CF021A FLOW MAIN BUSHING 'T' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33, 2V3 (12) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA >1.4 WITH MKF83CF021B& 21C. ATRS ORIFICE PLT. OF 0-250 mbar. 270 MKF 83 CF021B FLOW MAIN BUSHING 'T' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33 2V3 (12) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA WITH MKF83CF021A& 21C. ORIFICE PLT. OF 0-250 mbar.

2.3-4030-10555/21 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 271 MKF 83 CF021C FLOW MAIN BUSHING 'T' 0-1.8 DPT 1.5 X <1.4,<1.33 <1.33 2V3 (12) DELAY OF 5SEC & M.VAL 0-153-00-01069 m3/hr 4-20mA WITH MKF83CF021A& 21B. ORIFICE PLT. OF 0-250 mbar. 272 MKF 83 CT001A TEMP. AFTER MAIN BUSHING 0-100 RTD 60 C X >70 C - - 0-153-00-01069 DEG.C Pt 100 273 MKF 83 CT001B TEMP. AFTER MAIN BUSHING 0-100 RTD 60 C - - - SPARE 0-153-00-01069 DEG.C Pt 100 274 MKF 83 CT501 TEMP. AFTER MAIN BUSHING 0-100 TG 60 C - - - - 0-153-00-01069 DEG.C - 275 MKF 91 CP001 GAS PRESS. PW TANK 0-1 PS 0-0.2 X >0.3 - LEAKAGE OF H2 IN PW CKT. 2-149-00-01085 Kg/Cm2 COC 276 MKF 91 CP501 GAS PRESS. PW TANK 0-1 PG 0-0.2 - - - - 2-149-00-01085 Kg/Cm2 - 277 MKG 11 CP001 PRESS. H2 CYLINDER 0-250 PT 15-150 X <15 - 0-149-00-01214 Kg/Cm2 4-20mA 278 MKG 11 CP501 PRESS. H2 CYLINDER 0-250 PG - - - - - 0-149-00-01214 Kg/Cm2 -

279 MKG 25 CP001 PR. H2-STATOR (FOR SO/H2 DP) 0-10 PT 3.5 - - DP>1.2 DP FOR ATRS WITH MKW71CP011 0-149-00-01214 Kg/Cm2 4-20mA 280 MKG 25 CP002 PR. H2-STATOR (FOR SO/H2 DP) 0-10 PT 3.5 X >3.7, DP>1.2 DP FOR ATRS WITH MKW71CP021 0-149-00-01214 Kg/Cm2 4-20mA <3.3 281 MKG 25 CP003 PRESS. H2-FRAME 0-6 PT 3.5 - - >3.0 ATRS 0-149-00-01214 Kg/Cm2 4-20mA 282 MKG 25 CP503 PRESS. H2-FRAME 0-6 PG - - - - - 0-149-00-01214 Kg/Cm2 - 283 MKG 25 CQ001 PURITY H2 CASING 100-90% GA >97% X <95%, >95% 3 RANGE GAS ANALYSER, ATRS 0-149-00-01214 % - <90% & M/C OPERATION NOT RECOMM. BELOW 90%H2 PURITY IN AIR. 284 MKG 25 CQ002 PURITY H2 CASING 100-90% GA >97% X <95%, >95% 3 RANGE GAS ANALYSER, ATRS 0-149-00-01214 % - <90% & M/C OPERATION NOT RECOMM. BELOW 90%H2 PURITY IN AIR. 285 MKG 31 CP502 PRESS. N2 FLASH 0-250 PG 150 - - - - 0-149-00-01214 Kg/Cm2 -

2.3-4030-10555/22 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 286 MKG 51 CP501 PRESS. CO2 CYLINDER 0-160 PG 100 - - - - 0-149-00-01214 Kg/Cm2 - 287 MKG 51 CT001A TEMP.CO2 FLASH EVAP. 0-250 RTD 120-150 X >150 C <145, FOR SWITCHING 0-149-00-01214 DEG.C Pt 100 >150 ON/OFF CO2 FLASH EVAP. 288 MKG 51 CT001B TEMP.CO2 FLASH EVAP. 0-250 RTD 120-150 - - - SPARE 0-149-00-01214 DEG.C Pt 100 - 289 MKG 51 CT501 TEMP.CO2 FLASH EVAP. 0-250 TG - - - - - 0-149-00-01214 DEG.C - 290 MKG 69 CL001 LEVEL IN OIL TRAP DRIER I/L - LS X >MAX 0-149-00-01214 - COC 291 MKG 69 CM001 DEW POINT AT DRIER I/L OR O/L -60+20C MS - X >MAX - 4-20mA OUT PUT TO GAMP 0-149-00-01214 - - FROM DEW POINT EQPT. 292 MKW 01 CL001 OIL LEVEL IN SOS TANK - LS - X < MIN >MIN SO PUMPS INTERLOCK 0-149-00-01213 - COC COMM ANN. WITH MKW01CL002 293 MKW 01 CL002 OIL LEVEL IN SOS TANK - LS - X < MIN - COMM ANN. WITH MKW01CL001 0-149-00-01213 - COC 294 MKW 01 CP501 PRESS. OIL INLET HEADER 0-2.5 PG - - - - 0-149-00-01213 KG/CM2 - 295 MKW 03 CL001 OIL LEVEL IN SO TANK - LS - X <MIN <MIN SWITCHING OFF 0-149-00-01213 - COC H2 -SIDE S.O. PUMP 296 MKW 03 CL002 OIL LEVEL IN SO TANK - LS - X <MIN - - 0-149-00-01213 - COC 297 MKW 03 CL501 OIL LEVEL IN SO TANK 0-470 LG - - - - - 0-149-00-01213 MM - 298 MKW 03 CT001A TEMP H2 SIDE SO DRAIN (TE) 0-100 RTD <70C X >70 C - COMM ANN. WITH MKW03CT002A 0-149-00-01213 DEG.C Pt 100 299 MKW 03 CT001B TEMP H2 SIDE SO DRAIN (TE) 0-100 RTD <70C - - - SPARE 0-149-00-01213 DEG.C Pt 100 300 MKW 03 CT002A TEMP H2 SIDE SO DRAIN (EE) 0-100 RTD <70C X >70 C - COMM ANN. WITH MKW03CT001A 0-149-00-01213 DEG.C Pt 100

2.3-4030-10555/23 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 301 MKW 03 CT002B TEMP H2 SIDE SO DRAIN (EE) 0-100 RTD <70C - - - SPARE 0-149-00-01213 DEG.C Pt 100 302 MKW 11 CP001 SO PR. AFT SO PUMP 1 (AIR-S) 0.5-16 PS 9 X <5.0 >5.0, COMMON ANN. WITH 0-149-00-01213 Kg/Cm2 COC <5.0 MKW21CP001 303 MKW 11 CP501 SO PR. AFT SO PUMP 1 (AIR-S) 0-16 PG 9 - - - - 0-149-00-01213 Kg/Cm2 - 304 MKW 13 CP001 PR. AFT SO PUMP 4 H2-S 0.5-16 PS 10 X <7.0 >7.0 ATRS 0-149-00-01213 Kg/Cm2 COC 305 MKW 13 CP501 PR. AFT SO PUMP 4 H2-S 0-16 PG 10 - - - - 0-149-00-01213 Kg/Cm2 -

306 MKW 21 CP001 PR. AFT SO PUMP 2 A-S 0.5-16 PS 9 X <5.0 >5.0, COMMON ANN. WITH 0-149-00-01213 Kg/CM2 COC <5.0 MKW11CP001 307 MKW 21 CP501 PR. AFT SO PUMP 2 A-S 0-16 PG 9 - - - - 0-149-00-01213 Kg/Cm2 - 308 MKW 31 CP001 PR. AFT SO PUMP 3 A-S 0.5-16 PS 9 X <8.5 - - 0-149-00-01213 Kg/Cm2 COC 309 MKW 31 CP501 PR. AFT SO PUMP 3 A-S 0-16 PG 9 - - - - 0-149-00-01213 Kg/Cm2 - 310 MKW 31 CP502 OIL PRESSURE EMERGENCY OIL I/L PG 9 - - - - 0-149-00-01213 Kg/Cm2 - 311 MKW 51 CP001 DIFF.PR. S.OIL FILTER A-S 0-1.6 DPT <0.9 X >0.9 - - 0-149-00-01213 Kg/Cm2 4-20mA 312 MKW 51 CP502 SO PR. BFR SO CLR (A-S) 0-16 PG 9 - - - - 0-149-00-01213 Kg/Cm2 - 313 MKW 51 CT001A S.OIL TEMP SO CLR (A-S) 0-100 RTD <70C X >70 C - - 0-149-00-01213 DEG.C Pt 100 314 MKW 51 CT001B S.OIL TEMP SO CLR (A-S) 0-100 RTD <70C - - - SPARE 0-149-00-01213 DEG.C Pt 100 315 MKW 51 CT501 S.OIL TEMP SO CLR (A-S) 0-100 TG <70C - - - - 0-149-00-01213 DEG.C -

2.3-4030-10555/24 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 316 MKW 53 CP001 DIFF PR. S.OIL FILTER H2-S 0-1.6 DPT <0.9 X >0.9 - - 0-149-00-01213 Kg/CM2 4-20mA 317 MKW 53 CT001A S.OIL TEMP SO CLR (H2-S) 0-100 RTD <70C X >70 C - - 0-149-00-01213 DEG.C Pt 100 318 MKW 53 CT001B S.OIL TEMP SO CLR (H2-S) 0-100 RTD <70C - - - SPARE 0-149-00-01213 DEG.C Pt 100 319 MKW 53 CT501 S.OIL TEMP SO CLR (H2-S) 0-100 TG <70C - - - - 0-149-00-01213 DEG.C - 320 MKW 71 CF511 SO FLOW (TE) AIR SIDE 10-100 FM - - - - - 0-149-00-01213 LPM - 321 MKW 71 CF521 SO FLOW (EE) AIR SIDE 10-100 FM - - - - - 0-149-00-01213 LPM - 322 MKW 71 CP001 SO PRESS. AIR SIDE 0-10 PT 5.2 X <4.5, - - 0-149-00-01213 Kg/CM2 4-20mA >0.6 323 MKW 71 CP002 SO PRESS. AIR SIDE 0.5-10 PS 5.2 - - <4.5, TO SWITCH OFF H2-S SO PUMP 0-149-00-01213 Kg/CM2 COC >4.5 & ATRS 324 MKW 71 CP003 SO PRESS. AIR SIDE 0.5-10 PS 5.2 - - <4.5 DIRECT SWITCH 'ON' OF 0-149-00-01213 Kg/CM2 COC DC SEAL OIL PUMP. 325 MKW 71 CP011 SO PRESS. (TE) AIR SIDE 0-10 PT 5.2 X <4.9 >4.9, C.ANN WITH MKW71CP021,UCB IND 0-149-00-01213 Kg/CM2 4-20mA DP<10mbar DP>1.2, DP FOR ATRS WITH MKG25CP001 DP WITH MKW73CP001 FOR ANN 326 MKW 71 CP021 SO PRESS. (EE) AIR SIDE 0-10 PT 5.2 X <4.9 >4.9, C.ANN WITH MKW71CP011,UCB IND 0-149-00-01213 Kg/CM2 4-20mA DP<10mbar DP>1.2, DP FOR ATRS WITH MKG25CP002 DP WITH MKW73CP011 FOR ANN 327 MKW 71 CP501 SO PRESS. AIR SIDE 0-10 PG 5.2 - - - - 0-149-00-01213 Kg/CM2 - 328 MKW 71 CP511 SO PRESS. (TE) AIR SIDE 0-10 PG 5.2 - - - - 0-149-00-01213 Kg/CM2 - 329 MKW 71 CP521 SO PRESS. (EE) AIR SIDE 0-10 PG 5.2 - - - - 0-149-00-01213 Kg/CM2 - 330 MKW 71 CT001A SO TEMP AFT SO CLRS (AIR SIDE) 0-140 RTD <50C X >50C, >55 C 2V3 (13) & MEAN VALUE

0-149-00-01213 DEG.C Pt 100 >55C WITH MKW71CT002A&3A

2.3-4030-10555/25 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 331 MKW 71 CT001B SO TEMP AFT SO CLRS (AIR SIDE) 0-100 RTD <50C - - SPARE 0-149-00-01213 DEG.C Pt 100 332 MKW 71 CT002A SO TEMP AFT SO CLRS (AIR SIDE) 0-140 RTD <50C X >50 C >55 C 2V3 (13) & MEAN VALUE 0-149-00-01213 DEG.C Pt 100 >55C WITH MKW71CT001A&3A 333 MKW 71 CT002B SO TEMP AFT SO CLRS (AIR SIDE) 0-100 RTD <50C - - SPARE 0-149-00-01213 DEG.C Pt 100 334 MKW 71 CT003A SO TEMP AFT SO CLRS (AIR SIDE) 0-140 RTD <50C X >50 C >55 C 2V3 (13) & MEAN VALUE 0-149-00-01213 DEG.C Pt 100 >55C WITH MKW71CT001A&2A 335 MKW 71 CT003B SO TEMP AFT SO CLRS (AIR SIDE) 0-100 RTD <50C - - SPARE 0-149-00-01213 DEG.C Pt 100 336 MKW 71 CT501 SO TEMP AFT SO CLRS (AIR SIDE) 0-100 TG <50C - - - - 0-149-00-01213 DEG.C - 337 MKW 73 CF511 SO FLOW END H2 SIDE 10-100 FM - - - - - 0-149-00-01213 LMP - 338 MKW 73 CF521 SO FLOW END H2 SIDE 10-100 FM - - - - - 0-149-00-01213 LMP - 339 MKW 73 CP001 SO PRESS. (TE) H2 SIDE 0-10 PT - X <MIN - COM ANN. WITH MKW73CP011 0-149-00-01213 Kg/CM2 4-20mA DP>10mbar DP WITH MKW71CP011. 340 MKW 73 CP011 SO PRESS. (EE) H2 SIDE 0-10 PT - X <MIN - COM ANN. WITH MKW73CP001 0-149-00-01213 Kg/CM2 4-20mA DP>10mbar DP WITH MKW71CP021. 341 MKW 73 CP511 SO PRESS. (TE) H2 SIDE 0-10 PG 5.2 - - - - 0-149-00-01213 Kg/CM2 - 342 MKW 73 CP521 SO PRESS. (EE) H2 SIDE 0-10 PG 5.2 - - - - 0-149-00-01213 Kg/CM2 - 343 MKW 73 CT001A TEMP. SO AFT CLR H2 SIDE 0-100 RTD <50C X >50 C - C.ALARM WITH MKW73CT002A 0-149-00-01213 DEG.C Pt 100 344 MKW 73 CT001B TEMP. SO AFT CLR H2 SIDE 0-100 RTD <50C - - - SPARE 0-149-00-01213 DEG.C Pt 100 345 MKW 73 CT002A TEMP. SO AFT CLR H2 SIDE 0-100 RTD <50C X >50 C - C.ALARM WITH MKW73CT001A 0-149-00-01213 DEG.C Pt 100

2.3-4030-10555/26 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 346 MKW 73 CT002B TEMP. SO AFT CLR H2 SIDE 0-100 RTD <50C - - - SPARE 0-149-00-01213 DEG.C Pt 100 347 MKW 73 CT501 TEMP. SO AFT CLR H2 SIDE 0-100 TG <50C - - - - 0-149-00-01213 DEG.C - 348 MKW 76 CF511 SEAL FLOW RELIEF OIL(TE) 2.66-26.6 FM - - - - - 0-149-00-01213 LPM - 349 MKW 76 CF521 SEAL FLOW RELIEF OIL(EE) 2.66-26.6 FM - - - - - 0-149-00-01213 LPM - 350 MKW 76 CP001 PRESS. RING RELIEF OIL-(TE) 0-10 PT 6.5 X <MIN - C.ALARM WITH MKW76CP011 0-149-00-01213 Kg/CM2 4-20mA 351 MKW 76 CP011 PRESS. RING RELIEF OIL-(EE) 0-10 PT 6.5 X <MIN - C.ALARM WITH MKW76CP001 0-149-00-01213 Kg/CM2 4-20mA 352 MKW 76 CP511 PRESS. RING RELIEF OIL-(TE) 0-10 PG 6.5 - - - - 0-149-00-01213 Kg/CM2 - 353 MKW 76 CP521 PRESS. RING RELIEF OIL-(EE) 0-10 PG 6.5 - - - - 0-149-00-01213 Kg/CM2 - 354 MKW31CP502 OIL PRESS AT EMERGENCY OIL I/L PG 0-149-00-01213 355 MKX 81 CL011 WASTE FLUID IN DRAIN TANK - LS - X >MAX - - 3-149-00-01025 - COC 356 MKY 01 CE001 MESU.BRUSH ROTOR E/F RELAY 100 REF >80 X <80,<5 - 2 STAGE ALARMS AT <80K 2-145-00-01026 K.Ohm - AND E. ALARM AT <5K,MANUAL TRIPPING ON MACHINE 357 MKY03CE001 END WNDG VIB(TE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 Ma IN DAS. 358 MKY03CE002 END WNDG VIB (TE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 359 MKY03CE003 END WNDG VIB (TE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 360 MKY03CE004 END WNDG VIB (TE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS.

2.3 -4030-10555/27

0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 361 MKY03CE005 END WNDG VIB (TE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 362 MKY03CE006 END WNDG VIB (TE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 363 MKY04CE001 END WNDG VIB (EE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 364 MKY04CE002 END WNDG VIB (EE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 365 MKY04CE003 END WNDG VIB (EE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 366 MKY04CE004 END WNDG VIB (EE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 367 MKY04CE005 END WNDG VIB (EE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 368 MKY04CE006 END WNDG VIB (EE) 10-100 VIB - - - STAND ALONE SYSTEM 0-139-00-01260 PC/G 4-20mA - - MONITORING OF 4-20 mA IN DAS. 369 PGB 30 CP001 PRESS. H2 CLRS WATER I/L 0.5-10 PS - X >MAX - - 0-139-00-01260 KG/CM2 4-20mA 370 PGB 30 CT501 WATER TEMP H2 CLRS 0-100 TG - - - - - 0-139-00-01260 DEG.C - 371 PGB 31 CP501 PRESS. AT THE OF H2 CLR A 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 372 PGB 31 CP502 PRESS. AT THE OF H2 CLR B 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 373 PGB 31 CP503 PRESS. AT THE OF H2 CLR C 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 374 PGB 31 CP504 PRESS. AT THE OF H2 CLR D 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 375 PGB 31 CT001A WATER TEMP H2 CLRS 0-100 RTD <38 C X >38 C - C.ANN OF PGB31CT001A & 2A 0-139-00-01260 DEG.C Pt 100

2.3-4030-10555/28 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 376 PGB 31 CT001B WATER TEMP H2 CLRS 0-100 RTD <38 C - - - SPARE 0-139-00-01260 DEG.C Pt 100 377 PGB 31 CT002A WATER TEMP H2 CLRS 0-100 RTD <38 C X >38 C - C.ANN OF PGB31CT001A & 2A 0-139-00-01260 DEG.C Pt 100 378 PGB 31 CT002B WATER TEMP H2 CLRS 0-100 RTD <38 C - - - SPARE 0-139-00-01260 DEG.C Pt 100 379 PGB 32 CP501 PRESS. AT O/L OF H2 CLR A 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 380 PGB 32 CP502 PRESS. AT O/L OF H2 CLR B 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 381 PGB 32 CP503 PRESS. AT O/L OF H2 CLR C 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 382 PGB 32 CP504 PRESS. AT O/L OF H2 CLR D 0-10 PG - - - - - 0-139-00-01260 KG/CM2 - 383 PGB 32 CT001A WATER TEMP H2 CLR A 0-100 RTD 62-45C X >67 C - C.ANN OF PGB31CT001A,2A, 0-139-00-01260 DEG.C Pt 100 3A & 4A 384 PGB 32 CT001B WATER TEMP H2 CLR A 0-100 RTD 62-45C - - - SPARE 0-139-00-01260 DEG.C Pt 100 385 PGB 32 CT002A WATER TEMP H2 CLR B 0-100 RTD 62-45C X >67 C - C.ANN OF PGB31CT001A,2A, 0-139-00-01260 DEG.C Pt 100 3A & 4A 386 PGB 32 CT002B WATER TEMP H2 CLR B 0-100 RTD 62-45C - - - SPARE 0-139-00-01260 DEG.C Pt 100 387 PGB 32 CT003A WATER TEMP H2 CLR C 0-100 RTD 62-45C X >67 C - C.ANN OF PGB31CT001A,2A, 0-139-00-01260 DEG.C Pt 100 3A & 4A 388 PGB 32 CT003B WATER TEMP H2 CLR C 0-100 RTD 62-45C - - - SPARE 0-139-00-01260 DEG.C Pt 100 389 PGB 32 CT004A WATER TEMP H2 CLR D 0-100 RTD 62-45C X >67 C - C.ANN OF PGB31CT001A,2A, 0-139-00-01260 DEG.C Pt 100 3A & 4A 390 PGB 32 CT004B WATER TEMP H2 CLR D 0-100 RTD 62-45C - - - SPARE 0-139-00-01260 DEG.C Pt 100

2.3 -4030-10555/29

0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 391 PGB 32 CT501 TEMP. AT O/L OF H2 CLR A 0-100 TG - - - - - 0-139-00-01260 DEG.C - 392 PGB 32 CT502 TEMP. AT O/L OF H2 CLR B 0-100 TG - - - - - 0-139-00-01260 DEG.C - 393 PGB 32 CT503 TEMP. AT O/L OF H2 CLR C 0-100 TG - - - - - 0-139-00-01260 DEG.C - 394 PGB 32 CT504 TEMP. AT O/L OF H2 CLR D 0-100 TG - - - - - 0-139-00-01260 DEG.C - 395 PGB 33 CG001A COLD GAS TEMP CONTROL VALVE 0-100 POS - - - - ANALOG CONTROL WITH

0-139-00-01260 % 4-20mA X MOTORISED ACTUATOR, IND. ON CRT 396 PGB 33 CT001A WATER TEMP H2 CLR 0-100 RTD 62-45C X >67 C - - 0-139-00-01260 DEG.C Pt 100 397 PGB 33 CT001B WATER TEMP H2 CLR 0-100 RTD 62-45C - - - SPARE 0-139-00-01260 DEG.C Pt 100 398 PGB 33 CT501 WATER TEMP H2 CLR 0-100 TG - - - - - 0-139-00-01260 DEG.C - 399 PGB 42 CP503 WATER PRESS I/L OF AIR CLR E 0-10 PG - - - - - 2-145-00-01026 Kg/CM2 - 400 PGB 42 CP504 WATER PRESS I/L OF AIR CLR F 0-10 PG - - - - - 2-145-00-01026 Kg/CM2 - 401 PGB 42 CP505 WATER PRESS O/L OF AIR CLR E 0-10 PG - - - - - 2-145-00-01026 Kg/CM2 - 402 PGB 42 CP506 WATER PRESS O/L OF AIR CLR F 0-10 PG - - - - - 2-145-00-01026 Kg/CM2 - 403 PGB 42 CT001A WATER TEMP EXCITER CLR E 0-100 RTD <42 C X >42 C - COMM ANN WITH PGB42CT002A 2-145-00-01026 DEG.C Pt 100 404 PGB 42 CT001B WATER TEMP EXCITER CLR E 0-100 RTD <42 C - - - SPARE 2-145-00-01026 DEG.C Pt 100 405 PGB 42 CT002A WATER TEMP EXCITER CLR F 0-100 RTD <42 C X >42 C - COMM ANN WITH PGB42CT001A 2-145-00-01026 DEG.C Pt 100

2.3-4030-10555/30 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 406 PGB 42 CT002B WATER TEMP EXCITER CLR F 0-100 RTD <42 C - - - SPARE 2-145-00-01026 DEG.C Pt 100 407 PGB 50 CP501 PR. BEF SO (AIR & H-SIDE) 0-10 PG - - - - - 0-149-00-01213 KG/CM2 - 408 PGB 50 CT001A CW TEMP AT I/L TO SO CLRS 0-100 RTD - - - - 0-149-00-01213 DEG.C Pt100 409 PGB 50 CT001B CW TEMP AT I/L TO SO CLRS 0-100 RTD - - - - SPARE 0-149-00-01213 DEG.C Pt100 410 PGB 50 CT501 CW TEMP AT I/L TO SO CLRS 0-100 TG <38 C - - - - 0-149-00-01213 DEG.C - 411 PGB 52 CP501 PR. AFT SO (H2-S) 0-10 PG - - - - - 0-149-00-01213 KG/CM2 - 412 PGB 52 CT001A TEMP-OUTLET H2-S SO CLRS 0-100 RTD - - - - - 0-149-00-01213 DEG.C Pt100 413 PGB 52 CT001B TEMP-OUTLET H2-S SO CLRS 0-100 RTD - - - - SPARE 0-149-00-01213 DEG.C Pt100 414 PGB 52 CT501 TEMP AFT SO CLR 1 (H2-S) 0-100 TG <43 C - - - - 0-149-00-01213 DEG.C - 415 PGB 52 CT502 TEMP AFT SO CLR 2 (H2-S) 0-100 TG <43 C - - - - 0-149-00-01213 DEG.C - 416 PGB 62 CP501 PR. AFTER SO CLR (A-S) 0-10 PG <43 C - - - - 0-149-00-01213 KG/CM2 - 417 PGB 62 CT001A TEMP- O/L A-S SO CLRS 0-100 RTD - - - - - 0-149-00-01213 DEG.C Pt100 418 PGB 62 CT001B TEMP- O/L A-S SO CLRS 0-100 RTD - - - - SPARE 0-149-00-01213 DEG.C Pt100 419 PGB 62 CT501 TEMP AFT SO CLR 1 (A-S) 0-100 TG <43 C - - - - 0-149-00-01213 DEG.C - 420 PGB 62 CT502 TEMP AFT SO CLR 2 (A-S) 0-100 TG <43 C - - - -

0-149-00-01213 DEG.C -

2.3-4030-10555/31 0609E

SLNO TAG NUMBER SERVICE RANGE INSTRUMENT OPERATING ANN SETPTS VALUE REMARKS BDCS PID_REF DRAWING UNIT TYPE VALUE DDCMIS CODE 421 PGB 70 CT001A TEMP AT INLET PW CLRS 0-100 RTD <38C - - - - 0-153-00-01069 DEG.C Pt100 422 PGB 70 CT001B TEMP AT INLET PW CLRS 0-100 RTD <38C - - - SPARE 0-153-00-01069 DEG.C Pt100 423 PGB 70 CT501 TEMP AT INLET PW CLRS 0-100 TG <38.0 C - - - - 0-153-00-01069 DEG.C - 424 PGB 71 CP501 CW PR.AT INLET PW CLR-1 0-10 PG - - - - - 0-153-00-01069 KG/CM2 Pt100 425 PGB 71 CP502 CW PR.AT INLET PW CLR-2 0-10 PG - - - - - 0-153-00-01069 KG/CM2 Pt100 426 PGB 72 CP501 PR. AT O/L OF PW CLR-1 0-10 PG - - - - - 0-153-00-01069 KG/CM2 - 427 PGB 72 CP502 PR. AT O/L OF PW CLR-2 0-10 PG - - - - - 0-153-00-01069 KG/CM2 - 428 PGB 72 CT001A TEMP- O/L OF PW CLR-1 0-100 RTD 38-67C - - - - 0-153-00-01069 DEG.C Pt100 429 PGB 72 CT001B TEMP- O/L OF PW CLR-1 0-100 RTD 38-67C - - - SPARE 0-153-00-01069 DEG.C Pt100 430 PGB 72 CT002A TEMP- O/L OF PW CLR-2 0-100 RTD 38-67C - - - 0-153-00-01069 DEG.C Pt100 431 PGB 72 CT002B TEMP- O/L OF PW CLR-2 0-100 RTD 38-67C - - - SPARE 0-153-00-01069 DEG.C Pt100 432 PGB 72 CT501 TEMP.AFTER PW CLR-1 0-100 TG 38-67C - - - - 0-153-00-01069 DEG.C - 433 PGB 72 CT502 TEMP.AFTER PW CLR-2 0-100 TG 38-67C - - - - 0-153-00-01069 DEG.C - 434 PGB 73 CG001 PW TEMP.CNTRL VALVE 0-100 POS - - - - ANALOG CONTROL WITH 0-153-00-01069 % 4-20mA X MOTORISED ACTUATOR, IND. ON CRT CONSOLE

2.3-4030-10555/32 0609E

BHEL, Haridwar

Turbogenerators

Operation

Running Routine

General

2.3-4100-0500/10609 E

1. Operating LogDuring initial startup and during normal operation, the

hydrogen-cooled Turbogenerators, auxiliaries and allinstruments and controls should be monitored to assurecontinuous reliable operation. The observations andreadings should be recorded. A typical operating log iscontained in these operating instructions. This table will,of course, have to be adapted to the particular conditionsof the plant. The important requirement is that all checksand readings be made at certain predetermined intervalsand preferably at the same load point. Any specialconditions regarding the operation of the hydrogen-cooled

turbogenerators should be noted separately. Such notesmay be useful in determining the cause of any subsequenttrouble and speeding up corrections.

2. Normal and Special Operating ConditionsThe Generator should be continuously monitored from

startup to shutdown. During initial startup, all checks shouldbe made at frequent intervals. Hourly readings may betaken after completion of the initial period.

A generator at standstill is considered to have beentaken into service and must be continuously monitored afterone supply system was placed in operation.

BHEL, Haridwar

Turbogenerators

Operation

2.3-4120-0500/10609 E

Operating Log

Generator Supervision

* Data should be recorded during steady-state conditions after constant operation for several hours.

Operating values* Unit Tag DateNumber

Active power MW

Reactive power MVARStator current kA

Stator voltage kV

Rotor current A

Speed s-1

Generator gas pressure kg/cm2

Slot 1 0C

20C

Slot temperature 30C

40C

50C

60C

Primary water Measuring point 10C

outlet temperature Measuring point 2 0C

TE water manifold measuring point 3 0C

Measuring point 1 0C

TE Measuring point 2 0C

Stator core Measuring point 3 0C

temperature Measuring point 10C

EE Measuring point 20C

Measuring point 30C

Coolers a/b cold0C

Coolers c/d cold0C

Gas temperature Coolers a/b hot0C

Coolers c/d hot 0C

EE After coolers a/b 0C

EE After coolers c/d 0C

Inlet 0C

Bearing oil TE 0C

temperatureOutlet

EE 0C

Generator bearing TE0C

temperatures EE0C

TE kg/cm2

Shaft lift oil pressureEE kg/cm

2

Generator bearing vibrationTE ahv mm

EE ahv mm

Job name ............................................................ Sl. No. ............................................ Remark .............................................

BHEL, Haridwar

Turbogenerators

Operation

2.3-4150-0500/10609 E

Operating Log

Seal Oil System

* Data should be recorded during steady-state conditions after constant operation for several hours.


Air side pressure after seal oil pumps kg/cm2

Hydrogen side pressure after seal oil pump kg/cm2

Air side seal oil pressure after orifice kg/cm2

TE kg/cm2

Air side seal oil pressureEE kg/cm

2

TE kg/cm2

Hydrogen side seal oil pressureEE kg/cm

2

TE mbarSeal oil differential pressure

EE mbar

TE kg/cm2

Ring relief oil pressureEE kg/cm2

TE kg/sAir side seal oil volume flow

EE kg/s

TE kg/sHydrogen side seal oil volume flow

EE kg/s

TE kg/sRing relief oil volume flow

EE kg/s

Seal oil temperatures, Inlet0C

hydrogen side seal oil cooler Outlet0C

Hydrogen side seal TE0C

oil drain temperature EE0C

Seal oil temperatures, Inlet 0C

air side seal oil coolers Outlet 0C

Inlet 0C

Outlet, H2 side cooler 1 0C

Cooling water Outlet, H2 side cooler 2 0Ctemperatures

Outlet, air side cooler 1 0C

Outlet, air side cooler 20C


BHEL, Haridwar

Turbogenerators

Operation

2.3-4160-0500/10609 E

Operating Log

Gas System

* Data should be recorded during steady-state conditions after constant operation several hours.** To be recordced only on failure of electrical purity meter system.

Operating values* Unit Tag. DateNumber

H2 boottle pressure kg/cm2

CO2 boottle pressure kg/cm2

N2 boottle pressure kg/cm2

H2 purity (elec. purity meter system) % H2

H2 purity (mech. purity meter system)** % H2

Gas flow for measuring H2 purity I/h

H2 casing pressure kg/cm2

Temperature before gas dryer 0C

Pressure before gas dryer kg/cm2


BHEL, Haridwar

Turbogenerators

Operation

2.3-4170-0500/10609 E

Operating Log


Operating values* Unit Tag. DateNumber

Generator inlet 0C

Prinary water Stator winding outlet 0C

Temperature Bushing outlet 0C

Before coolers 0C

After collers 0C

Stator winding oulet dm3/s

Bushing outlet U dm3/s

Prinary water flow Bushing outlet V dm3/s

Bushing outlet W dm3/s

Treated water dm3/s

Primary water Stator winding inlet kg/cm2

pressure After PW pumps 1/2 kg/cm2

Primary water After main filter µS/cm

conductivity After ion exchanges µS/cm

Primary water level in primary water tank %

Gas pressure in primary water tank kg/cm2

Job name ............................................................ Sl. No. ............................................ Remark .............................................Job name ............................................................ Sl. No. ............................................ Remark .............................................

BHEL, Haridwar

Turbogenerators

Operation

2.3-4190-0500/10609 E

Operating Log

Exciter Supervision

* Data should be recorded during steady-state conditions after constant operation several hours.


Cold air 0CCooling air Main exciter

Hot air0Ctemperature

Rectifier wheels Hot air0C

Cooling water Coolers e/f Inlet 0C

temperature Cooler e Outlet 0C

Cooler f Outlet0C

Measuring Point 10C

Exciter bearing temperatureMeasuring point 2 0C

Bearing oil outlet temperature 0C

Exciter shaft vibration Relative µm

Exciter bearing vibration Absolute µm

Shaft lift oil pressure kg


BHEL, Haridwar

Turbogenerators

Operation

Preparations for Starting

Introduction

2.3-5000-0500/10609 E

Also refer to the following information :[1] 2.1 - 1883 Gas Specification[2] 2.1 - 1885 Primary Water Specification[3] 2.3 - 4010 Gas Quantities

It is a prerequisite for startup of the turbine generatorthat continuous contracts be maintained between all plantsections directly or indirectly involved in the startingprocedure.

Prior to startup, it should be ascertained that thefollowing auxiliaries are in operation and will continue toremain in service.

Seal oil systemGas systemPrimary water systemSecondary cooling water system

If auxiliaries were taken out of operation, theoperating media required to fill the auxiliary systemsshould be made available.

1. Operating Media

The operating media used, i.e.

Turbine oilCarbon dioxide (CO2)Hydrogen (H2)Nitrogen (N2)Primary water

must conform to the specifications [1] and [2].

1.1 Seal Oil SystemThe seal oil circuits should be filled with turbine oil.

The quantity of turbine oil required to fill the seal oil circuitsshould be taken into consideration when filling the turbineoil tank.

1.2 Gas System

1.2.1 Carbon Dioxide (CO2)The carbon dioxide quantity to be provided should

suffice for two complete generator fillings [3], i.e. fordisplacement of the air prior to hydrogen filling and for

immediate removal of the hydrogen from the generator.1.2.2 Hydrogen (H2)

The hydrogen gas quantity to be provided shouldsuffice for displacing the CO2, for filling the generator tooperating pressure and to compensate for the H2 lossesduring operation [4].

1.2.3 Nitrogen (N2)For primary water purging [4].

1.3 Primary Water SupplyThe water quantity to be provided for filling the entire

primary water circuit should amount to approximately twotimes the primary water filling quantity. This allows for thewater quantity required for rinsing the primary water circuit.

1.4 Cooling Water SupplyThe coolers to be placed in operation should be filled

with water. To do this, the cooler vents should be opened.

Note : Continuous vents should remain open. The ventsshould be kept open until the air on the water side ofthe coolers has been completely expelled.

Before startup, the operating staff should ensure thata sufficient cooling water supply is available.

2. Checking the Transmitters

Prior to startup, all connections should be rechecked.This applies to piping as well as to cabling. When checkingthe cabling special attention should be paid to testing themetering and signal cables. All alarm systems should bechecked.

All temperature measuring points should also bechecked. This applies to the local as well as the remotereading thermometers. Unless temperature rises werebrought about by other preparatory work at the measuringpoints, temperatures of approximately ambient or roomtemperature should be indicated. When doubts existregarding the electrical temperature measurement,calibration and line compensation should be repeated.

BHEL, Haridwar

Turbogenerators

Operation

2.3-5003-0500/10609 E

Hints for Cooler Operation

1 General

The heat exchangers of the generator and itsauxiliaries have copper, copper alloy or stainless steeltubes. Admiralty brass (CuZn28Sn) is primarily used forfresh-water applications, while aluminium brass(CuZn20Al) is selected for sea- water service.

Copper and copper alloy tubes must from aprotective film on the cooling water side to ensureadequate resistance to corrosion attack. The formationand the preservation of the protective film are essentiallydependent on the conditions during initial commissioningand subsequent service.

2 Cooler Tube Materials

The coolers of the unit described have copper,copper alloy or stainless steel tubes.

Details of the cooler tube materials are specifiedin the Technical Data section of this manual [1].

2.1 Copper or Copper Alloy Cooler TubesInfluences on the cooling water side can cause

damage to the copper or copper alloy tubes of thecoolers, primarily in the form of erosion/corrosion andcorrosion attack due to

insufficient protective film formationexcessive cooling water velocitylocalized, excessive cooling water velocity resultingfrom tube blockage by foreign bodies.deposits on tubes caused by suspended materialand/or remnants of microorganisms which impairthe formation of a protective film and promotecorrosion, especially in (standby) coolers havingno cooling water flow for some time.

2.2 Stainless Steel Cooler Tubes

Cooler tubes of stainless steel are susceptible topitting and crevice corrosion under deposits, especiallywhen the cooling water has a high salt content andprimarily when no cooling water is passed through the(standby) coolers for some time. The corrosion ratedecreases with increasing cooling water velocity.

3 Cooling Water Properties

The cooling water used for the coolers must meetthe following requirements :

The cooling water must be free from coarseimpurities

The amount of suspended material must be assmall as possible.The growth of micro organisms and, in case ofseawater installations, the growth of mussels mustbe prevented.

Cooling water obtained from a closed secondarycooling water circuit mostly meets these requirementsprovided that the necessary care is exercised duringinitial operation, for example, by flushing the systemwithout passing water through the coolers.

When using water directly obtained from naturalwater sources, adverse influences should be minimizedby suitable treatment procedures (e.g. filtration, dispersantdosing, chlorination and similar methods as specified inthe literature).

4 Initial Operation of Coolers

Prior to placing the coolers in operation for the firsttime the cooling water system should be thoroughlycleaned by flushing to remove impurities and foreignmatter.

During this flushing procedure, the coolers shouldnot be in service on their cooling water sides, i.e. bypassarrangements must ensure that the flushing procedurecan be carried out without passing water through thecoolers. Following the flushing procedure, cooling watermust be continuously passed through coolers with copperalloy materials for the longest possible period of time(four to eight weeks) to ensure the formation of aneffective protective film on the cooler tubes.

5 Preventing Standstill Corrosion

Depending on the cooler material and the kind andproperties of the cooling water, standby coolers throughwhich no cooling water flows for some period of time aresubjected to all corrosive influences that can occur duringan outage.

This involves the risk that the microorganisms onthe tube walls will die due to the lack of oxygen resultingfrom the loss of fresh water supply and form decayproducts during decomposition, such as ammonia.Depending on the material used, this may lead tocorrosion and/or stress corrosion cracking.

Using cooler tubes of stainless steel with coolingwater having a high salt content involves the risk of pittingand crevice corrosion when residual amounts of coolingwater, possibly in conjunction with deposits, produce acorrosive influence.

Corrosion damage can only be safely prevented ifthe standby coolers are drained on their water sides,

2.3-5003-0500/2

Also refer to the following information :[1] 2.1 - 1830 Cooler data

cleaned, completely dried, vented, and maintained in adry condition.

For cleaning, the coolers may be flushed with waterhaving a low salt content (Cl content < 500 mg/l forcopper alloy tubes, < 100 mg/1 for stainless steel tubes).

For drying the medium to be cooled can be passedthrough the coolers via the filler and vent pipes. However,this measure cannot be always implemented in practice,especially in the case of brief outages and because ofthe need to maintain the cooler ready for operation.

If a cooler has to maintained ready for service infiled condition, it should be flushed with the full coolingwater volume flow for a brief period twice every week. Inaddit ion, i t is recommended to perform a coolerchangeover once every week so that the normal-servicecooler and the standby cooler will be alternately inoperation.

6. Preventing Deposits in Cooler Tubes

Deposits in the cooler tubes are best preventedby supplying the normal-service coolers with the fullcooling water volume flow.

If the temperature of the medium to be cooled iscontrolled by varying the cooling water volume flow, it isrecommended to supply the normal-service cooler withthe full cooling water volume for a brief period twice everyweek in order to flush away any deposits formed on thetubes due to insufficient cooling water velocity.

During occasional outages of sufficient duration orduring an overhaul, it should than be checked whetherin-service flushing is sufficient or whether manualcleaning is required. If frequent manual cleaning isnecessary on account of poor cooling water conditions,the installation of a high-velocity water cleaning systemor of a cleaning system using sponge rubber balls shouldbe considered.

7. Special Measures for Wet Preservation

If a cooler has to be maintained ready for servicein filled condition, the water volume in the cooler mustnot be hermetically sealed from the cooling water systemor from the surrounding atmosphere, respectivelyimproper cooler changeover would then result in heatingand excessive expansion of the cooling water volume,leading to damage to the cooler gaskets or piping due toexcessive pressure.

For wet preservation always open a cooler venton the water side or a shutoff valve by a small amountmaking sure to avoid a low-velocity water flow that wouldpromote the entry of suspended material.Note : Standby coolers should be maintained ready foroperation in dry condit ion in preference to wetpreservation.

8. Cooler Changeover

Make sure to fill and vent standby coolers on theirwater sides prior to changing over the coolers. Fully openshutoff valves. After cooler changeover, which must beperformed by experienced personnel, perform allmeasures required for preservation of the coolerremoved from normal service and now on standby.

To do this, close shutoff valves upstream anddownstream of the standby cooler, since the coolingwater system is mostly designed only for supply of thecooling water flow through the normal-service cooler(s).Then open the shutoff valve on the outlet side by a smallamount to avoid the effects of a water expansion due towater heating.

8.1 Criteria for Cooler ChangeoverA cooler changeover is necessary when, with the

valves in the cooling water circuit fully open, thetemperature of the medium to be cooled is rising abovethe normal level or when required on account of abnormalevents (e.g. leakage).

BHEL, Haridwar

Turbogenerators

Operation

2.3-5110-0500/10609 E

Filling and Initial Operation

of Air Side Seal Oil Circuit

Prerequisites for filling of air side seal oil circuit

Seal oil circuit must have been cleaned and flushed.Direction of pump rotation and oil level in seal oilpumps must have been checked.All level detectors in seal oil system must be calibratedand activated.All relief valves must be set.Seal oil storage tank must be filled with oil.

Note: All operating procedures should be performedin sequence specified.

MKW11 AA506 (air side oil signal to A1 valve)MKW31 AA506 (air side oil signal to A2 valve)MKA23 AA503 (gas signal to A1 valve)MKA23 AA504 (gas signal to A2 valve)MKW71 AA513 (air side oil signal, TE)MKW73 AA513 (hydrogen side oil signal, TE)MKW71 AA523 (air side oil signal, EE)MKW73 AA523 (hydrogen side oil signal, EE)

MKW01 AA503 (at seal oil storage tank)MKW11 AA504 (before A1 valve)MKW11 AA505 (after A1 valve)MKW31 AA504 (before A2 valve)MKW33 AA 505 (After A2 Valve)MKW11 AA501 (before seal oil pump 1)MKW21 AA501 (before seal oil pump 2)MKW31 AA501 (before stand by seal oil pump 3)MKW11 AA003 (after seal oil pump 1)MKW21 AA002 (after seal oil pump 2)MKW31 AA003 (after standby seal oil pump 3)MKW31 AA004 (after standby seal oil pump 3)MKW11 AA004 (after seal oil pumps)MKW03 AA502 (before float valve, oil inlet)MKW03 AA501 (after float valve, oil drain)MKW03 AA505 (for oil level gauge)

1 Preparatory work forstart-up

2Fill air side seal oil circuit

2.1Open all pressure gauge shutoff valves

2.2Open shutoff valves in signal pipes

2.3Open shutoff and gate valves in air side sealoil circuit

2.3-5110-0500/2

2.4Place seal oil coolers in operation

2.5Place seal oil filters in operation

2.6Place bearing vapor exhausters inoperation

2.7Start air side seal oil pump MKW11 AP001

MKW03 AA506 (for oil level gauge)MKW71 BP501 (adjustable orifice)MKW71 AA512 (after volume flow indicator

MKW71 CF511)MKW71 AA522 (after volume flow indicator

MKW71CF521)MKW76 AA512 (after volume flow indicator


MKW76 CF521)MKW76 AA513 (seal ring relief oil, TE)MKW76 AA523 (seal ring relief oil, EE)

Place both seal oil coolers in operation on oil sidewith rotary transfer valve assembly in its center position.

When the coolers are filled with seal oil, turn rotarytransfer valve assembly to right-hand or left-hand stop. Withthe valve, assembly in this position, one cooler is in serviceand one cooler on standby.

The seal oil cooler placed in operation on the oilside should also be filled and vented on its water side.Note : After filling, the shutoff valve for cooling water afterthe cooler should be closed.

Place both seal oil, filters in operation with rotarytransfer valve assembly in its center position.

When the filters are filled with seal oil, turn rotarytransfer valve assembly to right-hand or left-hand stop. Withthe valve assembly in this position, one filter is in serviceand one filter on standby.

Place one exhauster in operation electrically.Ensure that second exhauster is ready for start-up.

With seal oil storage tank MKW01 BB001 filled andshutoff valve MKW01 AA503 open, seal oil is available atseal oil pump 1 after a short time. Start seal oil pump 1.Note : To avoid a temporary excessive pressure built up inthe piping system, air in the piping must be slowly displacedwith oil. Start and immediately stop main seal oil pumpseveral times until the pressure gauges at the generator,i.e.

MKW71 CP511 (air side seal oil pressure, TE)MKW73 CP521 (air side seal oil pressure, EE)

indicate a constant pressure. The pump should then remainin continuous operation.

De-energize seal oil pump immediately when the

BHEL, Haridwar

Turbogenerators

Operation

2.3-5110-0500/30609 E

2.8Observe oil level in seal oil tank MKW03BB001

2.9Set three-way valves before volume flowindicators to position for normal operation

3Air side seal oil circuit is filled

level detector system in the seal oil storage tank signals alow oil level. Restarting the seal oil pump is only permissibleafter the seal oil storage tank has been filled to the requiredlevel.

During filling of the air side circuit, the seal oil tankis simultaneously filled with seal oil via float valve MKW03AA002. The float valve closes when the oil level reaches apredetermined level, and the flow of oil from the air sidecircuit into the seal oil tank is interrupted. However, oil willcontinue to flow from the hydrogen side of the shaft sealinto the seal oil tank, resulting in a rise of the oil level abovethe sight glass. This is caused by the lack of pressure inthe generator.

Set three-way valvesMKW71 AA511 (before volume flow indicator

MKW71 CF511)MKW71 AA521 (before volume flow indicator



MKW76 CF521)to position where no oil passes through the volume flowindicators.

Start with filling of hydrogen side seal oil circuit.

BHEL, Haridwar

Turbogenerators

Operation

2.3-5120-0500/10609 E

Filling and Initial Operation

of Hydrogen Side Seal Oil Circuit

Prerequisites for filling of hydrogen side seal oil circuit :

Air side seal oil circuit was filled and is in operation.

Note: All operating procedures should be performed insequence specified.

MKW13 AA507 (signal equalization, C valve)MKW13 AA505 (air side oil signal, C valve)MKA13 AA506 (hydrogen side oil signal, C valve)

MKA13 AA501 (before hydrogen side seal oil pump)MKW13 AA003 (after hydrogen side seal oil pump)MKW13 AA510 (after C valve)MKW73 AA512 (after volume flow indicator


MKW73 CF512)MKW13 AA503 (before seal oil cooler)

Place both seal oil coolers in operation on oil sidewith rotary transfer valve assembly in its center position.

When the coolers are filled with seal oil, turn rotarytransfer valve assembly to right-hand or left-hand stop. Withthe valve assembly in this position, one cooler is in serviceand one cooler on standby.

The seal oil cooler placed in operation on the oilside should also be filled and vented on its water side.Note : After filling, the shutoff valve for cooling water afterthe cooler should be closed.

Pace both seal oil filters in operation with rotarytransfer valve assembly in its center position.

When the filters are filled with seal oil, turn rotarytransfer valve assembly to right-hand or left-hand stop. Withthe valve assembly in this position, one filter is in serviceand one filter on standby.

1 Preparatory work forstart-up

2Fill hydrogen side seal oil circuit

2.1Open shutoff and signal pipes

2.2Open shutoff and gate valves

2.3Place seal oil coolers in operation

2.4Place seal oil filters in operation.

2.3-5120-0500/2

Place hydrogen side seal oil pump in operationelectrically. Start and immediately stop pump several timesuntil the air has been displaced from the piping. The pumpshould then remain in continuous operation.

Set three-way valves :MKW73 AA511 (before volume flow indicator


MKW73 CF521)

to position where no oil passes through the volume flowindicators.

Start with venting of seal oil circuits.

2.5Place and keep hydrogen side seal oil pumpMKW13 AP001 in operation

2.6Close signal equalizing valve MKW13AA507 at C valve

2.7Set three-way valves before volume flowindicators to position for normal operation

3Hydrogen side seal oil circuit is filled.

BHEL, Haridwar

Turbogenerators

Operation

2.3-5130-0500/10609 E

Venting of Seal Oil Circuits

Keep vent valves at differential pressure regulatingvalves open until oil emerges without bubbles.

Then loosen venting screws and vent main bellowsof differential pressure regulating valves.

Vent seal oil coolers in air side and hydrogen sideseal oil circuits by means of vent valves :

MKW51 AA511 (air side seal oil cooler 1)MKW51 AA510 (air side seal oil cooler 2)MKW53 AA511 *hydrogen side seal oil cooler 1)MKW53 AA510 (hydrogen side seal oil cooler 2)

Close vent valves when oil emerges without bubbles.

Vent seal oil filters in air side and hydrogen sidecircuits through venting screws on filter housings.

Venting should be performed as follows :

Open vent valvesMKW73 AA514 (in hydrogen side signal pipe)

MKW71 AA514 (in air side signal pipe)

for venting the signal pipes up to the pressureequalizing valve. Close valves when oil emergeswithout bubbles.Close shutoff valveMKW71 AA513 (for air side oil signal)

1 Vent seal oil circuit

1.1Vent signal pipes and main bellows ofdifferential pressure regulating valves (A1,A2 and C valves)

1.2

Vent seal oil coolers

1.3

Vent seal oil filters

1.4Vent all signal pipes to the pressuremeasuring devices through the ventingscrew of the respective pressure gaugeshutoff vale.

1.5Vent signal pipes and main bellows ofpressure equalizing value MKW73 AA011

2.3-5130-0500/2

and open vent valve

MKW71 AA514

to vent the main bellows of the pressure equalizingvalve close vent valve when oil emerges withoutbubbles. Shutoff valve MKW71 AA513 should thenbe reopened.

Venting should be performed as follows :

Open vent valves:

MKW71 AA524 (in hydrogen side signal pipe)

MKW71 AA524 *in air side signal pipe)

for venting the signal pipes up to the pressureequalizing valve. Close valves when oil emergeswithout bubbles.Close shutoff valve

MKW71 AA523 (for air side oil signal)

and open vent valve

MKW71 AA524

to vent the main bellows of the pressure equalizingvalve. Close vent valve when oil emerges withoutbubbles. Shutoff valve MKW71 AA523 should thenbe reopened.

Close shutoff valveMKW73 AA523 (for hydrogen side oil signal)

and open vent valve

MKW73 AA524

to vent the main bellows of the pressure equalizingvalve close vent valve when oil emerges with bubbles.Shutoff valve MKW73 AA523 should then bereopened.

1.6Vent signal pipes and main bellows ofpressure equalizing valve MKW73 AA021

2Venting of all circuits and components ofthe seal oil system is cimpleteed.

BHEL, Haridwar

Turbogenerators

Operation

2.3-5150-0500/10609 E

Setting of Seal Oil Pressures

1 Set seal oil pressures

1.1Adjust A1 valve MKW11 AA002

1.2Set seal oil pressure for seal ring relief

1.3Adjust C valve MKW13 AA002

1.4Adjust pressure equalizing valves MKW73AA011 and MKW73 AA021 for hydrogenside circuit

Note : Values indicated below apply to the generator atstandstill and seal oil temperatures after coolers of 20 to300C. Check that temperatures of air side and hydrogenside seal oil are approximately equal.

When setting the pressures, make sure to observethe static head of the respective units and instruments.

Loosen lock nut at valve stem. Turn adjusting nutto set A11 valve so that a seal oil pressure of approximately1.5 bar above the gas pressure in the generator isestablished at shaft seals.Note : Clockwise turning of adjusting nut increases sealoil pressure at shaft seals.

Counterclockwise tuning of adjusting nut decreasesseal oil pressure at shaft seals.

Adjust orifice MKW71 BP501 and A valve MKW11AA002 so that the seal oil pressure for seal ring relief willbe higher than the seal oil pressure at the shaft seals byapproximately 1 bar.Note : Adjustment is preliminary only since shaft seals arenot yet subjected to generator casing pressure.

Final adjustment can only be made when thegenerator is filled to rated pressure and operated at ratedspeed. When making the final adjustment, also check therunning condition of the turbine-generator, since anincorrectly set seal oil pressure may impair the runningcondition of the generator.

Use C valve to adjust oil pressure after hydrogenside seal oil pump. Setting should be made in the sameway as for the A valve by turning the adjusting nut.

The seal oil pressure after the hydrogen side sealoil pump must be higher than the seal oil pressure at theshaft seals. This higher pressure is required to enable thepressure equalizing valves to maintain a constant seal oilpressure.

Remove lower cap and loosen lock nut.Hydrogen side seal oil pressure is decreased by

turning threaded stem clockwise and increased by turningcounterclockwise.

pressure differences between air side and hydrogenside seal oil pressures are indicated by differential pressuregauges MKA06 CP501 and MKA07 CP501.

2.3-5150-0500/2

After completion of the adjustment, tighten lock nutand replace cap.

Make sure that position of upper threaded stem hasnot been changed.

Note : The operating values for the A1 and C valves shouldbe measured so they can be used as target values beforestarting with adjustment of A2 valve.

Stop operation of seal oil pumps 1 and 2. Standbyseal oil pump 3 will start automatically.

Make adjustment in the same manner as was donefor A1 valve. During operation with A2 valve, the seal oilpressure must be the same as when operating with A1valve. Under normal condition, A1 valve is the controllingvalve.

Recheck and , if required, correct setting when thegenerators is in operation.

Set alarm and changeover contacts.

1.5Adjust A2 valve MKW31 AA002

2Setting of seal oil pressures is completed

BHEL, Haridwar

Turbogenerators

Operation

2.3-5160-0500/10609 E

Setting of Operating Values

for Seal Oil system

Check function of complete control and supervisoryequipment.

Alarm contacts at differential pressure indicators areset so that alarm will be initiated when filters arecontaminated.

Check function of all pressure switches in installedcondition. If necessary, correct pressure switch setting tomatch actual pressure conditions.

This check is only permissible when the generatoris filled with air at 0 bar. Separate functional testing isrequired for each level detector.

Remove hex plug from stator end shield locatednear the level detector. Close shutoff valve MKW03 AA501.Take seal oil pump MKW13 AP001 out of service. The oillevel in the generator pre-chambers will rise. The alarm isactivated as soon as the oil level reaches the level detector.

Shutoff valve MKW03 AA501 should then beopened immediately and secured to prevent closing. Theoil level will drop. Cancel the alarm.

1Set operating values

for seal oil system

2Alarm contacts at twin filters in air side andhydrogen side circuits

3Check function of pressure switches

4Check function of level detectorsMKA06CL001 and MKA07 CL001 ininstalled condition

1 Stator end Shield2 Hex Plug3 Level Detector

Fig. 1 Level Detector

1 2 3

2.3-5160-0500/2

5Set limit cards for temperature monitoring

6checking and setting of supervisoryequipment is completed

If seal oil flows from the threaded hole without analarm being give, the cause of the level detector malfunctionshould be investigated, in such a case, shutoff valveMKW03 AA501 should then also be opened immediately.After completion of a successful test, replace hex plug,making sure that a gas tight seal is obtained.

Set limit cards for temperature monitoring to operating

BHEL, Haridwar

Turbogenerators

Operation

2.3-5163-0500/10609 E

Measurement of Seal Oil Volume Flows

MKW71 AA512 (before TE shaft seal)MKW71 AA522 (before EE shaft seal)

Adjust three-way valves MKW71 AA511 andMKW71 AA521 so that seal oil flow via volume flow meters.

MKW73 AA512 (before TE shaft seal)MKW73 AA522 (before EE shaft seal)

Adjust three-way valves MKW73 AA511 andMKW73 AA521 so that seal oil flows via volume flow meters.

MKW76 AA 512 (for seal ring relief, TE)MKW76 AA522 (for seal ring relief, EE)

Adjust three-way valves MKW76 AA511 andMKW76 AA521 so that relief oil flows via volume flowmeters.

Start with next settings.

1 Measure volume flows

2Open shutoff valves for seal oil volume flowmeasurement in air side circuit

3Open shutoff values for seal oil volume flowmeasurement in hydrogen side circuit.

4Open shutoff valves for ring relief oilvolume flow measurement

5Volume flow meters are activated

BHEL, Haridwar

Turbogenerators

Operation

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Functional Testing of Pumps and

Exhausters

Measure vacuum in bearing compartments with a U-tubepressure gauge while the bearing vapor exhauster is inoperation. The vacuum should be between approximately5 to 10 mbar.

1 Perform functional test

2Check standby seal oil pump for properoperation

3Check pumps for automatic operation

4.When a seal oil temperature more than400C has been reached, turn on the coolingwater supply to cooler selected foroperation so as to obtain the specified heatremoval capacity.

5Check bearing vapor exhausters for properoperation

6Filling and startup procedures arecompletedbeing normal running routine

BHEL, Haridwar

Turbogenerators

Operation

2.3-5210-0500/10609 E

Startup of Air Side Seal Oil Circuit

The seal oil system must be in operation when thegenerator is :

to be filled with hydrogen.to be filled with air for leakage testing orto be operated under load.

Prior to startup, make sure that all indicating devicesare ready for operating and that the Preparations forStarting have been carried out. The system will normallybe ready for startup when it was shut down in accordancewith the respective instructions.

Place one bearing vapor exhauster in operation.

Open shutoff valves in specified sequenceMKW01 AA503 (at seal oil storage tank)MKW11 AA504 (before A1 valves)MKW11 AA505 (after A1 valve)MKW31 AA504 (before A2 valve)MKW31 AA505 (after A2 valve)MKW11 AA501 (before seal oil pump 1)MKW21 AA501 (before seal oil pump 2)MKW31 AA501 (before standby seal oil pump 3)MKW11 AA003 (after seal oil pump 1)MKW21 AA002 (after seal oil pump 2)MKW31 AA003 (after standby seal oil pump 3)MKW31 AA004 (after standby seal oil pump 3)MKW11 AA004 (after seal oil pumps)MKW03 AA502 (before float valve, oil inlet)MKW03 AA501 (after float value, oil drain)MKW03 AA505 (for oil level gauge)MKW03 AA506 (for oil level gauge)MKW71 BP501 (adjustable orifice)MKW71 AA512 (after volume flow indicator



MKW76 CF521)

1 Startup of air sideseal oil circuit

1.1Check to ensure that all pressure gaugeshutoff valves are open

1.2Check if shutoff valves in seal oil circuit areopen

2.3-5210-0500/2

MKW11 AA506 (air side oil signal to A1 valve)MKW31 AA506 (air side oil signal to A2 valve)MKW23 AA503 (gas signal to A1 valve)MKW23 AA504 (gas signal to A2 valve)MKW71 AA513 (air side oil signal, TE)MKW73 AA513 (hydrogen side oil signal, TE)MKW71 AA523 (air side oil signal, EE)MKW73 AA523 (hydrogen side oil signal, EE)

Check oil level in seal oil pumps. Place seal oil pumpin operation.Note : To avoid a temporary excessive pressure build upin piping system, air in piping must be slowly displacedwith oil. Start and immediately stop seal oil pump severaltimes until all air is removed from the piping system. Sealoil pump 1 should then be kept in continuous operation.

During filling of air side circuit, the seal oil tank issimultaneously filled with seal oil via float valve MKW03AA002. The float valve closes when the oil level reaches apredetermined level. Oil will continue to flow from thehydrogen side of the shaft seal into the seal oil tank,resulting in a rise of the oil level above the sight glass. Thisis caused by the lack of pressure in the generator.

Start with filling of hydrogen side seal oil circuit.

1.3Verify that shutoff valves in signal lines ofair side circuit are open

1.4Start air side seal oil pump 1, MKW03BB001

1.5Check oil level in seal oil tank MKW03BB001

2

Air side seal oil circuit is now in operation

BHEL, Haridwar

Turbogenerators

Operation

2.3-5220-0500/10609 E

Startup of Hydrogen Side Seal Oil

Circuit

The air side seal oil circuit must be in operation.

MKW13 AA501 (before hydrogen side seal oil pump)MKW13 AA003 (after hydrogen side seal oil pump)MKW13 AA510 (after C valve)MKW73 AA512 (after volume flow indicator


MKW73 CF521)MKW13 AA513 (before seal oil cooler)

MKW13 AA507 (signal equalization, C valve)MKW13 AA505 (air side oil signal to C valve)MKW13 AA506 (hydrogen side oil signal to C valve)

Start with venting of seal oil circuits

1

1.2Fill seal oil circuit

Start-up of hydrogen sideseal oil circuit

1.1Seal oil level is observable at sight glassof seal oil tank

1.3Check to assure that shutoff valves inhydrogen side circuit are open

1.4Verify that shutoff valves in signal lines ofhydrogen side circuit are open

1.5Start hydrogen side seal oil pumpMKW13 AP001

2Hydrogen side seal oil circuit is now inoperation

no

BHEL, Haridwar

Turbogenerators

Operation

2.3-5230-0500/10609 E

Venting of Seal Oil Circuits and

Checking of Seal Oil Pressures

Keep vent valves of all seal oil coolers and vent plugsof seal oil filters open until the oil emerges without bubbles.

The degree of filter contamination can be seen at thedifferential pressure gauge. When the indicator iscompletely red. Cleaning will be required.

1 Vent and check oil pressures

2Vent coolers and filters

2.1Vent seal oil coolers (oil side) and seal oilfilters

2.2Check seal oil filters for contamination andclean filters, if required

2.3Fill service seal oil cooler on water sideand vent cooler

3.1Vent oil signal lines, Adjust A1, A2, C valvesand pressure equalizing valves.

3.2Ven pressure gauges

3.3

Is pressure gauge reading correct ?no

yes

2.3-5230-0500/2

Note : Final adjustment of the pressure for ring relief canonly be made when the generator has been filled withhydrogen to rated pressure, when the seal oil is hot andwhen the generator operates at rated speed.

Start with functional tests.

3Oil pressures are in agreement with theprevious operating values.

4Check and, if required, adjust operatingvalues for seal ring relief

5Seal oil pressures are set

no

BHEL, Haridwar

Turbogenerators

Operation

2.3-5280-0500/10609 E

Checking Automatic Operation of

Seal Oil Pumps

1 Perform functional test

2Check standby seal oil pump for properoperation

3Check automatic operation of pumps

4

When a seal oil temperature is more than400C, turn on the cooling water supply tocooler selected for operation so as to obtainthe specified heat removal capacity

5Check bearing vapour exhausters forproper operation.

6

End of starting procedure. Begin withnormal running routine

BHEL, Haridwar

Turbogenerators

Operation

2.3-6107-0500/10609 E

Positions of Multi-Way Valves

in Gas System

BHEL, Haridwar

Turbogenerators

Operation

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Scavenging the Electrical

Gas Purity Meter System

Prior to activating the purity meter system, leak testsof the generator and its auxiliaries must be finished.

Check gas lines and wiring of the meter system forcorrect installation. Transmitter terminals not connected toan indicator must be connected to the equivalent resistor(200 or 290 ohm, incorporated in transmitter) by insertinga jumper (connect negative terminal with terminal (*)).

With the power supply switched off, set outputinstruments to their mechanical zeros. In case of indicators,this should be done by means of the zero setter. In case ofrecorders, make setting in accordance with applicableservice instructions.

During commissioning make sure that no hydrogen (H2) isintroduced into the air filled generator. Close shutoff valvesand three-way valves.

MKG25 AA519 (H2 filter line)MKG25 AA518 (CO2 filter line)MKG25 AA502 (vent gas)MKG25 AA512 (sampling)

Scavenge piping system with hydrogen prior toelectrical commissioning of the meter system.

Connect one full bottle of H2 to the bottle rack

Loosen the locks for the adjusting screws of H2

pressure reducers.

MKG11 AA001 (H2 pressure reducer 1, H2 bottle rack)MKG19 AA001 (H2 pressure reducer 2, H2 unit)MKG12 AA001 (H2 pressure reducer 1, H2 bottle rack)MKG19 A002 (H2 pressure reducer 2, H2 unit)

Turn adjusting screws counterclockwise to bringeach pressure reducer to lower end of low-pressure range.

1 Preparatory work

2Set mechanical zeros

3Scavenge measuring gas system

3.1Prepare to scavenge measuring gassystem

3.2Set H2 pressure reducers to minimum low-pressure setting

2.3-6110-0500/2

To set the flow path, open the following shutoff valves :

MKG11 AA501 (H2 Bottle)MKG11 AA531(H2 Bottle rack manifold)MKG11 AA561(Before H2 pressure reducer-1, H2 bottle rack)MKG15 AA501 (after H2 pressure reducer-1, H2 bottlerack)MKG15 AA504 (for H2 high pressure)MKG15 AA502 (before H2 pressure reducer-1, H2 unit)MKG15 AA501 (after H2 pressure reducer, H2 unit)

orMKG11 AA501(H2 bottle)MKG11 AA531(H2 bottle rack manifold)MKG12 AA501 (before H2 pressure reducer- 2, H2 bottlerack)MKG16 AA501 (after H2 pressure reducer-2, H2 bottlerack)MKG15 AA504 (for H2 high pressure)MKG17 AA505 (before H2 pressure reducer-2, H2 unit)MKG19 AA502 (after H2 pressure reducer, H2 unit)

Set H2 pressure reducers 1 and 2 in bottle rack to a gaugepressure of approximately 8 bar. Set H2 pressure reducers1 and 2 in H2 unit to rated gas pressure. Subsequently, thelocks for adjusting screws of the pressure reducers must beretightened firmly. Flow path upstream of three-way valveMKG25 AA507 is now open.

Loosen the lock for adjusting screw of the pressurereducer. Turn adjusting screw counterclockwise to beingpressure reducer to low end of low-pressure range.

Switch three-way valve MKG25 AA507 to H2 flow towardsgas purity meter system.

Increase gas volume flow at pressure reducer MKG25AA003 until float in flow indicator MKG25 CF501 reaches ascale value of 220 (=20 dm3/h H2 ).

Gas side of meter system is ready for measurement aftera scavenging period of 30-60 Minutes.

Reduce gas volume flow at pressure reducer MKG25AA003 until in flow indicator MKG25 CF501 reaches a scalevalue of 140 (=18dm3/h H2 ). Check and readjust flow rateseveral times during the next few minutes.

Start with setting of electrical zero.

3.3Set flow path of measuring gas. Openshutoff valves

3.4Set H2 pressure reducers to rated gaspressure.

3.5Set pressure reducer for measuring gas tominimum low-pressure setting.

3.6Three-way valve MKG25 AA507

3.7Set scavenging gas volume flow

3.8Terminate scavenging procedure and setmeasuring gas volume flow

4End of scavenging procedure

BHEL, Haridwar

Turbogenerators

Operation

To check bridge supply current, connect an ammeterwith a range of 0 ....... 0.5 A and an internal resistance of750 milli-ohm between terminal (+) (balancing terminal ofpower supply) and the lead run from this terminal to terminal(+) of the purity transmitter.

Switch on power supply (if required) to amplifier,regulator or recorder for electrical commissioning of thepurity meter system.

Bridge supply current must be 335 + 1.7 mA.If another value is obtained, adjust ridge supply current

at potentiometers R3 and R6 in power supply unit.

Set electrical zero after a warm-up period of 30 minutes.Turn range selector to positing III. Indicator (100-76%

H2 in air) should read 100% H2.The hydrogen volume flow set prior to checking of the

bridge supply current is used for the setting of the electricalzero.

Hydrogen is now used as measuring and comparisongas and therefore the bridge must be balanced. No currentflows between the dividing points of the bridge. The outputvoltage of purity transmitter must be 0 mV. and accordinglya 100% H2 indication should be displayed on the indicatorsselected by means of the range selector switch. Anydeviation can be adjusted by miens of zero adjustingresistor R3.

The H2 volume flow passing through the transmitter isnow set and must not be changed.

De-energize purity meter system and remove ammeter.

MKG11 AA501 (H2 bottle)MKG11 AA531 (H2 bottle rack manifold)MKG11 AA561 (before H2 pressure reducer 1.MKG15 AA501 (after H2 pressure reducer 1,MKG15 AA504 (for H2 high pressure)MKG15 AA502 (before H2 pressure reducer 1, H2 unit)MKG19 AA501 (after H2 pressure reducer 1, H2 unit)MKG25 AA507 (measuring gas, calibration)orMKG11 AA501 (H2 bottle)MKG11 AA531 (H2 bottle rack manifold)MKG12 AA501 (before H2 pressure reducer 2,MKG16 AA501 (after H2 pressure reducer 2,MKG15 AA504 (for H2 high pressure)MKG17 AA505 (before H2 pressure reducer 2, H2 unit)MKG19 AA502 (after H2 pressure reducer 2, H2 unit)MKG25 AA507 (measuring gas, calibration)

The electrical purity meter system is now calibratedpurity measurements for CO2 and H2 filling and removaland for H2 operation can be performed.

2.3-6120-0500/10609 E

Setting Electircal Zero of

Electircal Gas Purity Meter System

1 Check bridge supply current

2Set electrical zero

2.1

Close shutoff valves and three-way valve.

3End of calibration procedure

BHEL, Haridwar

Turbogenerators

Operation

2.3-6130-0500/10609 E

Purity Measurement During CO2 Filling

Switch on power supply. After a shortened warm-upperiod, the system is ready for measurement during CO2

filling

Turn range selector to position 1 (0 to 100% CO2 inair).

The indicator should display a reading of 100% CO2 inair).

The flow path of the measuring gas (extracted beforeorifice MKG25 BP502) is as follows :Pressure reducer for measuring gasFlow meter for measuring gasCO2/ H2 purity transmitterTo atmosphere.

Since the purity meter measures the vent gas purity, itcan be seen from the indicator scale when the generator isfilled with CO2.

CO2 filling can be terminated when the purity amountsto approximately 95% CO2 in air.

1Measure purity

during CO2 filling

1.1Electrical commissioning of meter system

1.2Turn range selector to position 1

1.3Observe purity changes during CO2 filling

2Terminate purity measurement used duringCO2 filling

BHEL, Haridwar

Turbogenerators

Operation

2.3-6140-0500/10609 E

Purity Measurement During H2 Filling

Turn range selector to position II (0 to 100 % CO2 inH2)

The flow path of the measuring gas (extracted beforeorifice MKG25 BP502) is as follows :

Shutoff valve for measuring gas (filling)Pressure reducer for measuring gasFlow meter for measuring gasCO2/H2 purity transmitterTo atmosphere.

H2 filling is terminated when the purity is approximately98% H2.

1 Measure purityduring H2 filling

1.1Turn range selector to position II.

1.2Observe purity changes during H2 filling.

2Terminate purity measurement used duringH2 filling.

BHEL, Haridwar

Turbogenerators

Operation

2.3-6150-0500/10609 E

Purity Measurement During H2 Operation

Turn range selector to position III (100 to 76% H2 in air)The meter system measures the purity of the measuring

gas extracted from the generator housing

The measuring has volume flow is to keep the float ata scale value of 140 in flow indicator ST11 F501. Providevariations of the volume flow by pressure reducer ST11N501.

1Measure purity

during H2 operation

1.1Turn range selector to position III.

1.2Check measuring gas volume flow

2The H2 purity meter system is ready forservice. Start with normal running routinefor supervision of purity in generatorhousing

BHEL, Haridwar

Turbogenerators

Operation

Never use fire or an open flame (welding, flame-cutting,smoking, etc.) in the vicinity of the generator and thehydrogen system at any time, even when starting with thepreparations for generator filling.

Filling and emptying the generator should be performedwith the generator at rest or on turning gear. Filling duringturning gear operation will result in a higher gasconsumption due to the whirling motion between themedium to be displaced and the medium admitted.

For this reason, do not perform any filling or purgingoperations with the generator at higher speeds than duringturning gear operation.

The seal oil system and the bearing vapor exhaustermust be in operation and will positively remain in serviceperiod to starting with the gas filing procedure.

CO2 flash evaporator was filled with heat transfer liquidup to lower edge of the riser.

Ensure that the pose between compressed air filterMKG25 BT001 and shutoff valve MKG25 AA501 is norconnected. Making this connection should only be donewhen compressed air from the station air system is requiredfor removing the carbon dioxide (CO2) form the generatoror for performing a leakage test.

Check to ensure that all shutoff and three-way valvesin the gas valve rack, at the gas dryer and in the bottlerack are closed.

All lines carrying gas during this procedure arerepresented by yellow lines on the mimic diagram of thegas valve rack.

Switch on heater of CO2 flash evaporator. Observetemperature rise of heat transfer liquid at temperaturegauge. Wait until thermostat switches off the heater at thepreset temperature.

MKG25 AA519 (three-way valve in position H2 vent gas)MKG25 AA502 (shutoff valve in H2 vent gas line)MKG25 AA518 (three-way valve in position CO2 filling)MKG25 AA561 (shutoff valve for CO2 high pressure)

2.3-6310-0500/10609 E

Gas Filling

Replacing Air With CO2

1 Hints and preparatory work.

2Fill generator with carbon dioxide (CO2).

2.1Open all pressure gauge shutoff valves.

2.2Switch on heater of CO2 flash evaporator.

2.3Open shutoff and three-way valves.

2.3-6310-0500/2

Then open shutoff valves at CO2 bottles and at CO2bottle rack manifold. Replace empty CO2 bottles by fullbottles.

Check zero setting of CO2/H2 purity transmitter.Set range selector switch in CO2/H2 purity transmitter

to position 1 (0-100% in air)

Filling with CO2 may be terminated when a purity inexcess of 95% CO2 in air has been reached. If the openCO2 bottles are not yet completely empty, the residualcarbon dioxide should also be admitted into the generator.

Switch off heater of CO2 flash evaporator.

MKG25 AA 518 (three-way valve in CO2 filler line)MKG51 AA 561 (shut off value for CO2 high pressure)MKG25 AA 519 (three-way valve in H2 filler line)

Close all shutoff values at CO2 bottle rack manifold andCO2 bottles.

Prior to starting with H2 filling, check to ensure that asufficient amount of CO2 is available for the next generatorpurge.

Start with H2 filling.

2.4Turn range selector to position I andmeasure CO2 purity

2.5Terminate filling with carbon dioxide.

2.6Close shutoff and three-way valves.

2.7Check if sufficient CO2 is available for nextgenerator purge

3The generator is filled with carbon dioxide.

BHEL, Haridwar

Turbogenerators

Operation

All lines carrying gas during this procedure arerepresented by red lines on the mimic diagram of the gasvalve rack.

MKG25 AA518 (three-way valve in CO2 vent gasposition)

MKG25 AA519 (three-way valve in H2 filling position)MKG19 AA501 (shutoff valve after the pressure

reducer)MKG15 AA502 (shutoff valve before H2 pressure

reducer 1)MKG15 AA504 (shutoff valve in high-pressure H2 line)MKG15 AA501 (shutoff valve for low-pressure H2)MKG11 AA561 (shutoff valve for high-pressure H2)MKG11 AA531 (H2 bottle rack manifold)MKG11 AA501 (H2 bottle)orMKG25 AA518 (three-way valve in CO2 vent gas

position)MKG25 AA519 (three-way valve in H2 filling position)MKG19 AA502 (shutoff valve after the pressure

reducer)MKG17 AA505 (shutoff valve before H2 pressure

reducer 2)MKG15 AA504 (shutoff valve in high-pressure H2 line)MKG16 AA501 (shutoff valve for low-pressure H2)MKG12 AA501 (shutoff valve for high-pressure H2)MKG11 AA531 (H2 bottle rack manifold)MKG11 AA501 (H2 bottle)

Check to ensure that H2 pressure reducers adjustoperating pressure.Note: Pressure after pressure reducers in bottle rackmust be approximately 8 bar. Pressure after pressurereducers in H2 unit must be set to rated gas pressure.

H2 filling should be performed by operating the H2

bottles separately.

Turn range selector in CO2/H2 purity transmitter toposition II (0 to 100% CO2). The increase in H2 purity canbe seen at the indicator since the purity meter systemcontinues to measure the vent gas purity. In case ofindicator (position II) shows H2 purity.

In excess of 20% CO2 in H2, turn range selector switchto position III (100 to 76% H2 in air).

Continue H2 filling until indicator gives a reading ofapproximately 98% H2 in air.

Check and, if required, correct measuring gas flow.

2.3-6320-0500/10609 E

Gas Filling

Replacing CO2 With H2

1 Fill generator with H2

to operating pressure

1.1Open shutoff and three-way valves

1.2Turn range selector to position II

1.3Observe H2 purity indication and turnrange selector to position III

The contact settings for control of the seal oil pumpsmust be matched to the respective gas pressures. Setcontacts to operating values when rated gas pressure hasbeen reached.

When shutoff valve MKG55 AA502 is closed, thegenerator will be filled to operating pressure.

Filling the generator to operating pressure may alsobe performed during operation at rated speed.Note : Adjust pressure of seal ring relief oil to matchthe changed gas pressures during generator runup.

MKG05 AA501 (shutoff valve in measuring gas line)MKG05 AA502 (shutoff valve in measuring gas line)

Activate mechanical gas purity meter system. Whenthe generator operates at rated speed, the H2 purity canalso be measured by means of the mechanical gas puritymeter system.

The electrical purity meter causes a small gas loss sincethe measuring gas is vented to the atmosphere. For thisreason, sufficient H2 must always be available.

2.3-6320-0500/2

1.4Close shutoff valve MKG25 AA502

1.5Set contacts for pump control in seal oilsystem.

2Fill generator with hydrogen to operatingpressure.

3Measure H2 purity by means of mechanicalpurity meter.

3.1Open shutoff valves

3.2Activate mechanical gas purity metersystem

4The generator is filled with H2.Start with normal running routine

BHEL, Haridwar

Turbogenerators

Operation

After initial filling of the primary water circuit andfollowing the addition of larger quantities of primary water(>100 dm3 per month), the primary water tank should bepurged with nitrogen to reduce the oxygen content of theprimary water. During purging, O2 is extracted from theprimary water and discharged to the atmosphere via thevent gas line.

Prerequisites for N2 purging :

The external primary water circuit was filled with water.The primary water pumps must be in operation.A reliable nitrogen supply must be available.The N2 pressure reducer was set to a gauge pressureof 0.5 bar.

Note : The nitrogen used for purging must have a purityof 99.99%.

MKG31 AA501 (at N2 bottle)MKG31 AA502 (at N2 bottle rack manifold)MKG31 AA503 (before N2 pressure reducer)MKG35 AA501 (after N2 pressure reducer)MKF91 AA502 (in N2 purging gas line)

In addition, open shutoff valve for N2 bottle pressuremeasurement.

The nitrogen volume flow rate should be 600 dm3/h.corresponding to a bottle pressure drop of approximately15 bar/h for a 40 dm3 nitrogen bottle.

Continue nitrogen purging until a sufficiently low oxygencontent (≤ 100 µg/dm3) is reached in the primary watertank.

A sufficiently low O2 content for the most diverse initialconditions is obtained after the following purging periods.

30 hours after initial filling with subsequent refilling ofexternal circuit.10 hours after a refilling procedure during operation.

Note : The primary water must be continuously maintainedin circulation during nitrogen purging

2.3-6810-0500/10609 E

N2 Purging After Filing of


1 Preparatory work

2

Purging the primary water tank withnitrogen (N2)

2.1Open shutoff valves at bottle rack and inpurging gas system

2.2Check N2 purging gas volume flow

2.3Perform nitrogen purging procedure

MKG31 AA501 (at N2 bottle)MKG31 AA502 (at N2 bottle rack manifold)MKG31 AA503 (before N2 pressure reducer)MKG35 AA501 (after N2 pressure reducer)MKF91 AA502 (for N2 purging gas)

2.3-6810-0500/2

2.4Terminate nitrogen purging

2.5Close shutoff valves at bottle rack and inpurging gas system.

3continue filling or operation of primary watersystem.

BHEL, Haridwar

Turbogenerators

Operation

Caution : The primary water system may only be filledwith water complying with our specification [1]

Prerequisites for filling the primary water system :

The primary water pumps must have been checked forproper alignment after installation of the connectingpiping at the generator. The oil levels in the bearingsand direction of rotation must have been checked withpump uncoupled.Primary water circuit must have been cleaned [2]Primary water circuit must have been leak tested [3]The filter elements of all filters must be installed [4]the ion exchanger must be filled with resins.

2.3-7100-0500/10609 E

Filling and Initial Operation ofPrimary Water SystemPreparatory Work

1 Filling and initial operationof primary water system

2Preparatory work

2.1Set mechanical and electrical zeros of theconductivity meter system [5]

2.2Adjust primary water tank level system withprobe not immersed [6]

2.3Adjust the leakage water level detectorswith probes immersed [7]

2.4Check and set primary water volume flowindicators [8]

2.5Adjust relief valve for makeup line [9]

Note : Use only n i t rogen comply ing wi th ourspecification [10]

Make sure that shutoff valves MKF60 AA504 and MKF60AA520 are closed.

The filler line and make-up line should be carefullyflushed with de-ionate prior to being connected to theprimary water system inlet valves.

Water in filler or makeup line should be at a sufficient

pressure (ρ = 2 to 10 bar, 30 to 145 psig.)

2.3-7100-0500/2

Also refer to following imformations :[1] 2.1-1885 Primary water specification[2] 2.5-7382 Flushing external parts of Primary water circuit[3] 2.5-0310 Leakage tests[4] 2.4-4740 Maintenance and supervision of Primary water filters[5] 2.3-7530 Activating the Primary water conductivity meter system[6] 2.3-7520 Activating the Primary water level monitoring system[7] 2.3-7510 Activating the Primary water level detector system[8] 2.3-7540 Activating the Primary water Volume flow meter system[9] 2.3-4070 Operating and setting values[10] 2.1-1883 Gas specification

2.6Set mechanical zeros of all pressuregauges

2.7Set electrical zero of pressure transmitter

2.8Ensure that pure nitrogen is available atrequired pressure and in sufficient quantity.

2.9Ensure that water is available for filling ofthe primary water system.

3Fill external part of primary water system.

~¯

BHEL, Haridwar

Turbogenerators

Operation

2.3-7110-0500/10609 E

Filling and Initial Operation ofPrimary Water SystemFilling External Part of Primary Water Circuit

Prerequisites for filling external part of primary watercircuit :

Preparatory work was completed.External part of the primary water system consists of

the entire system except for.

Water treatment systemTerminal bushings and phase connectorsStator winding

MKF12 AA502 (drain valve before pump 1)MKF 22 AA502 (drain valve before pump 2)MKF52 AA521 (primary water drain valve for cooler 1)MKF52 AA522 (primary water drain valve for cooler 2)MKF52 AA523 (primary water drain valve for cooler 3)MKF52 AA544 (primary water drain valve manifold)MKF52 AA581 (drain valve at main filter 1)MKF52 AA591 (drain valve at main filter 2)MKF52 AA593 (shutoff valve after main filter 2)MKF60 AA502 (control valve for water treatment

system)MKF60 AA504 (shutoff valve in makeup line)MKF60 AA519 (shutoff valve after water treatment

system)MKF80 AA506 (shutoff valve before water level

indicator, bottom)MKF80 AA507 (drain valve at water level indicator)MKF80 AA509 (drain valve at level detectors)MKF80 AA512 (shutoff valve before level detector 1,

bottom)MKF80 AA513 (drain valve at level detector 1)MKF82 AA501 (control valve before stator winding)MKF83 AA501 (control valve before bushings)MKF83 AA502 (shutoff valve after bushings)MKF91 AA502 (shutoff valve for N2 purging gas)MKF91 AA506 (shutoff valve for vent gas line)

MKF12 AA501 (shutoff valve before pump 1)MKF12 AA504 (shutoff valve after pump 1)MKF22 AA501 (shutoff valve before pump 2)MKF22 AA504 (shutoff valve after pump 2)MKF52 AA501 (primary water shutoff valve before

cooler 1)

1Fill external part of

primary water circuit

2Close valve

3

Open valve

MKF52 AA502 (primary water shutoff valve beforecooler 2)

MKF52 AA503 (primary water shutoff valve beforecooler )

MKF52 AA511 (primary water shutoff valve aftercooler 1)



MKF52 AA531 (primary water vent valve forcooler 1)



MKF52 AA545 (primary water vent valve manifold)MKF52 AA580 (shutoff valve for main filter 1)MKF52 AA582 (vent valve at main filter 1)MKF52 AA583 (shutoff valve after main filter 1)MKF80 AA503 (shutoff valve in main circuit,

delivery pipe)MKF80 AA504 (shutoff valve in bypass of primary

water tank)MKF80 AA505 (shutoff valve before water level

indicator, top)MKF 80 AA508 (vent valve at water level indicator)MKF 80 AA511 (shutoff valve before level detector 1, top)MKF80 AA514 (vent valve at level detector 1)MKF91 AA505 (drain valve in vent gas line)MKF91 AA513 (shutoff valve at drain)

Fill circuit slowly with water. Terminate filling whenprimary water tank is filled with water up to 3/4 on the sightglass.Caution : Ensure that water does not enter purging gasline during filling or addition of makeup water.

Note : Water used for filling mist be at the required pressurebefore shutoff valve MKF60 AA520.

Vent external circuit through open vent valves.Close vent valves when water emerges without bubbles.

Throttle filler valve as soon as primary water tank isfilled up to 1/2 on the sight glass.

Open shutoff valve

2.3-7110-0500/2

4Filling procedure

4.1Open shutoff valve MKF60 AA520 in make-up line

4.2Vent during filling

4.3Adjust gas pressure in primary water tank

BHEL, Haridwar

Turbogenerators

Operation

2.3-7110-0500/3

MKF91 AA506 (shutoff valve for vent gas line)

and close shutoff valve

MKF91 AA505 (drain valve in vent gas line)

Close all vent valves. When air pressure in tankexceeds 0.2 bar, the compressed air escapes via theoutflow regulator.

Adjust primary water tank level system at the full level[1].

Caution : Take care to prevent dry running of primary waterpumps, since the sliding ring glands of the pumps must becontinuously supplied with water.

Carefully vent signal lines to pressure gauges via thetest connections at the respective pressure gauge shutoffvalve by filling them with water.

Vent circuit carefully by opening each vent valve severaltimes.

Maintain primary water circulation for approximately fourhours to clean the piping, coolers, etc.

Vent circuit several times, as required.

4.4Terminate filling procedure by closingshutoff valve MKF60 AA520 when tank isfilled up to 3/4 on sight glass.

5Place external cooling circuit into service

5.1Carefully vent signal lines to pressuregauges

5.2Place primary water pump 1 in operationfor approximately 10 minutes

5.3Venting and purging procedure

5.4Start pump 2 after pump 1 has beenstopped

5.5Maintain circulation in external part ofprimary water circuit by means of pump 1or 2

2.3-7110-0500/4

Also refer to following information :[1] 2.3-7520 Activating the primary water level monitoring

system[2] 2.3-7350 Activating the primary water conductivity meter

system

6Activate conductivity meter system MKF80CQ001 [2]

7External part of primary water circuit is filledwith water; start with filling and placing intoservice of water treatment system.

BHEL, Haridwar

Turbogenerators

Operation

2.3-7120-0500/10609 E

Filling and Initial Operation ofPrimary Water SystemFilling the Water Treatment System

Prerequisites for filling the water treatment system :

External part of primary water circuit was filled withwater.Water in external part of primary water circuit must havea conductivity of less than 10 µmho/cm.

In the limit of 10 µmho/cm is exceeded, the systemmust be drained and filled again with water (deionated)

Remove cover of ion exchanger tank after opening theflanged connection and removing pipe.

Remove upper nozzle tray.Thoroughly mix cation and anion exchanger resins of

a ratio of 1 : 1 and fill ion exchanger with mixture.After filling ion exchanger, replace upper nozzle tray

(nozzles facing the resin) and install cover. Make suregaskets are properly seated.

Tighten cover flange bolts uniformly at opposite pointsto prevent flange distortion.

Caution : During storage, the resin can decompose. Toprevent products of decomposition from entering theprimary water system, the resins should be flushed.

Filling the ion exchanger with water should be doneslowly to prevent whirling of the resin filling which may resultin separation of resin compounds.

MKF60 AA510 (drain after ion exchanger)MKF60 AA517 (drain for water treatment system)MKF60 AA511 (drain at fine filter)MKF60 AA522 (drain, primary water integrating

flow meter)

1 Fill water treatment system

2Fill ion exchanger with resins

3Activate conductivity meterMKF60 CQ001 [1]

4Flush ion exchanger resins

4.1Close shutoff valves

2.3-7120-0500/2

Also refer to following information :[1] 2.3-7530 Activating the primary water conductivity

meter system[2] 2.3-6810 N2 purging after filling of primary water

system

MKF60 AA503 (vent before ion exchanger)MKF60 AA509 (shutoff valve after ion exchanger)MKF 60 AA512 (vent at fine filter)MKF60 AA513 (shutoff valve after filter)

Open shutoff valve MKF60 AA504 in the makeup line sothat water is admitted very slowly. Close vent valves MKF60AA 503 and MKF60 AA512 as soon as water emergeswithout bubbles.

Adjust flushing water volume flow rate to approximately1 m3/h by means of drain valve MKF60 AA 517 (reading atflowmeter MKF60 CF502).

Discard flushing water.Terminate flushing procedure by closing drain valve MKF60AA517 when conductivity after ion exchanger is ≤ 1 mmho/cm (reading at conductivity transmitter MKF60 CQ001).

Vent the system several times during this procedure.Close makeup valve MKF60 AA504.

Open control valve MKF60 AA502 slowly. Vent inlet pipevia vent valve MKF60 AA503. Then open shutoff valveMKF60 AA519. Adjust a volume flow rate of approximately1 m3/h by means of control valve MKF60 AA502 (readingat flow indicator MKF60 CF502)

The flow path through the water treatment systemprovides fro treatment of the primary water.

N2 Purging of primary water tank reduces the O2 contentof the water in the external part of the circuit to < 100 ppb(100 µg/dm3)


4.3Perform flushing procedure

5Place water treatment system into service

5.1Treatment of water in cooling circuit

6Purge primary water tank with N2 [2]

7Water in external part of primary watercircuit is subjected to treatment; start withfilling of terminal bushings and phaseconnectors

BHEL, Haridwar

Turbogenerators

Operation

Prerequisites for filling the terminal bushings and phaseconnectors :

Primary water in external circuit must have aconductivity of ≤ 4 µmho/cm.Primary water in external circuit must have an O2

content of < 100 µg/dm3 (100 ppb). This O2 content isobtained by proper N2 purging.

Note : Do not add make-up water during filling procedureAdding makeup water is only permissible after the statorwinding as well as the terminal bushings and phaseconnectors were filled with water and isolated from theexternal part of the primary water circuit by closing therespective valves.

MKF83 AA502 (after bushings)MKF83 AA501 (before bushings)MKF83 AA503 (shutoff valve for flow indicator)MKF83 AA504 (shutoff valve for flow indicator)MKF83 AA505 (shutoff valve for flow indicator)MKF83 AA506 (shutoff valve for flow indicator)MKF83 AA507 (shutoff valve for flow indicator)MKF83 AA508 (shutoff valve for flow indicator)MKF83 AA513 (shutoff valve for flow indicator)MKF83 AA514 (shutoff valve for flow indicator)MKF83 AA515 (shutoff valve for flow indicator)MKF83 AA516 (shutoff valve for flow indicator)MKF83 AA517 (shutoff valve for flow indicator)MKF83 AA518 (shutoff valve for flow indicator)

After opening of the above valves, primary water isadmitted to the branch circuit.

Due to the open position of shutoff valve MKF80 AA504in the bypass, the volume flow rate through the bushingsand phase connectors is low. Therefore venting takes placeslowly.

The volume flow indicators may be placed into serviceonly after proper venting. Check that water flows throughsight glasses without bubbles.

MKF83 BR501 (for primary water flow in phase UXbushings)

MKF83 BR502 (for primary water flow in phase VYbushings)

MKF83 BR503 (for primary water flow in phase WZbushings)

2.3-7150-0500/10609 E

Filling and Initial Operation ofPrimary Water SystemFilling Terminal Bushings and PhaseConnectors

1Fill terminal bushings and

phase connectors

1.1Open shutoff and control valves

2

Filling procedure

Activate volume flow indicators [1] :

MKF83 CF001A (for volume flow in phase R bushings)MKF83 CF001B (for volume flow in phase R bushings)MKF83 CF011A (for volume flow in phase S bushings)MKF83 CF011B (for volume flow in phase S bushings)MKF83 CF021A (for volume flow in phase T bushings)MKF83 CF021B (for volume flow in phase T bushings)

Carefully vent transmission lines and flow indicatorsvia the shutoff and equalizing valve assemblies.

Check parallel connected flow indicators for identicalvolume flow readings.

MKF83 AA502 (before terminal bushings)MKF83 AA501 (after terminal bushings)

Terminal bushings can be placed into service again byopening the above control valves after the addition ofmakeup water to the primary water tank following filling ofthe stator winding and subsequent N2 purging.

2.3-7150-0500/2

Also refer to following information :[1] 2.3-7540 Activating the primary water volume flow

meter system

3Activate volume flow indicators

4Close control valves

5

Terminal bushings and phase connectorsare filled; start with filling of stator winding

BHEL, Haridwar

Turbogenerators

Operation

2.3-7160-0500/10609 E

Filling and Initial Operationof Primary Water SystemFilling the Stator Winding

Prerequisites for filling the stator winding :

Drain valves of primary water manifolds were closedand secured against opening.Primary water in external circuit must have aconductivity of < 4 µmho/cm.Primary water in external circuit must have an O2

content of < 100 µg/dm3 (100 ppb). This O2 content isobtained by proper N2 purging.

Note : Do not add make-up water during filling procedure.Adding make-up water is only permissible after the statorwinding as well as the terminal bushings and phaseconnectors were filled with water and isolated from theexternal part of the primary water circuit by closing therespective valves.

MKF82 AA502 (vent before stator winding)MKF82 AA503 (vent after stator winding)MKF82 AA504 (shutoff valve for flow indicator)MKF82 AA505 (shutoff valve for flow indicator)MKF82 AA507 (shutoff valve for flow indicator)MKF82 AA508 (shutoff valve for flow indicator)

Slowly open control valve MKF82 AA501 (stator windinginlet).

Close vent valves as soon as water emerge withoutbubbles.

Activate volume flow indicators [1]

MKF82 CF001A (flow indicator for primary water volumeflow, stator outlet)

MKF82 CF001B (flow indicator for primary water volumeflow, stator outlet)

Carefully vent transmission lines and flow indicatorsvia the shutoff and equalizing valve assemblies.

Check parallel connected flow indicators for identicalflow readings.

Increase volume flow rate through stator winding byslowly opening control valve MKF82 AA501. Simultaneouslythrottle shutoff valve MKF80 AA504 in bypass to obtainhigher volume flow rate through stator winding.Briefly openvents on inlet and outlet pipe at reasonable intervals.

Stator winding should be completely vented after aflushing period of approximately two hours.

1 Fill stator winding

2Open shutoff valves

3Filling procedure

4Activate volume flow indicators

5Flush and vent stator winding

2.3-7160-0500/2

Carefully vent signal lines to pressure gauges via thetest connections at the respective pressure gauge shutoffvalve.

Isolate filled stator winding from external part of primarywater circuit prior to restoring the required water level inthe primary water tank by the addition of makeup water.

To do this, fully reopen shutoff valve.

MKF80 AA504 (in bypass)

and then close control valve

MKF82 AA501 (before stator winding)

After the stator winding and terminal bushing with phaseconnectors were isolated from the external part of thecircuit, close shutoff valve.

MKF60 AA502 (before ion exchanger)

and slowly open shutoff valve

MKF50 AA504 (in makeup line)

Slowly raise water level in primary water tank to 75%of nominal value. Read nominal level at indicator of leveldetector MKF80 CL501.

Then close shutoff valve.

MKF60 AA504 (in makeup line)

and reopen control valve

MKF60 AA502 (before ion exchanger).

N2 purging of primary water tank reduces the O2 contentof the water in the external part of the circuit to ≤ 100µg/dm3 (100 ppb).

As soon as the water in the external part of the circuithas reached an O2 content of ≤ 100 ppb, open control andshutoff valves.MKF82 AA501 (before stator windings)MKF83 AA501 (before terminal bushings)MKF83 AA502 (after terminal bushings)

Slowly close shutoff valve MKF80 AA504 in bypass.Adjust volume flow rate [3] by means of the above controlvalves.

6Carefully vent all signal lines to pressuregauges

7

Isolate stator winding from external partof primary water circuit

8Adjust nominal water level in primary watertank

9Purge primary water tank with nitrogen [2]

10Open control and shutoff valves

11Close shutoff valve MKF80 AA504 inbypass

12

Stator winding is filled; start with filling ofprimary water coolers on cooling waterside.

Also refer to following information :[1] 2.3-7540 Activating the primary water volume flow meter system[2] 2.3-6810 Nitrogen purging after filling primary water system[3] 2.3-4070 Operating and setting values

BHEL, Haridwar

Turbogenerators

Operation

2.3-7180-0500/10609 E

Filling and Initial Operation ofPrimary Water SystemFilling Primary Water Coolers on CoolingWater Side

Note: Fill coolers with water on cooling water side onlyone day before start-up and loading of generator.

Close shutoff valves before and after cooler

MKF52 BC003 (and shutoff valves)MKF52 AA551 (drain valve at cooler 1)MKF52 AA552 (drain valve at cooler 2).

Open shutoff valves before and after coolers.

MKF52 BC001 (cooler 1)MKF52 BC002 (cooler 2)

and shutoff valves

MKF52 AA553 (drain valve at cooler 3)MKF52 AA561 (vent valve at cooler 1)MKF52 AA562 (vent valve at cooler 2)MKF52 AA563 (vent valve at cooler 3).

Fill primary water coolers with water after openingshutoff valves.

Close vent valves as soon as water emerges withoutbubbles.

Note: Fill and vent only two of three primary watercoolers on their cooling water sides 100% of the maximumcooler capacity required (at maximum cooling watertemperature and maximum generator output) will then bein service.

The third primary water cooler should not be filled onits cooling water side but left in a clean and dry conditionwith closed inlet and outlet valves and open drain and ventvalves.

1Fill and vent coolerson cooling water side

2

Check and activate primary watertemperature control system.

3Close shutoff valves

4Open shutoff valves

5

Filling procedure

6Primary water circuit is ready for opera-tion; start with necessary checks prior tostartup.

BHEL, Haridwar

Turbogenerators

Operation

2.3-7210-0500/10609 E

Activating Primary Water SystemAfter a Shutdown of Less Than 48Hours

Activate primary water systemafter a shutdown of less than 48 hours

The primary water must still be in the system.For activating the primary water system after a

shutdown in which the system or a branch circuit wasdrained, follow the corresponding instruction [1].

Note : Close shutoff valve MKF80AA504 after reactivation of statorwinding branch circuit

1

2.1Start one primary water pump and be surethe other pump is ready for starting

no

3.3Activate stator winding branch circuit byslowly opening control valve MKF82 AA501.

yes

3.2Activate bushing and phase connectorbranch circuit by slowly opening controlvalves MKF83 AA502 and MKF83 AA501

3.1Place water treatment system into serviceby slowly opening valves MKF60 AA502and MKF60 AA519

no3Are all primary water branch circuits inservice

4Check primary water circuit prior to start-up[2]

5Primary water system is now in service.Start with normal running routine

2Are primary water pumps in operation ?

Also refer to the following information[1] 2.3-7100 Filling and Initial Operation of

to 2.3-7180 Primary water System[2] 2.3-7610 Checks Prior to Startup

BHEL, Haridwar

Turbogenerators

Operation

Activate primarywater system after a shutdown

of more than 48 hours

2.3-7220-0500/10609 E

Activating Primary Water SystemAfter a Shutdown of More Than 48Hours

1

2.1Fill and activate primary water system orany branch circuits [1]

3Perform checks necessary prior to startup

4Primary water system is now in service;start with normal running routine

no

Also refer to the following information[1] 2.3-7100 Filling and Initial Operation of

.. to .. Primary Water System2.3-7180

[2] 2.3-7610 Checks Prior to Startup

2Primary water circuit is completely filled

BHEL, Haridwar

Turbogenerators

Operation

2.3-7530-0500/10609 E

Activating the Primary WaterConductivity Meter System

Prior to initial operation of the conductivity metersystem, check the wiring for compliance with circuit andconnection diagrams.

Set and check mechanical zero by adjusting zerosetting screw on the indicator.

Note : This check can only be performed if conductivitytransmitter is completely dry and therefore should beperformed prior to filling the primary water system.

Select the range 0 to 2 µmho/cm by means of jumperon printed circuit board of transmitter module.

Switch on the power supply.Check conductivity indication after a warm-up period

of approximately 15 minutes. If the indication is not zero, acorrection can be made at potentiometer P-O of transmittermodule.

This check may be performed either before or afterfilling primary water system.

Turn associated test selector switch to zero position.With switch in this position, a zero indication is given at theconductivity indicator.

Turn associated test selector switch to test value 1.5µmho/cm position. With switch in this position, instrumentshould indicate a value of 1.5 µmho/cm.

Turn test selector switch to the operation position. Withswitch in this position, conductivity indicator indicatesconductivity of primary water, provided that primary watersystem is filled and that water flows through the measuringdevice.

If conductivity of the primary water is still beyond theselected range, use jumper in transmitter module to selectone of the higher ranges:

0 to 5 µmho/cm0 to 10 µmho/cm0 to 25 µmho/cm

1 Activate conductivity meter system

2Check mechanical zero of conductivityindicator

3Check electrical zero

4Check complete conductivity metersystem by means of test switching unit

If the checks of conductivity meter system do not yieldresult as given in step 4, perform the following checks atthe transmitter module by using the furnished test resistor.Note : During generator operation, make sure that theconnections are disconnected and reconnected in thecorrect sequence. This prevents a full-scale deflectionof the conductivity indicator which would result ininitiation of an alarm during normal operation. The testresistor can be used to check the transmitter moduleand the conductivity indicator.

When using test resistor, be sure to only disconnectthe leads to terminals 2 and 3 of transmitter module. Leadto terminal 1 should not be disconnected.

The test procedure is as follows :

Disconnect lead to terminal 2 of transmitter module.Conductivity indicator should indicate zero.Disconnect lead to terminal 3 of transmitter module.Conductivity indicator should indicate 30% of maximumdeflection.Connect test resistor terminal 1 to terminal 1 oftransmitter module. Be sure that the lead frommeasuring device also remains connected to theterminal. Conductivity indicator should indicate 30% ofmaximum deflection.Connect test resistor terminal 3 to terminal 3 oftransmitter module. Conductivity indicator shouldindicate zero.Connect test resistor terminal 2 to terminal 2 oftransmitter module. Conductivity indicator wouldindicate value given on test resistor.Disconnect test resistor from terminal 3 of thetransmitter module. Conductivity indicator shouldindicate zero.Disconnect test resistor from terminal 1 of transmittermodule. Conductivity indicator should indicate 30% ofmaximum deflection.Reconnect leads to terminal 3, then terminal 2 oftransmitter module. Conductivity indicator shouldindicate conductivity of the primary water.

A deviation between the results described above andthe actual test results using the test selector switch andtest resistor can be due to an influence of the leads betweenthe conductivity measuring device and the transmittermodule. These deviations can be corrected by P-X or P-Y.Since these potentiometer settings influence each other,the correction may have to be repeated several times untilthe required accuracy is obtained for all scale pointsincluded in the check.

2.3-7530-0500/2

6Conductivity meter system is ready forcontinuous monitoring of the primarywater conductivity

5Check conductivity meter system attransmitter module by use of test resistor

BHEL, Haridwar

Turbogenerators

Operation

2.3-7540-0500/10609 E

Activating the Primary WaterVolume Flow Meter System

Prior to activating the flow meter system check wiringfor compliance with circuit arrangement and connectiondiagrams.

Check power supply voltage.

With primary water cooling circuit filled and requiredprimary water flow available, open equalizing valve andthe two shutoff valves and vent measuring mechanism. Todo this, follow descriptions [1] and [2].

After venting, close equalizing valve.The measuring mechanism is now subjected to the

differential pressure to be measured.

The differential pressure transmitter is now ready forchecking the lower range limit and upper range limit.

Lower range limit and upper range limit can bereadjusted independently from each other.

1 Activate volume flow meter system

2Vent medium-pressure cell

3Switch on auxiliary power supply

4Check lower range limit and upper rangelimit

1 Span Potentiometer2 Zero indicator3 Zero switch4 Test jack5 Zero Potentiometer

Fig.1 Differential Pressure Tranmitter

1

2

3

4

5

For zero check, set zero switch to T (test) position.

To do this, open equalizing valve of the equalizing valveassembly.

The electrical zero setting is indicated by the zeroindicator.

If the pointer of the zero indicator is not exactly in thecenter position, the zero setting can be corrected with thezero potentiometer (item 5).

After checking or correction of zero setting, reset zeroswitch to its N (normal) operating position.

Note : Check to ensure that no impurities are introducedinto the primary water circuit (apply upper range pressureat pressure gauge calibration rack).

An ammeter (voltage drop < 300 mV at 20 mA)connected to the test jack, should indicate the upper rangevalue of the output current = 20 mA. Any required correctioncan be made with the span potentiometer (item 1).

To do this, close equalizing valve of the equalizing valveassembly.

Flowmeter system is now ready for operation.

2.3-7540-0500/2

4.1Set zero switch to T (test) position

4.2Apply zero differential pressure tomeasuring mechanism

4.3Check indication of zero indicator

4.4Correct zero setting

4.5Set zero to N (normal) position

4.6Apply upper range differential pressure tomeausring mechanism (upper range value< orifice design)

4.7Correct upper range pressure setting

4.8Re-apply differential pressure to measuringmechanism

5Equipment is ready for volume flowmeasurement

Also refer to the following information[1] 2.1-7370 Primary Water Volume flow

Meter System[2] 2.1-8412 Pressure Transmitters

BHEL, Haridwar

Turbogenerators

Operation

Perform necessary checksprior to startup

2All primary water coolers are filled on theirprimary water side.

3Check or adjust vent and drain valves atprimary water coolers

4All units of primary water system areproperly vented.

5All pressure gauges and pressuretransmitters are properly vented.

Ensure that all three coolers are filled on their primarywater sides.

Make sure to open valves

MKF52 AA521 (shell side drain at primary water cooler1)MKF52 AA522 (shell side drain at primary water cooler2)MKF52 AA523 (shell side drain at primary water cooler3)MKF52 AA531 (shell side vent at primary water cooler1)MKF52 AA532 (shell side vent at primary water cooler2)MKF52 AA533 (shell side vent at primary water cooler3)

and close valves

MKF52 AA544 (shell side drain manifold of primary watercoolers)

MKF52 AA545 (shell side vent manifold of primary watercoolers)

Perform check by briefly opening shutoff valves

MKF52 AA541 (vent before primary water cooler)MKF52 AA578 (vent after primary water cooler)MKF82 AA502 (vent before stator winding)MKF82 AA503 (vent after stator winding)MKF60 AA512 (vent at fine filter)MKF60 AA503 (vent at ion exchanger)MKF52 AA582 (vent at main filter)MKF52 AA545 (shell side vent manifold of

primary water cooler)

Perform check by briefly opening vent plug at eachrespective pressure gauge shutoff valve.

2.3-7610-0500/10609E

Initial Operation of Primary WaterSystemChecks Prior to Startup

1

Check that primary water coolers are filled on their coolingwater sides and properly vented.

2.3-7610-0500/2

6Two primary water coolers are filled andvented on their cooling water sides

7Primary Water Temperature control systemis ready for operation

8Primary water circuit is ready for operation;start with regular monitoring of operation

BHEL, Haridwar

Turbogenerators

Operation

1 GeneralThe generator should be operated on the turning gear

and brought up to speed in accordance with the turbinestartup diagrams.

2 Turning Gear OperationPrior to operating the generator on turning gear, the

shaft lift oil pump and the bearing oil system must be placedinto operation.

The seal oil system for lubrication and sealing of thatshaft seals and the primary water system must be placedinto operation.

The oil flow to the bearings and shaft seals should bechecked prior to turning gear operation to ensure anadequate flow. In addition, drains should be inspected forproper operation.

The generator may be filled with hydrogen prior to orduring turning gear operation provided that leakage testshave been performed and the seal oil system is in operation.

3 Generator Cooling Gas TemperaturesThe hydrogen coolers should be placed into service

on their cooling, water sides as soon as the generator isfilled with hydrogen and on turning gear. The H2 coolanttemperature control system should be changed over fromthe Automatic to the Manual mode. Use manual mode toadjust a cooling water volume flow through the hydrogencoolers of approximately 5 to 10% of the nominal flow rate.

This results in a lower dew point temperature in thegenerator interior due to the condensation of moisturecontained in the gas on the cooler tubes and fins.

The cooling water volume flow through the hydrogencoolers should not be increased as long as the H2 cold gastemperature is not at rated value.

During runup, the cooling water volume flow throughthe hydrogen coolers should be increased by manualadjustment to maintain the cold gas temperature at least5 K below the primary water inlet temperature. Changingover the H2 coolant temperature control system from theManual to the Automatic mode is permissible as soon asthe primary water temperature control system, set for theautomatic mode, opens the final control element for thecooling water downstream of the primary water coolers.

4 Exciter TemperaturesThe exciter coolers must be filled with water and vented.

The shutoff valves in the lines upstream of the coolers areopen, and the control valves in the lines downstream ofthe coolers are closed.

2.3-8010-0500/10609 E

Turning Gear Operation andRunup of Generator

During runup of the turbine-generator, the cold airtemperature requires particular attention. Open controlvalves in cooling water outlet lines as soon as the cold airtemperature has risen to > 400C. Open control valves onlyto the extent required to adjust a cold air temperature of <400C in the exciter. In addition, adjust the two control valvesso that equal cooling water outlet temperatures are obtaineddownstream of the cooler sections (measured by meansof the thermometers in the outlet lines).

After load pickup, adjust control valves for a cold airtemperature of < 400C.

5 RunupDuring runup to rated speed, the bearing oil inlet

temperature should not be less than 350C but not higherthan 450C. The oil inlet temperature at the shaft seals shouldnot be less than 380C.Note : Do not run up generator to rated speed andvoltage as long as generator casing pressure [1] is notat rated value.

During runup, the critical speed ranges should bepassed through quickly and at a uniform rate.

Smooth running depends on several factors. Evenminor temperature differences of 1-2 deg C betweenopposite sides of the rotor may result in rotor distortionwhich could lead to inadmissible vibrations due tounbalance.

During runup, the bearing and oil temperatures shouldbe read and recorded at short intervals.

To prevent these thermal unbalances during runup, theturbine-generator should be run on turning gear. If thegenerator is run up following prolonged turning gearoperation, no restriction regarding the rate of runup needbe observed other than those required for the turbine.

6 Generator Air OperationBesides the above mentioned operating conditions. It

may be necessary in certain exceptional cases to operatethe generator without hydrogen. i.e. during initial runup ofthe unit to check the bearings and vibrations and for clean-up. In view of the high windage losses and the resultinghigh temperature rise of the air such air operation is onlypermissible for brief periods and only with generator non-excited.

The cold air temperature downstream of the coolersshould not exceed 400C. At higher cold air temperatures,the hydrogen coolers should be placed into service.

During generator air operation, the supply of seal oil tothe shaft seals must be ensured as well.

Also refer to the following information[1] 2.1-1850 Reactive capability curve

BHEL, Haridwar

Turbogenerators

Operation

Actual condition

in operationin operation

in operation

in operation

t = approx. 380C.

p = rated gas pressure > 96%

in operation

in operation

in service with reduced flow (approx. 10% of norminal flow)in operation and ventedfilled with water and vented, control valves closed

in operation

ready for operation

n >= 4 s–1 out of servicen >= 4 s–1 out of service

normalnormal

at r cold air > 400C, adjust cooling water flow required forremoval of loss heat.

n= approximately 90%

2.3-8011-0500/10609 E

Generator Startup Diagram

1 Command : Start up generator

Bearing vapour exhaustersExciter drying system

Primary water system

Seal oil system

Seal oil inlet temperature

Generator hydrogen pressureHydrogen purity

Measuring devices and supervisory equipment

Gas drying system

Hydrogen coolersPrimary water coolersExciter cooler

Coolant temperature control

Automatic voltage regulator

2 Command : Run up generator

Drying systemHeating system

Bearing vibrationBearing metal temperature

Exciter cooler

Speed

> 5 K

closed

set

n = rated speedset

set seal ring relief oil pressure for shaft seals

to required load, only within the region of the capabilitycurve

Differential temperature between H2 cooling gasand cold primary water

Field circuit breaker

Set point for rated voltage

SpeedPrimary water volume flows

Bearing vibrations

3 Synchronizing, parallelling and loading

SynchronizingParalleling

Loading

2.3-8011-0500/2

BHEL, Haridwar

Turbogenerator

Operation

2.3-8081-0500/10609 E

Permissible Synchronizing Criteria

BHEL, Haridwar

Turbogenerators

Operation

2.3-8170-0500/10609 E

Permissible Load Limits of Generator

Also refer to the following information[1] 2.1 - 1850 Reactive Capability curve[2] 2.1 - 1810 General and Electrical Data[3] 2.3 - 8181 Permissible Loading at Rated P.F.

during voltage and frequency deviations

1 Load Limits

For permissible generator loading, refer to the reactivecapability curve [1]. The following conditions are required:

Primary water cooling system is fully operational.Generator is filled with hydrogen at the rated pressureand all four hydrogen cooler sections are in operation.Generator is operated at rated frequencyGenerator is operated at rated voltage.

Any desired load setting is possible within the limitsindicated on the Reactive Capability Curve.

Load operation for long periods of time at reduced H2

pressure is, however, not permissible, since the statorprimary water pressure may then exceed the hydrogenpressure. This results in the possibility of primary waterescaping into the hydrogen atmosphere, should a leak bepresent in the primary water system within the stator.

2 Rate of Loading

During operation load variation is permissible withinthe limits or the reactive capability curve. The permissiblerate of loading depends on the condition of the windinginsulation Generators with a Micalastic stator windinginsulation and a rotor winding of silver-alloyed copper withglass laminate insulation can be suddenly loaded andunloaded if an automatic coolant control system isprovided and fully operational. The actual rate of loadingshould be matched to the permissible limits of the turbine.

3 Unbalanced Load

The continuously permissible unbalanced load asspecified [2] must not be exceeded under any operatingcondition. Unbalanced load is defined as the ratio ofnegative sequence current to rated current, with the ratedcurrent [2] not being exceeded in any of the three phases.

4 Load Restrictions

During the service life of the generator, operatingconditions may arise at the generator which require thegenerator to be operated at reduced load in order to avoid

damage to the unit. The following restrictions should beobserved for the conditions indicated :

4.1 Operation With Hydrogen Coolers Out of ServiceIf one of the four hydrogen cooler sections is out of

service, operation of the generator is permissible at notmore than 67% of rated load.

Operation at reduced load presupposes, however,that

Primary water cooling system of generator is fullyoperational.Dew point temperature of hydrogen atmosphere ingenerator is sufficiently below cold gas temperature.

This condition is normally obtained by drying theclosed generator with the gas drying system for not lessthan four weeks, with no leak developing in the generatorinterior during this period.Note : The actual-value transmitter for the hydrogentemperature control is located after cooler a, In theevent of a failure of this cooler, change over controlsystem from Automatic to Manual. The necessarycorrections should be performed manually.

4.2 Deviation of Rated Hydrogen PressureIf the specified hydrogen pressure [1] cannot be

maintained for unforeseeable reasons (e.g. lack of gas,high gas losses), the generator must be unloaded andde-excited when the rated pressure has dropped by 0.4kg/cm2. The cause of the gas loss should be identifiedand corrected.

4.3 Loss of Primary Water SupplyIf loss of primary water supply occurs, the generator

is disconnected from the system by the generatormechanical equipment protection and de-excited.Operation of the generator without full primary waterservice is not permissible.

4.4 Deviation of Rated Voltage and Rated FrequencyLoading of the generator with deviations from the

rated generator voltage and/or frequency is onlypermissible up to the limits shown in the attacheddiagram [3].

BHEL, Haridwar

Turbogenerators

Operation

Permissible Loading at Rated P.F.During Voltage and FrequencyDeviations

2.3-8181-0500/10609 E

10

9

8

7

6

5

4

3

2

1

0

-1

-5

-12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5

40

30

20

10

Continuous Operation At Rated MVA

Only Short Duration Operation At RatedMVA (But Continuous Operation at reducedload not permitted)

Continuous Operation At Reduced MVA ORRated MVA for Short Duration

PERMISSIBLE SHORT TIMEOPERATION (IN MINUTES) WITHRATED MVA AT RATED PF WITH10% VOLTAGE DEVIATION

FREQUENCY DEVIATION (%)

VOLT

AG

E D

EVIA

TIO

N (

%)

BHEL, Haridwar

Turbogenerators

Operation

2.3-8184-0500/10609 E

Generator Capability With HydrogenCoolers Out of Service on Water Side

Continuous Short time operationOperatopn Only permissible for cooler cleaning

100 % 66.6 %MVA MVA

Cooler in service

Cooler out of service

Operation with less coolers or higher output than shown is not allowed

123456123456123456123456123456

123456123456123456123456123456

BHEL, Haridwar

Turbogenerators

OperationUnbalanced Load-Time Curve

2.3-8187-0500/10609 E

RATED GENERATOR OUTPUT SN = 588.000 MVA (500 MW)RATED ARMATURE VOLTAGE UN = 21.000 kVRATED ARMATURE CURRENT IN = 16.166 kARATED FREQUENCY FN = 50.000 HzPOWER FACTOR PF = 0.850RATED H2 PRESSURE PE = 3.500 bar (G)COLD GAS TEMPERATURE TK = 45.000 Cel

PER UNIT NEGATIVE SEQUENCE CURRENT10

1

8 6 4 3 2 10 0

8 6 4 3 2 10-1 8 6 4 33

46

810

02

34

68

101

23

46

810

22

34

68

103

TIM

E T

IN S

EC

ON

DS

i 22 t

=10.

00 S

i 22 t

=0.0

8 , C

ON

TIN

UO

US

BHEL, Haridwar

Turbogenerators

OperationCurrent Overload Capability

2.3-8188-0500/10609 E

OVE

RLO

AD

CA

PAB

ILIT

Y

1

1.2

1.4

1.6

1.82

2.2

2.4

110

100

1000

TIM

E IN

SEC

STATOR CURRENT (P.U.)FIELD VOLTAGE (P.U.)

1

2

1.

AR

MA

TUR

E W

IND

ING

SH

OR

T TI

ME

TH

ER

MAL

R

EQ

UIR

EM

EN

TS (S

TATO

R C

UR

RE

NT

VS

TIM

E)

2.

FIE

LD W

IND

ING

SH

OR

T-TI

ME

TH

ER

MA

L

R

EQ

UIR

EM

EN

TS (F

IELD

VO

LTA

GE

VS

TIM

E)

BHEL, Haridwar

Turbogenerators

OperationRunback for Loss of Stator coolant

2.3-8190-0500/10609 E

CAUTIONIF STATOR COOLANT IS NOTRESTORED WITHIN 50 MIN-UTES OF INITIATION OFRUNBACK, THE TURBINE-GENERATOR MUST BETRIPPED.

CURRENT PER UNIT AMPERE

TIM

E I

N M

INU

TES

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

50

49

48

47

5

4

3

2

1

0

BHEL, Haridwar

Turbogenerators

Operation

Unloading Schedule For Increased

Cooling Water Inlet Temperature

2.3-8191-0500/10609E

40

4

2

44

46

48

50

52

54

45

4

7

49

51

53

55

60

62

CO

LD G

AS T

EMPE

RAT

UR

E (D

eg.C

)

CO

LD P

W T

EMPE

RAT

UR

E (D

eg.C

)

600

500

400

300

200

100 0

PERMISSIBLE LOAD OUTPUT (MW)

Gen

erat

or t

ype

THD

F 11

5/59

588.

00 M

VA, 5

00.0

00 M

W, 5

0 H

z, 0

.85

PF

BHEL, Haridwar

Turbogenerators

Operation

2.3-8310-0500/10609 E

Shutdown of Generator

During shutdown of the generator, the shaft liftoil pump must be started as soon as the unit reachesthe speed specified in the Turbine Instruction Manual.

To prevent any difficulties during a subsequentrunup due to thermal unbalances and the resultingrotor distortion, the turning gear must be started assoon as the turbine-generator coasts down to thespeed (turning gear speed) specified for the turbine(normally automatic) and maintained in operationwithout interruption until the rotor has cooled downto nearly room temperature.

Before the unit reaches turning gear speed, theH2 coolant temperature control system (if provided)should be changed over from the automatic to themanual mode. Use manual control to adjust a coolingwater vo lume f low through the H 2 coolers ofapproximately 5 to 10% of the nominal flow rate. Thisresults in a lower dew point temperature in thegenerator interior due to the condensation of moisturecontained in the gas on the cooler tubes and fins. Thecoolers should be operated with this cooling watervolume flow for approximately 15 hours.

BHEL, Haridwar

Turbogenerators

Operation

2.3-8311-0500/10609 E

Generator Shutdown Diagram

1 Command : Unload generator

Generator load

Generator main circuit breaker

Speed

Excitation

Exciter dryerAnticondensation heating system

Turning gear operation

Seal oil system

Gas system

Primary water system

Speed

Shutdown procedures

Actual condition

SN < 0.05 SN

automatic trip through reverse-power protection.

approximately 90%

field circuit breaker tripped

n<3.5s–1 inoperationn<3.5s–1 inoperation

see Turbine Instruciton Maual

in operation

in operation

in operation

n = 0 s–1; at room temperature

completed

BHEL, Haridwar

Turbogenerators

Operation

2.3-8400-0500/10609 E

Supervision of Generator DuringStandstillGeneral

1 Generator at Standstill With Seal Oil, Gas andPrimary Water System in Operation

Due to operational conditions, it may becomenecessary to shut down the generator for a shortperiod. With the unit at rest or on turning gear, themechanical hydrogen purity meter cannot give anindication due to the lack of differential fan pressure.When the unit at standstill, the bearing oil system canbe taken out of service. In the absence of anyoperat ional needs. e.g. inspect ion or faul ts ongenerator, the water and hydrogen should remain inthe generator in order to retain the most favorableprerequisites for a dry condition. All observationrequired for a generator partly taken into serviceshould be per formed, such observat ions beingessentially limited to the seal oil, gas and primarywater systems.

Normally it can be assumed that the generator wasoperated with the gas dryer during the precedingservice period. The generator interior will thus be indry condition provided that the cooling gas was notreplaced.

Special measures should be taken to preventcorrosion damage to the tubes of the hydrogen,primary water and exciter coolers during idle periods.During a brief outage, the coolers should be suppliedwith a small water flow. In addition, the coolers shouldbe flushed with the full water flow twice weekly.

In the case of prolonged outages, the coolersshould be drained on their water sides and dried.

To prevent the formation of a moisture film due tocondensation on the exciter coolers., the coolingwater supply should be isolated immediately aftershutdown of the unit, making sure that the exciterdrying system is functioning properly. In the case ofprolonged outages, the coolers should be drained on

thei r water s ides, dr ied and mainta ined in drycondition to prevent standstill corrosion in the coolertubes.

2 Generator at Standstill With Seal Oil, Gas andPrimary Water System Out of Operation

Preservation measures will have to be taken whenthe generator is to be shut down for a per iodexceeding two months with the seal oil, gas andprimary water systems to be taken out of operation.The scope of the preservation work required dependson the durat ion of the shutdown, on the overal lconditions in the vicinity of the unit and on the extentto which checks and inspections are possible duringsuch period.

After removal of the hydrogen from the generator,it is recommended to open the generator by removingtwo manhole covers and to connect a dryer or hot airblower for continuous drying or circulation of the airin the generator. Care should be taken to ensure thatthis equipment is connected in such a way that acirculation through the entire generator interior willbe accomplished.

To maintain the generator in satisfactory drycondition, the exciter enclosure must be kept closedand the exc i ter dry ing system must remain inoperation.

The hydrogen, primary water, exciter and seal oilcoolers should be drained to their water sides anddried by suitable measures.

These measures are intended to prevent anycondensation in the generator interior even undervarying environmental conditions to minimize the riskof stress corrosion cracking of the austenitic rotorretaining rings.

BHEL, Haridwar

Turbogenerators

Operation

2.3-8440-0500/10609 E

Supervision of GeneratorDuring StandatillCoolers

Suitable measures will have to be taken on all coolerstaken out of service to prevent standstill corrosion in thecooler tubes.

In the case of a brief outage, it will mostly be sufficient

to supply the coolers with a small water flow and to flushthem with the full water flow twice weekly.

In the case of a prolonged outage, the coolers shouldhowever, be drained on their cooling water sides anddried.

BHEL, Haridwar

Turbogenerators

Operation

2.3-8500-0500/10609 E

Supervision of GeneratorDuring StandstillSeal Oil System

After gas removal from the generator, the seal oilsystem can be taken out of operation, and monitoring ofthe generator is no longer required.

However, if the seal oil system remains activated,

monitoring of the generator must be continued. All sealoil pressure and temperature should be recorded at theprevious intervals, and attention should be given to allspecial occurrences.

BHEL, Haridwar

Turbogenerators

Operation

2.3-8510-0500/10609 E

Shutdown of Seal Oil System

The system should be taken out of service only for aprolonged shutdown of the generator requiring removalof the gas due to a major fault in the seal oil system.

The turbine-generator should be shut down and thegenerator rotor should be at standstill (n = 0 s–1)

Deactivate controls of seal oil pumps and bearingvapor exhausters.

If new shutoff valves or temperatures gauges mustbe installed, drain seal oil from respective pipe. Removedefective component and install a new part.

Draining of the seal oil circuit will not be required forother work. In the event of a longer shutdown of theturbine-generator, water must be drained completelyfrom the seal oil cooler or a small amount of water mustpass through the coolers continuously in order to preventstandstill corrosion.

To restart seal oil system if oil has been drained frompart of the circuit, the branch circuits should be refilledwith seal oil and placed in operation.

1 Shutdown of seal oilsystem

2Shut down turbine-generator

3Remove H2 gas from generator

4Stop seal oil pumps

5Terminate normal running routine

6Remove all faults, e.g. replace any defectiveshutoff valves or temperature gauges

BHEL, Haridwar

Turbogenerators

Operation

2.3-8520-0500/10609E

E

Draining the Air SideSeal Oil Circuit

The turbine-generator must have been shut down,and the generator rotor must be at standstill (n = 0 s–1).The hydrogen must have been removed from thegenerator, and all seal oil pumps should be out ofoperation.

MKW01 AA503 (after seal oil storage tank)MKW11 AA505 (after A1 valve)MKW31 AA505 (after A2 valve)MKW11 AA501 (before seal oil pump1)MKW21 AA501 (before seal oil pump 2)MKW31 AA501 (before standby seal oil pump 3)

MKW51 AA505 (drain, seal oil cooler 1)MKW51 AA511 (vent, seal oil cooler 1)MKW51 AA504 (drain, seal oil cooler 2)MKW51 AA510 (vent, seal oil cooler 2)

Air side seal oil circuit is now drained via the twodrain valves.

Before opening cooler drain and vent valves on waterside, close cooling water inlet valves.


After draining on their water sides, the coolers shouldbe dried to prevent standstill corrosion of the coolertubes.

Start with draining of hydrogen side seal oil circuit.

1 Preparatory work for drainingseal oil circuit

2Drain air side seal oil circuit

2.1Close shutoff valves

2.2Open cooler drain and vent valves on oilside

2.3Open cooler drain and vent valves on waterside

3Draining of air side seal oil circuit iscomplete

BHEL, Haridwar

Turbogenerators

Operation

2.3-8521-0500/10609 E

Draining the Hydrogen SideSeal Oil circuit

The turbine-generator must have been shut down,and the generator rotor must be at standstill (n = 0 s–1).The hydrogen must have been removed from thegenerator, and all seal oil pumps should be out ofoperation.

MKW03 AA501 (after seal oil tank)MKW13 AA503 (after hydrogen side seal oil pump)MKW03 AA502 (before seal oil tank)MKW13 AA510 (bypass of hydrogen side seal oilpump)

MKW13 AA504 (hydrogen side seal oil drain)MKW13 AA511 (hydrogen side seal oil drain)

Start hydrogen side seal oil pump. The seal oil pumpshould be kept in operation only until the seal oil hasbeen removed from the seal oil tank MKW93 BB001. Stopseal oil pump immediately afterwards.

The remaining seal oil can be drained through thedrain plug in bottom of seal oil tank.


Hydrogen side seal oil circuit is now drained via thetwo drain valves.

1 Preparatory work for drainingseal oil circuit

2Drain hydrogen side seal oil circuit

2.1Close shutoff valves at seal oil unit

2.2Open shutoff valves at seal oil unit.

2.3Start seal oil pump

2.4Open shutoff valve MKW113 AA503

2.5Open cooler drain and vent valves on oilside

2.3-8521-0500/2

Close cooling water inlet valves :


After draining on their water sides, the coolers shouldbe dried to prevent standstill corrosion of the coolertubes.

Start with draining of signal lines.

2.6Open cooler drain and vent valves on waterside

3Draining of hydrogen side seal oil circuit iscomplete

BHEL, Haridwar

Turbogenerators

Operation

2.3-8522-0500/10609 E

Draining the Seal Oil Signal Linesand Seal Ring Relief Piping

MKW11 AA507 (oil signal to A1 valve)MKW31 AA507 (oil signal to A2 valve)MKW13 AA508 (oil signal to C valve)MKW13 AA509 (oil signal to C valve)

MKW71 AA514 (air side vent valve, TE)MKW73 AA514 (hydrogen side vent valve, TE)MKW71 AA524 (air side vent valve, EE)MKW73 AA524 (hydrogen side vent valve, EE)

Drain seal oil filters through drain plugs in filterhousings.

MKW76 AA513 (TE seal ring relief)MKW76 AA523 (EE seal ring relief)

Loosen flanges at shutoff valves and drain seal oilfrom pipes for seal ring relief.

When restarting the system, ensure that all flangesare bolted to the shutoff valves, that all vent and drainvalves are closed and that valves closed for seal oildraining are reopened.

1Draining seal oil signal lines and

seal ring relief piping

2Drain signal pipes

2.1Open drain valves in signal pipes

2.2Open vent valves in seal oil valve rack

3Drain seal oil filters

4Drain seal ring relief piping

4.1Close shutoff valves in seal oil valve rack

5Draining of seal oil circuit is complete

BHEL, Haridwar

Turbogenerators

Operation

2.3-8600-0500/10609 E

Supervision of Generator DuringStandstillGas System

It is recommended to leave the hydrogen in thegenerator and to reduce the hydrogen pressure if thegenerator is to be shut down for a period up to twomonths.

It should, however, be observed that all alarmdevices must be set to the new operating values.Monitoring of the gas system must be continued as during

normal operation.

The gas must, however, be removed from the generatorif the seal oil system is taken out of service or for carryingout welding work within the range of the gas supplysystem or work on the generator. If the generator is filledwith air, the seal oil system can be taken out of service.

BHEL, Haridwar

Turbogenerators

Operation

2.3-8610-0500/10609 E

Gas RemovalLowering Hydrogen Gas Pressurein Generator

Prior to removing hydrogen (H2) from the generatorhousing, the generator must be at standstill or on theturning gear.

Carbon dioxide must be available in sufficientquantity. Check to ensure that the CO2 flash evaporatoris filled with heat transfer liquid up to lower edge of riser.

MKG25 AA519 (H2 filler line)MKG19 AA501 (after H2 pressure reducer, H2 unit)MKG19 AA502 (after H2 pressure reducer, H2 unit)MKG15 AA502 (before H2 pressure reducer 1, H2 unit)MKG17 AA505 (before H2 pressure reducer 2, H2 unit)MKG15 AA504 (for H2 high pressure)MKG15 AA501 (after H2 pressure reducer 1,

H2 bottle rack)MKG11 AA561 (before H2 pressure reducer 1,

H2 bottle rack)MKG16 AA501 (after H2 pressure reducer 2,

H2 bottle rack)MKG12 AA501 (before H2 pressure reducer 2,

H2 bottle rack)

Close all shutoff valves at H2 bottle rack manifoldand at H2 bottles.

Lower the gas pressure in the generator toapproximately 0.1 bar by opening shutoff valve MKG25AA 502. Switch three way valve MKG25 AA519 in positionH2 Vent Gas and vent the gas to atmosphere via orificeMKG25 BP502.

1 Preparatory work

1.1Check zero setting of CO2/H2 puritytransmitter

1.2Close shutoff valves and three-way valves

1.3Lower gas pressure in the generator

2Generator is ready for filling with CO2

BHEL, Haridwar

Turbogenerators

Operation

2.3-8620-0500/10609 E

Gas RemovalReplacing H2 With CO2

All lines carrying gas during this procedure arerepresented by yellow lines on the mimic diagram onthe gas valve rack.

Set range selector switch in CO2/H2 purity transmitterto position II (0 to 100% CO2 in H2)

Switch on heater of CO2 flash evaporator. Observetemperature rise of heat transmitting liquid at thetemperature gauge. Wait until the thermostat switchesoff the heater.

MKG25 AA502 (shutoff valve in H2 vent gas line)MKG25 AA518 (three-way valve in position CO2 Filling)MKG59 AA507 (shutoff valve after CO2 f lashevaporator)MKG51 AA561 (shutoff valve for high-pressure CO2)MKG25 AA519 (three-way valve in position H2 VentGas)

Then open shutoff valves at CO2 bottles and CO2bottle rack manifold. Replace empty CO2 bottles by fullbottles.

The CO2/H2 purity system measures the purity of thevent gas.

The generator is filled with CO2 when the indicatorshows a purity reading in excess of 95% CO2 in H2 Fillingwith CO2 can be terminated.

Then close shutoff valves :

MKG25 AA518 (three-way valve in CO2 filler line)MKG25 AA519 (three-way valve for measuring gas)MKG51 AA561 (shutoff valve or high-pressure CO2)MKG59 AA507 (shutoff valve after CO2 f lashevaporator)and all shutoff valves at CO2 bottles and CO2

bottle rack manifold.Switch off heater of CO2 flash evaporator.

Start with air filling.

1 Fill generator with carbon dioxide

1.1Set range selector switch to position II

1.2Switch on heater of CO2 flash evaporator

1.3Open shutoff valves and three-way valves

1.4Close three-way valve MKG25 AA507

1.5Measure CO2 purity

1.6Terminate filling with CO2

2Generator is filled with CO2

BHEL, Haridwar

Turbogenerators

Operation

2.3-8630-0500/10609 E

Gas RemovalReplacing CO2 With Air

All lines carrying gas during this procedure arerepresented by blue lines on the mimic diagram of the gasvalve rack.

Set range selector switch in CO2/H2 purity transmitterto position I (0 to 100% CO2 in air).

Establish hose connection between compressed airfilter MKG25 BT001 and shutoff valve MKG25 AA501.

MKG25 AA501 (shutoff valve in compressed air line)MKG25 AA509 (shutoff valve in compressed air line)MKG25 AA518 (three-way valve in position CO2 Vent Gas)

Ensure that compressed air is clean and dry, i.e. neitheroil nor water should be entrained in the air. Adjust thecompressed air pressure by means of shutoff valve MKG25AA509 so that the pressure in the generator will not exceed1 bar.

When the indicator gives a reading of 0% in air, thecarbon dioxide has been driven out of the generator.

Open shutoff valves downstream of the liquid leveldetectors and close three-way valve MKG25 AA518 forpurging the terminal box and the pipes to the leveldetectors. After purging, switch three-way valve MKG25AA518 to position CO2 Vent Gas and close shutoff valvesdownstream of liquid level detectors.

Close shutoff valves MKG25 AA501 and MKG25 AA509.

Disconnect hose connection between compressed airfilter MKG25 BT001 and shutoff valve MKG25 AA501 atbayonet fitting.

After approximately 15 minutes, close all shutoff valvesand three-way valves of the gas supply that are still open,except for the pressure gauge shutoff valves.

With the generator rotor at standstill (n = 0s–1), the sealoil supply to the shaft seals may also be shut down.

1 Fill generator withair

1.1Set range selector switch to position I

1.2Establish hose connection


1.4Terminate filling with air

1.5Remove hose connection

1.6Close shutoff valves and three-way valves

2

Stop normal running routine of gas system

BHEL, Haridwar

Turbogenerators

Operation

2.3-8650-0500/10609E

N2 Purging Before Drainingof Primary Water System

Primary water tank must be purged with nitrogen priorto complete or partial draining of primary water circuit toensure a removal of the H2 atmosphere and of the H2contained in the primary water. During purging, thehydrogen removed is vented to the atmosphere via thevent gas line.

Primary water pumps must be in operation.A reliable nitrogen supply must be available.

Note : The nitrogen used for purging must have a purityof 99.99%.

MKG31 AA501 (at N2 bottle)MKG31 AA502 (at N2 bottle rack manifold)MKG31 AA503 (before N2 pressure reducer)MKG35 AA501 (after nitrogen pressure reducer)MKG91 AA502 (in N2 purging gas line)

The nitrogen volume flow rate should be 600 dm3/h,corresponding to a bottle pressure drop of approximately15 bar/h for a 40 dm3 nitrogen bottle.

After a purging period of 12 hours, there will be nopotential hazards due to hydrogen atmosphere.

MKG31 AA501 (at N2 bottle)MKG31 AA502 (at N2 bottle rack manifold)MKG31 AA503 (before N2 pressure reducer)MKG35 AA501 (after N2 pressure reducer)MKG91 AA502 (in N2 purging gas line)

1 Preparatory work

2Purge primary water tank with nitrogen

2.1Open shutoff valves in N2 bottle rack andpurging gas system

2.2Check nitrogen purging gas volume flow

2.3Perform nitrogen purging procedure

2.4Terminate nitrogen purging

2.5Close shutoff valves in N2 bottle rack andpurging gas system

3Continue shutdown of primary water system

BHEL, Haridwar

Turbogenerators

Operation

After shutdown of the turbine-generator, the primarywater supply to the generator is maintained by keepingthe primary water pumps in service. This condition ispermissible for a prolonged period of time. Monitoringof the primary water system must be continued as duringnormal operation.

2.3-8700-0500/10609 E

Supervision of Generator During StandstillPrimary Water System

Water circulation in the primary water circuit or inindividual branch circuits can be stopped for shutdownsup to 48 hours if work must be performed on the primarywater system. If the water circulation is to be stoppedfor longer periods of time, complete or partial drainingof the primary water circuit will be required.

BHEL, Haridwar

Turbogenerators

Operation

2.3-8720-0500/10609 E

Shutdown of Primary Water Systemfor Less Than 48 Hours

Caution : The primary water system may only be shutdown when generator is carrying no load and has beentaken out of operation (n = 0s–1).

Shutdown is defined as any of the following.

Stopping water circulation in branch circuits byclosing respective valves.Completely or partially draining primary water system.

If primary water circulation cannot be maintainedbecause of faults in the primary water cooling circuit,the entire cooling circuit may be shut down for a periodup to 48 hours.

Primary water circulation is stopped by taking primarywater pumps out of service.

When taking branch circuits out of service, theprimary water pumps can be maintained in operation.

Temporary drinking of individual branch circuitsshould be performed in accordance with the followinginstructions.

Close control valve MKF82 AA501. When this valveis closed, primary water remains in stator winding branchcircuit.Caution : Open shutoff valve MKF80 AA504 prior totaking stator winding branch circuit out of service.

Take bushing and phase connector branch circuit outof service by closing valves.

MKF83 AA501 (control valve before bushings)MKF83 AA502 (shutoff valve after bushings)

1Shut down primary

water system for lessthan 48 hours

2Will entire primary water cooling circuitbe deactivated?

Yes

2.1Stop primary water circulation

2.2Primary water cooling circuit can be leftin this condition for a period up to48 hours

3Take branch circuits out of service

3.1Take stator winding branch circuit outservice

3.2Take bushing and phase connector branchcircuit out of service

No

2.3-8720-0500/2

Isolate the water treatment system by slowly closingvalves.

MKF60 AA502 (control valve for water treatmentsystem)MKF60 AA519 (shoutoff valve after water treatment system)

3.3Take water treatment system out ofservice

4Primary water can be left in individualbranch circuits for periods up to 48 hours

BHEL, Haridwar

Turbogenerators

OperationShutdown of Primary Water Systemfor More Than 48 Hours

2.3-8730-0500/10609 E

Caution : The primary water system may only be shutdown when generator is carrying no load and has beenshut down (n = 0s–1).

The primary water system should be deactivated onlywhen faults occur in primary water system or duringprolonged turbine-generator shutdowns requiringpreservation measures.

For shut downs of more than 48 hours complete ofpartial draining of the primary water circuit is required.

Caution : Primary water contains dissolved hydrogen.Primary water tank must be purged with nitrogen priorto complete or partial draining of primary water coolingsystem, purge with inert gas for 12 hours to avoidpotential hazards due to hydrogen atmosphere.

During nitrogen purging, the primary water must becirculated by means of the primary water pump to ensurea uniform removal of the H2 gas in the entire primarywater cooling circuit.

Reduce pressure in primary water tank toatmospheric level by adjusting overflow regulator MKF91AA003.

De-energize :

Conductivity transmittersLevel detector system at primary water tankVolume flow indicators for stator winding and

bushingsTemperature detectorsCoolant temperature control systemPower circuits of pumps

Complete of partial draining of primary water circuitis necessary only if work must be performed on the circuitwhich requires an empty system.

If only one branch circuit is drained for performingthe repair works, remaining branch circuits may remainfilled provided that

Electrical measuring devices in remaining branch

1Shut down primary water

system for more than48 hours

2 Purge primary water tank with nitrogen (N2)[1]

3 Reduce pressure in primary water tank

4 De-energize electrical equipment in primary water system

5Drain compeleteprimary water circuit orbranch circuits

2.3-8730-0500/2

6Stop normal running routine of branchcircuits taken out of service

circuits remain activated.

Nitrogen purging of primary watertank is continued.Primary water is treated.Primary water circulation is maintained by primarywater pumps

Draining of individual branch circuits should beperformed in accordance with the following instruction.

BHEL, Haridwar

Turbogenerators

Operation

If the coling qwater cirvulation is stopped for maorethan three days, the coolers shoud be drained and dried.

If operation can presumably be resyume within theeedays, the coolerw may remain filled with cooling waterprovided that the cooler tubes are free from deposits. Withdeposti fuild-up, the cooling water should be drained andthe tubescleaned and flushed with clean water. Teh waterchannels whould be kept open untill the unit is restarted.

During brief shutdowns (less that three days) thecoolers may also be kept in service at low cooling watervelocities if this serves to avoid deposits in the tubes.

Close shutoff valve before and after coolers filled ontheir cooling water sides. Check shutoff valves of standbycooler for closed position.

Close drain valve of standby cooler not filled on itscooling water side. Ten open drain and vent valves ofcoolers filled on their cooling water sides.

After opening of the valves, the water is drained fromthe coolers filled on their cooling water sides. Reopen drainvalve of standby cooler as soon as water has been drainedfrom coolers.

Establish a compressed air connection at vent manifoldof primary water coolers.

Make sure that compressed air is free from oil, dustand other contaminants.

Blowing out may be rerminate when air leaving the drainvlaves is free of atomized water.

2.3-8732-0500/10609 E

Draining the Primary Water SystemPrimary Water Coolers (Cooling Water Side)

1 Drain primary water coolerson cooling water side

2 Close shutoff valves before and after coolers

3Open drain and vent valves at coolers

4

Dry coolers with compressed air

5Primary water coolers are dained and dryon their cooling water sides

BHEL, Haridwar

Turbogenerators

Operation

2.3-8734-0500/10609 E

Draining the Primary Water SystemStator Winding

Prerequisites for draining :

Primary water tank was purged with N2 [1].Measuring devices and supervisory equipement inthis primary water branck cirvuit nust have beendeactivated.

Close control valve before stator winding.Remove inlet and outlet pipes, If required, clean the

two strainers inthe sttor winding inlet and outlet. Establishhose connections between waste water wywtem anddrain, valves of primary water manifolds.

Stator winding is drained by blowing out winding withcompressed air.

Make sure that the compressed air is free from oil,dust and other contaminants.

Establish a compressed air connection at primarywater inlet flange of exciter end water manifold.

Open drain valves at primary water manifolds.Close drain valve at exciter end primary water

manifold when water is no longer being drained.Open compressed air valve briefly at reasonable

intervals, permitting water to be driven out via the drainvalve at the turbine end primary water manifold.

Open compressed air valve fully when only a smallamount of water accumulates.

Shut off compressed air supply at times during thisprocedure to allow water to accumulate.

Open drain valve at exciter end primary watermanifold briefly several t imes during blowing-outprocedure to drain accumulated water.

Blowing out stator winding may be terminated whenair leaving the system is free of atomized air.

Slowly empty one nitrogen bottle through the statorwinding. connect nitrogen supply to primary water inletflange of exciter end manifold. Purging period shouldamount to approximately two hours. Carefully close inletand outlet after purging. N2 purging should be performeddaily.

1 Drain stator winding

2

Preparatory work prior to draining

3

Blow out stator winding with compressedair

4 Purge stato winding with N2

If the stator winding is to be preserved for a prolongedshutdown, obtain the help of manufacture’s product servicepersonnel.

2.3-8734-0500/2

After refer to the following information[1] 2.3-8650 N2 Purging Before Draining the Primary

Water System

5

Pressure stator winding

6

Stator winding is drained and preserved

BHEL, Haridwar

Turbogenerators

Operation


2.3-8738-0500/10609 E

Draining the Primary Water SystemTerminal Bushings and Phase Connectors

Primary water tank was purged with N2 [1].Measuring devices and supervisory equipement in thisprimary water branch circuit have been deactivated.

Close valves:

MAKF83 AA501 (before bushings)MAKF83 AA501 (after bushings)

Remove inlet pipe near the neutral point.

Phase connectors and bushings are drained by blowingthem out with compressed air.

Make sure that the compressed air is free from oil, dustand other contaminants.

Connect a compressed air source to inlet flange.Establish a hose connection between the waste watersystem and the outlet fkange.

Deactivate voulume flow indicators

MKF83 CF001A (phase A bushings)MKF83 CF001B (phase A bushings)MKF83 CF011A (phase B bushings)MKF83 CF0011B (phase B bushings)MKF83 CF021A (phase C bushings)MKF83 CF021B (phase C bushings)

by closing shutoff valves at valve assemblies.Open compressed air valve, and blow out phase

connectors and bushings for several hours.Intermittetly shut off compressed air supply during this

procedure, allowing water to accumulate.Blowing out can be terminated when air leaving the

system is free of atomized air.

To prevent oxidation, purge phase connectors andbushings with nitrogen. Connect nitrogen supply to inletflange. The purging period should amount to approximatelytwo hours,and the bottle pressure should drop byapproximately 5 bar (70 psi). Carefully close inlets andothers after ourging. N2 purging should be performed daily.

1 Drain terminal bushingsand phase connectors

2

Preparatory work prior to draining

3Blow out phase conectors and bushingswith compressed air

4Purge phase conectors and bushingswith N2

If the phase connectors and busings are to be preservedfor a polonged shutdown. Obtain the help ofmanufacturerer’s product service personel.

2.3-8738-0500/2

After refer to the following information[1] 2.3-8650 N2 Purging Before Draining the Primary

Water System

5

Pressure phase conectors and bushings

6Phase conectors and bushings aredrained and preserved

BHEL, Haridwar

Turbogenerators

Operation

2.3-8746-0500/10609 E

Draining the Primary Water SystemWater Treatment System

Also refer to the following information[1] 2.3-8650 N2 Purging Before Draining the Primary

Water System


Primary water tank was purged with N2 [1].Measuring devices and supervisory equipement in thisprimary water branch circuit have been deactivated.

Note: When draining primary water treatment system,make sure that ion exchanger resins remain immersedin water.

To do this, isolate ion exchanger by closing valves:

MKF60 AA502 (control valve before ion exchanger)MKF60 AA509 (shutoff valve after ion exchanger).

Drain water treatment system by closing shutoff valve

MKF60 AA519 (shutoff valve for primary watertreatment system)

and opening shutoff valves:

MKF60 AA503 (vent before ion exchanger)MKF60 AA511 (drain,fine filter)MKF60 AA512 (vent, fine filter)MKF60 AA510 (drain, primary water treatment system)MKF60 AA517 (drain, water treatment system).

Connect vent valve MKF60 AA503 to compressed airsystem.


Blowing out can be terminated when air leaving thedrain valve is free of atomized air.

1 Drain water treatemnt system

2

Take ion exchanger out of service

3Drain water treatment system

4Drain and dry piping system withcompressed air

5Water treatment system is drained anddry

BHEL, Haridwar

Turbogenerators

Operation

2.3-8748-0500/10609 E

Draining the Primary Water SystemExternal Part of Primary Water Circuit

Also refer to the following information[1] 2.3-8650 N2 Purging Before Draining the Primary

Water System


Primary water tank was purged with N2 [1].All branch circuits were drained or isolated from externalpart of primary water circuit by closing valves. Isolatingbranch circuits is, however, only permissible if externalpart of primary water circuit is filled again with waterand taken into service within 48 hours.Primary water pumps are not in service.

Drain primary water from external primary water circuitby closing all drain and vent valves in the externalprimary water circuit.

Establish a connection to the compressed air system at asuitable point (high static head of the external primary watercircuit.


Blowing out can be terminated when air leaving thevent and drain valves is free of atomized air.

1 Drain external part ofprimary water circuit

2Dry piping system with compressed air

3

External part of primary water circuit isdrained and dry

BHEL, Haridwar

Turbogenerators

Operation

2.3-8900-0500/10609 E

Supervision of GeneratorDuring StandstillExciter

With the generator on turning gear or at standstill,the dryer and the space heaters must be in operation.

The filter pads installed at the dryer inlet shouldbe carefully checked for contamination at regularintervals and cleaned or replaced in due time.Caution : Never place dryer into operation without

make-up air filter.The brushes of the ground fault detection system

should be lifted off the measuring sliprings to preventthe formation of rust on the sliprings. In the case of aprolonged outage, a protective coating should beapplied to the measuring sliprings.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9000-0500/10609 E

Fault TracingGeneral

The details given herein on faults, their possible causesand the corrective measures cannot be consideredcomplete in every respect, since all possible troubles cannotbe covered in advance. In most cases, the operator willhave to decide on the measures to be taken. The individualmeasures required depend on the mode of operation.

Unless corrective measures can be taken in accordancewith the following instruction. The turbine-generator shouldbe shout down and the hydrogen should be replaced withcarbon dioxide. If required, the services of the manufacturershould be requested. In most cases, however, sufficientdetails will be found in the Turbogenerator Manual.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9200-0500/10609 E

Fault TracingStator and Generator SupervisoryEquipment

Fault/CauseDifferences in slot temperatures between individualphases of stator winding

High hot gas temperatureand/orHigh cold gas temperature

Hydrogen temperature control is disturbed. Insufficientcooling water flow volume through hydrogen coolers.

Insufficient cooling water volume flow through asingle hydrogen cooler.

Unbalanced load due to unequal phase loading ofthe system connected to generator

Liquid in generator

RemedyThe embedded RTD's should be checked when

different slot temperatures are indicated while statorcurrents are of equal magnitude in all the three phases.Such a check should only be made with the generator atrest and in non-excited condition. The check shouldinclude resistance measurements as well as testing ofthe detector leads, the measuring point selector switchesand the indicators. Care should be taken duringresistance measurements of the embedded RTD's toensure that they are not heated as this will falsify theresults. In many cases, a fault can be cleared byrecalibration of the RTD's.

Note: If cold gas temperature continues to rise, aturbine trip is activated via the generator mechanicalequipment protection.

Verify cause of disturbance by checking analogindicators (uniform rise of temperatures at all coolers).

Set temperature control from Automatic to manualmode and increase cooling water volume flow by openingthe final control element. If necessary, the final controlelement should be manually opened.

Verify cause of disturbance by checking analogindicators (temperature rise at one cooler).

Check to ensure that the cooling water inlet valve isfully open. Lower cold gas temperature of disturbedcooler by adjusting the cooling water volume flow withthe cooling water outlet valve. Ensure that cold gastemperatures after all hydrogen coolers are of equalmagnitude.

If the generator is operated with unbalanced load dueto particular system conditions, care must be taken thatthe continuously permissible unbalanced load is notexceeded [1]. The unbalanced load is defined as theratio of negative sequence current to rated current. Thepermissible rated stator current should not be exceededin any stator phase. When the unbalanced load, stepsshould be taken for bringing about a uniform system load.The generator should be shut down if it is impossible todistribute the system load more uniformly over the threephases.

The l iquid in the generator casing should beinspected to determine its origin, i.e. defective hydrogencooler section, oil from shaft seals, primary water ormoisture condensate.

To do this, close shutoff valve before level detector

Also refer to the following information

[1] 2.1-1810 General and Electrical Data[2] 2.3-8170 Permissible Load Limits of Generator[3] 2.3-9440 Fault Tracing-Coolers[4] 2.3-9561 Fault Tracing- Oil Level in Seal Oil System

2.3-9200-0500/2

Fault/Cause

Moisture condensate

Cooling water from a defective hydrogen cooler

Primary water

Oil

Remedy

which activated the alarm. Drain the liquid via the shutoffvalve after the level detector and inspect liquid.

Then close shutoff value after level detector andreopen shutoff valve before level detector.

Repeat this procedure until no liquid is drained fromthe shutoff valve.

If the liquid cannot be drained from the generator inthis manner within a reasonable period of time, whichwill be the case on occurrence of a large leakage, thegenerator should be shut down immediately.

Very small water quantities are indicative of moisturecondensate. Place gas dryer in operation.

A hydrogen sample should be extracted from thegenerator and examined in a laboratory to determine itsmoisture content.

Larger amounts of water point to a leaking coolersection.

Identify defective cooler section. Reduce generatorload [2] and take cooler section out of service by closingthe shutoff valves. Then take measures outlined in therespective instruction [3].

Since the primary water pressure is lower than theH2 casing pressure during generator operation at ratedhydrogen pressure, liquid accumulation in the generatorcan only occur in case of a larger leakage (tube failure,burst Teflon hose). The leakage water quantities require,however, a shutdown of the turbine-generator.As soon as the generator has been disconnected fromthe system and de-excited, take primary water pumpsout of service and close control valves before statorwinding and bushings. Remove hydrogen from thegenerator immediately. Fault tracing and correctiveaction may be started as soon as the generator is filledwith air.

Oil level control in seal oil tank is disturbed.Prechambers in generator are overflowing.Take corrective actions as described in [4]

immediately.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9280-0500/10609 E

Fault TracingGenerator Supervisory EquipmentCoolant Temperature Control

Fault/CauseLow coolant differential temperature

Hydrogen temperature control is disturbed. Coolingwater volume flow through hydrogen coolers isinsufficient.

Primary water temperature control is disturbed. Coolingwater volume flow through primary water coolers isexcessive.

Low coolant differential temperature

Hydrogen or primary water temperature control isdisturbed.

Remedy

The temperature difference between the cold primarywater and the cold gas amounts to 3 K only.

Verify cause of disturbance at analog indicators.Change over control to manual mode and increase

cooling water volume flow until a temperature differenceof 5 K is obtained. If necessary, open control valvemanually on unit.

If the temperature difference cannot be increased bythis corrective measure, change primary watertemperature control over to manual mode and throttlecooling water volume flow through primary water coolers.

Verify cause of disturbance at analog indicators.Change over control to manual mode and increase

cooling water volume flow until a temperature differenceof 5 K is obtained. If necessary, throttle control valvemanually on unit.

If the temperature difference cannot be increased bythis corrective measure, change hydrogen temperaturecontrol over to manual mode and increase cooling watervolume flow through hydrogen coolers.

Caution: Temperature difference between coldprimary water and cold gas has dropped to 1 K.

Condensation may occur on primary water cooledcomponents when surface temperature of thesecomponents drops below dew point of surroundinghydrogen atmosphere.

If the temperature difference between the coldprimary water and the cold gas cannot be increased by\the above corrective measures, it is recommended tounload and de-excite the generator at once.Note: On-load running is possible when the dew pointtemperature of the hydrogen in the machine issufficiently below the cold gas temperature. This willnormally be the case when the closed generator wasdried with the gas dryer for not less than four weeksand provided that no leakage occurred in the generatorinterior during this period.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9310-0500/10609 E

Fault TracingRotor

Fault/Cause

Sudden deterioration of rotor running condition.

Remedy

Check whether the deteriorated running conditionoriginated due to the turbine or whether the rotorbearings are damaged. A deterioration of the runningcondition may be caused by a change in the balancingcondition or by a rotor winding short. Unload and shutdown turbine generator as soon as feasible if causecannot be located and corrected for severe condition.Since it is very difficult in most cases to find a definitecause, i t is adv isable to obta in the help ofmanufacturer's product service personnel.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9440-0500/10609 E

Fault TracingCoolers

Fault/Cause

Liquid in Generator

This fault is due to a leaking or defective H2 coolertube.

Remedy

Identify the defective cooler section. First, close coolingwater outlet of this cooler section and then the cooling waterinlet.

Close shutoff valve before the level detectors that haveinitiated the alarm. Drain the liquid by means of shutoffvalves after the level detectors. Repeat this procedure untilno liquid is drained through the shutoff valves. Thisprocedure ensures that no hydrogen can escape form thegenerator through the shutoff valves.

Shut down generator and remove the hydrogen withcarbon dioxide. Fill generator with air to a gauge pressureof approximately 0.5 bar (7 psig). Remove the returnwater channel. Ensure that gaskets are not damaged.

After removal of the cover of the return water channel,the defective tube can be easily identified since air bubblesemerge from this tube. Mark defective tube and drain coolingwater. Detach cooling water lines, seal cap and inlet/outletwater channel. Ensure that gaskets are not damaged. Plugthe defective tube at both ends. Insert plugs by light hammerblows into upper and lower tube sheets. To reassemble thecomponents, follow disassembly procedure in reverse order.The cooler section should be filled with water and

1 Shutoff valve before level detector2 Level detector3 Sight glass4 Shutoff valve after level detector

Fig. 1 Arrangement of Level Detectors

1

2

3

4

2.3-9440-0500/2

Fault/Cause

vented. Check water channels to ensure there is no leakage.The generator should be filled with gas, run up,

synchronized and loaded.This temporarily repaired cooler may be maintained in

operation until next inspection or outage, at which time thetube bundle or defective cooler tube should be replaced.

1 Plug2 Upper tubesheet3 Cooler tube4 Lower tubesheet

Fig. 2 Plugging a Defective Cooler Tube

1

2

3

4

BHEL, Haridwar

Turbogenerators

Operation

2.3-9450-0500/10609 E

Fault TracingBearings

Fault/Cause

Generator bearing temperatures vary.

Bearing oil pressure indicated in the shaft lift oil pipe drops.

Remedy

Temperature variations at the generator bearingsmay be due to different causes. Turbogenerator canbe kept in operation as long as permissible bearingtemperature is not exceeded. When a variation isnoted, the operating temperatures should be carefullymonitored to ensure the l imit temperature is notexceeded.

I f a dev iat ion occurs, f i rs t check co ld o i ltemperature (oil temperature after cooler) and bearingoil pressure for deviation from normal. If bearingtemperature rise does not result from a variation ofthese values, the oil pressure indicated in the shaftlift oil pipe should be checked. If bearing temperatureexceeds permissible value, turbogenerator should beshut down.

Oil pressure depends in part on the bearing oil inlettemperature. Check first to determine whether thepressure drop was caused by an oil temperaturevariation. If not, the shaft lift oil system should bechecked for leakages. The fault may be due to a leakat the check valve in the lift oil pipe. To determine ifthe check valve is leaking, close globe valve in thelift oil line. Prior to closing valve, check and recordthe setting (Throttling valve as set for operation). Thischeck is performed by counting the number of turnsor by measuring the travel.

If, on closing the globe valve, the pressure gaugeshows an increase over the previous operating valve,the check valve is leaking. Replace or repair the checkvalve at the next shutdown or inspection. A preciseadjustment of the throttling element will again benecessary during re-commissioning.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9521-0500/10609 E

Fault TracingBearing Vapour Exhausters

Fault/Cause

Bearing vapour exhauster 1 failed.

Fuses or thermal overload device have tripped maincontactor, result ing in fai lure of bearing vapourexhauster 1.

Bearing vapour exhauster 2 failed.

Fuses or thermal overload device have tripped maincontactor, resulting in failure of bearing vapourexhauster.

Bearing vapour exhauster 1, loss of control voltage.

Fuse has blown, resulting in loss of control voltage.

Bearing vapour exhauster 2, loss of control voltage.

Fuse has blown, resulting in loss of control voltage.

Remedy

Bearing vapor exhauster 2 automatically takes overventing of generator bearing compartments. Verify thatvoltage is a available. Check fuses and thermal overloaddevice. Examine bearing vapor exhauster 1 for properelectrical and mechanical condition. Check operating pointsof flow transmitters.

Bearing vapor exhauster 1 automatically takes overventing of generator bearing compartments. Verify thatvoltage is available. Check fuses and thermal overloaddevice. Examine bearing vapor exhauster 2 for properelectrical and mechanical condition. Check operating pointsof flow transmitters.

Identify cause of blown fuse (overcurrent or short incable). Replace defective fuse and restart bearing vaporexhauster 1.

Identify cause of blown fuse (overcurrent or short incable). Replace defective fuse and restart bearing vaporexhauster 2.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9523-0500/10609 E

Fault TracingSeal Oil Pumps

Fault/Cause

Seal oil pump 1 failedFuses or thermal overload device have tripped main

contactor, resulting in failure of seal oil pump 1.

Seal oil pump 2 failedFuses or thermal overload device have tripped main

contactor, resulting in failure of seal oil pump 2.

Seal oil pump 3 failedFuses or thermal overload device have tripped the

main contactor, resulting in failure of seal oil pump 3(stand by seal oil pump). Hydrogen side seal oil pump isstopped simultaneously.

Seal oil pump 1, loss of control voltageFuse has blown, resulting in loss of control voltage.



Remedy

In the event of a failure of seal oil pump 1, seal oil pump2 automatically takes over the seal oil supply to the shaftseals.

Check if voltage is available. Check fuses and thermaloverload device. Examine seal oil pump for propermechanical and electrical condition.

Start seal oil pump 1 after fault is corrected.

In the event of a failure of seal oil pump 2, seal oil pump3 (stand-by seal oil pump) automatically takes over the sealoil supply to the shaft seals if seal oil pump 1 has failedtoo.Caution: If one of the two failed seal oil pumps cannottake over the seal oil supply to the shaft seals immediately,make all preparations for shutdown of generator and gasremoval.

Check if voltage is available. Check fuses and thermaloverload device. Examine seal oil pump 2 for propermechanical and electrical condition.

Correct fault immediately so that seal oil pump can bepromptly restarted.

Sealing and lubrication of shaft seals with seal oil canno longer be maintained.Caution: Hydrogen glows into generator bearingcompartments via sealing gap and is extracted bybearing vapour exhauster in service.

If another seal oil pump cannot be started immediately,de-excite and shut down generator and remove hydrogengas promptly.

Isolate H2 supply to generator by means of therespective shutoff valves. Bring three-way valve MKG19AA519 to H2 vent gas position and place CO2 flashevaporator in operation.

Displace hydrogen with carbon dioxide.

Identify cause of blown fuse (overcurrent or short incable). Replace defective fuse and ensure that seal oilpump 1 can be restarted.

Identify cause of blown fuse (overcurrent or short incable). Replace defective fuse and ensure that seal oilpump 2 can be restarted.

Identify cause of blown fuse (overcurrent or short in

2.3-9523-0500/2

Fault/Cause

Hydrogen side seal oil pump failedFuses or thermal overload device have tripped main

contactor due to loss of control voltage.

Remedy

cable). Replace defective fuse and ensure that seal oilpump 3 can be restarted.

Shaft seals are now supplied with seal oil from the airside seal oil circuit only. Seal oil drained towards thehydrogen side of the shaft seals is returned to the seal oilstorage tank via seal oil tank MKW03 BB001 and float valveMKW03 AA001.Note: Seal oil saturated with air is now also supplied tohydrogen side shaft seals. Air entrained in seal oil escapesinto generator, resulting in a deterioration of H2 purity.

Verify that voltage is available. Check fuses and thermaloverload device.

Visually examine pump to determine condition ofmechanical parts. Start pump immediately after the fault iscorrected. Verify that pressure gauges indicate previousoperating values.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9531-0500/10609 E

Fault TracingSeal Oil Pressures and Temperatures

Fault/Cause

Low seal oil pressure after air side oil filterSeal oil filter in service is contaminated.

High differential pressure across air side oil filterSeal oil filter in service is contaminated.

High differential pressure across hydrogen side oilfilter

Seal oil filter in service is contaminated.

Low air side seal oil pressure, TE/EEA1 or A2 valve no longer controls to operating value.Air side seal oil pump MKW11 AP001 or MKW21

AP001 is disturbed.Seal oil filter MKW51 BT002 is contaminated.

Low hydrogen side seal oil pressure, TE/EEC valve no longer controls to operating value.

Hydrogen side seal oil pump MKW13 AP001 is disturbed.Seal oil filter MKW53 BT002 is contaminated.

Low differential seal oil pressure, TEPreset differential pressure between air side and

hydrogen side seal oil systems no longer exists.

Low differential seal oil pressure, EEPreset differential pressure between air side and

hydrogen side seal oil systems no longer exists.

High seal oil temperature after air side / Hydrogenside cooler

Cooling water flow is too low or cooler is contaminated.

Remedy

Place stand by filter into service in order to determinewhether pressure drop is due to a contaminated filter.

Change over to stand by filter with changeover valveassembly. Deactivate contaminated filter.

Remove filter cover and screen filter. Thoroughly cleanscreen filter and reassemble filter. Fill filter housing withturbine oil prior to reassembly.

Change over to stand by filter with changeover valveassembly. Deactivate contaminated filter.

Remove filter cover and screen filter. Thoroughly cleanscreen filter and reassemble filter. Fill filter housing withturbine oil prior to reassembly.

Check settings of A1 and A2 valves. Check air sideseal oil pump in service. Check and, if required, clean airside seal oil filter.

Alarm is activated through pressure gauge with contact.Check setting of C valve. Check hydrogen side seal oilpump. Check and, if required, clean hydrogen side seal oilfilter.

Vent pressure equalizing valve.

Vent pressure equalizing valve.

Verify that correct relationship exists between coolingwater flow and seal oil temperature. If cooling water flow istoo low, increase the cooling water flow by opening theshutoff valves in cooling water outlet pipes. Failure of sealoil temperature to decrease is indicative of a dirty cooler.

Place stand by cooler in operation by means of rotaryvalve set.

Ensure that other cooler is properly vented on its oiland water sides. Thoroughly clean cooler taken out ofoperation on its water side.

2.3-9531-0500/2

Fault/Cause

Varying pressure gauge indicationsEntrapped air in pipes.

Transmission of mechanical vibrations.

Insufficient control range of differential pressureregulating valves

Remedy

Variations in oil pressure are usually due to entrappedair in regulating valves or oil delivery lines. Thoroughly ventall lines and regulating valves.

Check whether mechanical vibrations transmitted tomovements are due to lines or foundation.

Insufficient control range of A1 valve:Keep shutoff valve MKW11 AA505 closed until pressure

gauge readings remain constant.Insufficient control range of A2 valve:Keep shutoff valve MKW31 AA505 closed until pressure

gauge readings remain constant.Insufficient control range of C valve:Keep shutoff valve MKW13 AA505 closed until pressure

gauge readings remain constant.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9551-0500/10609 E

Fault TracingRelief Valves in Seal Oil System

Fault/Cause

Relief valve of seal oil pump in service operatesduring operation with A1 valve

Shutoff valves MKW11 AA505 and MKW11 AA504are closed.

Main bellows in A1 valve is defective, resulting in arise of seal oil pressure before the shaft seals. A1 valvemay only be taken out of service when operation withA2 valve is ensured.

Relief valve of seal oil pump in service operatesduring operation with A2 valve

Shutoff valves MKW31 AA505 and MKW31 AA504are closed.

Main bellows in A2 valve is defective, resulting in arise of seal oil pressure before the shaft seals. A2 valvemay only be taken out of service when operation withA1 valve is ensured.

Relief valve MKW13 AA001 operates.Shutoff valve MKW13 AA510 is closed.Main bellows in C valve is defective, resulting in a rise

of seal oil pressure before the shaft seals.

Remedy

Open shutoff valves MKW11 AA505 and MKW11AA504.

Open shutoff valve MKW11 AA508.Check that A2 valve regulates to operating pressure.Close shutoff valve MKA23 AA504 in gas signal line

and shutoff valve MKW11 AA506 in oil signal line.Close shutoff valves MKW11 AA504 and MKW11AA505.Disconnect gas signal l ine from valve head.

Dismantle valve head and replace main bellows.Refit valve head and gas signal line.Slowly open shutoff valve MKA23 AA504 and

afterwards shutoff valve MKW11 AA506. Vent oil signalline through vent plug.

Open shutoff valves MKW11 AA504 and MKW11AA505 and close shutoff valve MKW11 AA508.

Ensure that previous operating values are restoredduring operation with A1 valve. If required, readjust A1valve.

Open shutoff valve MKW31 AA505, MKW31 AA504and MKW11 AA508.

Open shutoff valve MKA23 AA504, MKW11 AA506and MKW11 AA504 and MKW11 AA505 and check thatA1 valve regulates to operating pressure.

Close shutoff valve MKW23 AA503 in gas signal lineand shutoff valve MKW31 AA506 in oil signal line.

Close shutoff valves MKW31 AA504 and MKW31AA505.

Disconnect gas signal l ine from valve head.Dismantle valve head and replace main bellows.

Refit valve head and gas signal line.Slowly open shutoff valve MKA23 AA503 and

afterwards shutoff valve MKA31 AA506. Vent oil signalline through vent Valve MKW31 AA507. Open shutoffvalves MKW31 AA504 and MKW31 AA505 and closeshutoff valve MKA23 AA504, MKW11 AA506, MKW11AA504 AND MKW11 AA505.

Ensure that previous operating values are restoredduring operation with A1 valve.

Open shutoff valve MKW13 AA510.Take hydrogen side seal oil pump out of service. The

shaft seal are now supplied with seal oil from the airside seal oil circuit only.

2.3-9551-0500/2

Remedy

Close shutoff valve MKW13 AA510.Close shutoff valve MKW13 AA505 in air side seal

oil signal line and shutoff valve MKW13 AA506 inhydrogen side seal oil signal line.

Disconnect air side seal oil signal line from valvehead. Dismantle valve head and replace main bellows.Refit valve head and air side seal oil signal line.

Open shutoff valve MKW13 AA507. Then openshutoff valves MKW13 AA505, MKW13 AA506 andMKW13 AA510.

Place hydrogen side seal oil pump in operation.Close shutoff valve MKW13 AA507.Vent hydrogen side and air side seal oil signal lines

through vent plugs. Ensure that previous operatingvalues are restored. If required, readjust C valve.

Fault/Cause

BHEL, Haridwar

Turbogenerators

Operation

2.3-9561-0500/10609 E

Fault TracingOil Level in Seal Oil System

Fault/Cause

High oil level in TE/EE prechambersOil level in generator prechambers has risen to such

a height that one level detector is immersed in oil. Oillevel control is malfunctioning.

Low oil level in seal oil storage tankLevel detector is malfunctioning

Leak in seal oil storage tank

Low oil level in seal oil tankLow oil level in seal oil tank has dropped to such an

extent that level detector is no longer immersed in oil.

Remedy

Make sure that valve MKW03 AA501 is fully open.With valve open, oil level control should maintain in aconstant level of oil in seal oil tank. If unsatisfactory,control valve MKW03 AA001 is not functioning properly.Determine cause of trouble and correct it. Correctiveaction is only practicable following shutdown andemptying of generator and lowering of oil level in sealoil tank. Emergency operation is possible with manualcontrol of valve MKW03 AA504. Make sure that oil levelremains visible in oil sight glass.

Cautiously open shutoff valve MKW03 AA504 by a smallamount. Seal oil is forced into the seal oil storage tank bythe H2 casing pressure acting on the oil in the tank.

Close shutoff valve MKW03 AA504 immediately whenoil level is visible in oil sight glass.Caution: If the shutoff valve is left open, the completeoil volume contained in the seal oil tank is forced intothe seal oil storage tank. Hydrogen flows into the sealoil storage tank via the seal oil tank.

Check level detector and probe.

In the event of a leak in the seal oil storage tank, theseal oil pumps can no longer draw oil for supply to theshaft seals. Shut down generator and remove gasimmediately.

Make sure that shutoff valve MKW03 AA504 is closed,and shutoff valve MKW 03 AA501 OPEN.

If the level detector is no longer immersed in seal oil,the level detector stops the hydrogen side seal oil pump toprevent dry running of the pump.

Correct fault immediately.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9640-0500/10609 E

Fault TracingGas Pressures

Fault/Cause

Low H2 bottle pressure.

H2 bottle connected is empty.

Low H2 casing pressure.

There are leaks at generator or piping.

Setting of pressure reducers incorrect.

Remedy

Connect now H2 bottle.

Identify leaks by means of a leak detector.Check whether leaks are due to generator, piping or

gas dryer.Note: Reduce load when gas pressure drop amountsto 0.4 bar. Unload and shut down generator whenpressure continues to drop.

Set H2 pressure reducers to operating pressure.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9680-0500/10609 E

Fault TracingGas Purity Meter System

Fault/Cause

Low H2 puritySeal oil pump MKW13 AP001 supplying the hydrogen

side of the shaft seal has failed. In this case, the airentrained in the air side seal oil circuit will escape intothe generator, resulting in deterioration of the H2 purity.

The supply of measuring gas to CO2 /H2 purity transmitterMKG25 CQ001 has been interrupted, resulting in faultyindication of the instrument.

No indication at indicators of purity meter system.

Faulty indication of electrical purity meter system.

Gas flow decreases in spite of constant operatingpressure.

Remedy

The H2 purity should be re-established throughscavenging with Hydrogen. Momentarily bring three-wayvalve MKG25 AA518 to CO2 vent gas position. Pressurein generator wil l decrease. Pure hydrogen isautomatically replenished via the pressure reducers.

Check the complete meter system for CO2/H2 puritytransmitter MKG25 CQ001. To do this, interruptmeasuring gas flow to meter system by means of three-way valve MKG25 AA519. Bring three-way valve MKG25AA507 in H2 calibration position and re-calibrate metersystem with pure hydrogen.

Check power supply voltage at power supply input.Check power supply fuses and, if required, replace

fuses.

Check bridge supply currentSwitch off power supply voltage ahead of power supply.Connect an ammeter with an internal resistance of

750 mili-ohm and of an accuracy class below 0.5% tothe positive terminal of the power supply and the leadoriginating at this terminal.Warning: Be sure no explosion hazard exists.

Switch on power supply.The bridge supply current can be set to the desired

value of 335 ± 1.7 mA by means of potentiometer R6.Deviations from the desired value of more than 10 mAare indicative of a fault in the power supply.

Switch off power supply voltage and disconnectammeter.

Check output voltage of transmitter by means of avoltmeter.

Check output voltage of transmitter by means of avoltmeter.

Check setting of electrical zero.If when setting the electrical zero, the indication is

higher than 100% H2 and cannot be reset to zero by thezero point adjuster, leaking comparison gas cell isindicated. The thermal gas analyser cell should then bereplaced.Warning: Isolate all H2 carrying lines prior to openinggas flow path to prevent mixing of gases.

Check bridge supply current.Check burden resistor for correct value and ensure

that all necessary equivalent resistors have beeninserted.

Isolate measuring gas supply to meter system bymeans of three-way valve MKG25 AA519 and remove

2.3-9680-0500/2

RemedyFault/Cause

and clean dust filter.If required, insert new filter.Remove and clean throttle by means of a throttle

needle; re-insert throttle.Warning: Do not perform any work on purity transmittersother than that described under Fault Tracing, since theexplosion proof design may be adversely affected.Warning: Isolate all H2 carrying lines prior to opening gasflow path to prevent mixing of gases.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9720-0500/10609 E

Fault TracingPrimary Water Pumps

Fault/Cause

Primary water pump 1 failedorPrimary water pump 2 failed

The fuses or thermal overload devices haveoperated.The starting contactor has dropped out due to lossof voltage

Primary water pump 1, loss of control voltageorPrimary water pump 2, loss of control voltage

The fuses have operated. The starting contactor hasdropped out due to loss of voltage.

Remedy

Check whether voltage is available. Check fuses orminiature automatic circuit breakers and thermaloverload devices. Check pump for mechanical defect.

After clearing the fault, return pump to serviceimmediately.

In the event of a failure, the standby pump isautomatically started and takes over the water circulationas long as the fault prevails. The pump is activated eitherby a drop of the pressure downstream of the pre-selectedpump or by a loss of voltage.

Take corrective actions as described for the above fault.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9730-0500/10609 E

Fault TracingWater Pressures and Temperaturesin Primary Water System

Fault/Cause

Low pressure after primary water pump 1orLow pressure after primary water pump 2

Primary water circulation disturbed.

High pressure in primary water tank

Gas in primary water tank is compressed due toprimary water being added at an excessive rate, theoutflow regulator being unable to releasecorresponding gas quantities.

Excessive hydrogen leakage, with the outflowregulator being unable to handle leakage gas flow.

High differential pressure across fine filterFine filter is contaminated.

High differential pressure across main filterMain filter is contaminated.

Low pressure in stator windingMain filter is contaminated.

Remedy

Correct disturbance and/or identify causeimmediately. Generator operation with insufficient coolingwater pressure will impair cooling of the unit and is thusnot permissible.

The standby pump is automatically started and takesover the water circulation.

Reduce rate of make-up primary water.

Check system for hydrogen leakage by determininghydrogen losses of generator. In the event of a leak beingdetected, reduce outflowing gas quantity by reducinghydrogen pressure in generator; if necessary shut downgenerator.

Take water treatment system out of service andreplace filter inserts in fine filter [1].

External part of primary water circuit is assembledwith extreme care and thoroughly flushed and cleanedprior to startup. A contamination of the main filter willthus normally not occur, and contaminations from outsideare also not feasible. Contaminations originating fromthe primary water circuit are possible due to resins inthe water treatment branch circuits and due to corrosionproducts. However, due to precautions inherent in theplant design and mode of operation the occurrence ofsuch a fault is very unlikely. Should it nevertheless occur,place main filter 2 into operation and take main filter 1out of service by filter changeover [2].

After changeover to the stand by main filter, makesure that specified operating data have been restored.

After filter cleaning, operation of the primary watersystem can be continued either with the cleaned filter ofwith the filter placed into operation by filter changeover.

Cleaning the main filter during operation is possibleas described above.

2.3-9730-0500/2


[1] 2.4-4740 Maintenance and Supervision of Primary Water Filters[2] 2.3-9740 Filters in Primary Water System

Fault/Cause

High temperature after primary water coolerCooler fouling (cooling water side).

Primary water temperature control disturbed.

Insufficient venting of coolers.

Remedy

In case of cooler fouling, place standby primary watercooler into operation and take fouled cooler out of serviceby cooler changeover.

After cooler cleaning, return cooler to service bycooler changeover. The standby cooler should be drainedor, its cooling water side and, if necessary, cleaned anddried.

Always check vents prior to performing any coolerchangeover.

Check the primary water temperature control systemand, if required, change over to manual control.

Open vent values (primary water side and coolingwater side) until only water emerges.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9740-0500/10609 E

Fault TracingFilters in Primary Water System

Fault/Cause

High differential pressure across fine filterFine filter is contaminated.

High differential pressure across main filterMain filter is contaminated.

Remedy

Take fine filter out of service by closing shutoff valves:MKF60 AA509 (after ion exchange).MKF60 AA513 (after fine filter).

Open shutoff valves:

MKF60 AA512 (vent at fine filter)MKF60 AA511 (drain at fine filter)

to drain the primary water from the filter. Discardwater.Open filter housing and replace filter element [1].

Recommissioning the fine filter:Close shutoff valve

MKF60 AA511 (drain at fine filter).

Open shutoff valve

MKF60 AA509 (after ion exchange)to admit primary water into the fine filter.

Close vent valve MKF60 AA512as soon as the primary water emerges without bubbles.

Open shutoff valve

MKF60 AA513 (after fine filter)

External part of primary water circuit is assembledwith extreme care and thoroughly flushed and cleanedprior to startup. A contamination of the main filter willthus normally not occur, and contaminations from outsideare also not feasible. Contaminations originating fromthe primary water circuit are possible due to resins inthe water treatment branch circuits and due to corrosionproducts. However, due to precautions inherent in theplant design and mode of operation the occurrence ofsuch a fault is very unlikely. Should it nevertheless occur,place main filter 2 into operation and take main filter 1out of service by filter changeover [1].

Place main filter 2 into operation by opening shutoffvalves:

MKF52 AA590 (before main filter 2)MKF52 AA592 (vent at main filter)MKF52 AA593 (after main filter 2).

Close shutoff valve


[1] 2.4-4740 Maintenance and Supervision of PrimaryWater Filters

2.3-9740-0500/2

MKF52 AA591 (drain at main filter 2)

immediately and shutoff valve

MKF52 AA592 (vent at main filter 2)

as soon as water emerges without bubbles.Main filter 2 is now in service. Take main filter 1 out

of service by closing shutoff valves.

MKF52 AA580 (before main filter 1)MKF52 AA583 (after main filter 1).

Open shutoff valves:

MKF52 AA581 (drain at main filter 1)MKF52 AA582 (vent at main filter 1)to drain the primary water from main filter 1. Discardwater.

After filter cleaning, operation of the primary watersystem can be continued either with main filter 2 or withcleaned main filter 1. When using main filter 1, operatevalves as specified above.

Fault/Cause

BHEL, Haridwar

Turbogenerators

Operation

2.3-9760-0500/10609 E

Fault TracingWater Level in Primary Water Tank

Fault/Cause

High water level in primary water tankNatural expansion of primary water due totemperature rise.

Defective primary water cooler.

Low water level in primary tank

Leakage in primary water system.

Water losses due to filling operation, evaporation andwater sampling.

Remedy

A rise of the primary water level in the tank above thehigh level mark calls for particular attention. If the tankoverflows, water will enter into the waste gas systemcausing damage to the equipment.

The primary water tank is dimensioned so thatexpansion of water due to temperature rise during operationwill not cause the water level to rise above the high levelmark if the tank is filled to an excessive level, the levelshould be corrected by draining.

Should the rise of the water level be due to leakage ofcooling water, the defective cooler should be taken out ofservice by primary water cooler changeover.

Any leakage of cooling water into the primary watercircuit can only take place when the pressure in the coolingwater circuit is higher than in the primary water circuit.

Immediately take measures for shutdown of the turbine-generator. If it is no longer practicable to maintain watercirculation, shut down generator.

Stop the leakage and restore normal water level inprimary water tank by adding fully demineralised water.

If the primary water pressure exceeds the pressure inthe cooling water system, the primary water cooler shouldlikewise be checked for leaks.

Add water to restore required water level in primarywater tank.

BHEL, Haridwar

Turbogenerators

Operation

Fault TracingConductivity in Primary Water System

2.3-9782-0500/10609 E

Remedy

Deactivate the water treatment system by closing valves:

MKF60 AA502 (control valve for water treatment system)MKF60 AA519 (shutoff valve after water treatment

system).

Drain water from ion exchanger tank by openingshutoff valves:

MKF60 AA503 (vent before ion exchanger).MKF60 AA510 (drain after ion exchanger).

Terminate draining by closing shutoff valves:

MKF60 AA503 (vent before ion exchanger).MKF60 AA510 (drain after ion exchanger).

After opening flanged connection and removingconnecting pipe, the cover of the ion exchanger tankshould be lifted off. Remove upper nozzle tray. Tilt tankin its tilting device; remove exhausted resin mixture formthe tank and discard it, taking care that the nozzles inthe lower nozzle tray are not damaged.

Fill ion exchanger with new resins of quality KR andplace ion exchanger into service again [1].Note: The use of reactivated resins is onlypermissible in exceptional cases.

In such a case, the resins must be thoroughlyflushed to prevent the entrance of reactivating agentinto the primary water circuit.

It is recommended to procure new resins in due timeeither directly from the competent representative of thesupplier,

Bayer Leverkusen AGSparte OC, Vertrieb 1-2D 5090 Leverkusen,

or from

BHEL Haridwar

in order to maintain the recommended quality and a long,reliable service period of the water treatment system.The resins should be stored so that they are protectedform frost and prolonged exposure to temperatures inexcess of 300 C. According to the manufacturer'sinstructions, storage of the resins at approximately 200

C should not exceed three months.

Fault/Cause

High conductivity after ion exchangerIon exchanger resins are exhausted and should bereplaced.

2.3-9782-0500/2


[1] 2.3-7120 Filling the Water Treatment System[2] 2.3-7530 Activating the Primary Water Conductivity

Meter System

Fault/Cause

Erratic behavior of conductivity meter system.

High conductivity in main circuitand/orHigh conductivity after ion exchanger

Ion exchanger resinsd are exhausted and should bereplaced.Defective primary water cooler.

Erratic behavior of conductivity meter system.

Remedy

Check the conductivity meter system [2].Disturbances which seem to be caused by the transmitter

may possible be corrected by the following measures:Remove transmitter form flow vessel and dip in

chromosulfuric acid. Clean electrodes and remove anyresidual acid by rinsing in condensate or a similar mediumprior to reinstalling transmitter. Even minor traces of acidat transmitter electrodes may result in a significanttemporary increase in the primary water conductivity. It isrecommended to measure the insulation resistance (500V megger) between terminals 1/2 and 2/3 after transmittercleaning. With a dry transmitter, the insulation resistanceshould not be less than 1 mega ohm.

Take corrective actions as described above.

A defective primary water cooler will result in a rise ofprimary water conductivity before the generator, withminimum effect on the conductivity after the ion exchanger.When it is obvious from these observations that a cooler isdefective, the defective cooler should be identified andtaken out of service by service by cooler changeover.

Any leakage of cooling water into the primary watercircuit can only take place when the pressure in the coolingwater circuit is higher than in the primary water circuit.

Take corrective actions are described above.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9784-0500/10609 E

Fault TracingVolume Flow Rates in Primary WaterSystem

Fault/Cause

Low flow rate in stator windingLow flow rate in phase A bushingsLow flow rate in phase B bushingsLow flow rate in phase C bushings

Insufficient discharge pressure, clogging or leakage.

Remedy

Insufficient cooling water flow results in insufficientheat removal and mostly in serious damage to thegenerator.

Since the effects of a cooler fai lure becomeeffective very quickly, a further drop in the flow ratecauses the signals to act on the generator mechanicalequipment protect ion, wi th the generator beingdisconnected from the system and shut down.

Prior to reloading the generator, the fault must beremoved and/or identified.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9785-0500/10609 E

Fault TracingAlkalizer Unit for Primary Water System

Remedy

Note: All possible alkalizer unit faults are displayedas single alarms on the control panel of the alkalizerunit and normally also as a group alarm in the controlroom. Apart from the faults/causes covered in thisinstruction, also faults of the alkalizer unit itself arepossible which can lead to a deactivation or failureof the alkalizer unit. For details on fault tracing orrepair of the alkalizer unit, see manufacturer'sinstructions.

If the alkalizer unit has been deactivated due to a fault,the loss of primary water conditioning will not immediatelyresult in a risk for the generator. It should, however, be alwaysattempted to continue NaOH injection by changing over themetering pump from the automatic to the manual mode.

Maintaining the alkalizer unit in operation on occurrenceof faults in the general supervisory system of the generatoris only permissible with intensive operator supervision !

Cancel alarm by pressing the acknowledge key onthe alkalizer unit as soon as the conductivity hasdecreased below the limit value after fault removal.

Check the conductivity meter system.Faults which seem to be caused by the transmitter

may possibly be corrected by the following measures:Remove transmitter from flow vessel and dip in RBS

solution (available from Messrs. Roth, Karlsruhe) orchromosulfuric acid. Clean electrodes and remove anyresidual acid by rinsing in condensate or a similar mediumprior to reinstalling transmitter. Even minor traces of acidat transmitter electrodes may result in a significanttemporary increase in primary water conductivity. It is alsorecommended to measure the insulation resistance (500V megger) between terminals 1/2 and 2/3 after transmittercleaning. With a dry transmitter, the insulation resistanceshould not be less than 1 mega ohm.

Adding make-up water to the primary water circuittoo quickly can result in a decrease in conductivity belowthe limit value. Cancel alarm at the alkalizer unit afterthe addition of make-up water has been completed. Nofurther action required.

The following criteria result in stopping of the meteringpump and thus in deactivation of the alkalizer unit:

— Low volumetric flow rate in treatment circuit— High conductivity in treatment circuit— High conductivity in main circuit— Cable breakage in measuring circuit— Defect of metering pump

Fault/Cause

Low conductivity in treatment circuit

Measuring circuit of conductivity transmitter is faulty.

Make-up water was added too quickly.

Alkalizer unit has been deactivated because meteringpump was stopped

Fault/Cause

Controller is disturbed.

Automatic circuit breaker F1 has tripped.Alarm provided Via CB Trip group alarm.

Automatic circuit breaker F2 has tripped.Alarm provided via CB Trip group alarm.

Fine-wire fuse of metering pump is defective.

Automatic circuit breaker F3 has tripped.Alarm provided Via CB Trip group alarm.

Low conductivity in main circuit

Measuring circuit of conductivity transmitter is faulty.

2.3-9785-0500/2

Remedy

Trace and correct fault, taking into account also otheralarms prevailing at the same time.

Conductivity has decreased because the pump wasstopped. The controller attempts to restore the conductivityto the proper level. Since the conductivity does not respondafter the metering pump has been stopped, the controlleroutput current rises to the maximum value preset byparameterizing. It is therefore advisable to change over thecontroller to the manual mode and to lower the controlleroutput current to zero. Then start metering pump by pressingthe Metering Pump On key twice and reset controller forautomatic mode. The controller adjusts the conductivity tothe set point level within approximately 10 to 15 minutes.

The fault display on the controller front lights up.Press reset key and try to reactivate the controller. Checkand if necessary, correct controller setting.

NaOH injection can be continued until the fault is removed.To do this, change over metering pump to the manual modeand adjust stroking rate to get the required conductivity.

The alkalizer unit is de-energized.Re-close automatic circuit breaker F1 in control

cabinet of alkalizer unit.If circuit breaker is tripped again, identify and correct

tripping cause.

Signal transmitters and metering pump have beendeactivated due to loss of supply voltage. The controlleradjusts the output current to the safety set point level.

Take corrective actions as described above.Prior to restarting the metering pump, change over

controller to manual mode and lower controller outputcurrent to zero. Start metering pump and reset controllerfor automatic mode.

Check and, if necessary, replace fine-wire fuse atright-hand top of metering pump (mode 1) front panel.

In an alkalizer unit equipped with a model 2 meteringpump, the fine-wire fuse is located behind the front panel.After having shut off the voltage supply, e.g. activatingthe automatic circuit breaker F1 and loosening of thescrews, carefully remove the front panel.

Controller and A/D converter have been deactivateddue to loss of supply voltage (no flashing light signals).Check and, if necessary, correct controller setting,Reactivate control circuit.

Re-close automatic circuit breaker F3 in controlcabinet of alkalizer unit.

Cancel alarm by pressing the acknowledge key assoon as the conductivity has decreased below the limitvalue after fault removal.

Take corrective actions as described above.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9785-0500/30609 E

Fault/Cause

Alkalizer unit has been deactivated for several hours.

Low NaOH level in tankSodium hydroxide solution has been largely consumed.Remaining quantity its only sufficient for about 40 hours.

Low volumetric flow rate in treatment circuit

A valve in treatment circuit was throttled or closeddue to incorrect operation.

High conductivity in treatment circuitand/orHigh conductivity in main circuit

Note: The following status indications are signalledby lamps on the alkalizer unit.

Loss of supply voltage

Power supply of alkalizer unit has failed.

Automatic circuit breaker F1 has tripped.

Controller deactivated

Metering pump stopped

Remedy

Take corrective actions as described above.If possible, change over metering pump to the manual

mode at once [3] and adjust stroking rate to get therequired conductivity.

Fill NaOH tank with dilute sodium hydroxide solution [1].Then renew soda lime filter [1].

Note: The alarm signal also stops the metering pump,which in turn adivates an alarm for low conductivityin treatment circuit after a short time.

Check valve positions in treatment circuit andreadjust volumetric flow rate.

Note: If the conductivity continues to rise, themetering pump is stopped, with in turn activates analarm for low conductivity in treatment circuit aftera short time.

The alarm is signalled to the control room and to thegenerator supervisory control board as a single alarm.

Details on possible causes and the corrective actionsrequired are given elsewhere in this manual [2].

If one of the lamps fails of light up during NaOHinjection, a lamp test should be performed first. To dothis, press lamp test key. All pilot and status indicatinglamps should light up.

The supply voltage lamp on the control panel isextinguished. A group fault alarm is displayed in thecontrol room.

After fault removal, reactivate alkalizer unit as follows:

— Press acknowledge key.— Press On key for controller.— Press Metering Pump On key twice.

Correct fault and switch on supply voltage.


If circuit breaker is tripped again, identify and correcttripping cause.

The lamp is extinguished when the controller isdeactivated.

The Metering Pump On lamp is extinguished whenthe pump has been stopped by a planned shutdown ordue to a limit-value excursion.

2.3-9785-0500/4


[1] 2.4-4785 Maintenance and supervision - Alkalizer Unit[2] 2.3-9782 Fault Tracing - Conductivity in Primary

Water System.

Fault/Cause

Automatic circuit breaker F3 has tripped.

Remedy


If the circuit breaker is tripped again, identify andcorrect tripping cause.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9901-0500/10609 E

Fault TracingFuses on Rectifier Wheels

Fuse indicator operatedFailure of one or several diodes.

Note: After operation of one or several fuses, itmay be necessary to observe the respectiveoperating limitations [1].

If the number of blown fuses per bridge arm andrectifier wheel has reached the maximum admissiblevalue, it si no longer permissible to continue on-loadoperation of the generator. The number of blown fusesindicates a severe fault in the excitation system, thecause of which must be identified and removed. Todo this, the turbine-generator must be shut downimmediately.

Work on the exciter should be performed with thefield ground fault detection system shown and themeasuring brushes lifted off the sliprings. Remove theexciter enclosure and half of the enclosure over therotating rectifier wheels. Rotate entire shaft assemblyof turbine-generator until defective fuse is brought toan accessible posit ion. While rotating the shaft,visually check all fuses in both wheels. To removedefective fuse, detach contact splice strap of the heatsink by unscrewing lock nut. Unlock and unscrew thescrew attaching the fuse to the wheel on front side. Acontinuity test of the fuse will indicate whether fusefailed due to an electrical or mechanical fault. Amechanical fault is unlikely.

If fuse failed electrically, the cause of the fault(defective diode) should be located by megger test.To do this, disconnect flexible lead from the three-phase power lead. In cases where two diodes aremounted in each heat sink, both flexible leads mustbe disconnected. A controlled DC voltage source ofnot less than 1000V with constant output voltage mustbe available for the measurements. Apply DC voltageto diode in reverse direction. Use another connectionto tie the rectifier wheel to the voltage potential.Connect a micro-ammeter for determination of reversecurrent in circuit between the voltage source and thediode connection.

To obtain the blocking characterist ic of a diode,increase applied voltage in steps up to a maximum levelof 1000 V and determine the reverse current for eachstep. At least three measurements are necessary forplotting the characteristic, the recommended voltagesteps being 500 V, 750 V and 1000 V. The maximumpermissible reverse current at 1000 V amounts to 500µA. If this limit is exceeded, the diode must be replaced.

If the shaft assembly cannot be shut down forseveral hours, e.g. because cool down of turbine isstill in progress, the measuring setup described abovecan probably not implemented. In such a case, the

Fault/Cause Remedy

2.3-9901-0500/2

Fault/Cause Remedy


[1] 2.1-1810 General and Electrical Data

shaft should be stopped for brief periods only toenable a replacement of the diode(s) in the respectivebranch circuit. Plotting the blocking characteristic andassessing the reusability of the diode(s) can then bedone while the unit is running.

The defect ive diode(s) should be caut iouslyunscrewed from the heat sink using the special diodewrench.

Before insta l l ing new diodes and fuses, thefollowing checks must be made:

Af ter c leaning the heat s ink, the insulat ionresistance between isolated heat sink and wheel mustbe measured using a 500 to 1000 volt megger.Insulation resistance should be more than 10 MΩΩΩΩΩ.

Fuses and diodes are both individually tested atthe BHEL factory. Checking the characteristic databefore installing new diodes and fuses will thus notbe required. Only make sure that each replacementdiode is of the same type as the defective diode(observe forward direction).

Before installing any replacement diodes, apply alubricant (Teflon spray) to the threads and coat diode/heat sink contact surface with a contact agent (siliconepaste). Diodes should be screwed into the heat sink byhand and then torqued to 10 mkg.

Use self-locking nuts for attaching the flexibleleads to the three-phase power lead.

Be sure that the contact surface (front face) of fusebears flush against the contact surface of wheel. Afterthe fuse has been properly screwed into the wheeland strap of the heat sink, check clearances betweenfuse and wheel using a feeler gage. If a distance ofmore than 0.1 mm is measured between fuse andwheel, fuse should be re-filing of bore in fuse strap.Finally, the front-side set screw should be locked. Ifseveral fuses and diodes are to be replaced, thisprocedure should be repeated.

No replacement of fuses or diodes must take placewithout checking.

Running behaviour of the exci ter wi l l not beaffected by an exchange of diodes and fuses becauseof small differences in the weights of replacementparts.

Prior to re-assembly of the exciter enclosures,insulat ion resistance of exci ter, inc luding rotorwinding, should be checked. If measured by a meggerapplying a measuring voltage of 500 volts, insulationresistance must not be below 1 MΩ.

Af ter insta l la t ion of the enclosures andreactivation of field ground fault detection system, thegenerator may again be placed in service.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9911-0500/10609 E

Fault TracingExciter Temperatures

High hot air temperature at main exciterand/ orHigh hot air temperature at rectifier exciter

The cause is a change in the cool ing waterconditions.

High cool air temperatureThe cause is an insufficient cooling water flow.

Trapped air has accumulated in cooler.

Cooler is fouled on water side.

With a rise in cold water temperature, highercooling water flow is required for removal of the lossheat. Increase cooling water flow.

Increase cooling water volumetric flow rate up tothe maximum permissible limit.

Vent cooler by means of vent screws.

If the cold air temperature continues to rise abovethe permiss ib le level , the generator should beoperated at a reduced load.

Unload and shutdown the generator at the nextpossible occasion.

Remove the exciter enclosure, isolate the coolingwater supply and detach return water channel forcooler cleaning.

Thoroughly clean individual cooler tubes with atube cleaning brush. If this should not lead to thedesired result, the coolers should be disassembledand cleaned by hydraulic or chemical means.

Use new gaskets for refitting water channels.We recommend cleaning the exciter coolers on the

air side as weld. Make sure the emergency ventilationflaps are in the emergency ventilation position so thatthe dirt removed from the fins cannot enter the exciter.

For this purpose, cover main exciter, rectif ierwheels and pilot exciter with a tarpanlin. Blow outcoolers with clean and dry compressed air. Aftercareful cleaning, the trapanlins should be removedand the exciter enclosure placed in position over theexciter. Check to make sure the seals are tight aroundthe exciter enclosure to prevent the exciter fromdrawing unfiltered air into the enclosure.

Fault/Cause Remedy

BHEL, Haridwar

Turbogenerators

Operation

2.3-9914-0500/10609 E

Fault TracingExciter Cooler

Fault/Cause

Liquid in exciterThe cause is a leak or a tube rupture at the coolertube bundle.

Remedy

Unload and shut down turbine-generator.Identify the defective cooler section. Close cooling

water inlet and outlet of this cooler section.Drain the water from the cooler. If the defective

cooler tube cannot be identified by a simple visualexamination, disassemble the cooler section removewater inlet/outlet and return water channels. All coolertubes must be separately subjected to a leakage test.

Leakage Test of Individual TubesTo perform the leakage test, use rubber plugs at

one end and a hollow plug with a small tube fitting forconnection to a water or air line at the opposite end.See Fig. 1.

Plug the tube to be tested at both ends and applya low test pressure via the air or water line.

For checking purposes, a pressure gauge can beinstalled in the line, which will indicate a pressuredrops even for minor leaks after a short time.

If the leakage test in performed without pressuregauge, a visual examination on the air side must bepossible.

Leakage Test With Air in WaterDry the individual tubes by blowing air through the

tubes. Plug all tubes of the cooler section at one endand place cooler section in a water basin. Each tubecan now be leak tested with air at 0.5 bar, max. Duringthe leakage test, air bubbles will escape from thetube(s).

Note that isolated air bubbles may r ise fromaccumulations of trapped air in the cooler section

1 Compressed air hose 5 Tube2 Hose 6 Plug3 Hollow Plug 7 Tube sheet4 Cooler section

Fig. 1 Identifying a Defective Cooler Tube

1 2 3 4 5 6 7

2.3-9914-0500/2

Fault/Cause

1 Plug2 Tube sheet3 Cooler tube4 Tube sheet

Fig. 2 Plugging a Defective Cooler Tube

1 2 3 4

which have nothing to do with the leak to be identified.Note: If several defective tubes are identified, itmust be decided right away whether the heatremoval capacity remaining after plugging of thedefect ive tubes is suff icient for emergencyoperation.

Plug the defective tube at both ends as shown inFig.2. Remove all plugs from the remaining tubes.Then bolt on water inlet/outlet and return waterchannels and perform a leakage test of the coolersection at the specified test pressure. If no leak isdetected, the cooler section should be installed, filledwith water and vented. The cooler section may remainin operation until the next inspection or outage, atwhich time the cooler section should be replaced.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9941-0500/10609 E

Fault TracingStroboscopeType LX5 (220 V)

Fault/Cause

Stroboscope defectivePins 2 and 9 on plug board 2 are interconnected for

a supply voltage of 220 V.

Printed circuit board 1 defectiveSupply voltage of 220 V is available at pins 3 and 8.

Plug board 1, printed circuit board viewed from below

1 2 3 4 5 6 7

8 9 10 11 12 13

Printed circuit board 2 defectiveSupply voltage of 220 V is available at pins 1 and 9.

Plug board 2, printed circuit board viewed from below

1 2 3 4 5 6 7

8 9 10 11 12 13

Printed circuit board 3 defectivePlug board 3, printed circuit board viewed from below

1 2 3 4 5 6 7

8 9 10 11 12 13

Remedy

Check to ensure that supply voltage is available atpins 1 and 9 on plug board 2. If no voltage is available,check cable and fuse.Note: Voltage specified below may vary within atolerance range of ±±±±±15 %.

Verify that following voltages are available:

Ground/pin 12 abt. 310 V DCGround/pin 6 abt. 23 V DCGround/pin 7 abt. 5 V ACGround/pin 11 abt. 24 V AC

Replace printed circuit board if, on pressing the Onpush button (hold push button if relay fails to pick up) thesupply voltage is available at pin 2/3 and 8/9 and is notavailable at pins 6, 7, 11 and 12. If one of the voltagesmeasured at these pins greatly deviates from the specifiedvalue, the cause may be a short on another printed circuitboard. Extract printed circuit boards 2 to 4: voltages at thepins must now reach or exceed the specified value. Switchoff stroboscope and insert one printed circuit board afterthe other until voltage at the respective measuring pointcollapses. Replace printed circuit board identified in thismanner.

Relay d1 must pick up on depressing the On pushbutton. If the relay drops out again on releasing the pushbutton, the push button should be pressed again and heldin position. Measure voltage at pins 11 and 5 with respectto ground (15 V DC). If no voltage is available, replaceprinted circuit board 3. If voltage is available, replace printedcircuit board 2.

Ground/pin 13 abt. 23 V DCGround/pin 7 abt. 15 V DCGround/pin 11 abt. 5 V ACGround/pin 9 abt. 6-9 V AC

If no voltage is available at pin 7 or with 15 V or 0 V atpin 9, replace printed circuit board provided that voltage isavailable at pins 13 + 11.

2.3-9941-0500/2

Fault/Cause

Defect on plug board 4Plug board 4, printed circuit board viewed from below

1 2 3 4 5 6 7

8 9 10 11 12 13

One flash tube failed

Remedy

Verify that the following voltages are available:

Ground/pin 12 abt. 310 V DCGround/pin 11 abt. 310 V DC

Ground/pin 9 voltage should not exceed 280 V but mustnot be zero. Replace printed circuit board if above voltagesare not obtained.

If only one flash tube functions properly, the cause ofthe malfunction is the flash tube and not the control unit.Replace failed flash tube.

Functional check: Interchange the flash tube connectors.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9955-0500/10609 E


[1] 2.4-4925 Maintenance and Supervision Exciter Dryer

Fault TracingExciter Drying System

Fault/Cause

Exciter dryer disturbedLimit switch failed to operate, i.e. motor-actuatedflap is hot in Open position.

Overheat protection has switched off the exciterdryer. In most cause is no or an insufficient airflow.

Remedy

Set lever for manual operation at flap shaft toOpen position and lock lever with locking device.

Check f lap inc lud ing actuator for propermechanical condition.

Check 6.3A f ine-wire fuse of f lap motor forcontinuity.

After fault removal and loosening of the lever lock,the lever should remain in the Open position.

Open door in exciter enclosure behind which thedryer is located from the operating floor. Following ashort cool down period, the overheat protect ionautomatically returns the dryer to service.

Check whether air is drawn in via the intake partson both side of the air dryer.

If yes, the air flow passage is obstructed. Inspectprefilter in door for contamination [1].

If no air is drawn in via both intake parts, theventilator motor in the dryer has failed. The exciterdryer should be de-energized, disassembled andreturned to the manufacturer's works for repair. A2 kWheater-blower should be used inside the exci terenclosure for dehumidification as long as the dryer isnot available due to repair.

BHEL, Haridwar

Turbogenerators

Operation

2.3-9980-0500/10609 E


[1] 2.4-4990 Maintenance and Supervision or GroundFault Detection System

[2] 2.5-3300 Insulation Resistance Measurements onRotor and Exciter Windings

Fault TracingGround Fault Detection Systemin Exciter Field Circuit

Fault/Cause

Ground fault detection system disturbedCarbon brushes have poor or no contact withmeasuring sliprings.

Exciter voltage response takes longer than 5 s.

High-resistance ground fault in exciter circuit(RE < 80 k ΩΩΩΩΩ)

Low-resistance ground fault in exciter circuit(RE < 5 k ΩΩΩΩΩ)

Remedy

Install carbon brushes and plug-in brush holdersstrictly in accordance with maintenance instruction [1].

Fault alarm is automatically extinguished afterremoval of cause.

Immediately investigate cause of ground fault alarm.Measure insulation resistance in exciter circuit if the

generator can be disconnected from the system and de-excited [2].

If an insufficient insulation resistance is measured,operation of the generator should be continued only afterconsultation with the manufacturer to avoid possiblemajor damage.

At RE < 5 k Ω, a TUSA trip is activated by the electricalgenerator protection, and the generator is disconnectedfrom the system and de-excited.

If the insulation resistance measurement confirms theground fault, the generator must be removed fromservice. The manufacturer should be notified andentrusted with the fault removal.

If no ground fault can be identified by the insulationresistance measurement, check system once more forground faults at rated speed before exciting the generatoragain.

BHEL, Haridwar

Turbogenerators

Maintenance

Maintenance and SupervisionIntroduction

2.4-4200-0500/10609 E

The turbogenerator and its auxiliaries requirecontinuous maintenance and supervision to as-sure reliable operation and serviceability of thecomplete plant. Maintenance and monitoring arerequired both during operation and when the unitis at standstill.

Some maintenance work shouldpreferably be performed with the unitat rest, e.g. in the case of any specialconditions being noted in the operat-ing log, while other maintenance workmay be carr ied out during normaloperation.

The maintenance work required on thegenerator described herein is specified indetail in the following.

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4210-0500/10609 E

Maintenance and Supervision of Stator

1 Monitoring the Temperature of Components

It is important that all temperatures remain withinthe specified upper and lower limits. If a temperaturedeviation is observed the cause must be determinedimmediately and the original temperature restored.

I f there exists the danger of overheat ing, acorresponding load reduction should be made.

The temperature between the top and bottom barsof the stator winding are measured with resistancetemperature detectors (RTD’s).

The RTD’s are embedded in the winding anddistributed uniformly over the three phases. TheRTD’s in the stator winding should t ransmitapproximately identical values for identical currentsin all three phases. If different temperatures areindicated with identical currents in the three phases,a check should be performed to determine if the slotRTD’s are correctly calibrated and/or compensated.Differences in the temperature indication upto 5°Cmay be due to to lerances in the s lot RTD’s,compensating resistors and tolerances caused bydifferences in the contact at the measuring pointselector switch. Other small temperature differencesmay be due to different mounting conditions at theRTD’s.

2 Monitoring the Cooling Gas and Cooling WaterTemperatures

The temperature of the cool ing gas in thegenerator is measured with one RTD before and aftereach cooler section. The RTD’s installed after thecoolers indicate the temperature of the gas used forgenerator cooling. The cooling water supply to theindividual cooler sections should be adjusted so thatthe gas outlet temperatures at all cooler sections areapproximately identical. The setting of the coolingwater f low should be made by changing theadjustment of the cooling water outlet valves. The

cooling water inlet valves at the individual coolersections should be fully opened.

To prevent undue stressing of the generator, it isdesirable to maintain a constant temperature in thegenerator by control of the cooling water flow.

In addition to the gas temperatures, the coolingwater temperature is also measured. The coolingwater inlet temperature of all cooler sections shouldbe measured in the cooling water inlet pipes, whilethe cool ing water out let temperature should bemeasured separately for each cooler section in thecooling water outlet pipe after each cooler section.

3 Hydrogen Pressure in Generator

On-load running should always be performed atthe specified hydrogen pressure, since it results inminimum thermal stresses in the generator interior.

If the specif ied hydrogen pressure cannot bemaintained for unforeseeable reasons (e.g. lack ofgas, high gas losses), the generator should beunloaded and de-excited when the pressure hasdropped by 0.4 bar (5.7 psig).

4 Primary Water Flow Rates

An insuf f ic ient pr imary water f low resul ts ininsufficient cooling of the water-cooled components.Therefore, the flow rate must not fall below the lowerlimit value.

5 Primary Water Temperature

Cont inuous record ing of the pr imary watertemperature is essential to ensure safe on-loadrunning of the turbine-generator. Many faults can thusbe recognised and remedied at an early stage. Thisis par t icu lar ly important for a d is turbed coolerperformance (fouling, venting etc.).

Maintenance Intervals

Work required

Check grounding brushes ×

Check sight glasses after level detectors for liquid level ×

Dai

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Mon

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2.4-4210-0500/2


[1] 2.1-1820 Mechanical data

Note: The temperature of the cold primarywater should be higher than the H2 cold gastemperature by not less than 5°K (9°F) underall conditions of operation in order to positivelyavoid the formation of moisture condensate onthe components carrying primary water. Thedifference between the primary water inlettemperature and the cold gas temperature ismeasured directly and monitored continuously. Analarm is act ivated when this di fferent ialtemperature drops below the predetermined value.When no differential temperature exists any longeror when the primary water inlet temperature iseven lower than cold gas temperature, thegenerator must be unloaded and de-excited atonce.

6 Primary Water Pressure Before Stator Winding

The pressure of the primary water before enteringthe stator winding can be taken as a reliable criteriafor a safe cooling water supply to the various branchcircuits.

A small change in pressure up to a maximum of10% has no influence on cooling of the stator winding.Major changes with rising tendency may be indicative

of a disturbance in uniform cooling in individual branchcircuits. To avoid any risk in cooling of the statorwinding, it is recommended to contact manufacturer’sproduct service department and to ask for removal ofthe cause.

7 Liquid Leakage Detection at Level Detectors

Liquid entering the generator housing is sensedby level detectors. Sight glasses, located before andafter the level detectors, permit any leakage to bereadily detected before the liquid level will have risenup to the level detectors.

8 Grounding Brushes

The carbon brushes should be checked at regularintervals. During operation, the useful length of eachindividual carbon brush can be determined by a visualinspection. For limits of wear, see Description [1].

The carbon brushes should be replaced with newones having contact faces which match the rotor shaftcontour.

Note: Ensure to insert the grounding brushes sothat the brush with carbon layer is followed by abrush with si lver layer when looking in thedirection of rotation of the rotor shaft.

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4240-0500/10609 E

Maintenance and Supervisionof Generator Coolers


[1] 2.3-5003 Hints for cooler operation

1 General

Special measures should be taken to prevent corro-sion damage to the cooler [1]. Cooler sections havingno cooling water flows for some time may be subject tostandstill corrosion. In addition to many other corrosiveinfluences, such as the different elements of the coolingwater, locally differing deposits, raw materials, etc., thereexists the danger that microorganisms on the tube wallsmay die and decay due to a loss of fresh water supply(lack of oxygen). Ammonia is formed from such decaywhich may lead to stress corrosion cracking. Corrosiondamage can only be properly prevented if the cooler isdrained on the water side, cleaned, completely dried andmaintained in a dry condition. With the generator in com-mercial operation, such measures are often unfeasible,particularly in cases of short outages. In such cases,

the measures outlined below should be taken.

2 Coolers

During normal operation, the cooling water flowthrough all cooler sections. Since the coolers are de-signed for 100 % capacity at maximum cooling watertemperature, the condition may arise that the coolersare supplied with smaller cooling water flows for longperiods. Depending on the purity of the cooling water,this may result in deposits due to the lower water veloc-ity in the cooler. To prevent cooler damage, it is there-fore recommended to rinse the coolers with the full wa-ter flow during short outages. In addition, the coolersshould be frequently cleaned with brushes. For heavycooler contamination and if operational restrictions andshutdowns are undesirable, it is recommended to installa continuous cooler water purification system.

Fig. 1 Cooler Section (disassembled) Fig. 2 Purification Brush


Work required

Check cooler vents ×

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BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4250-0500/10609 E

Maintenance and Supervisionof Bearings

Maintenance interval

Dai

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Mon

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Mon

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Eve

ry 6

Mon

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Ann

ualyWork required

Check EE ground bearing insulation

Check EE shaft seal insulation

Check exciter bearing insulation

X

X

X1 General

During normal operation, no service or maintenancework is required on the bearings of the generator, how-ever, bearing vibrations, bearing temperatures, oil tem-peratures, and oil pressures should be continuouslymonitored.

The generator bearings require particular attentionduring each new startup, following brief shutdown. Care-ful monitoring will also be necessary within the first fewminutes after runup until the normal operating valuesare restored. If the operating values prevailing after arestart exceed the permissible limit values, the unitshould be shut down immediately.

The lift oil pressure for the shaft journals should beadjusted so that the shaft is lifted by not more than 50 %of the bearing top clearance (top clearance amounts to0.12 % of the bearing diameter). To prevent any dam-age to the bearings the shaft lift oil system must be inoperation at speeds as specified in the turbine instruc-tion manual.

At higher speeds, the lift oil pressure will settle at 40to 80 bar. The oil pressure should be recorded in theoperating log. If a lower oil pressure is observed the re-

spective bearings should be checked. Such pressure re-duction may be indicative of damage in the area of con-tact surface, the bearing babbitt, leaking supply pipes,or defective pressure limiting and check valves.

The temperature of the lubricating oil supplied to thebearings is controlled by the cooling water flow to thebearing oil cooler. The temperature of the generatorsleeve bearings are displayed in the control room.

2 Checking the Shaft Seal and Bearing InsulationChecking the shaft seal and bearing insulation dur-

ing operation [1] may be done by way of the shaft volt-age prevailing with the generator running in an excitedcondition. For the purpose, the potential of the insulatedshaft seals and bearings is accessible external to thegenerator. With the generator running, the componentscoming into contact with the shaft are separated fromthe shaft by an oil film, which has insulating properties.Consequently, a non-defined resistance value is set upat the potential measuring points of the shaft seals andbearing sleeves which is dictated by the magnitude ofthe resistances of the oil film and insulating parts.

Also refer to the following information[1] 2.5-0300 Checking the Bearing and Seal Insulation

Fig. 1 Generator Bearing and Seal Insulation

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4310-0500/10609 E

Maintenance and Supervisionof Rotor

Also refer to the following information[1] 2.5 – 3300 Insulation Resistance Measurement

on Rotor and Exciter Windings

1 Monitoring Rotor Vibrations

The vibrations of the generator rotor should be moni-tored and any change should be carefully observed.Should a change in vibration characteristics be noted, itis recommended to have the manufacturer’s product

service personnel determine the cause and assist incorrecting any problems.

2 Measuring Insulation Resistance

The insulation resistance of the rotor winding towardsground should be measured once a year [1].


Work required

Measure insulation resistance ×

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BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4520-0500/10609 E

Maintenance and SupervisionSeal Oil Pumps andBearing Vapor Exhausters

1 Seal Oil PumpsTo prevent dry running of the pump and to ensure

proper lubrication of the shaft seal, each new oroverhauled seal oil pump should be filled with turbine oilvia the oil filling plug, unless this has already beenaccomplished through the oil supplied to the oil inlet ofthe pump. In addition, the oil ensures proper sealing ofthe shafts for pump priming.

Change over seal oil pumps 1 and 2 at monthlyintervals. To do this, start standby pump by manualcontrol. Then stop pump so far in service by manualcontrol.

Perform functional check of standby seal oil pump 3once per month. To do this, start standby pump by

manual control. After a short running period, this pumpwill then be automatically stopped again after elapse ofa present time delay. Check to ensure that the indicationsshowing that the standby seal oil pump is in operationare displayed during the short running period.

Perform changeover to standby pump once permonth. Check pump delivery pressure and then changeover to normal-service pump.

2 Bearing Vapour ExhaustersThe bearing vapor exhausters are provided with a

regreasing device for the axial shaft seal. Repackregreasing devices with grease every six months.

The exhausters should be changed over once permonth. To do this, follow the same procedure as for theseal oil pumps.

1 Regreasing device2 Drive motor

Fig. 2 Bearing Vapour Exhauster


Work required

Change over seal oil pumps 1 and 2 ×

Perform functional check of standby seal oil pump ×

Change over bearing vapor exhausters ×

Repack regreasing devices of bearing vapor exhauster shaft seals with grease ×

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1 Venting Screw/oil filling plug2 Discharge flange3 Pressure relief valve4 Drive shaft

Fig. 1 Seal Oil Pump

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4540-0500/10609 E

Maintenance and SupervisionSeal Oil Coolers

1 GeneralOne of the two seal oil coolers in the air side and

hydrogen side seal oil circuits will be in service.Serving as standby unit, the second cooler is filledon its oil side, while it should be empty, clean and dryon its cooling water side in order to preclude standstillcorrosion on the cooling water side. The cooling watervent and the drain valve should be kept open tomaintain the cooler in a dry condition.

2. Cooler ChangeoverWhen changing over the coolers, the standby

cooler must first be filled on its water side, with carebeing taken to ensure that the cooler is properlyvented on both the water and oil sides.

The three-way valves should be changed over byturning the common handwheel, which actuates bothvalves simultaneously. The right-hand seal oil cooleris placed into service on its oil side by turning thehandwheel counter-clockwise upto the stop. If thehandwheel is turned clockwise, the left-hand cooleris taken into operation. The changeover proceduredoes not result in an interruption of the oil flow.

When making a changeover on the oil side, take

care that the three-way valve for cooling water inletis actuated simultaneously. The cooling water volumeflow for the cooler taken into service should beadjusted at the outlet valve so that the specified oiloutlet temperatures obtained.

3. Cooler CleaningIn-service cleaning of the standby seal oil cooler

on its cooling water side is possible after disassemblyof the upper return water channel. During cleaning,the cooler can be kept filled on its oil side. The sealoil cooler removed from service should be cleanedwith tube brushes. The use of Perlon brushes ensuresboth a careful treatment of the tube wall and goodcleaning results. To ensure thorough tube cleaning,the tube interior should be wet, since dry dirt depositsare more diff icult to remove. After completion ofcleaning and refitting of the upper water channel, thecooler should briefly be flushed with the full waterflow for the complete removal of any residual dirtdeposits. Deposits which cannot be removed bymechanical means may require chemical cleaning. Ifthere is insuf f ic ient exper ience and equipmentavailable, it is recommended to have this cleaningwork performed by a suitably qualified contractor.


Work required

Check service cooler for proper venting ×

Check seal oil supply lines and shutoff valves for leakages ×

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Turbogenerators

Maintenance

2.4-4550-0500/10609 E

Maintenance and SupervisionSeal Oil Filters

The degree of contamination of the seal oil filtercan be directly seen at the differential pressure indi-cator. As the contamination of the filter increases, cor-responding to an increase in the pressure drop acrossthe seal oil filter, a higher differential pressure is in-dicated. At a preset value, an alarm signal is activated.When the alarm signal has been act ivated, thestandby filter should be placed in service and the con-taminated filter removed from service by means of the

change-over valve assembly. Check filter valve forclosed position.

Drain the seal oil from the filter housing via thedrain plug and remove the filter cover. The screen fil-ter should be removed and cleaned thoroughly. Priorto reassembly, the filter should be flushed with tur-bine oil to remove any solvent residue. The filter hous-ing should be filled with turbine oil and the filter reas-sembled. Open filler valve and vent the filter.

Clean the filters during each inspection.


Work required

Check degree of contamination of seal oil filters ×

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BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4610-0500/10609 E

Maintenance and SupervisionGas Consumption


Work required

Check gas consumption ×

Check shutoff valves for free movement ×

Check gas supply lines and shutoff valves for leaks ×

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1 General

Caution: The CO2 bottle rack should be equipped withfull bottles so that a sufficient quantity of carbon dioxidewill be available for any required displacement of thehydrogen.

A sufficient number of full hydrogen bottles shouldbe kept in stock at all times taking into consideration thegas consumption rate of the unit and the availability ofnew hydrogen.

According to section 4.6e in VDE 0530, Part 3, notmore than two H2 bottles should be connected and openduring normal operation.

On occurrence of a leak and the resulting higher gasconsumption, only the open H2 bottles would be emptiedat a faster rate. In addition an alarm is activate to alertthe operator in due time.

It is recommended that, to improve the operatingreliability, only the hydrogen bottles in service should beconnected to the hydrogen bottle rack, while the otherconnections should be isolated by means of the shutoffvalves at the H2 bottle rack manifold.

The connection of new gas bottles should be enteredin the operating logs.

2 Gas Consumption

During operation, the loss of H2 gas must bemonitored continuously on the basis of H2 consumption.

The total gas consumption consists of the hydrogenquantities escaping both controlled and uncontrolled.

The gas quantity escaping under control is composedof the hydrogen flowing out continuously via the puritymeter system for measuring the gas purity in thegenerator, and the gas removed from the generatorthrough the seal oil and discharged into the vent gasline.

Gas quantities escaping uncontrolled are those lostthrough leaks in the generator and gas system.

If an undue loss of gas occurs on the unit, the locationof the leak must be determined [1].

Since this leakage gas may present a danger to theenvironment, it should not amount to more than 12m3

(s.t.p.) during 24 hours. In the event of the gas leakagelosses exceeding 12m3 (s.t.p.) during 24 hours, leak testsshould be performed and the gas losses reduced belowthis limit. In case such measures are not successful, evenon reduction of the gas pressure in connection with acorresponding load reduction, the unit should be shutdown and the hydrogen removed from the generator (seesection 4.6d in VDE 0530, Part 3).

2.1 Handling the Handy-Tector

The sniffer probe of the Handy-Tector should be ledover the surface of the test object as slowly as possible.Note that with a leakage gas lighter than air the leakdetection should be carried out above the object andwith gases heavier than air underneath of the test object.

Also refer to the following information[1] 2.5-0310 Leakage Tests

Fig. 1 Handy-Tector

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4720-0500/10609 E

Maintenance and SupervisionPrimary Water Pumps

1 Checking Oil Levels in Pump Bearing HousingsThe shafts of the primary water pumps are supported

in oil-lubricated bearings. Check oil levels in bearings atregular intervals.

The exact oil level in the pump in service cannot bedetermined at the oil sight glass due to oil foaming. Theoil level in the pump in service should be visible in themiddle of the oil sight glass. The oil should be changedafter about 3000 operating hours (at least once a year).

2 Checking Readiness for StartingTo ensure that the standby pump is ready for

operation on a continuous basis, start and immediatelystop this pump once a week.

3 Changing Over PumpsThe primary water pumps should be changed over

at regular intervals (at least once a month) so thatthey will be alternately in service.


Work required

Check oil level in bearing housings of primary water pumps ×

Check that standby primary water pump is ready for operation ×

Change over primary water pumps ×

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Turbogenerators

Maintenance

2.4-4740-0500/10609 E

Maintenance and SupervisionPrimary Water Filters

1 GeneralThe degree of contamination of the primary water

filters can be seen at the differential pressure indicator.At predetermined differential pressures, alarms areactivated in addition to signal filter contamination.

During each inspection of the unit, the main filtersshould be cleaned and the filter element of the fine filterreplaced.Warning : Primary water contains dissolved hydrogen.When draining he filter, care should be exercisedbecause of resulting degassing of water.

2 Main FilterThe main filter is only insignificantly contaminated

even after a service period of several years due to thepurity of the primary water and the cleanliness of theentire primary water system. Cleaning during operationwill therefore normally be not required. Should itnevertheless become necessary to clean the main filterduring service, place main filter 2 in operation and takemain filter out of service.

To do this, close shutoff valve

MKF52AA591 (drain, main filter 2)

Open shutoff valves :

MKF52AA590 (before main filter 2)MKF52AA593 (after main filter 2).

Close shutoff valve :

MKF52AA592 (vent, main filter 2)

as soon as water emerges without bubbles. Main filter 2is now in service.

Close shutoff valves :

MKF52AA580 (before main filter 1)MKF52AA583 (after main filter 1).

Open shutoff valves :

MKF52AA581 (drain, main filter 1)MKF52AA582 (vent, main filter 1).

Discard primary water drained from main filter 1. Mainfilter 1 can now be cleaned [1].

After filter cleaning, operation of the primary watersystem can be continued either with main filter 2 or withcleaned main filter 1.

3 Fine FilterThe fine filter can also be taken out of service during

normal operation for replacement of the contaminatedone-way filter element.

The procedure for any required filter element replace-ment of the fine filter is as follows :

Take fine filter out of service [2].Remove contaminated filter element.

Remove vent pipe and hex nuts from filter cover andlift off cover.

Hold filter insert at handle and turn counterclockwise.After removal of filter insert from filter housing, loosenhex nuts and remove bottom seating ring. Withdraw con-taminated filter element.

Insert new filter element and close filter.

Prior to installing a new filter element, clean filtersealing faces and seating rings and check O-rings fordamage. Install filter element and replace bottom seat-ing ring. Fit and tighten one hex nut until the supportplate rests on the upper seating ring. Fit and firmly tighten(lock) second hex nut.

Hold filter insert at handle and turn clockwise untilfilter insert is firmly locked in filter housing.

Reposition and bolt down filter cover. Uniform con-tact pressure must be obtained by tightening nuts alter-nately at opposite points.

Refit vent pipe to filter cover so that a tight connec-tion is obtained.

Fine filter can be taken into service [2].


[1] 2.5-7300 Primary Water System[2] 2.3-9740 Filters in Primary Water System


Work required

Check service cooler for proper venting ×

Check seal oil supply lines and shutoff valves for leakages ×

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BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4750-0500/10609 E

Maintenance and Supervisionof Primary Water Coolers

1 Maintenance of Coolers on Primary Water SideWith normal cool ing water condi t ions and the

generator carrying rated load, two of the three primarywater coolers will be in operation. The standby thirdcooler should be filled on its primary water side.

A small amount of primary water continues to flowthrough the standby cooler via the parallel-connecteddrain and vent valves. In this way, deterioration of theconductivity of the primary water volume in the coolercan be avoided.

When making a cooler changeover take care thatthe primary water f low through the coolers is notinterrupted.

2 Maintenance of coolers on Cooling Water SideThe standby cooler, filled on its primary water side,

should be empty, clean and dry on its cooling water sidein order to preclude standstill corrosion. The vent anddrain valves on the secondary side should be kept opento maintain the cooler in satisfactorily dry condition.

Note: If the second primary water cooler is not requiredfor a longer period of time, due to the cooling waterconditions and the heat loss to be dissipated, it can betaken out of service on its cooling water side, i.e.,drained, cleaned and dried.

Special measures should be taken to preventcorrosion damage to the coolers. Cooler sections havingno cooling water flows for some time may be subject to

standst i l l corrosion. In addit ion to many othercorrosive influences, such as the different elementsof the cooling water, locally differing deposits, rawmaterials, etc., there exists the danger that microorganisms on the tube walls may die and decay dueto a loss of fresh water supply (lack of oxygen).Ammonia is formed from such decay which may leadto stress corrosion cracking. Corrosion damage canonly be properly prevented if the cooler is drainedon the water side, cleaned, completely dried andmaintained in a dry condition. With the generator incommercial operation, such measures are oftenunfeasible, particularly in cases of short outages.In such cases, the measures outlined below shouldbe taken:

During normal operation, the cooling water flowsthrough two cooler sections. Since the coolers aredesigned for 100 % capacity at maximum coolingwater temperature, the condition may arise that thecoolers are frequently supplied with small coolingwater volume flows for long periods. Depending onthe purity of the cooling water, this may result indeposits due to the lower water velocity in the cooler.To prevent cooler damage, i t is thereforerecommended to rinse the coolers alternately withthe ful l cooling water volume flow during shortoutages. In addi t ion, the coolers should befrequently cleaned with brushes. For heavy coolercontamination and if operational restrictions andshutdowns are undesirable, it is recommended toinstall a continuous cooler water purification system.All continuous vents should be checked for properfunctioning.


Work required

Check primary water cooler vents x

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BHEL, Haridwar

Turbogenerators

Maintenance


[1] 2.3-6810 N2 Purging After Filling of Primary Water system

2.4-4760-0500/10609 E

Maintenance and Supervisionof Water Level in Primary Water Tank

The Primary water tank is mounted on the stator frameand serves as an expansion tank during operation. Asufficient water level in the primary water tank is theprerequisite for reliable primary water circulation.

The water level in the pr imary water tank isdisplayed on a local water level gauge. One capacitivelevel monitoring system is provided to activate a lowwater level alarm.

Any loss of primary water in the total circuit canbe compensated for by introducing make-up waterupstream of the ion exchanger. The quantity of make-up water is totally at a water meter and is indicativeof the leak tightness of the primary water system.

If it is necessary to add make-up water to theprimary water system during operation, close controlvalve.

MKF60 AA502 (before ion exchanger)

and then open shutoff valve

MKF60 AA504 (in make-up line)

to admit water into the primary water system via theion exchanger.

Note: During make-up operation, the flow velocityshould not be higher than during normal operationof the water treatment system. Check volume flowat volume meter MKF60 CF502.

During make-up operation, a maximum of 100dm3 (26 US gallons) of water may be added to theprimary water circuit. Added water volume istotally on volume flow meter MKF60 CF501.

However, if this amount of make-up water isinsufficient, purge the primary water tank withnitrogen [1].

Nitrogen purging must also be performed if thecumulat ive amount of added water exceeds100dm3 within the past month.

During this procedure, the water level in theprimary water tank should be observed carefully,making sure that no primary water enters the ventgas system.

Addition of water is stopped by closing shutoff valve

MKF60 AA504 (in make-up line)

as soon as the water level in the primary water tank hasreached its nominal value.

Reopen shutoff valveMKF60 AA502 (before ion exchanger).

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4780-0500/10609 E

Maintenance and SupervisionConductivity Meter System

Also refer to the following information[1] 2.3-9782 Conductivity Meter System


Maintenance work to the conductivity meter systemis restricted to monthly checking of the transducer bymeans of the test selector switch.

The check can be performed while the units is inoperation.

Turn associated test selector switch to zero positionXk=0 µmho/cm. With switch in this position, a zeroindication is given at conductivity indicator.Turn associated test selector switch to test value 1.5µmho/cm . With switch in this position, instrumentshould indicate a value of 1.5mmho/cm.Turn test selector switch to operation position Xk=µmho/cm. With switch in this position, conductivityindicator indicates current conductivity of primary

water.

2. Ion Exchanger

2.1 Replacing Ion Exchanger ResinsA replacement of the ion exchanger resins is required

when the conductivity downstream of the ion exchangeris higher than in main circuit or rises to a value 0.5µmho/cm.

The main circuit may be left in operation during resinreplacement. The various operations for resinreplacement should be accomplished so that the workwill be completed before a conductivity of 1.5mmho/cmhas been reached in the main circuit. With the ionexchanger out of operation, this value will be obtainedafter a few days only.

For details on the replacement of the ion exchangerresins, see under Fault Tracing [1].


Work required

Record conductivity after ion exchanger and in main circuit ×

Check conductivity meter system by means of test selector switch ×

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Turbogenerators

Maintenance

2.4-4785-0500/10609 E

Maintenance and SupervisionAlkalizer Unit

The controller in the alkalizer unit maintains theconductivity of the treated primary water at a constantvalue.

Alkalizer unit monitoring requires regular checkingof the volumetric flow rate and level in the NaOH tankand water sampling.

1 Level in NaOH Tank

Check and record level in NaOH tank during dailyinspection of turbogenerator.

About 2dm3 of dilute sodium hydroxide is injectedinto the primary water circuit each day.

With the given capacity of the NaOH tank, refillingthe tank with sodium hydroxide will be required atintervals of about two months.

Fill NaOH tank with dilute sodium hydroxide solutionafter a low level alarm has been given at the latest.

1.1 Adding Sodium Hydroxide SolutionWhen preparing the sodium hydroxide solution and

filling the NaOH tank of the alkaline unit, make sure toavoid the formation of carbonates as far as practicableby reducing the time of free exposure to the atmosphereto the absolute minimum.

To prepare the sodium hydroxide solution and to fillthe NaOH tank, observe the following procedure:

Prepare concentrated sodium hydroxide solution inlaboratory (observing the specification [1]). To dothis, dissolve the necessary quantity of sodiumhydroxide (caustic soda) in approximately 8-10dm3

of water [2] to obtain the specified concentration of10 to 20g of NaOH per dm3.

Caution: When handling sodium hydroxide (causticsoda), make sure to observe the applicable safetyregulations.

Set controller in control cabinet of alkaline unit for

manual control and then lower manipulatedvariable (controller output current) to zero.Open NaOH tank and add concentrated sodiumhydroxide solution.Fill NaOH tank with water [2] to the required level,Stir solution for proper mixing.Reclose NaOH tank so that it is tightly sealed andsecure against opening.Reset controller for automatic control.

Note: Due to temporary deactivation of the alkalizer unit,the conductivity of the treated water will drop to < 0.1mmho/cm, and a corresponding alarm will be activatedin the control cabinet of the alkalizer unit. Cancel thealarm by depressing the Acknowledge button as soonas conductivity of the treated water has been restoredto its nominal value.

Replace the lime filter in the NaOH tank vent eachtime the NaOH tank is refilled. To do this, observe thisprocedure:

Hold glass vessel and loosen wing bolt untilclamping fixture can be moved.Position clamping fixture with wing bolt beneath


Work required

Check level in NaOH tank ×

Analyze water sample taken from primary water circuit ×

Analyze water sample taken from treatment circuit ×

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Also refer to the following information[1] 2.1-1888 Additive Specification for Alkalizer Unit[2] 2.1-1885 Primary Water Specification[3] 2.1-1887 Specification for Ion Exchange Resins

2.4-4785-0500/2

the glass vessel and carefully tighten wing bolt.Slowly lower glass vessel to a point below theimmersion tube.Fill glass vessel to about 80-90% with soda limecomplying with the applicable specification [1].Clean sealing faces and slowly press glass vesselagainst gasket from below by moving it to and fro.

2 Water AnalysisWe recommended chemical analysis of the primary

water in the main circuit and treatment circuit (samplingdownstream of fine filter) at monthly intervals. Keepingthe sample excluded from the atmosphere at a constanttemperature of 25oC, the following parameters shouldbe determined:

ConductivitypHNa+ ion concentrationCu concentration (total)Fe concentration (total)

Table 1 shows the normal and limit values to beexpected.

Parameters Normal Limit

Conductivity 1.8-2.0 µmho/cm 2.0 µmho/cmpH 8.5-9Na+ ionconcentration 25 to 250 ppb 300 ppbCu concentration <5 ppb 10 ppbFe concentration <5 ppb 10 ppb

Table1 Normal and Limit Values of Primary WaterChemistry

Operation at the limits given in Table1 involves noimminent risk for the generator: these limits, however,indicate abnormalit ies and the cause must beinvestigated.

If the results of the water analysis do not provideconclusive proof of correct water treatment, theconductivity of the water should be measureddownstream of a highly acidic cation exchanger (H+

form). The conductivity provides information on thepresence of other unwanted anions in addition to theOH ions that determine the alkalinity. The measurementshould be performed with the sample excluded from theatmosphere to prevent a falsification of the reading bythe carbon dioxide contained in the ambient air. Whencorrect water treatment, the conductivity at 25oC shouldbe ≤ 0.1 µmho/cm.

Unwanted anions, such as HCO3-, CO3

- -, SO4- - and

Cl- can be admitted with

the makeup waterair or H2 leakagefilter elements or ion exchanger resins notcomplying with the specifications [3].

The anions are normally absorbed by the anionexchanger resins in the mixed-bed filters and can havea permanently detrimental effect on the alkalizationprocess only when the ion exchanger is exhausted.

BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4910-0500/10609 E

Maintenance and SupervisionFuses on Rectifier Wheels


[1] 2.5-1810 General and Electrical Data[2] 2.5-9000 Excitation System

1 Fuse Monitoring

With the aid of the stroboscope whose light fre-quency is automatically controlled, it is possible toobserve each separate fuse on both wheels. To acti-vate the stroboscope, press the On push-button. It isthen possible to select either flash tube 1 or flash tube2 by pressing the corresponding push-button Lamp1or Lamp2 to observe each successive fuse on therectifier wheel. By pressing the feed or return push-button, the flashes can be timed so that a continuousslow-motion observation of each fuse is possible.

The position of the fuse indicator shows whethera fuse is intact or blown due to diode failure. If thecolor-coded fuse indicator has taken a radial position,the fuse has blown. To determine the condition of theentire rectifier wheel, it is necessary to know in whicharm of the bridge each blown fuse belongs. The bridge

arm can be determined from the color marking abovethe fuse on the edge of the rectifier wheel.

The operating limitations [1] must be observed ifseveral fuses have blown.

In normal operation, the fuses should be monitoredat least once each day. A check is required at oncefollowing abnormal operating conditions, e.g. short-circuit on the system close to the power plant, asyn-chronous running, etc. If the exciter is operated withdefective fuses, monitoring should be done on anhourly basis. If no additional fuses have blown aftertwo further shifts, normal running routine may be con-tinued.

2 Measuring the Insulation Resistances

Check the insulation resistances of the windingsto ground and the insulation resistances between thediode heat sinks and the rectifier wheel [2].


Work required

Check Fuses ×

Measure insulation resistance ×

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Turbogenerators

Maintenance

2.4-4925-0500/10609 E

Maintenance and SupervisionExciter Dryer

Note : The life of the prefilter depends on the dust con-centration in the power house and on the service hoursof the exciter dryer. It is recommended to inspect theprefilter at shorter intervals during the commissioningphase because of the high dust content of the air andthe relatively long period of exciter dryer operation.

1 Prefilter

The prefilter is installed in the door behind which theexciter dryer is located. This door is an integral part ofthe exciter enclosure.

The prefilter consists of a coarse (Acelan) filter anda fine (Microsorlit-F) filter. The coarse filter is locatedupstream of the fine filter.

1.1 Replacing the Prefilter

To inspect or replace the prefilter, open the dooraccommodating the prefilter.

Loosen wing nuts and then remove filter frame andthe two filter pads.

A slightly contaminated coarse filter can be cleanedby beating or blown out with compressed air fromthe air-leaving side. The fine filter can be reused ifin proper condition.

In case of more severe contamination, both filterpads should be replaced.

For reassembly of the filter, follow the sameprocedure in reverse order.

2 Dust Filters

One dust filter each is provided behind the intakebranches on both sides of the exciter dryer. Withproper and regular maintenance of the prefilter, dustfilters will be required only once per year.

2.1 Replacing the Dust Filters

De-energize the exciter dryer. Open the door containing the prefilter. Disconnect electrical and mechanical connections,

if necessary, and remove dryer. Loosen screws at connection branch by about

three turns Turn connection branch counterclockwise for

removal. Remove filter frame with dust filter. Blow out dust filter with compressed air from the

air-leaving side or wash dust filter. If necessary,replace dust filter.

Reinsert filter frame with clean dust filter into thedryer, making sure that the filter frame joint is inthe bottom center position.

Refit connection branch and turn it clockwisebefore tightening the screws.

After replacement of both dust filters, properlyrestore all connections.

Close door and energize exciter dryer.The exciter dryer is ready for further operation.


Work required

Inspect and, if necessary, replace prefilter ×

Inspect and, if necessary, replace dust filter in Exciter dryer ×

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BHEL, Haridwar

Turbogenerators

Maintenance

2.4-4930-0500/10609 E

Maintenance and SupervisionVentillation andMake-Up Air Filter of Exciter

1 Make-up Air Filters in Exciter EnclosureThe make-up air filters in the exciter enclosure are

contaminated by the continuous addition of the air inthe exciter cooling circuit. They should be checked atregular intervals and replaced, if required.

2 Exciter Drying SystemSlightly contaminated filter pads should be blown out

with clean compressed air from the clean air side orwashed in a water bath at a water temperature of ap-proximately 30oC, adding a neutral detergent.

Depending on the operating conditions, the ball bear-ing of the ventilator and the generator should be filledwith new grease every two to three years.


Work required

Check make-up air filters in exciter enclosure ×

Perform functional check of exciter drying system and clean filters, if necessary. ×

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Maintenance and Supervisionof Exciter Coolers

Also refer to the following information[1] 2.3-5003 Hints for Cooler Operation

1 GeneralSpecial measures should be taken to prevent corro-

sion damage to the cooler[1]. Cooler sections having nocooling water flows for some time may be subject tostandstill corrosion. In addition to many other corrosiveinfluence, such as the different elements of the coolingwater, locally differing deposits, raw materials, etc. thereexists the danger that micro-organisms on the tube wallsmay die an decay due to a loss of fresh water supply(lack of oxygen). Ammonia is formed from such decaywhich may lead to stress corrosion cracking. Corrosiondamage can only be properly prevented if the cooler isdrained on the water side, cleaning completely dried andmaintained in a dry condition. With the generator in com-mercial operation, such measures are often unfeasible,particularly in cases of short outages. In such cases,special measures should be taken.

2 Exciter CoolersDuring normal operation, the cooling water flows

through the cooler sections. Since the coolers are de-signed for 100% capacity at maximum cooling watertemperature, the condition may arise that the coolersare supplied with smaller cooling water flows for longperiods. Depending on the purity of the cooling wa-ter, this may result in deposits due to the lower watervelocity in the cooler. To prevent cooler damage, it istherefore recommended to rinse the coolers with thefull water flow during short outages. In addition, thecoolers should be frequently cleaned with brushes.For heavy cooler contamination and if operationalrestrictions and shutdowns are undesirable, it is rec-ommended to install a continuous cooler water purifi-cation system.


Work required

Check exciter cooler vents ×

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Maintenance and Supervisionof Ground Fault Detection System


Work required

Check carbon brushes of ground fault detection system ×

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1 Ground Fault Detection SystemThe ground fault detection system runs continuously.

On occurrence of a ground fault between the windingand ground an alarm is activated and indicated on thedanger alarm panel.

If a ground fault is indicated, the cause of the groundfault alarm must be investigated at once. To do this, theinsulation resistance should be measured with a 500Vmegger. The ground fault detection system should bedisconnected at the brush gear or isolated if achangeover switch is provided.Caution: If, as described below, the measurement isperformed with the generator running and excited, handlesliprings and brush gear with extreme care since at theworst the full field voltage may be applied to the slipringconnected to the exciter circuit.

I f the insulation resistance drops during themeasurement, exchange polarities at the megger forchecking purposes and repeat measurement.

If insulation resistance measured is not sufficient,operation of the generator should be continued only afterconsultation with the manufacturer to avoid majorconsequential damage.

2 Carbon Brushes of Ground Fault DetectionSystemThe carbon brushes should be checked at regular

intervals. During operation, the useful length of eachcarbon brush can be determined without removing thebrush holder by inserting a gauge stick of insulatingmaterial into the bore of the brush holder.

If a carbon brush must be replaced, the brush holdershould be released from its lock and a new carbon brushfitted, making sure that the carbon layer comes beforethe silver layer in direction of rotation and that the newbrush has a contact face which matches the slipringcontour. Grinding of the new brushes to the requiredcontour should be done using a model of the ring contouror by grinding to size at the slipring when the unit is atrest. Carbon brush wear depends on several factors. Thenormal service life of a set of carbon brushes may bedetermined by keeping a record of brush replacementsover a period of several years.

Note: Remove only one brush holder at a time in ordernot to disturb proper operation of the ground faultdetection system. When inserting a new double-layercarbon brush, make sure that silver layer comes aftercarbon layer in direction of rotation

1. Terminal board2. Bore for gage stick3. Plug-in brush holder4. Brush carrier segment5. Slipring

Fig.1 Brush Holder for Ground Fault Detection

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Turbogenerators

Inspection


[1] 2.5-1003 Measures to Prevent Corrosion During Inspections

2.5-0010-0500/10609 E

Introduction

Reliable operation of the turbogenerator will be ensuredonly if inspections and overhauls are carried out at regularintervals so that any faults can be detected and correctedbefore they result in costly failures. Following eachinspection or overhaul, the next inspection should bescheduled.

Provided that commercial tools can be used and that nospecial skills are required for the dismantling and erectionwork, the inspections can be performed by skilled powerstation staff. In all other cases, however, such as for theinspection of the shaft seals and their auxiliaries, theservices of the manufacturer’s product service personnelwill be required.

During an inspection, special attention should be givento avoiding the effects of moisture on austenitic retainingring materials as a preventive measure against stresscorrosion.

According to the conventional interpretation, theconditions for stress corrosion to occur are given by thecombination of sufficiently high tensile stresses and asensitive material/corrosion medium system. In high-tensile steel, this sensitive system already develops whenthe material is exposed to the moisture in the air. Extendedstorage until startup and extended shutdown or stand-by

periods of turbogenerators may thus result in a latent hazardto components which are made of a material sensitive tostress corrosion. Endangered parts of the turbogeneratorare, for instance, the rotor retaining rings which consist ofhigh-tensile austenitic steel. This latent hazard can only bepositively avoided by taking all preventive measuresrequired to fully protect those components of theturbogenerator which may be affected by stress corrosionagainst the effects of moisture [1].

The shutdown of a turbogenerator for inspection shouldbe made in exactly the reverse order as duringcommissioning. It should be noted in particular that thehydrogen must be removed from the generator housingwith carbon dioxide only. Should opening of the gas systemor of the generator proper be required during an inspection,it is required to replace the carbon dioxide with air.

In the event the manufacturer’s personnel are requiredfor a scheduled inspection or overhaul, it is recommendedto notify the manufacturer well in advance. The estimatedduration of the inspection or overhaul should also be stated.

The spare parts stored for repairs and overhaulsshould be checked at regular intervals. Components packedin plastic sheeting mostly contain a desiccant which mustbe replaced or reactivated from time to time.

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Determination ofDewpoint Temperature

Relative humidity in %

Example: Relative humidity of ambient air = 50 % and room temperature = +20oC result in adew point temperature (DT) of + 9oC, corresponding to an absolute humidity of 8.6 g/m3

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Packing, Transport and Storageof Generator Rotors

NoteGenerator rotors are high-grade components which

are sensitive to moisture. For this reason, they must beprotected against corrosion and mechanical damage duringtransport and storage.

The packing precautions and the organizationalmeasures for protection during transport and storage aredescribed below and summarized in [1]. This descriptioncontains all details required for restoring the standardpacking provided by BHEL for delivery of the rotor. If arotor is to be returned to the manufacturer’s works foroverhaul or in the case of a prolonged outage of thegenerator involving a separate storage of the rotor, therequirements specified in the following must be met forprotection of the rotor.

Any deviations from the standard packing due to specialcircumstances shall be subject to the approval of BHEL.

Contents

1. Basic Makeup of Packing

2. Definitions

3. Summary of Rotor Packing Requirements

4. Sealed Packing4.1 Production Appliances and Packing Materials4.2 Protection of Metallically Bright Shaft Ends4.3 Providing the Plastic Sheeting Covers4.4 Desiccant

5. Skid and Outer Protection5.1 Land Transport

(Less Than One Month)5.2 Land Transport or Sea Transport

or Longer Duration

6. Protection of Packing During Transit6.1 Organizational Measures6.2 Loading6.3 Receiving Inspection

7. Storage7.1 Storage Area7.2 Checks During Storage Period7.3 Removal From Storage

1. Basic Makeup of PackingThe packing precautions and organizational measures

during transport and storage are intended for reliablypreventing the effects of moisture on the rotor andespecially on the rotor retaining rings which may be

endangered by stress corrosion and for protection againstmechanical damage during transport and transshipmentprocedures.

For protection against the effects of moisture, the rotorretaining rings and the rotor body are packed in sealedplastic sheeting covers, adding materials for moistureabsorption. This sealed packing is protected with a secondplastic sheeting cover. In the case of sea transport, a thirdplastic sheeting cover is provided for the rotor retainingrings and the rotor body. This cover forms a secondadditional barrier against the diffusion of moisture into theinnermost plastic sheeting cover.

The metallically bright shaft ends (shaft journals andcouplings) are protected with a hard wax coating.

The rotor is then placed on a skid with closed bottomand secured in position for protection against mechanicaldamage. For land transport not exceeding one month, thisunit is protected against external influences by a woodenenclosure resting on the bottom frame of the skid. Thisenclosure must be removed prior to each transshipment tohitch the rotor with a lath grid in place at the middle of therotor body.

In the case of land transport exceeding one month andwith sea transport, the enclosure forms an integral part ofthe skid. The hitch should then be taken directly at the skid.The complete cargo is covered with tarpaulins forprotection from the elements.

Rotors with water-cooled windings are protectedagainst corrosion by filling the water passages with purenitrogen after drying to a gauge pressure of 0.5 to 1 barvia a cover at the exciter end. The pressure can be readon a permanently installed pressure gauge.

2 Definitions

2.1 Land TransportThe packing provided for this mode of shipment affords

sufficient protection for land transport under moderateclimatic conditions and for a scheduled transit period ofnot more than one month. This provides a reliable protectionfor short-distance transport (from BHEL, Haridwar todestinations in India ).

This type of packing also ensures sufficient protectionduring subsequent storage in a covered hall, e.g.powerhouse. Following the receiving inspection, theinsulation resistance of the rotor winding and the conditionof the desiccant should be checked at intervals of onemonth and the desiccant reactivated, if necessary.2.2 Sea Transport

The packing provided for this mode of shipment

2.5-0030-0500/2

affords protection during shipment by sea, duringunavoidable outdoor storage and for transport periods andunder conditions exceeding those under item 2.1. Theadditional packing, as compared to land transport, consistsof a third plastic sheeting cover and a closed, seaworthyouter packing. The desiccant included in the plastic sheetingcovers is sufficient for the scheduled transport period,but for not more than six months.

The inspections required during storage are the sameas specified for land transport under item 2.1.

3 Summary of Rotor Packing Requirements

This summary [1] contains information on the makeupof the packing and on the procedures required to maintainthe packing in sealed condition. A detailed description isgiven in the following section.

4 Sealed Packing

The obtain a reliable and long-lasting corrosionprotection, both suitable production appliances andmaterials and appropriate methods of packing are required.The basic prerequisites are:

Dry Condition of Rotor Prior to PackingThe rotor must be dried if it is expected to be in a wetcondition due to operational faults. To do this, the rotorand especially the rotor retaining rings and end windingportions should be dried with dry air by means of an airdryer (e.g.. Munters dryer).

Water-Cooled Rotor WindingDrying the cooling water circuit of the rotor windingshould be performed with a vacuum pump, heating thewinding with direct current to approximately 60 to 70°C.Drying can be terminated when a pressure of less than5 torr has been maintained on the hot rotor for a periodof five hours. Following this, the rotor winding shouldbe filled with pure nitrogen to a gauge pressure of 0.5bar via the end cover at the exciter end.The equipment and power sources required for vacuumdrying should be obtained by the user in due time. Themechanical data required for the procurement of theequipment are available from the manufacturer onrequest.

Weather-Protected Packing AreaPacking and unpacking is only permissible in a weather-protected area, preferably in a hall.

No Delays in Packing ProcedureCare must be taken to ensure that after its removal therotor will not suffer any moisture condensation oraccidental wetting. Packing the rotor should thereforebe performed immediately after withdrawal of the rotorand any required drying in order to minimise anyuncontrolled phases.

4.1 Production Appliances and Packing MaterialIn addition to the standard tools, such as scissors,

knife, etc., special appliances are required for obtaining apacking affording corrosion protection.

Heat-impulse fixture for heat sealing of polyethyleneplastic sheeting, consisting of:heat – impulse generator andheat – sealing tongs for a minimum seam length of 200mm,Heated plate to melt wax-coated sheeting for bonding(e.g. electric iron).

· Blower with small delivery rating for checking the plasticsheeting cover for tightness and for extracting the testair (e.g. vacuum cleaner).Air dryer for any required drying of rotor end windingsprior to packing.

The following packing materials are used, which areavailable from BHEL, HARIDWAR on request:

Polyethylene sheeting, 0.2 mm thick, endless, preferredwidth 6000 mmRubber board with canvas reinforcement, 3 mm thick,minimum width 1000 mmWax-coated linen binding with 1 mm wax coating, 100mm wide (e.g. Denso binding)Hard wax for application by brush (e.g. Tectyl 506)Cold degreasing agentWax-coated aluminum foilAdhesive for plastic sheetingAdhesive tape for plastic sheetingFoam material, which does not absorb water, 5 to 10mm thick (e.g. polyurethane)Silica gel in linen pouches as desiccantMoisture indicators for functional checking of desiccant(color indicators for 30%, 40% and 50% relativehumidity)Hemp rope, 2 mm thick, for attaching desiccant pouchesFabric tape, 20 mm, endlessSteel band, 1 mm thick, 30 mm wide, with turnbuckleand tensioning deviceLath grid for taking a hitch at the rotor body consistingof hardwood laths 50x80x3000mm, nailed to 5mm thickfabric mat.

4.2 Protection of Metallically Bright Shaft EndsThe metallically bright shaft ends should be cleaned

and degreased and protected with a hard wax coating(e.g. Tectyl 506) of sufficient thickness (dark-brown). Inaddition, the areas of support in the skid should be wrappedwith two layers of wax-coated bindings (e.g. Densobinding) and a 3 mm thick canvas-reinforced rubber mat.All other areas contacting the skid should also be coveredwith 3 mm thick rubber board.

4.3 Providing the Plastic Sheeting CoversThe polyethylene sheeting covers are made directly

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Inspection

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on the components to be protected. To protect the plasticsheeting cover from damage, any contact with sharp edgesmust be avoided. Edges should be padded with layers ofrubber board or foam rubber. The use of excelsior,corrugated cardboard, felt or other hygroscopic materialsis not permissible. Care should be taken to ensure that theplastic sheeting cover remains intact during the subsequentpacking procedures. Even pinpricks and minute tears inthe plastic sheeting will render tight sealing ineffective.Within the range of rotor support in the skid and of othercontact points (upper shipping saddles), the polyethylenesheeting should be inserted between two rubber boardsof sufficient size for protection against damage. At theend winding, each plastic sheeting cover is provided witha 500 mm dia. opening for connection of a plastic sheetinghose having the same diameter and a length ofapproximately 1m. After checking the cover for tight sealing,the desiccant is added via this hose, which is then closedby heat-sealing.

To maintain the sealed range in a dry conditiondesiccant (see Item 4.4) is added to each plastic sheetingcover.

After heat-sealing and tight wrapping with wax-coated bindings, each plastic sheeting cover should bechecked for tight sealing. To do this, one corner of theplastic sheeting hose should be cut for insertion of avacuum cleaner hose (discharge end) and tightly sealedwith a binding. If the cover remains inflated during thefollowing two hours, the cover is properly sealed. Followingthis check, the air should be drawn off.

4.3.1 First Plastic Sheeting CoverAs a first step, the entire rotor body should be

wrapped with wax-coated aluminum foil with 50 to 70 mmoverlap, with the wax coating facing the rotor body. Seamsand overlapping portions should be sealed airtight by meltingthe wax coating with an electric iron.

To protect the aluminum foil from being damaged bythe handling ropes, a canvas-reinforced rubber mat, 3 mmthick and approximately 2500 to 3000 mm wide (dependenton overall length of rotor) should be placed around thecenter of gravity of the rotor. This rubber mat consists ofindividual sections, each having a length corresponding tothe rotor body diameter + 100 mm and arranged with anoverlap of not less than 100 mm. All overlap seams aresealed with wax-coated canvas bindings. Axial overlapseams are additionally secured with steel bands. Theoverlap seam at the top on the circumference is secured inaxial direction by wooden lath, 80x40 mm, which is alsoheld in place with steel bands.

Finally, a lath grid (hardwood laths attached to fabricmat or fabric tape) should be placed in position for hitching.The grid should cover not less than the lower half two-thirds of the rotor body circumference and be adequatelysecured with steel bands. The wooden laths must be onthe outside and arranged so that the rubber mat is

approximately 150 mm wider at each end of the rotor. Therange between the free shaft portion protected with hardwax and the end of the rotor body should then be wrappedwith polyethylene sheeting which is to be sealed tightlywith wax-coated canvas bindings at the rotor body andfree shaft portion.

Experience has shown that in the case of largerrotor body diameters (>1300 mm), the aluminum foil cannotbe wrapped around the rotor with sufficient tightness andmay thus be omitted. In such cases, the above mentionedpolyethylene sheeting should extend beyond the rubbermat at the middle of the rotor body and should be sealedtightly with wax-coated canvas bindings at these points.

The precautionary measures specified under Items4.2 to 4.3.1 provide for the minimum packing requirementsand are sufficient for land transport not exceeding 20hours. In the case of rotors provided with aluminum foilwithin the range of the rotor body, sealing of the rubbermat at the middle of the rotor body will not be required forshort-distance transport.

4.3.2 Second Plastic Sheeting CoverIn addition to the first plastic sheeting cover described

under Item 4.3.1, a second polyethylene sheeting cover ofthe same type should be provided between the shaft endsand the rubber mat at the middle of the rotor body. Toseparate the two plastic sheeting covers, a 5 to 10 mmthick layer of foam material should be placed over the tophalf circumference of the rotor retaining rings and rotorbody.

Two plastic sheeting covers are required for landtransport and storage as defined under Item 2.1.

4.3.3 Third Plastic Sheeting CoverFor sea transport and outdoor storage as defined

under Item 2.2, an additional diffusion barrier is provided.This third polyethylene sheeting cover protects the entirerange of the rotor between the shaft journals at eitherend. It is placed over the plastic sheeting covers accordingto Items 4.3.1 and 4.3.2 and is to be made in the samemanner.The plastic sheeting is placed over the rotor before therotor is supported on the skid. Within the range of rotorsupport the plastic sheeting is inserted between two rubbermats of 3 mm thickness each. After the rotor has beensupported on the skid, its upper half portion (rotor bodyand retaining rings) should be covered with a 5 to 10 mmthick layer of foam material outside the lath grid area, andthen the plastic sheeting cover should be heat-sealed.

4.4 Desiccant4.4.1 Type and Application

The desiccant consists of silica gel in dust-free andair-permeable pouches. It should be inserted into eachplastic sheeting cover via the plastic sheeting hoses at theend windings. The desiccant must be placed so that it can

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Inspection

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be easily replaced when this becomes necessary and thatit does not come into contact with steel or windingcomponents (danger of corrosion). If necessary, covercontact area with polyethylene or rubber sheeting.

All pouches must be tied together with a hemp rope,and, when used, they must be in an active, i.e. absolutelydry condition

4.4.2 Desiccant QuantitiesThe desiccant quantities [1] are proportioned to

accommodate highly adverse climatic conditions. Themaximum quantity is sufficient for a shipping time notexceeding six-month.

4.4.3 Checking and ReactivationThe moisture absorption capacity of the desiccant

must be checked after completion of shipment, afterinterruptions in transit involving a storage period of morethan one month and during normal storage at the site (seeItem 7.2). To do this, use the moisture indicators (Fig. 3)inserted in the plastic sheeting covers at a distance of notless than 5 cm from the sheeting. The moisture indicatorsare marked with their respective location identifications asillustrated in Fig. 2 and show the relative humidity insidethe cover in three ranges (>30%, >40% and >50%). Withthe packing in dry condition, all circles are blue. A changein color to pink in the respective circle indicates the relativehumidity in percent. As soon as the 40% indicator changesto the pink color, the desiccant must be removed andreplaced or reactivated by drying.

All circles pink: danger of corrosion 50

Two circles pink: replace desiccant 40

One circle pink: warning 30

Make sure that sufficient replacement desiccant orthe necessary drying facility for reactivation is available.After opening, the plastic sheeting cover should beprovisionally resealed, but must not be left in this conditionfor more than 20 hours.

For reactivation, the pouches should be dried in adrying oven at a temperature of 110°C for 12 hours. If adrying oven is not available, the desiccant should beremoved from the pouch, spread out in a thin layer on ametal plate and dried at 110 to 130°C for several hours untilthe weight of the desiccant remains constant. Thedesiccant should then be filled back into the pouches which

are to be closed and reinserted into the plastic sheetingcovers as quickly as possible. Care should be taken toensure that the pouches do not come into contact withmetal parts. The opening in the plastic sheeting cover shouldthen be resealed with a heat-sealing unit.

5 Skid and Outer Protection

BHEL, HARIDWAR generator rotors are delivered inbox type shipping containers, consisting of a skid and anenclosure. Figs. 4 and 5 depict typical examples. It isrecommended to keep this shipping container for futureneeds, unless an adjustable universal skid is used for landtransport which is available from BHEL, HARIDWAR, ifrequested in due time. The information given in the followingrelates to the remounting of the rotor in sealed packing onthe skid and to the provision of the outer protection.

5.1 Land Transport (Less Than One Month)For land Transport, the rotor should be supported on a

skid similar to Fig. 4. The points of support should be paddedwith rubber mats for protection of the plastic sheetingcovers. At the shaft ends, the rotor should be attached tothe skid by means of upper saddles and secured in axialdirection.For loading operations, the hitch should be taken either atthe middle of the rotor body (lath grid) or at the rotor ends.During transit, the rotor should be protected against externalinfluences by a wooden enclosure resting on the bottomframe of the skid. Both long sides of this protectiveenclosure should be clearly stencil-marked with thefollowing note.Caution: Remove protective enclosure for rotortransshipment.

The complete cargo should be covered with a lashedtarpaulin.

5.2 Land Transport or Sea Transport of LongerDuration

For land transport exceeding one month and for seatransport, the rotor should be packed in a closed, self-supporting container. The setup for two-pole rotorscorresponds to Fig. 2. The container bottom should haveopenings with perforated–plate covers for ventilation andto prevent the accumulation of water. In addition, inspectionopenings with covers should be provided on the long sidesfor access to the desiccant pouches via the plastic sheetinghoses. An inspection opening at the exciter end shouldprovide access to the contact pins on the exciter-end endcover of the rotor for measurement of the insulationresistance of the rotor winding.

Prior to closing the container, the rotor should becovered with 3 mm thick pressboard panels andpolyethylene sheeting, taking care to avoid the formationof troughs in which water might accumulate. The containerlid should be covered with tar board sanded on one side

Fig. 3 Moisture Indicator

and folding down over the edges not less than 200 mm.The total weight and the dimensions of the cargo should

be marked on the container. In addition the hitching rangeshould be color-marked. The complete cargo should becovered with a tarpaulin for protection against the elements.

6 Protection of Packing During Transit :6.1 Organizational Measures :

Proper packing of the rotor will prevent both the ingressand the condensation of moisture during transit, unlessthe sealed packing is damaged by improper loadingprocedures or customs inspections. This should be avoidedby suitable precautions, enabling a quick restoration of thedry condition of any damaged sealed packing. Thesemeasures include :

On the Cargo:

Instructions for correct handling.Reference to “Sealed Packing” on shipping container.Indication of desiccant quantity inserted into eachindividual plastic sheeting cover behind inspection holecover.Attaching this instruction 2.5 – 0030.

In the Accompanying Documents:Reference to “Sealed Packing”.Reference to arrangements for customs clearance atplace of installation.Request for immediate drying in case of transportdamage with moisture penetration.Check list relating to condition of desiccant [2].Checklist relating to insulation resistance of rotorwinding [3].

6.2 LoadingIf a flatcar is used for transport, the cargo should be

loaded so that it can slide on the car, i.e., the skid must notbe secured in position and must be free to move in bothdirections of running. Provision should be made for a slidingdistance of approximately 1.5m at either end.

Planks , approximately 50 mm thick, should be nailed tothe long sides adjacent to the battens.

If a deep well wagon is used for transport, the skid-mounted rotor should be secured in position at both endsof the loading bridge. The bridge through should be sealedwith boards for protection against stones.

During shunting operations, the car must never beallowed to pass over a hump. A corresponding note shouldbe included in the waybill and affixed to the car in a wellvisible location.

6.3 Receiving InspectionAfter arrival of the rotor, the consignee should examine

the packing for external damage. The condition of thedesiccant can be ascertained at the moisture indicators. Inaddition, the insulation resistance of the rotor winding

should be checked. In the case of a water-cooled rotorwinding the pressure of the nitrogen blanket should alsobe checked. The date of the receiving inspection shouldbe entered in the respective section on the inspection holecovers. The results of the receiving inspection should berecorded in the check lists [2], [3], copies of which shouldbe forwarded to the consignor.

If the packing is found in damaged condition, it shouldbe resealed as soon as possible. The same requirementapplies if the seals were opened by the customs authorities.

If the moisture absorption capacity of the desiccant isno longer sufficient (40 % indicator is pink), the desiccantshould be removed from the plastic sheeting cover, withthe shipping container protected from the environment, andreactivated (see Item 4.4.3). If the rotor is unpackedimmediately after delivery, it may become necessary tobring it to ambient temperature level for protection againstmoisture condensation. If the rotor temperature is equal toor higher than the room temperature, there will be no needfor raising the temperature of the rotor to the level of theambient temperature. The rotor temperature can bemeasured at the accessible rotor ends using a temperaturemeasuring instrument. If the rotor temperature is lowerthan the ambient temperature, steps must be taken toensure that the rotor temperature will be 5 degC (safetymargin) higher than the dew point temperature of theambient air [4].

In the case of outdoor units, the rotor installation phaseshould be timed so that the unpacked rotor will not beexposed to extreme changes in temperature as this willinvolve the risk of moisture condensation.

7 Storage

The preventive measures during storage provide formaintaining the dry condition of the rotor in the sealedpacking without any interruptions until commencement ofthe installation.

To this end, certain minimum requirements must beobserved, which are dependent on the condition of thestorage area. In addition, the condition of the packing andof the desiccant contained in the packing must be checkedat regular intervals. To obtain additional verification, theinsulation resistance of the rotor winding should bemeasured.

As long as the nitrogen pressure is still slightly aboveatmosphere, it will normally not be necessary to rechargea water-cooled rotor winding with nitrogen. If the nitrogenpressure has dropped to zero, the winding should be filledwith pure nitrogen to a gauge pressure of 0.5 bar from thenitrogen bottle permanently installed in the shippingcontainer.

7.1 Storage AreaSufficiently ventilated and dry storage rooms for stable

support of the parts in a fully accessible location arefavorable preconditions for storage. If outdoor storage

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cannot be avoided, a heavy-duty outer packing of theseaworthy type must be provided. The outdoor storagefacility must be set up in such a way that the stored item isprotected against rainfall and moisture from the ground.This would include placing a waterproof shelter over theshipping container which affords sufficient ventilation. Inaddition, the stored item should be blocked up on the solidground for protection against moisture. Enough space mustbe left between the boxes to permit inspections and checks.

7.2 Checks During Storage PeriodFollowing the receiving inspection, surveillance of the

equipment should be conducted by repeat checks atintervals of four weeks. The checks required are the sameas specified for the receiving inspection under Item 6.3.

The dates of the repeat checks should be recorded on theouter packing below the date of the receiving inspectionand in the check lists [2],[3].

7.3 Removal from StorageIf the storage area and the place of installation are not

located in the same room (power house or workshop), therotor temperature may be below the dew point level ontransfer of the rotor from a cold storage area to a warmpower house. To protect the rotor from moisturecondensation, it should be left in its sealed packing forseveral days and allowed to assume the ambienttemperature prior to removing the packing for immediateinstallation.


[1] 2.5-0031 Preventive Measures for Transport andStorage of Generator Rotors (Summary)

[2] 2.5-0032 Checking Desiccant in Generator RotorPacking

[3] 2.5-0033 Insulation Resistance Measurements onRotor and Exciter Windings During Storage(Test Report)

[4] 2.5-0019 Determination of Dewpoint Temperature

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Preventive Measures for Transport andStorage of Generator RotorsSummary

Protective Materials and SetupLand Transport Sea Transport

Purpose/ Component Short-Distance Shipment by Sea or Phase Transport Period Less Transport Period More

Than One Month Than One Month

ACorrosion Shaft journals 1 Hard wax coating (e.g. Tectyl 506) of sufficient thickness (dark-brown color).Protection Couplings Additionally protect areas of support in skid with two layers of wax-coatedof shaft bindings and one layer of 3 mm canvas-reinforced rubber mat.ends

BCorrosion Water- 2 Fill dried rotor winding with pure nitrogen to a gauge pressure of 0.3 to 0.5 barProtection cooled through cover at exciter end.of rotor rotorwinding winding

CFirst packing Rotor 3 Place wax-coated aluminum foil over entire range of rotor body (only for rotor bodyof rotor Body diameters < 1300 mm, due to difficult handling)retaining 4 Place 3 mm canvas-reinforced rubber mat, 2500 to 3600 mm wide (dependent onrings and length of rotor) around center of gravity; seal overlap seams with wax-coated bindingsrotor body and steel bands; secure axial overlap seam with wooden lath.in plastic

5 Place lath grid on fabric mat, about 300 mm narrower than 4 , around two-thirds ofsheetingrotor circumference and secure at top.cover

Retaining 6 Place 0.2 mm polythene sheeting between shaft ends 1 and body ends 3 andrings rubber mat 4 , respectively, seal joints with wax-coated bindings at both ends,Fans heat-seal seams

(sufficient (water boxes) 7 Check plastic sheeting cover for tight sealing by inflation with air and recheck after

for short- two hours.distancetransport up 8 Add desiccant per m2 of sheeting surface shipping time up to 1 month: 500 g; up toto 20 hours 3 months : 1000 g; up to 6 months: 1500 g. Plus 280 g for each Kg of wood and 35 gand imme- for each Kg of foam material within plastic cover. Moisture indicators for relativediate instal- humidity > 30%, > 40%, > 50%.lation)

DProtection Rotor body 9 Place 0.2 mm polythene sheeting between shaft ends 1 and rubber mat 4 over aof first and 5 to 10 mm foam mat around top half circumference of rotor retaining rings and rotorpacking retaining body.C by rings

10 Check heat-sealed and tightly wrapped plastic cover 9 for tight sealing as second under 7plastic sheet-ing cover 11 Add desiccant and moisture indicators as under 8 .

EProtection Rotor body 12 Not required for land transport.of packings andC and D by retainingthird plastic ringssheetingcover

foam mat and cover entire rotor between shaft endsas under 9 . With four-pole rotors, foam mat is splitwithin range of lath grid; insert plastic sheetingbetween 3mm rubber boards. Check for tight seal-ing as under 7 . Add desiccant as under 8 .

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Protective Materials and Setup

Land Transport Sea TransportPurpose/ Component Short-Distance Shipment by Sea orPhase Transport Period Less Than One Month Transport Period More Than One Month

One Month

FTransit Tightly 13 Tightly sealed rotor 1 to 11 on skid Tightly sealed rotor 1 to 11 in closedprotection sealed rotor with closed bottom under enclosure and self-supporting shipping container Under

tarpaulin tarpaulin.

GLoading Complete 14 Hitch point on rotor at lath grid in center Hitch point on shipping container; in the

cargo of gravity after removal of enclosure. case of four-pole rotors on Steel sleeveat mid-length of skid.

HReceiving Complete 15 Check outer packing and relative humidity inside plastic sheeting at moisture indicators.of cargo packing Replace desiccant when relative humidity is higher than 40 %. Return check list with

and rotor details on condition of packing and insulation resistances of rotor windingwinding to consignor.

16 Prior to unpacking the rotor in a weather-protected location, a cold rotor must haveambient or dewpoint temperature plus 5 K safety margin to prevent moisture condensation.

J Storage area 17 With packing for land transport, only in a hall kept at a moderate temperature. ForStorage outdoor storage, seaworthy packing plus additional precautions are required: storage

on well tamped and suitably reinforced ground and set on blocks for protection against moisture, case under protective roof.

Complete 18 During storage (including interruptions in transit), check outer packing for damage andpacking tight sealing, insulation resistance of rotor winding and, if applicable, nitrogen blanket atand rotor intervals of four weeks.winding

KRemoval Rotor 19 Maintain tight sealing of packing as long as possible until rotor is installed. Protectionfrom storage against condensation hazard by preventive measure 16

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BHEL, Haridwar

Turbogenerators

Inspection

Desiccant Checking RequirementsThe absorbent capacity of the desiccant must be

checked after shipment has been completed and at inter-vals of one month during any subsequent storage period.

The results should be recorded in the table below. Thedesiccant must be removed and replaced or reactivatedby drying when a change in the color of the 40% moistureindicator is observed.

2.5-0032-0500/10609 E

Checking Desiccant inPacking of Components

Job name: Sl. No.: Type:

Shipping Location Moisture indicator Weight of Replacement oror identification blue or pink? desiccant reactivationstorage of moisture Bottom Center Top in packing of desiccantphase indicator circle circle circle in Kg

(30%) (40%) (50%)

Prior to TE 1shipment TE 2

TE 3

EE 1

EE 2

EE 3

TE 1

TE 2

TE 3

EE 1

EE 2

EE 3

TE 1

TE 2

TE 3

EE 1

EE 2

EE 3

TE 1

TE 2

TE 3

EE 1

EE 2

EE 3

TE 1

TE 2

TE 3

EE 1

EE 2

EE 3

Dat

e

Nam

e

Com

pany

Stor

age

area

of c

ompo

tent

Con

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n of

oute

rpa

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BHEL, Haridwar

Turbogenerators

Inspection

2.5-0033-0500/10609 E

Insulation Resistance Measurementson Rotor and Exciter WindingsTest Report

Checking the Insulation Resistancesof Rotor Windings in Sealed Packing

The insulation resistance of the rotor winding should

be checked after shipment has been completed and atintervals of one month during any subsequent storageperiod. The results should be recorded in the table below.

Notes:1 The insulation resistance should be measured with an

insulation measuring device, applying a voltage of 100V, but not more than 250 V.

2 Prior to each measurement, any static charges shouldbe removed by grounding the windings as a precau-tionary measure (10 minutes).

3 The connection to the rotor winding should be made ata specially identified bolt on the exciter-end end cover.

4 The connection to the rotor body should be made at aspecially identified bolt on the exciter-end end cover.

5 After each measurement, any static charges shouldbe removed by short-circuiting the winding throughthe rotor body (not less than 20 minutes).

Job name : Sl No.: Type : Component :

Shipping or Prior to storage phase shipment

Date

Name

Company

Storage area

Temperature in Storage area in °C

Rel. humidity of ambient Air in storage area in %.

Rotor temperature in °C

Moisture 50 Indicator TE1 40 in packing 30 blue or 50 pink? TE1 40

30

Pressure of Nitrogen blanket in bar

Applied voltage in V

15 s30 s45 s1 min2 min3 min4 min5 min6 min7 min8 min9 min10 min

Inau

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n R

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BHEL, Haridwar

Turbogenerators

Inspection

2.5-0200-0500/10609 E

Preparation of Machinery Parts

1 General

The machinery parts to be assembled are deliveredready for mounting, unless certain portions must beprotected during transport against corrosion or damage.

In case of orders for delivery to other countries, allsensitive portions of the machinery parts, e.g., journals,are provided with a protective coating and protected againstdamage.

In case of orders for delivery to overseas countries,all machined surfaces are provided with a protectivecoating. In addition, complete assemblies are sealed inplastic sheeting.

2 Removal of Protective Coating

The protective coating applied at the manufacturer’sworks should be carefully removed prior to assembly. Thesurfaces to be cleaned should be washed with petroleumor a similar agent. When using trichlorethylene, the cleanedsurfaces should be carefully dried and afterwards a thinoil film should be applied. Non-observance of thisrequirement implies the danger of corrosion.

Particularly thick layers of protective coating should besoftened by applying one of the above-mentioned cleaningagents and then be removed by means of a hardwoodboard (approximately 10 cm x 10 cm x 1 cm).Caution: Never use scrapers, finishing trowels orsheet metal strips for removing the protectivecoating from highly sensitive machinery parts(journals, etc.)

The covers protecting the components of the DC plug-in contact assembly should be removed shortly beforecoupling the rotors.

Make sure that the sleeves and bolts of the DC.

plug-in contact assembly of the exciter rotor willnot come into contact with any solvent.

Cleaning of internal and external threads should bedone by chasing, using suitable taps or cutting dies. Thedimensions of the external and internal threads may betaken from the respective drawings. Use dry compressedair to blow out the re-tapped holes.

Where no taps are available cleaning of the tappedholes may also be carried out with the aid of the originalscrews. At first, the screws should be cleaned by meansof solvent and a brush. The cleaned screws should thenbe dipped into a solvent and immediately afterwards bescrewed into the holes for thread cleaning.

If required, this procedure should be repeated severaltimes until the threads are free from protective coating.

3 Remedying Minor Damage

Damaged machinery parts should be reconditioned asdictated by the extent of the damage and the operationalrequirements unless the nature of the damage does notwarrant such remedying.

Seriously damaged parts should be returned to themanufacturer’s works together with a damage or failurereport.

The machinery parts and the fixing and locatingelements should be checked for burrs and compressionmarks, and such imperfections should be removed bymeans of a smooth-cut file. Fine –finished surfaces shouldonly be polished by means of an oilstone.Caution: Burrs and compression marks on bearingmetal surfaces should only be removed by means ofa spoon scraper or flat scraper.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-0300-0500/10609 E

Checking the Bearing and Seal Insulation

1 GeneralDuring operation of a generator, voltages are set up along

the rotor due to magnetic unbalances and ring excitation.This shaft voltage would cause a destructive current to flowthrough the bearing, shaft seal and other components if therotor were not insulated from ground at least at the exciterend. For reasons of interchangeability, all stator componentscoming into contact with the generator rotor are insulated. Atthe exciter, all bearings or the complete exciter are insulated.

2 Checking the Shaft Seal and Bearing InsulationDuring Installation

2.1 Bearing SaddlePrior to inserting the rotor and supporting it on the

bearings, the insulation resistance of the built-in bearing saddleshould be measured separately by means of a 100 V meggerapplied between the bearing saddle and the lower part of thestator frame. The values measured should be recorded.

With satisfactory insulation, a value in excess of 10megohms is to be expected. If an insulation resistance valuebelow three megohms is measured, the insulating parts shouldbe checked for moisture, contamination or metallic contacts.If required, the insulation should be dried at 80°C maximum.

The measurement should be repeated immediately afterthe rotor has been supported on the bearings.Caution: With this measurement and the followingchecks both rotor bearings must be insulated, and thegenerator rotor must not come into contact with theturbine shaft through measuring devices or similarparts, to prevent the generator rotor from beinggrounded.

Since, with the rotor inserted, all individualresistances measured previously are now in parallelin the measuring circuit, the total resistance will beslightly lower than the lowest individual resistancevalue measured before.

2.2 Inner and Outer Labyrinth RingsInner and outer labyrinth rings are insulated from other

components. The insulation resistance of each individuallabyrinth ring should be measured after installation in order topreclude any lengthy search for faulty mounting onmeasurement of a poor insulation resistance. Proceed withmounting of the next component only after having identifiedand removed the cause of a poor insulation resistance. Afterinstallation of all insulated components the total resistancewill be slightly lower than the lowest individual resistancevalue measured before.

2.3 Shaft SealsBoth shaft seals are mounted such they are insulated.

To check the insulation resistance, follow the same procedureas outlined for the labyrinth rings. It is also be expected that

the total resistance will likewise be lower than the lowestindividual resistance measured before.

2.4 Pedestal Bearing of ExciterThe insulation resistance between the bearing pedestal

and base frame should be measured immediately aftermounting of the pedestal.

With satisfactory insulation, a value in excess of 10megohms is to be expected. Following this, bolt the associatedoil pipe to the bearing pedestal being careful to insulate it. It isalso recommended to repeat the insulation resistancemeasurement after fitting of each individual pipe. If a sufficientlyhigh resistance value is measured (five megohms) proceedwith fitting of the next pipe. Finally, measure the insulationresistance to the base frame of the bearing pedestal with theconnected pipe work. If this value is higher than threemegohms , proceed with mounting of the exciter rotor.

2.5 Final CheckingAfter the exciter rotor has been coupled to the generator

rotor and insulated from the bearing pedestal, a final insulationcheck should be performed. The total insulation resistancemust not be less than one megohm. Due to contact with theshaft, the measuring circuit covers in parallel.

TE/EE bearingsTE/EE shaft sealsExciter bearing pedestal with pipe work

3 Checking the Shaft Seal and Bearing Insulation ofthe Assembled UnitChecking the shaft seal and bearing insulation during

operation may be done by way of the shaft voltage prevailingwith the generator running in an excited condition. For thispurpose, the potential of the insulated shaft seals and bearingsis accessible external to the generator. With the generatorrunning, the components coming into contact with the shaftare separated from the shaft by an oil film, which has insulatingproperties. Consequently, a non-defined resistance value isset up at the potential measuring points of the shaft sealsand bearing sleeves which is dictated by the magnitude ofthe resistances of the oil film and insulating parts. Thefollowing method permits the insulation to be checked withoutdisassembly of components being required.

Useful results are, however, to be expected only if theturbine end of generator rotor and the turbine shaft aregrounded properly as defined during the measurements.Grounding must be maintained to discharge to ground anystatic charges occurring continuously during operation dueto steam and oil film friction.

3.1 Checking the Insulation with the Generator in anExcited Condition

2.5-0300-0500/2

Due to the rotor grounding arrangement at the turbineend, the shaft voltage should be measured at the exciter end.Since the result depends, however, on the function of therotor grounding system (carbon brush sliding on shaft), theshaft voltage should first be measured according to Fig.1with the generator running and excited. Normally, this will bean AC voltage of a few volts on which a small dc componentis superimposed.

Measurement should be performed by means of an AVO-meter in the AC range. The voltage should be picked off theshaft through a sliding contact with an insulated handle, whichis connected to the meter by a circle.

The shaft voltage measured in this way should then becompared with the voltage according to Fig. 2. If the two

readings are not identical, the rotor grounding system shouldbe rectified first before taking any further readings to checkthe insulation for shaft currents.

If the shaft voltage can be exactly measured accordingto Fig.2, the measuring brush on the shaft should first beconnected to the potential measuring terminal of the insulatedcomponent (bearing sleeve or shaft seal) at the exciter endby means of a cable. The oil film of the component is thusbridged, with the component assuming the shaft potential.With satisfactory insulation, the instrument will continue toindicate a shaft voltage of the original magnitude. In the eventof insufficient insulation resistance, a current will flowthrough the insulation, which may be read at the ammeterconnected into the circuit. Bridging of the oil film results in a

reduction of the original shaft voltage or in its completecollapse.

The resulting current can be measured for a brief momentby means of an ammeter connected into the circuit betweenthe measuring brush and the potential measuring terminal.

3.2 Checking the Insulation With the Generator in Non-Excited ConditionIf the previous tests are inconclusive, additional tests

may be performed in consultation with the manufacturer

to locate insulation defects with the generator running and innon-excited condition. A bridge instrument must be used. Tomeasure the resistance of the insulated component withrespect to the shaft and ground, the bridge instrument shouldbe connected between this component and ground.The resistance (Roil and Rins in series) of the parts in contactwith the shaft are then connected in parallel with themeasuring voltage. This measurement is not practicable withthe generator at standstill, since a stable oil film providing forfull insulation can be formed above a speed of approximately3.33 to 6.66 s-1.

In case of a low insulation resistance, it must be assumedthat the insulation is defective, requiring detailed checking ofthe insulating parts. (Contact the manufacturer).

1 Voltmeter (AC range)

Fig.1 Measurement of Shaft Voltage With theGenerator in Excited Condition

1 Voltmeter (AC range)

Fig. 2 Measurement of Shaft Voltage at Exciter EndWith the Generator in Exciter Condition

1 Voltmeter (AC range) 2 Ammeter

Fig. 3 Measurement of Shaft Current With theGenerator in Excited Condition

1 Measuring BridgeFig. 4 Measurement of Insulation Resistance With the Unit in

Non-Excited Condition

BHEL, Haridwar

Turbogenerators

Inspection

2.5-0305-0500/10609 E

Test Norms During Overhaul

1 Hydraulic pressure test of hydrogen gas coolers. 8 bar for 30 mts(No leakage is allowed)

2 Hydraulic pressure test for brushless exciter coolers 8 bar for 30 mts(No leakage is allowed)

3 Gas tightness test of TG Rotor. (No visual leakage 6 bar for 6 hrs.is allowed. The test is to be conducted either with Press. drop notnitrogen or helium). more than 0.5 bar

4 Gas tightness test of exciter rotor. (Condition of ——do——-testing same as a Sl. 3 above)

5 Hydraulic test for stator winding and primary water system. 6 bar for 48 hours(No visual leakage is allowed) by N2 cushion

6 Hydraulic test pressure for seal oil and ring relief oil 10 bar for 15 mtsinlet pipeline in the end shield(No leakage and pressure drop is allowed)

7 Pneumatic test for seal oil and ring relief oil inlet 6 bar for 30 mtspipeline. (No leakage & pressure drop is allowed).

8 Hydraulic test of seal oil cooleri) Shell side 10 Kg for 30 mtsii) Tube side 10 Kg for 30 mts(No leakage is allowed)

9 Hydraulic test of stator water coolersi) Shell side 10 Kg for 30 mtsii) Tube side 10 Kg for 30 mts(No leakage is allowed)

10 Test on diodes for reverse blocking capability IR > 5 Mega ohms(by 1KV megger with two diodes in parallel circuit)

11 Measurement of fuse resistance on the diode wheel 155+6% Micro ohmby passing 10 Amps regulated D.C. current at 20 deg. C(Fuse Type 800V/800Amp)

12 IR measurement of heat sinks. Min. 10 Mega ohms.(By 500V megger)

BHEL, Haridwar

Turbogenerators

Inspection

2.5-0310-0500/10609 E

Leakage Tests of Generator andGas System

To ensure trouble free operation, all systems should bechecked and operated strictly in accordance with sound,safe and accepted practice.

1 Leakage Test of Primary Water Circuit

The primary water circuit must be filled with water forleakage testing. The pressure gauge in the waste gas pipeshould be replaced for the duration of the test with a pres-sure gauge having a range of not less than 6 bar. A nitro-gen cushion at a gauge pressure of 6 bar is to be providedon the water level in the primary water tank and main-tained for a test period of not less than 48 hours. Duringthe test, the entire circuit should be carefully checked forleakage. Any leaks detected should be repaired, and theleakage test repeated.

2 Leakage Test of H2 Gas System Using Air

After assembling the generator and placing the seal oilsystem into operation, the generator, including the con-nected gas system, must be leak tested using compressedair. A special connection is provided for this purpose.

The test pressure should be equal to the generatoroperating pressure. A class 0.6 precision pressure gaugeshould be used for pressure measurement.

The duration of the leakage test should be at least 48hours.

During this test the stator winding should be filled withwater. The primary water tank should be at atmospherepressure and the waste gas pipes closed. Though theprimary water circuit has already been leak tested, theinternal primary water circuit should be included in theleakage test of H2 gas system. For this purpose, the pres-sure gauge in the waste gas pipe of the primary watertank should be replaced by a U-tube gauge, permitting evensmall pressure increases to be measured. Should a pres-sure increase be observed in the primary water tank, aleak of the primary water system within the generatorwould be expected and must be located and repaired.

The H2 gas system may be considered sufficiently tightif the loss of air is below 1.5 m3/24 hrs = 100 dm3/hr(s.t.p.)* at this test.

The loss of air is determined as follows : 0.2694 x 24 p1 + pB1 p2 + pB2V = ——————— . VG ( ————— - ————— )

Z 273 + t1 273 + t2

WhereV = loss of air in m3 (s.t.p.)* per 24 hour periods

273°K0.2694 = ———————

1013.25 mbar

z = duration of leakage test, hrsVG = generator volume, m3 (see Mechanical

Data)p1 = gauge pressure within the system at

beginning of leakage test, mbarp2 = gauge pressure within the system at end

of leakage test, mbarpB1 = barometer reading at beginning of leakage

test, mbarpB2 = barometer reading at end of leakage test,

mbart1 = temperature of the gaseous atmosphere at

beginning of leakage test, °Ct2 = temperature of the gaseous atmosphere at

end of leakage test, °C

If an air loss higher than 2.4 m3 (s.t.p.)*/24 hrs results,a search for the leak must be made. The likely location ofleaks, such as

flange connections,joints,screw couplings,welds,bushings, etc.,

should be examined thoroughly. Suspected areas shouldbe brushed with Diprol or other foaming solution. Theformation of bubbles (foam) indicates a leak.

If a satisfactory tightness is established the generatormay be filled with CO2, and subsequently with H2.

If, as an exception, a leakage test using hydrogen isperformed, the leakage rate may be four times as high asduring a leakage using air. Leak detection during this testshould be performed by means of a gas leak detection.

3 Leakage Control of H2 System During ActualOperation

During operation, the loss of H2 gas must be monitoredcontinuously on the basis of H2 consumption. The quantityof hydrogen leaking uncontrolled may amount to 12 m3

(s.t.p.)*/24 hrs. Note that only the quantity of gas leavinguncontrolled should be used for evaluating the tightness.Losses such as the steady controlled gas loss occurringat the electrical purity meter system and the gas removedfrom the generator through the seal oil should not becounted.

2.5-0310-0500/2

* s.t.p. = Standard temperature and pressure, 0oC and 1.013 bar

4 Leak Detection by Means of a Gas Leak Detector

If an undue loss of gas occurs on the unit, thelocation of the leak must be determined. To do this, werecommend a leak detector of the Handy-Tector typewith battery charger (product of Edwards HochvacuumGmbH, Frankfurt/Main, West Germany).

4.1 Description of the Handy-TectorThe equipment consists of a battery driven manually

operated leak detector with two sniffler probes (madeof stainless steel and plastic) and a battery charger.

The Handy-Tector is accommodated in a handycase and is provided with a pistol grip. It weighs about0.5 Kg and enable access to all components of the uniteven when locations are obstructed. Equipped with athermistor bridge as a sensing element it detects leaksfrom which, for instance, H2 gas escapes by initiatingthe difference in thermal conductivity of the gas andthe ambient atmosphere (normally air). The sensingelement is not subject to wear and cannot be overloaded,damaged or contaminated by too h igh a gasaccumulation. All operating elements, e.g. indicators(measuring range 0 to 5 with adjustment mark for batterytesting), switch for polarity reversal, On-Off switch,key for battery voltage testing, and a potentiometer byzero setting, are arranged in an easily surveyed and

practical manner. The pistol form allows one-handoperation. The overall dimensions of the equipment are150 x 160 x 65 mm. The Handy-Tector is supplied in aportable leather case.

4.2 Handling the Handy-TectorThe sniffer probe of the Handy-Tector should be

led over the surface of the test object as slowly aspossible. Note that with a leakage gas lighter than airthe leak detection should be carried out above the object,and with gases heavier than air underneath of the testobject.

Fig.1 Handy-Tector

BHEL, Haridwar

Turbogenerators

Inspection

2.5-0320-0500/10609 E

Flushing the Oil Piping

1 Measures to be Taken at Inspections, Repairsor Checks

When opening parts of the oil systems for inspection,repair or checking, make sure that no dirt is introduced intothe oil circuits. In the event of a contamination beingunavoidable due to the work to be performed, take care toreduce such contamination to a minimum and perform athorough cleaning afterwards.

In case of more extensive inspections, i t isrecommended to drain the oil, to clean the oil coolers, theoil tank and the bearing compartments in the same way asfor initial operation of new plant, and refill the oil via filters.After each inspection, the oil system should be subjectedto a short flush. It is recommended to install screens in thethrottle valves and to perform flushing for 12 hours. Oncompletion of this flushing procedure, all filters and screensshould be cleaned again.

If the oil piping must be flushed the following procedureshould be used.

2 Preparation of Bearing Compartments

Prior to commencement of the flushing procedure, thebearing compartments should be cleaned carefully. If anyreworking has been done in the bearing compartments(e.g. drilling), the chips should be removed by means of amagnet. In addition, the bearing compartments should becleaned with lint-free rags (never use cotton waste). Thecleaning agents used should leave no residue. Aftercleaning, the bearing compartments should be subjectedto a thorough visual inspection.

3 Preparing the Lube Oil System for Flushing

During flushing, the highest possible oil velocity is tobe maintained in the pipes.

When the bearings are installed, make sure that nocontaminated oil is introduced between shaft and babbit.To do this, remove the upper half bearing sleeves and fittemporary oil drain pipes to the inlet openings of the lowerhalf sleeves. Remove the valve cones from the permanentlyadjustable throttle valves before the bearings and insertthe flushing screens supplied with the throttle valves. Makesure that the hoses of the shaft lift oil system are notconnected to the bearings, as otherwise contaminated oilwill be admitted to the bearing journal.

4 Flushing Oil

The oil used for flushing must be provided by the user

and oil supplier as laid down in the generator manufacturer’soil specification. In this connection, it may become necessaryto consult the turbine manufacturer too.

The following methods are possible :

Use of the same oil grade for both flushing andoperation. On completion of the flushing procedure, oilsamples should be taken and analyzed to decidewhether the flushing oil charge can be used as serviceoil change after treatment by the oil supplier.Use of an oil grade intended for use as flushing oilonly. Its properties, particularly its viscosity, arematched to the special application. The oil charge iscompletely drained on completion of the flushingprocedure and replaced by a new service oil charge.The properties of the service oil and flushing oil mustbe suitably matched.

5 Flushing Procedure

Flushing all bearing oil lines and all shaft lift oil pipesof the generator should be performed in conjunctionwith the turbine according to the instructions issued forthe turbine.

During flushing, the oil lines should be hammeredregularly to remove dirt particles from the walls. Duringthe last third of the entire flushing period, the screens

1 Oil drain2 Bearing saddle3 Seal4 Bearing sleeve

Fig. 1 Oil Drain at Generator Bearing

1 2 3 4

2.5-0320-0500/2

should be temporarily installed in the throttle valvesupstream of the bear ings for checking the d i r taccumulation.

After draining of the flushing oil, remove any left dirtdeposits from the bearing compartments. Remove allbypasses, orifice plates or blank flanges as well as theadditionally installed filters. Refit the valve cones in thethrottle valves before the bearings. Assemble thebearings ready for operation. The hoses of the shaft liftoil system should be connected to the bearings and

checked for tightness.

6 Supervision of Oil Circuits

After recommissioning, all screens and filters shouldbe replaced and/or cleaned as frequently as possible.During commissioning, the oil should be checked forcontamination, e.g. via vent ports. In case of an extremelyhigh dirt content due to carbon dust, construction work,etc., special precautionary measures should be taken.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-1003-0500/10609 E

Measures to Prevent CorrosionDuring Inspections

The high strength austenitic material used for the rotorretaining rings, etc. is susceptible to stress corrosion if itis simultaneously subjected to high tensile stresses andmoisture (e.g. moisture condensing from the ambient air).If persisting for a sufficiently long period, stress corrosionwill lead to crack initiation and crack growth. Since tensilestresses are due to the shrink fit of these components andthus unavoidable, any prolonged exposure to moisture mustbe positively prevented.

During an inspection, the individual components of thegenerator are exposed to the ambient conditions whichmay result in hazards to these components. It is thereforestrongly recommended to take suitable measures forpreventing any exposure to moisture, especially rain, snow,liquids of any kind and condensation., Covering thecomponents will not afford sufficient protection.

To avoid the above-mentioned hazards, the assemblywork during an inspection should be accomplished underprotection from weather conditions. The generator shouldonly be opened if an uninterrupted execution of the workwill be ensured and provided that the necessary protectivemeasures can be taken. After opening of the unit andwithdrawal of the rotor, the stator openings should bepromptly reclosed. The stator should be dried by means ofa portable air dryer or fan-forced heater and kept aboveambient temperature level. The air dryer or fan-forcedheater should be arranged so that the air will circulatethrough the stator interior in a closed circuit for ventilation

of the entire internal space .The rotor should be protected in such a manner that

especially the retaining ring area can be kept dry and aboveambient temperature level. The air dryer or fan forcedheater should be arranged so that the air will circulate in aclosed circuit.

Primary water circulation should be maintained alsoduring the inspection work, as far as practicable. The heatloss of the pump is sufficient to keep the temperature ofthe primary water and thus of the stator winding aboveambient temperature level.

The cooling water should be drained from the coolers.The coolers should be cleaned, dried and maintained in drycondition by suitable measures.

During inspection work on the exciter unit , it should beobserved that the devices installed as a precautionarymeasure, such as anticondensation heating system andair dryer will no longer be effective after removal of theexciter enclosure. The required protection should berestored by suitable measures (covers, etc.) and portabledryers or hot-air blowers.

Normally, a condensation hazard can be recognizedwith the help of dewpoint measuring device. In case ofdoubt, however, it is recommended to dry the componentson a continuous basis in order to achieve a markedly lowdewpoint temperature on these components, i.e. to maintaintheir temperature above ambient temperature level.

BHEL, Haridwar

Turbogenerators

Inspection

* RR = Rotating rectifier

2.5-1005-0500/10609 E

Preventive Measures to Avoid StressCorrosionSurvey

Phase Keyword Precautionary Measure and Checks

Transport Packing: 1 Dry rotor retaining rings and RR* wheels by blowing dry air into rotor endwindings and RR* wheels portable air dryersshortly before packing. Multiple drypacking in sheetings with desiccant added:

Accompanying 2 Reference to special packing and request for restoration after opening due todocuments: customs or in-transit damage.

Damage to 3 Restore proper condition of dry packing immediately. For details, see descriptionPacking: accompanying the cargo.

Receiving: 4 Check effectiveness of dry packing and desiccant. Record condition in checklist.Request for repeat checks according to checklist during subsequent storage.

Storage Condition: 5 Maintain dry packing until immediately before assembly.

Check: 6 Monthly functional check of dry packing and desiccant according to checklist.

Storage area: 7 Indoor storage in dry building; outdoor storage in seaworthy packing, under shelterprotected against precipitation/ground moisture.

Installation Outdoor 8 Transport to job site in dry packing. Acclimatization in dry packing to avoid conden-installation: sation after unpacking.

9 Installation under shelter. Removal of dry packing from retaining rings (1st layer) aslate as possible.

Open generator 10 With danger of condensation (outdoor installations and open power house), blowrotor installed: dry air from portable air dryers into rotor end windings and RR* wheels

Ready for Generator closed, 11 H2 –cooled generators:Operation filled with Pass small cooling water flow through H2 cooler to ensure that cooler is coldest(standstill H2 gas: component in the generator (condensation hazard!).or turninggear Exciter unit 12 RR* exciter units:operation) in enclosure Drying process with stationary or mobile air dryer.

Sched. Outdoor 13 Generator closed: Measures as under “Ready for operation”mainten. installation: 14 Generator open: Shelters must prevent precipitation from entering the generator;Without the retaining ring areas must be covered and kept dry by supplying dry air.rotorremoval

Sched. Indoor 15 If rotor is set down in dry power house with even temperature, it is sufficient if themainten. installation: entire rotor is covered against dirt and wetness. If danger of condensation, the rotorwith areas between the bearing journals must be provided with dry packing.rotor

Outdoor 16 Set down rotor under shelter and provide rotor areas between bearing journals withremovalinstallation: dry packing

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Turbogenerators

Inspection

2.5-1010-0500/10609 E

Inspection ScheduleForeword

Preventive maintenance of generators serves toavoid major problems or damage while the unit is inservice.

Apart from its scope, the timing of an inspection isimportant. To account for the deterioration and stressesdue to different modes of operation, both the number ofoperating hours and the number of starts are used ascr i ter ia determin ing the in terva ls between theinspections.

The intervals recommended in the following are thesame as those indicated in the VDEW Recommendationsfor intervals between Generator Inspections (publishedby Vereinigung Deutscher Elektrizitatswerke – VDEW– e.V. in 1980). This Foreword contains a large numberof extracts from the VDE Recommendations.

The guid ing values g iven in the VDEWRecommendations are to assist the power plant owners/operators in scheduling inspections, taking into accountalso own experience on the performance of theirgenerators and that of sister machines.

1 Types of Inspections

Depending on the scope of work, a differentiation ismade between initial inspection, minor inspection andmajor inspection.

Type Feature DurationInitial Extensive checks, incl. Approx.Inspection removal of rotor 6 to 9 weeks

Minor Specific checks and Approx.Inspection maintenance without 1 to 3 weeks

removal of rotor

Major Removal of rotor Approx.Inspection 6 to 9 weeks

Table 1 Types of Inspection

The initial inspection is the first major inspection of thegenerator involving the removal of the rotor and is anessential prerequisite for assuring high reliability on a long-term basis. The scope of work and checks to be performedshould be agreed upon with the manufacturer in good time.The date of the initial inspection should be determined underdue consideration of changes that are likely to occur aftera relatively short service period.

The time periods given are guiding values. Dependingon the scope of the planned work of inspection findings,the inspection period is either shortened or lengthened.

2 InfluencesScheduling of the initial inspection and of the

subsequent inspections mainly depends on the number ofoperating hours and on the number of starts. Bothinfluences are considered in the parameter equivalentoperating hours.

Tequiv = Tact + ns . Ts

where

Tequiv = equivalent operating hoursTact = actual operating hoursns = number of startsTs = additional number of operating hours to be

considered for one start. According to thepresent state of knowledge 20 hoursaccount for one start of a turbogenerator.

The recommendations given in the following apply tonormal operation without major disturbances. Abnormaldisturbances, such as close-in system faults, faultysynchronizing, asynchronous running and inadmissibly highunbalanced load, may necessitate shortening of therespective inspection interval or an immediate check.

When scheduling inspections, also consider thefollowing factors :

Wear and deterioration of components.Deterioration of running behaviour.Frequency of load rejections associated with overspeed.Earth faults or interturn faults in generator field circuit.Hydrogen, water or cooler leaks.Change in coolant flow rates.Fouling of air-cooled generators.Deterioration of shaft insulation.Inherent fault (recognized deficiency in comparable

machines or components).

With proper performance of the generator and providedthat the inspection findings obtained by the preceedinginspection(s) have been favourable, the intervals betweeninspections may be lengthened within reasonable limits.

3 Recommendations for Scheduling InspectionsIt is recommended to perform the initial inspection after

10,000 h < Tequiv < 20,000 h

equivalent operating hours and to observe an interval of

40,000 h < Tequiv < 60,000 h

equivalent operating hours between two major inspections.It is recommended to perform minor inspections, i.e.

specific brief checks and maintenance work, during theservice period between major inspections. Whenscheduling minor inspections consideration has to be givennot only to the technical requirements of the generator butalso to those outage periods of the unit that are notattributable to the generator.

Scheduling of the initial inspection is primarily dictatedby the state of the art embodied in the end winding andstator slot support systems. The synthetic and insulatingmaterials used in generator manufacturing tend to developplastic flow (creep) under the influence of pressure andtemperature, especially during the initial period after

2.5-1010-0500/2

Operating duty Tact ns ns. Ts Tequiv

hours Starts/year hours hours

A Continuous/base load 7000 10 200 7200

B Continuous/occasional peak load 4000 100 2000 6000

C Peak load (abt. 1 start/day) 2000 300 6000 8000

D Peak load (abt. 2 starts/day) 1000 500 10000 11000

Table 2 Equivalent Operating Hours Tequiv for One-Year Operation With Different Operating Duties

commissioning. The resulting setting and looseness canbe corrected during the initial inspection. Any deficienciesdue to manufacture, assembly or new design can thus beidentified and eliminated at an early date.

The specified interval between major inspections is inaccordance with the present state of the art in generatorengineering.

The special stresses attributable to each start orshutdown of the unit are considered in the equivalentoperating hours Tequiv of the generator which account forthe number of starts (ns). These stresses include :— effects of expansion and friction on winding andinsulation due to thermal and centrifugal force cycles.— special vibratory forces arising when passing throughnatural frequencies of various generator components.— material fatigue, especially of rotating parts, resulting

from the centrifugal force cycle.

The additional number of 20 operating hours to beconsidered for one start (Ts) has been determined by anagreement reflecting the present state of knowledge.

4 Inspection ScheduleAll important maintenance activities required for

maintaining the generator and its auxiliaries in propercondition are listed on the following Inspection Schedulepages.

If the work required in each case is performed at thespecified intervals, major financial losses and prolongedoutages can be minimized, the result being a high availabilityof the generator.

Actual operating hours Tact (103 Hr)Fig.1 Typical equivalent operating hours of Turbogenerators

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Turbogenerators

Inspection

2.5-1010-0500/30609 E

0 2000 4000 6000 8000 Hrs

Fig.2 Graph for Determining the Equivalent Operating Hours of Turbogenerators

BHEL, Haridwar

Turbogenerators

Inspection

2.5-1020-0500/10609 E

Inspection ScheduleStator

* Normally required only at every second major overhaul1) Dissipation factor measurement, charging and leakage current measurement, and, in particular cases, high potential test.

Measure insulation resistance of stator winding x x x

Stator winding insulation x x

Dismantle stator end shield and replace gaskets x x

Dismantle bushing compartment and replace all gaskets x*

Dismantle bushings and replace gaskets x*

Check condition of stator core x x

Check slot wedging system and end winding support structure x x

Check coil connections (preloading, voltage drop) x x*

Replace all generator flange gaskets x x

Replace all gaskets on water-carrying parts x*

Replace seals on teflon hoses of primary water system x*

Replace all gaskets of casing penetrations x*

Check teflon expansion joints x x

Clean filters in primary water circuit x x x

Check balancing orifices in phase connector x*

Check strainers at phase connector flanges x*

Leakage test of primary water system x x x

Leakage test of H2 system x x x

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Turbogenerators

Inspection

2.5-1030-0500/10609 E

Inspection ScheduleRotor

Perform runout check x x

Withdraw and check rotor x x

Perform ultrasonic testing of rotor retaining rings x x

Check rotor wedges and retaining rings x x

Check end windings and gas outlet ducts x x

Measure insulation resistance of rotor winding x x x

Check bearing surfaces x x

Check shaft seal contact faces x x

Check rotor fan x x

Check coupling flanges x x

Check rotor alignment x x

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Turbogenerators

Inspection

2.5-1040-0500/10609 E

Inspection ScheduleCoolers

Note: No cleaning on water side is required on coolers supplied with condensate.

General

Check cooling water inlet and outlet pipes, vent pipes, drain pipes and mounting of all coolers x x x

Check condition and performance of temperature and pressure measuring devices at all coolers x x x

Hydrogen Cooler

Clean H2 on water side x x x

Check condition and, if required, recondition H2 cooler water channels x x x

Dismantle H2 cooler; check water and oil sides; clean, if required; replace gasketsand perform pressure tests x

Seal oil Cooler

Clean seal oil coolers on water side x x x

Check condition and, if required, recondition seal oil cooler water channels x x x

Dismantle seal oil coolers; check water and oil sides; clean, if required; replace gasketsand perform pressure tests x


Clean primary water coolers on secondary water side x x x

Check condition and, if required, recondition water channels of primary water coolers x x x

Dismantle primary water coolers; check and clean primary and secondary water sides; replacegaskets and perform pressure tests x

Exciter Cooler

Clean exciter water coolers on water side x x x

Check condition and, if required, recondition exciter cooler water channels x x x

Dismantle exciter coolers; check and clean water and air sides; replace gasketsand perform pressure tests x

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Turbogenerators

Inspection

2.5-1050-0500/10609 E

Inspection ScheduleBearings

Check and , if required, replace bearing insulation x x

Check bearing surfaces and babbitt bonding x x

Check bearing clearances x x

Check seating of bearing sleeves on bearing saddles x x

Check labyrinth rings and, if required, replace seal strips x x

Check condition and performance of bearing temperature monitoring system x x

Check condition and performance of shaft lift oil system x x

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Turbogenerators

Inspection

2.5-1060-0500/10609 E

Inspection ScheduleShaft Seals

Check shaft seal insulation x x

Replace shaft seal insulation and gaskets x x

Check sliding contact faces of seal rings and seal ring carriers x x

Check contact faces of seal rings x x

Check seal rings clearances x x

Check inner labyrinth rings and, if required, replace seal strips x x

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Turbogenerators

Inspection

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Inspection ScheduleSeal Oil System

* Normally required only at every second major inspection(1) Regrease bearings after 8000 operating hours at the least

Perform functional check × × ×

Seal oil pumps Check coupling × × ×

and Regrease bearings of drive motors (1) × ×

drive motors Replace bearing of drive motors ×

Replace gaskets of seal oil pumps ×

Replace antivibration pads × *

Check control and safety valves (including float valves) x x x

Replace control valve bellows x x x

Check all valves x x x

Replace valve inserts x

Replace gaskets in and at valves x

Replace complete flange gaskets × *

Check and clean seal oil filters, replace gaskets x x x

Check condition and performance of measuring devices x x x

Check condition and performance of level monitoring system (oil level); check sight glasses x x x

Perform functional check of complete seal oil system x x x

Check seal oil flows of individual shaft seals (at rated gas pressure and n=50 s-1 and n=0 s-1) x x x

Perform functional test of bearing vapour exhausters x x x

Check drain in vent gas line of bearing vapour exhausters x x x

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Turbogenerators

Inspection

2.5-1072-0500/10609 E

Inspection ScheduleGas System

* Normally required only at every second major inspection

Check condition and performance of all pressure reducers x x x

Check performance of all valves (leakage, operation) x x x

Replace valve gaskets and inserts x

Replace flange gaskets x *


Perform functional check of gas dryer (leakages, heater and fan) x x x

Replace gas dryer desiccant (replace cover gaskets) x

Replace PTFE sleeves in multi-way valves x *

Replace flange gaskets of gas dryer x

Replace gaskets and coating of CO2 flash evaporator x

Check condition and performance of CO2 flash evaporator x x x

Replace dust filter in gas purity meter system x

Check complete gas system for leakages x x x

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Turbogenerators

Inspection

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Inspection SchedulePrimary Water System

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* Normally required only at every second major inspection 1) Change Bearing oil in pump casing at intervals of 3000 operating hours 2) Regrease antifriction bearings of drive motors at intervals of 8000 operating hours

Functional check × × ×

Check coupling × × ×

Change bearing oil in pump casings 1) × × ×

Primary water pumps Regrease bearing of drive motor 2) × ×

Check and, if required, replace bearing of drive motors and pumps × ×

Replace bearings and oil seal rings of drive motors and pumps ×

Replace sliding-ring glands of pumps x x

Check and clean main filter x x

Perform functional check of ion exchangers (replace resins, if required) x x x

Perform functional check of fine filter x x x

Replace Micro-Clean cartridges in fine filter x x x

Check shutoff valves and non-return flaps for leakage x x x

Perform functional test of valves and, if required, replace wearing parts x

Replace valve stuffing boxes x *

Check condition and performance of all measuring and supervisory devices x x x

Replace all flange gaskets x *

Check complete primary water system for leakage x x x

Inspect and, if required, clean NaOH tank in alkalizer unit x x x

Check feed valve in alkalizer unit for tight shutoff x x x

Check cable and pipe conduits in NaOH tank for firm attachment x x x

Replace diaphragm pump x

Work required

BHEL, Haridwar

Turbogenerators

Inspection

2.5-1080-0500/10609 E

Inspection ScheduleGenerator Suppervisory Equipment

* Normally required only at every second major inspection

Check condition and performance of temperature gauges and alarms x x x

Replace gaskets at temperature measuring points x *

Check condition and performance of level meter system (liquid level alarm switches) x x x

Check condition and performance of grounding brush x x x

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Turbogenerators

Inspection

2.5-1090-0500/10609 E

Inspection ScheduleExcitation System

* Normally required only at every second major inspection.1) To be performed before H2 removal; using liquid leak indicators (e.g. DIPROL) is not permitted.

Check radial bolts for H2 leakage 1) x x x

Dismantle exciter x x

Check insulation resistances of windings x x x

Replace fuses x

Check condition and performance of rectifier wheels; check stator and rotor windings x x

Check coupling flange x x

Check contact pin and Multicontact-strip and, if required, replace x x

Replace Multicontact-strip x *

Check alignment x x

Check bearing and pipe insulation x x

Replace bearing and pipe insulation x *

Check bearing surface and babbitt bonding x x

Check bearing clearances x x

Clean seating of spherical portions of bearings x x

Check labyrinth rings and, if required, replace seal strips x x

Check air filter x x x


Check condition and performance of ground fault detection system x x x

Clean prefilter for exciter dryer and replace if required x x x

Perform functional test of emergency cooling flaps x x x

Check emergency cooling flaps for tight closing by in-service pressure measurement x x x

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Turbogenerators

Inspection

2.5-1100-0500/10609 E

Measures for Preservation of GeneratorDuring Standstill

Also refer to the following information[1] 2.5 – 0030 Packing Transport and Storage of Generator Rotors

Preservation measures will have to be taken when awater-cooled generator is to be shut down.

The scope of the preservation work required dependson the duration of the shutdown, on the overall conditionsin the vicinity of the unit and on the extent to which checksand inspections are possible during such period. Thepreservation measures recommended in the following aresufficient under normal conditions. High relative humidityin combination with severe temperature changes involvesthe risk that the temperature of certain surfaces in thegenerator may drop below the dew point, resulting in thepossible formation of a moisture film due to condensationon these generator components. In such a case, specialmeasures may be required for preservation of the rotorretaining rings and rectifier wheels [1].

1 Generator InteriorThe hydrogen gas should be removed from the

generator. The stator and rotor windings should then beprotected against moisture by maintaining the generatorinterior at a moderate temperature or in dry condition bysuitable means. This may, for instance, be achieved by theprovision of a hot air blower or dryer. The generator interiorcan also be maintained in a sufficiently dry condition bykeeping the primary water system in operation as mentionedunder Item 7 with activated primary water heating system,if provided. No additional blowers are then required.

If additional blowers are used for drying, the air shouldbe admitted and discharged via branches at the exciterand turbine end manhole covers

Prior to recommissioning the generator, the insulationresistances of the stator and rotor windings should bemeasured and the windings dried, if required.

2 Bearing and Shaft SealsNo preservation measures are required on the bearings

of the turbogenerator and exciter and on the H2 shaft seals.However, the bearing and seal oil systems should be

placed into operation once a week and the entire systemadequately flushed with water free oil. After activation ofthe oil systems, the shaft should be operated on the turninggear for approximately three to four hours.

The supply of water to the bearing oil and seal oilcoolers is not required during this period.

3 CoolersAll coolers should be drained on their water sides

and dried by suitable measures. During the outage, thedrains and vents should be kept open.Caution : Never leave water-filled coolers standingidle for several weeks.

For cooler drying, hot air or dry ambient air may beused which should be admitted by means of blowersvia the cooling water inlet/outlet flanges. A fan-forcedheater with a rating of 1-2 kW has proved satisfactoryfor this purpose.

4 ExciterThe exci ter should be protected against the

formation of a moisture film due to condensation To dothis, the cooler should be drained, dried and maintainedin a dry condition, and the exciter drying system shouldbe kept in operation continuously.

The carbon brushes should be lifted off and thesliprings covered with oiled paper.

5 Bright ComponentsAll accessible bright components, e.g. exposed shaft

portions, should be protected with a suitable corrosioninhibiting oil or grease, e.g. Tectyl.

6 Seal Oil and Gas SystemsExcept for the work a l ready ment ioned, no

preservation measures are required on the coolers ofthe seal oil system.

During the weekly activation of the seal oil systemfor turning the shaft, the system should be inspectedfor proper functioning by checking all operating values.

All valves in the gas system should be closed. Noadditional measures are required.

7 Primary Water SystemAfter completion of the assembly or following a

prolonged shutdown of the unit, the primary watersystem should be placed into operation or kept inservice, with monitor ing and maintenance to beperformed in accordance with the information given inthe turbogenerator manual.

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Turbogenerators

Inspection

2.5-2000-0500/10609 E

Stator


[1] 2.5 – 2300 Insulation Resistance Measurement on StatorWinding

[2] 2.5 – 3300 Insulation Resistance Measurement on Rotor andExciter Windings

[3] 2.5 – 2310 Drying the windings

After each shutdown, the insulation resistances shouldbe measured prior to carrying out the inspection [1], [2],[3]. Depending on the scope of the inspection, the slotwedges should be checked for proper seating. The seatingof the end windings should also be checked.

After opening the generator, the interior should alwaysbe inspected for contamination of any kind. If contaminationis detected, its cause should be determined and correctedin order to preclude any new contamination. The generatorinterior should be cleaned thoroughly.

The bushings and expansion joints should be inspectedto ensure a proper connection between the bushings andthe phase connectors. The bushings should also bechecked for proper connection to the bus bars arrangedexternal to the generator.

All primary water hoses and pipes should be checked,leaving the generator filled with primary water, if possible.

When dismantling of the hydrogen cooler is requiredfor inspection, the cooler wells in the stator frame shouldbe checked for cleanliness.

All stator flanges should be checked for properalignment and seating. The stator should be checked fortight anchoring to the foundation.

All metering connections should be checked for propermounting and condition as far as practicable. This shouldinclude both the electrical metering connections and thepipe connections to the measuring instruments.

Prior to recommissioning, the insulation resistance ofthe stator winding should be measured and, if necessary,improved.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2120-0500/10609 E

Cementing the Joints ofProfiled Gaskets

1 Survey of Adhesives

1.1 Sicomet 50Profiled gaskets should preferably be cemented

together by means of Sicomet one-component adhesive.This adhesive meets all requirements, its only disadvantagebeing the difficulties encountered in storage.

Sicomet should be protected from moisture, heat andsunlight and should therefore be stored in a dry, cool anddark place. To prevent an increase in viscosity anddiscoloring of the adhesive Sicomet is best stored at atemperature of –10°C. If stored under these conditions,Sicomet has an unlimited working life. Defrost Sicometprior to use and bring to room temperature.

Repeated freezing and defrosting does not affect thebonding properties. The maximum storage time at roomtemperature is six months. The adhesive not used up mustbe stored at a temperature of –10°C immediately.

1.2 PattexPattex cannot be used for cementing together gaskets

because of its low temperature stability (50°C max.) andinsufficient oil resistance.

The use of other adhesives, as, for instance, rubbercement, is likewise not permissible.

2 Preparatory Work and Application of Adhesive

2.1 Preparatory WorkThe exact length of profiled gasket is determined by

inserting it in the center of the sealing groove, allowing 30

to 40 mm in length for overlapping at the joint. The jointfaces could be cut so that the overlapping portion to becemented is approximately 30 to 40 mm long. When cuttingtake care that the profiles does not suffer any visibledistortion and that the pressure applied after pullingtogether the part to be mounted is exerted on the area ofcut (see arrow in Fig. 1). The faces to be cemented togethershould be well roughened.

2.2 Cementing the JointThe adhesive should be applied in drops on the joint

areas to be cemented together, using a plastic or metalspreader for obtaining a thin film Immediately afterwardsthe joint faces should be assembled and located in position.Because of the short curing time of 10 to 30 sec. anyreadjustment will be almost impossible. After curing, anycement residue should be removed from the outer surfaceof the bonded joint by means of emery paper.Warning : Sicomet should only be used in wellventilated work areas. Care must be taken to avoidbody contact. In the event of contact with the eye,rinse immediately with ample amounts of distilledor potable water to dilute the adhesive. The eyeshould then be treated to sooth any inflammationand a physician immediately consulted.

2.3 Breaking the Cemented JointsCemented joints which are to be broken should be

placed in a bath of either dimethyl-formamide for a briefperiod or ethylacetate for a longer time, resulting in swelling.

Fig. 1 Cementing of a Profiled Gasket

30 to 40 mm

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2160-0500/10609 E

Sealing Generator End Shield Joints

Fig. 1 Mounting the Upper Half End shield

1 GeneralThe joints of the end shields and their flange

surfaces toward the generator frame are sealedgastight with profiled gaskets. Experience has shownthat an additional sealing compound must be applied inorder to obtain a gastight seal at the Tee-joints of thesepackings and at the flange surface of the seal ringcarrier.

2 Sealing CompoundThe recommended sealing compound is silicone

compound S with hardener TL.These should be mixed in a ratio of 100 g silicone

compound S to 3g hardener TL.

2.1 Preparing the Sealing CompoundMixing of silicone compound S and hardener TL

in the above-mentioned ratio should be done in a cleanand completely dry container. At a temperature of +20°C,the prepared mixture is usable for about 1 to 1½ hours.Following this period, the sealing compound starts tothicken and will have completely solidified after 3 to 4hours.

3 Bonding AgentPrior to applying the sealing compound, the surfaces to

be sealed should be wiped with a bonding agent using aclean, lint free cloth.

4 Mounting the Lower Half End ShieldPrior to attaching the lower half end shield to the

generator frame, wipe the flange surface with boundingagent over a width of 100 mm at the location of the agent.Wipe the mating flange surface of the generator framewith bonding agent too. Immediately before mounting therespective lower half end shield, silicone compound Sand hardener TL should be thoroughly mixed using theratio mentioned earlier. A thick coating of the compoundshould be brushed on the surfaces previously treated withbonding agent. The lower half end shield should then becarefully mounted, paying particular attention to the gasket.After curing, any surplus seating compound should beremoved with of a knife, scraper or similar device.

5 Mounting the Upper Half End ShieldSuspend the upper half end shield from the crane and

wipe its flange surface with bonding agent within the range

2.5-2160-0500/2

Note : Detaching the flat iron bar and cutting flush thegasket should be done immediately prior to mounting therespective seal ring carrier. Experience has shown thatthe gasket will be forced out if seal ring carrier is notmounted immediately.

Caution : Any spaces coming into contact with turbineoil must not be contaminated with silicone compound.Should this happen, the area should be cleaned withextreme care after the sealing compound has cured.

1 Inner labyrinth ring2 Gasket3 Shim, 3 mm4 Flat iron bar for gasket5 Mounting screw for retaining device6 Lower half end shield

Fig. 3 Gasket in Lower Half Stator End Shield WithRetaining Device

1 2 3 4 5 6

1 Lower half end shield2 Gasket3 Mounting screw for retaining device4 Flat iron bar for gasket5 Lower half bearing6 Rotor shaft

Fig. 4 Retaining Device for Gasket

1 2 3 4 5 6

1 Upper half end shield2 Retaining device for gasket3 Joint bolt4 Lower half bearing5 Rotor shaft

Fig. 2 Upper Half End Shield Lowered in Position

1

2

3

4

5

of the joint over a width of 100mm at the location of thegasket. Wipe the mating flange surface of the generatorframe with bonding agent too. Following this, the joint

surfaces of the lower and upper half end shields shouldbe wiped with bonding agent within the range of the Teejoint and within the range of the flange surface for the sealring carrier over a width of 100 mm.

Apply a thick layer of ready mixed sealing compoundon the surfaces previously treated with bondingagent.The upper half end shield should then be carefullymounted, paying particular attention to the flange and jointgaskets.

After lowering the upper half end shield, but prior tobolting the end shield joint, secure the gasket in place witha flat iron bar to be attached with a 3 mm shim for spacing.If this is not done the gasket will be forced out too far atthe mounting face of the seal ring carrier during bolting ofthe end shield joint (see Figs. 2,3 and 4).

The gasket projecting slightly from the joint in this planeas a result of the contact pressure established by boltingthe end shield halves together as well as any surplussealing compound should be cut flush with the flangesurface with a sharp knife.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2300-0500/10609 E

Insulation Resistance Measurementson Stator Winding

During manufacture and transport, the insulation of thestator winding may have been exposed to moisture whichwould reduce the insulation resistance of the windings.The insulation resistance should therefore be measuredprior to initial startup, after prolonged shutdowns and afterwork on the windings. If required, the generator should bedried until a sufficient insulation resistance is obtained.

1 Required Insulation Resistance of Stator WindingThe insulation resistance measured is dependent on

the temperature. To permit a proper assessment, acorrection to an agreed reference temperature (formerly75oC) must be made.

An insulation resistance of 1 megohm per each kilovoltof rated voltage at 75oC is normally attainable without anydifficulties.

New international standards specify an insulationresistance of not less than 1 megohm per each kilovolt ofrated generator voltage at 40oC.

A correction of the insulation resistance measured at

the winding temperature prevailing during the measurementto the above reference temperature can be made usingthe diagram in Fig.1.

If the insulation resistance measured is lower than thespecified minimum value, the neutral connections must beseparated and the insulation resistances of the individualwinding phases measured. During the test, the other twophases which are not involved should be grounded. If theinsulation resistances of the individual phases are likewiselower than the required limit value, drying of the windingswill be indispensable. Great differences in the insulationresistance values are indicative of local contaminations,e.g. insulators at bus duct or terminal bushings. Ifpracticable, additional connections should be separated.

If this measure does not result in an improvement, it isrecommended to obtain the services of a specialist fromthe manufacturer’s work.

2 Measurement of Insulation ResistancePrior to each measurement, the generator must be de-

excited and any static charges removed by grounding thewindings. The windings should also be grounded aftereach measurement for the duration of the rechargingperiod.

The insulation resistance of the stator is measuredbetween the winding copper and the stator core.

Prior to primary water filling, the insulation resistancesof the individual stator winding phases with respect to thesteel part should be measured by means of a 2.5 to 5 kVmegger.

During normal operation, the winding bars areelectrically connected to the grounded cooling watermanifolds through the water in the water inlet and outlethoses.

Because of the considerably lower resistance in thehoses, a determination of the insulation resistanceaccording to the known methods is no longer practicable.

To enable, nevertheless, a measurement of theinsulation resistance, this turbogenerator with water-cooled stator winding incorporates the following designfeatures:

The water manifolds for the cooling water are insulatedfor 5 kV against the frame and connected outside thegenerator via cables to the insulated contacts. Duringnormal operation, these contacts are connected to theframe, and thus grounded.The bushing hoses are provided with contact sleeves.

During measurements, the primary cooling water mustbe flowing, the required conductivity being < 1 µµµµµmho/cm.

Fig. 1 Diagram for Correction of insulation ResistanceMeasured to a Temperature of 40oC

|

10000

500030002000

1000

500

300200

100

503020

10

5

32

1

Insu

latio

n R

esis

tanc

e R

in m

egoh

m

0 20 40 60 80 100 120 140 160

Temperature in oC

2.5-2300-0500/2

To measure the leakage current according to Fig.2, thewater manifolds should be disconnected from ground,joined to the contact sleeves and connected to the samepower source as the windings. A micro ammeter should beinserted in the connection to the windings. Since, in additionto the very low leakage current, the power source is nowrequired to supply the possibly very high partial currentsvia the cooling water connections, batteries are not suitablefor this purpose. The dc voltage should therefore beobtained from a stabilized power supply.

The measuring circuit is shown in Fig.2.

To determine the insulation resistance of water-cooledwindings, the currents due to any cells resulting from thecooling water in the hoses between the winding copperand the water manifolds of steel must be taken intoconsideration. For this reason, the insulation resistance ofthe complete winding should first be measured by applyinga positive voltage. After discharging, the measurementshould be repeated with a negative voltage.

Note : Current may pass through zero. In such a case, theammeter should be changed over and the current read

Note:The primary water must flow through the windingduring the measurement.After measurement, the water manifolds shouldbe grounded again via the ground contacts.

Fig. 2 Circuit Arrangement for Measuring the insulation Resistance R10

and recorded, observing the negative sign. The rechargingcurrent is the mean value of the tests performed withpositive and negative voltage.

Individual phases can be tested by a similar procedure.The insulation resistance (R10) is calculated from the appliedvoltage and the 10 minute recharging current,

U (kV) R10 = ————— = 103 MΩΩΩΩΩ

I (mA)

Note : When the generator is filled with hydrogen, makesure that the rotor shaft ends are properly grounded duringmeasurement and discharging.

During measurement, the movement of ammeter AN isconnected to the positive pole of the stabilized powersupply (approximately 1000V to ground).

Temperature detectors may be installed in the ring-shaped water manifold. To protect the connected meteringleads and measuring instruments, the metering leadsshould be disconnected at the generator terminal strip (atstator frame) during the above test.

After completion of the measurements the measuringcircuit should be removed.

Stator winding connection and terminal arrangement asshown in the diagram are schematic only and may not matchexactly with the machine.

1 = Stator2 = Rotor3 = Terminal Bushing4 = Water manifold ground contact5 = Generator ground connection6 = Hose with contact sleeve7 = Ground connection for manifoldsG1 = Grounding of generator frameG2 = Grounding of TE shaft endG3 = Grounding of EE shaft endB = Stabilized power supplyUB = VoltmeterAN = AmmeterIUVW= Current to windingS = Switch

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2310-0500/10609 E

Drying the Windings

The epoxy resin insulation used for the stator windingsabsorbs practically no moisture. Any reduction of theinsulation resistance during transport, erection or aprolonged shutdown is mostly caused by the formation ofa moisture film on the surface of the insulation. Such amoisture film can be prevented or removed by insertingone forced air heater (approximately 2 kW) into each ofthe two end shield compartments of the open machine viathe respective manhole covers.

The generator interior can thus be heated to atemperature slightly above the ambient temperature. Thiswill provide for adequate drying of the stator and rotorwindings. The primary water pump should also be kept inoperation when the generator is at rest in order to maintainlow conductivity of the primary water. The circulation ofthe water with closed primary water coolers will result ina slight temperature rise of the primary water and also of

the stator winding. The resultant temperature preventscondensation of new moisture of the windings. When thegenerator is again sealed, the windings will normally remaindry.

In the event of a prolonged shutdown of the generatorit is preferred that the hydrogen be retained in the generator,thereby eliminating surface moisture on the windings. Ifthe hydrogen has to be removed from the generator forany reason, the primary water pump should be kept inservice and the winding temperature maintained at a valueabove ambient temperature. This should eliminate moistureproblems.

Should it become necessary to check the insulationresistance of the stator windings, e.g. after operation ofthe differential or ground fault detection system theinsulation resistance should be checked for a low-resistance ground fault with a megger.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2340-0500/10609 E

Test Instruction forStator Slot Support SystemWith Top Ripple Springs

1 Function of Slot Support SystemThe slot wedging system serves to ensure that the

bars are, and remain, tight in the slots and that they arepermanently protected from possible vibrations in order toavoid damage to the insulation and the bars. Such forcedvibration of loose bars can be caused by the pulsatingelectromagnetic forces. A slot wedging system using apreloaded corrugated spring of epoxy-glass-laminate, theso-called top ripple spring (TRS), inserted between theslot material and the slot wedge-

- results in preloading forces far in excess of thepulsating electromagnetic forces,

- compensates for shrinkage (setting) of the slot materialby providing for resilience.

Bar vibrations are thus permanently suppressed.The required preloading force is obtained during

wedging by compressing the springs, except for a smallresidual amount of the normal spring deflection ofapproximately 2 mm. To achieve this, filler strips of therequired thickness are used. The force which the preloadedspring exerts on the slot material can be determined bydepressing the slot wedge from outside [1]. The testpressure to be applied for checking must be higher thanthe preloading force. The actual preloading of the TRS canbe accurately determined from the spring characteristicby way of the spring compression measured. To simplifythis evaluation in practice , limits are specified for thepermissible slot wedge movement which should normallynot be exceeded.

2 Test Procedure

2.1 Measuring PointsTo permit an assessment of the preloading, it will

normally not be necessary to check all slot wedges,however, the check should cover not less than 20 % ofthe total number of slot wedges. This means that at leastevery fifth slot wedge must be checked, excluding thebonded end wedges. However, not less than five wedgesmust be checked in each slot. The measuring points shouldbe distributed over the slot length so that a helicalconfiguration is obtained on the stator bore circumference,with the measuring points not being located side by sidebut staggered from slot to slot.

2.2 Test PressureThe test pressure to be applied to a particular slot

wedge depends on the thickness, number and compressedarea of the springs (approximately slot width x length ofslot wedge). The following versions are possible.

Top Ripple Springs Test Pressure FNumber x Thickness Per Wedge

1 x 0.8 mm 10 bar x NB in cm x KL in cm



2.3 Permissible Slot Wedge MovementsTo account for the very high electromagnetic forces on

generators, the permissible slot wedge movementsspecified below are very small. They include adequatesafety margins for preloading and resilience to ensure

1 Stator core F = Test pressure2 Slot wedge a = Spring deflection3 Driving strip NB = Slot width4 Filler strip (equated with TRS width)5 Compression strip KL = Length of slot wedge6 Top ripple spring (TRS) (equated with TRS length)7 Stator bar

Fig. 1 Stator Slot Support System Using Top RippleSpring

1 2 3

4 5 6 7

1

234-56

7

Also refer to following information[1] 2.5 – 2342 Test equipment for Stator Slot Support System[2] 2.5 – 2345 Rewedging of Stator Winding2.5-2340-0500/2

reliable bar support during the subsequent service period.

Slot wedge movement shall not exceed 0.55 mm for notless than 60 % of all measuring points.Slot wedge movement at remaining 40 % of measuringpoints shall not exceed 0.75 mm.If one slot wedge movement of more than 0.75 mm ismeasured in any slot, the number of measuring pointsfor this particular slot should be doubled. If twowedges in any slot exhibit movements of more than0.75 mm, all wedges of this particular slot shall bechecked (except for end wedges) to ensure thatnot more than two excursions per slot exist.For slot widths of more than 60 mm, an additionalslot wedge movement of 0.1 mm is permissible toaccount for the elastic spring action of the slotwedges.

If the actual slot wedge movements measured duringthe next major overhaul are larger than the aboveguiding values, the condition of the slot support systemwill be separately investigated by BHEL, Haridwar whowill then issue recommendations regarding the need forrewedging under due consideration of :

the specific electromagnetic forces and preloadingforcesthe specific relaxation due to settingthe statistical experience with comparable unitscustomer’s specific requirements in respect of futureinspection intervals.

The individual assessment of the preloadingconditions relies on a comparison of the actual spring

loading with the electromagnetic force arising in theparticular generator. The remaining deflection determinedby depressing the slot wedges permits the actualcondition of the spring to be readily derived from theknown stress-strain characteristic of the top ripplespring.

The test record with the results of the depressioncheck should be forwarded to BHEL for evaluation ineach case.

2.4 Permissible Slot Wedge Movements AfterRewedging

During a rewedging operation [2], the preloading ofthe spring is restored by inserting filler strips of therequired thickness. To enable an easier and more reliabledetermination of the thickness of the filler strips, it isrecommended to measure the movements of all wedgesprior to rewedging. A residual spring deflection isrequired for elastic compensation of the thermalexpansion of the bars in the slots. After rewedging ofthe complete winding, the fol lowing slot wedgemovements are permissible :

Slot wedge movement shall not be less than 0.1 mmbut not more than 0.3 mm for not less than 75 % ofall measuring points.Slot wedge movement at remaining 25 % of measuringpoints shall not exceed 0.45 mm.

For test pressure to be applied, see table under item 2.2.

Note : New top ripples springs must only be fittedif the existing springs are found damaged.

BHEL, Haridwar

Turbogenerators

Inspection

Stator Slot Support SystemRadial Wedge MovementsTest Record

Project name: Sl No: Generator type No of slots

Date of test Checked by: Deptt: Signature

* Radial movement of slot wedges at major overhaul* Radial movement of slot wedges after rewedging

Slot width NB mm, Length of slot wedge KL mmTRS thickness . . . . . mm, No of springs fitted . . . . .Test pressure F, (see 2.5-2340 Test Instruction for Slot

Support System With Top Ripple Springs)Piston area AK (see 2.5-2342 Test Equipment for Stator

Slot Support System)Slot no 1 = end of phase A top bar at EE, counting to be

continued in counterclockwise direction)

test pressure FPump pressure p =Piston area AK

p =

. . . . (bar) . . . . (cm) . . . . . (cm). . . . .(cm2)

p = . . . . . . . . . bar

Mean value of radial wedge movement in 1/100 mm derived from readings of two dial indicators ar thrust piece

2.5-2341-0500/10609 E

Slot TE Slot wedge No. EE No.

12345678910111213141516171819202122232425262728293031323334353637383940

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

2.5-2341-0500/2

4142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596

Slot TE Slot wedge No. EE No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2342-0500/10609 E

Test Equipment forStator Slot Support System

The test equipment consists of two principalassemblies:

Hydraulic systemMechanical system

The test equipment was designed for use on generatorsof any size without any significant modifications beingrequired and can normally be assembled from locallyavailable standard components.

1 Hydraulic System

The hydraulic system consists of an oil-hydraulic jackwith hand-operated pump. The equipment should be ofmoderate size and weight for convenient use in the statorbore.

For exact setting of the jack pressure, a precisionpressure gauge must be provided between the jack andthe pump.

The connections between the pump and jack shouldconsist of hydraulic hoses. Rigid pipe connections are notadvisable, since the equipment must be suitable for use inthe stator bore.

2 Mechanical System

The mechanical system consists of a light metal tube ofapproximately 50 mm dia. x 5 mm (part 2).

To prevent compression marks on the stator core, amating thrust shim of fabric base laminate measuringapproximately 100 x 100 mm should be provided, takingcare that this size matches the radius of the stator core(part 1).

Fig. 1 Test equipment

* Select range depending of pressure** Attach magnetic stand to stator core in bore. Place dial indicator stud to thrust piece.

1 Mating thrust shim (fabric base laminate)2 Tube Aluminium3 Hydraulic jack4 Thrust piece5 Hydraulic pump6 Hydraulic hose

7 Precision pressure gauge 8 Dial indicator 9 Magnetic stand10 Stator core11 Slot wedge

BA = Stator boreAK = Effective piston areaNB = Effective slot widthKL = Length of slot wedge

The thrust piece and jack should be connected to thetube with intermediate fittings to obtain a single unit forcase of handling.

The hydraulic pressure is transmitted to the slot wedgethrough a thrust piece. The thrust piece should match the

slot width (NB) and the length of the slot wedge (KL) andmust be approximately 70 mm high to ensure a sufficientresistance to bending (part 4).

Tube, thrust pieces and jack (part 3) should bedimensioned so that the length of the device correspondsto the stator bore diameter.

3 Pump PressureThe necessary pump pressure P for the check depends

on test pressure F and the effective piston area Ak (incm2) of the available jack (also see rating plate). It iscalculated according to the following formula:

F P = ——— [bar]

Ak

For test pressure, see [1].

4 Measurement of Radial Movement of SlotWedge

The device described transmits test pressure F tothe slot wedge via the thrust piece. The resulting radialmovement of the slot wedge is measured with the dialindicators located at both ends of the thrust piece. Takethe mean of the two readings and enter this value in thetest record [2].

Fig. 2 Checking the Stator Slot Support System

Fig. 3 Arrangement of dial indicators

Also refer to the following information[1] 2.5 – 2340 Test Instruction for Stator Slot Support

System With Top Ripple Springs[2] 2.5 – 2341 Stator Slot Support System radial Wedge

Movements – Test Record2.5-2342-0500/2

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2343-0500/10609 E

Instructions for Checking theStator Slot Support System

1 Stator Slot Support System Configuration

Number x thickness of top ripple springs : …….1……..x…….0.9… mm*Slot width (NB): ……..48…..mmSlot wedge thickness (KD) ……..14…..mm*

* Check thickness on site. Inform BHEL, Haridwar in case of deviations.

2 Magnetically Induced Slot ForcesPB = …..0.143…N/mm2

3 Specific Test PressurePF = …….18…..bar

4 Permissible Radial Wedge Movement

≤ ….0.90…. mm for not less than 60 % of measuring points≤ ….1.10…. mm for remaining measuring points (40 % max.)

If a wedge movement of more than …1.10.. mm is measuredin one slot, the number of measuring points in this slotshould be doubled. If the value is exceeded at two points,

all wedges in this slot (except for end wedges) should bechecked to ensure that not more than two excursions perslot exist.

Note: If the above guiding values are exceeded,consult BHEL, Haridwar for advice, who will thenissue recommendations regarding the need forrewedging under due consideration of :

the specific relaxation due to settingthe statistical experience with comparable units

customer’s specific requirements in respect of thefuture inspection intervals.

The test record with the results of the springdeflection check should be forwarded to BHEL,Haridwar for evaluation in any case.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2345-0500/10609 E

Rewedging of Stator Winding

1 Note

The need for rewedging may arise from the results ofa check[1]. The results of this check are contained in thetest record [2]. The permissible values specified in the testinstruction [1] include considerable safety margins toensure reliable operation during the service period untilthe next scheduled major overhaul. For this reason, thedecision on any major rewedging should only be takenafter consultation with the BHEL specialists.

Rewedging is done by inserting filler strips betweenthe top ripple spring (TRS) and the compression strip torestore the preloading of the top ripple spring. It isrecommended to have this work performed by BHELspecialists or under their supervision.

Prior to rewedging, the radial movement of all slotwedges should be measured as recommended in [1]. Thiswill enable an economical and fast implementation of therewedging work.

2 Removal of Slot Closing Elements

It is advisable to adopt a slot-wise approach forrewedging. As a first step, each slot wedge should bemarked with the slot No. and wedge No. on its top, using afelt pen. Marking should be done in accordance with thescheme specified in the test record [2].

In order to remove the slot wedges, start at one end ofthe stator core and remove wedges up to mid-length ofcore. Before proceeding with the removal of the remainingwedges, lock slot material in first half by inserting auxiliarywedges with a spacing of 500 mm. Set down each slotwedge removed together with the associated top ripplespring and the filler, compression and driving strips (tiedtogether with adhesive tape).

3 Checking the Slot Closing Elements Removed

All parts of the slot support system, including the topripple springs, can normally be reused.

Be careful to avoid damage when driving out the slotclosing elements. Slot wedges found with a permanentdeformation of 0.6 mm and more across their broad sideshould be replaced. The cemented end wedges requireparticular attention. Any end wedges found damagedshould be replaced by new wedges made with the samedimensions and geometry as the original end wedges. Theholes for the ventilating slots in the flanks of the end wedgeshould preferably be provided during the actual rewedgingprocedure.

Wear of the top ripple spring is revealed by lightdiscolorations at the peaks and valleys of the corrugations,these being indicative of separations between the individualglass cloth laminations. This effect has, however, hardlyany influence on the stress-strain characteristics of theTRS. Replacing such a TRS will normally not be required.The TRS should only be replaced in case of very seriousseparations extending over its entire width and length. Aspring replacement will be indispensable on fracture ofglass cloth laminations which can be easily checked withthe fingernails.

4 Rewedging Procedure

Provided that the slot closing elements removed can bereused, rewedging is done by inserting additional fillerstrips. The thickness of the filter strips depends on thedifference between the radial movement of the slot wedgemeasured prior to its removal as recorded in the test record[2] and the radial movement required after rewedging asspecified in [1]. In the case of units where all slot wedgeswere checked, the thickness of the filler strip can beseparately determined for each slot wedges :

Actual Value = Radial movement of slotwedges measured

- Nominal Value = Nominal radial movement ofslot wedge

= Thickness of filler strip

Example : 0.85 (radial movement of slot wedge

measured) - 0.20 (mean of upper and lower limit of

nominal value) = 0.65 mm (approximate thickness of filler strip

= 0.7 mm)

1 2 3

4 5 6 7

1 Stator core 5 Compression strip2 Slot wedge 6 Top ripple spring (TRS)3 Driving strip 7 Stator bar4 Filler strip

Fig. 1 Stator Slot Support System

Also refer to the following Information

[1] 2.5 – 2340 Text Instruction for Stator Slot SupportSystem With Top Ripple Springs

[2] 2.5 – 2341 Stator Slot Support System Radial WedgeMovements– Test Record

[3] 2.5 – 2346 Cementing Stator Slot End Wedges2.5-2345-0500/2

If only a restricted number of slot wedges is checked(not less than 20 %), adherence to the specified radialmovement may not be ensured. The thickness of the fillerstrip should preferably be determined on the basis of themean value of the radial wedge movement in the respectiveslot.

The filler strips corresponding to BHEL specifications.Rewedging should be started at mid-length of the core

in direction towards the core ends. To do this, remove theauxiliary wedges from one half slot section between mid-length of core end and then refit original slot wedges in thecorrect locations as marked. Proceed with the second halfsection by following the same procedure. After rewedgingof both halves of one slot has been completed, it isrecommended to check the radial movement of the slotwedges according to [1]. The results will be helpful inoptimizing the rewedging procedure. It is known from

experience that a comparison between the force requiredfor driving in the slot wedge and the radial movement ofthe slot wedge after rewedging provides informationenabling the fitter to make a correct assessment of thenecessary thickness of the filler strips. Such informationwill be particularly useful on units where not all slot wedgeswere checked.

Then proceed with rewedging of the remaining slots.Provided that sufficient experience is available checkingthe radial movement of the slot wedges will not be requiredafter rewedging of each slot. A final check [1] should beperformed after rewedging of all slots has been completed.This check should include not less than 20 % of the totalnumber of slot wedges.

Proceed with cementing of end wedges [3] aftercompletion of this check.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2346-0500/10609 E

Cementing Stator Slot End Wedgesat Trubine and Exciter Ends

1 Stator core2 End wedge3 Driving strip4 Top ripple spring

5 Filler6 Filler strip7 Compression strip8 Top bar

End of core 50 mm 1 2 3 4

A

B

10 mm C D 5 6 7 8

NotesA End wedges are positioned on supporting keyway of coreB Metallon bon; compression springmust be 10 mm longer than wedgeC Cementing lower surface of compression stripto bar is not permissibleD Thickness of filler (part 5) when using one top ripple spring : 1mm;

when using two top ripple springs: 2 mm

1 GeneralThe procedure described in the following presupposes

that the end wedges removed can be reused or that newend wedges have been made after the pattern of anydamaged wedges.

2 AdhesiveMetallon E 2082, or equivalent available from BHEL

Haridwar.

3 Preparing the AdhesivePress equal lengths of adhesive and hardener on to a

suitable base and mix to a uniform grey color. The preparedmixture is usable for approximately one hour at roomtemperature.

At room temperature, the adhesive has a cure time ofone to two days. After curing, the material is not brittle butsimilar to rubber.

4 Preparatory WorkThe end wedges should be cemented to the core on

both flanks over a length of not less than 50 mm as referredto the core end. These portions of the end wedge flanks arerecessed by 0.5 mm to provide reservoirs for the adhesive.When checking the installation of the end wedges, makesure that the end of the end wedge is positioned on thesupporting keyway of the core. If the wedge end coincideswith a ventilating slot in the core, the end wedge should beshortened by 5 mm. The top ripple spring pertaining to the

end wedge must be 60 mm shorter than the end wedge. Theresulting space should be packed with filter strips whichmust be cemented together and to the end wedge andcompression strip for protection against displacement.Cementing the top ripple spring is not permissible.

5 Cementing the End WedgesPrior to driving in the end wedge (part 2) roughen

surfaces of compression strip (part 7) with abrasive clothover a length of not less than 50 mm from core end, exceptfor surface in contact with the stator bar, and apply a thincoat of adhesive. Roughen filler strips (parts 5 and 6) withabrasive cloth over a length of 50 mm on both surfaces,brush both surfaces with a thin coat of adhesive and theninsert filler strips. Roughen driving strip (part 3) with abrasivecloth over a length of 50 mm and brush driving strip surfaceswith adhesive. Insert driving strip and top ripple spring.Roughen recessed portion of end wedge with abrasive clothand apply a thin coat of adhesive prior to driving in the endwedge with a mallet and hammer. Drive in end wedge, leavinga clearance of approximately 3m between the end wedgeand the adjacent slot wedge.

Place a suitably shaped piece of Metallon on thecompression strip ahead of the filler strips and the end wedgeand smoothen Metallon surface.

Caution: If bond extends over a length of two or three corepackets, make sure that no Metallon is left in ventilatingslots. Remove surplus Metallon prior to curing.

3 mm

BHEL, Haridwar

Turbogenerators

Inspection

2.5-2350-0500/10609 E

Treatment of Bolted Contact Surfaces

1 General

The silver plated contact surfaces and the bright coppersurfaces of the contact faces should be treated withcontact grease primarily to fill up the gaps remaining afterbolting.

In addition, the contact grease improves the electricalconductivity of the contact surfaces, it is chemically inertand water-repellent, it does not dry up, it cleans oxidizedcontact surfaces and protects them against corrosion.

Contact grease has a grease-like, pasty consistency.

2 Application

Degrease silver-plated contact surfaces by means of

a cloth wetted with solvent. In the case of the terminalbushing make sure that the insulators never come intocontact with the solvent.

Copper surfaces without silver coating should becleaned and degreased by means of solvent after emery-polishing.

After this preparatory treatment, apply the contactgrease to the contact surfaces with clean fingers in sucha quantity that a little excess grease is pressed out allaround on bolting of the contact faces.

If greased surfaces are soiled prior to making the boltedconnection, these should be cleaned and greased anew.

Excess contact grease should be wiped off with aclean rag.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-3000-0500/10609 E

Rotor


[1] 2.5 – 3300 Insulation Resistance Measurements onRotor and Exciter Windings

[2] 2.5 – 2310 Drying the Windings

1 Leakage Test of Field Current Lead

Before starting overhaul work and H2 purging, checkH2 seals at the field current lead for leakage. To do this,use a leak detector and check coupling flange betweengenerator and exciter rotors and field studs at rectifierwheels for gas leakage.

If no H2 gas leak is detected, the exciter should bedismantled. The exciter rotor should be uncoupled fromthe generator and a new leakage test of the central fieldconnection performed.

If a leak is detected during this leakage test, themanufacturer must be notified. The hydrogen should bepurged from the generator only after completion of theleakage test.

2 Rotor Wedges and Retaining Rings

If the rotor is removed, examine it carefully. The wedgesand retaining rings should be inspected for propercondition.

3 Shaft Journals and Shaft Seal Contact Faces

The shaft journals and shaft seal contact faces shouldbe checked for grooves. If any irregularities are detected,reconditioning should be carried out according toinstructions from our service personnel.

4 Cleaning the Rotor

After each withdrawal, the rotor should be cleaned

thoroughly, even if the visual inspection did not revealany contamination. Careful cleaning is important so asnot to damage any of the numerous insulated parts. Itis, therefore, recommended to make use of the servicesof our experienced product service personnel who willcarefully remove any dirt accumulations below theretaining rings and within the range of the end windingsby means of a special vacuum cleaner. Any inexpertuse of compressed air involves the risk of cooling ductclogging and of damage to insulated parts.

5 Contact Pins and Plug-in Socket Strips

The contact pins and plug-in socket strips should bechecked for arc erosion and proper contact resistances.Proper seating of the contact pins on the plug-in socketstrips can be verified by visual examination.

6 Coupling

The coupling flange at the rotor should be checkedboth at the guide flanges and at the fitting bolt holes.The coupling bolts should be inspected for propercondition.

7 Insulation Resistance Measurement

Prior to recommissioning, the insulation resistanceof the rotor winding should be measured and, i fnecessary, improved. Details are given elsewhere inthis manual [1], [2].

BHEL, Haridwar

Turbogenerators

Inspection

2.5-3300-0500/10609 E

Insulation Resistance Measurementson Rotor and Exciter Windings

During manufacture and transport, the insulation of therotor winding may have been exposed to moisture whichwould reduce the insulation resistance of the winding.The insulation resistance should therefore be measuredprior to initial startup, after prolonged shutdowns and afterwork on the winding. If required, the generator should bedried until a sufficient insulation resistance is obtained.

1 Required Insulation Resistance of Rotor Winding

The insulation resistance should amount to ≥≥≥≥≥ 1 megohmat 40oC.

At winding temperatures other than 40oC, a correctioncan be made using the curve shown in Fig.1

2 Measurement of Insulation Resistance

Prior to each measurement, the generator must be de-excited and any static charges removed by grounding thewinding

The insulation resistance should be measured betweena slipring which is electrically connected to the rotorwinding and a second slipring in contact with the shaft,using a megger with a maximum voltage of 250V. Thisvoltage will present no danger to any of the devices in theexcitation circuit. The duration of the test should beapproximately two minutes.

After each measurement, the winding capacitanceshould be discharged for not less than two minutes.

The measurement should be performed with themeasuring brushes for the ground fault detection systemlifted off the sliprings.

Note: When the generator is filled with hydrogen, makesure that the rotor shaft ends are properly grounded duringmeasurement and discharging

Fig. 1 Correction curve for Insulation resistanceMeasured (Rmeas) to a temperature of 40oC

R 40oC = R meas x K

0.1

1

10

100

0 10 20 30 40 50 60 70 80 90

Slot Temperature in oC

K

BHEL, Haridwar

Turbogenerators

Inspection

2.5-3357-0500/10609 E

Ultrasonic Examination ofRotor Retaining Rings at Power Plant

Austenit ic retaining r ings manufactured fromX55MnCr(N)18k steel are sensitive to stress corrosion,i f persist ing suff iciently long in an unfavourableenvironment during storage, operation or outages,stress corrosion may lead to crack initiation and crackgrowth. In addition to preventive measures to avoidstress corros ion, i t is advisable to arrange forexamination of the retaining rings at the power plant.Such an examinat ion is urgent ly required af terdisturbance during which the retaining rings are exposedto moisture. In the following the use of the ultrasonicinspection method for non-destructive examination isoutlined and recommendation are given on the testprocedure.

1 Purpose and Scope of Ultrasonic Examination

Ultrasonic examination of the shrink-fitted retainingrings serves to detect incipient cracks and particularlythose which have already grown to a dangerous size.The examination can only be performed with the rotorwithdrawn. It is therefore recommended to subject theretaining rings to such an examination during a majoroverhaul involving the withdrawal of the rotor.

In addit ion, i t is recommended to repeat thisexamination at regular intervals. Any changes detectedwhen comparing the test results with the previousresults provide useful information for assessing theintegrity of the retaining rings. The intervals at whichthe examination should be repeated can be the same asthe scheduled inspection intervals but should bedetermined on the basis of the inspection facts.

2 Flaw Detection

Ultrasonic examination of the shrink fitted retainingrings inevitably also involves the generation of spurious

echoes, resulting in the difficulties in the interpretationof the ultrasonic indications, particularly within the rangeof the shrink fits and on shapes deviating from thesmooth cy l indr ica l out l ine. Based on prev iousexperience and using special probe heads and referenceblocks, the BHEL specialists are in a position todetermine with a high degree of probability the flawsize from the indications obtained. According toexperience so far available, the detectable flaw size isfar below the critical flaw size that may result in asudden forced rupture. If the echoes reflected by aflaw are markedly above the spurious echo level of theinner periphery and can be interrupted as incipientcracks wi th a h igh degree of probabi l i ty, i t isrecommended to pull of the respective retaining ring forfurther examination.

3 Execution of Ultrasonic Examination

To perform the examination, the rotor must beremoved and supported so that an inspection ispracticable on the entire circumference of the retainingring. The coating of the retaining ring should be strippedwith a paint remover. Care should be taken to ensurethat the winding and insulating parts do not come intocontact with the paint remover. Openings in the poleareas and the gaps between the retaining ring and rotorbody should be sealed.

After completion of the examination, the oil-wettedportions of the retaining ring should be degreased witha solvent. When performing cleaning work care shouldbe taken to ensure that the winding and insulating partsdo not come into contact with the solvent. The retainingring should then be repainted and the rotor reinserted.

Approx imate ly three days are requi red forpreparations and execution of the examination, includingrepainting of the retaining rings.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-4000-0500/10609 E

Hydrogen Cooler

Also refer to the following information[1] TWA 57 905 Measures to prevent Corrosion damage

Depending on the extent of the inspection, thehydrogen coolers should be cleaned thoroughly bothon the gas and water sides. During a less extensiveinspection, when the hydrogen is left in the generator,the tubes should be cleaned on the water side only. Forthis purpose, no withdrawal of the coolers will benecessary. The return water channel can be removedafter the inlet and outlet valves at the coolers are closed.It is advisable for wet cleaning to slightly lower than thecooler water level by opening the outlet valve for ashort time.

The tubes are cleaned by special brushes, whichare moved up and down in the individual tubes of thetube bundle. After all tubes are well brushed, any dirtshould be drawn off through the drain connection in theinlet/outlet water channel. The vent pipe connection inthe inlet/outlet water channel should be detached forbrushing of the cooler vent pipe. After all tubes arebrushed, a new flat gasket should be fitted and thereturn water channel t ight ly bolted to the uppertubesheet of the cooler section. This should be followedby reopening the inlet and outlet valves. Whereby thetube bundle is flushed with cooling water. The coolercleaning interval depends on the cooling water conditionand is indicated when a substantial reduction of thecooling capacity is observed at the coolers. A repetitionof the tube cleaning every two months may be necessarywhen the cooling water is heavily contaminated. It maybe possible, however, that the interval between onecleaning and the next amount to several years. It isrecommended to perform the first cleaning operationtwo months after initial commissioning. The date at which

the next cleaning will be required can be determined atthat time. The intervals for cleaning can, however, bedefinitely fixed only after several years of operation.

Brushing of the tubes normally suffices for cleaning.Any scale deposits which cannot be removed bybrushing should be dissolved with a hydrochloric acidsolution. For this purpose, a 10% solution with the usualpicking additives left in the tubes for several hours willbe sufficient. It is advisable, in the event of sufficientexperience not being available, to have such chemicalcleaning work be performed by specialist firms.

The coolers should be withdrawn from their wellswhen more extensive inspection work is required. Afterwithdrawal, the coolers should be thoroughly inspectedon the gas side. On detection of any contaminations,the gas side should be cleaned by means of dry andclean compressed air. The coolers should then beinstalled in the generator housing, using new gasketsfor reassembly.

At every generators inspection, the return waterchannel and inlet/outlet water channel of the hydrogencooler sections should be removed. Care should betaken in this work so that the water channels andgaskets are not damaged and that their location issufficiently marked for easy reassembly. The waterchannels should then be cleaned thoroughly. Thesmallest trace of contaminations should be removed.Any damage detected on the protective coast must beproperly remedied prior to reassembly of the cooler.After cleaning, the water channels and gaskets can beinstalled observing of the aligning marks. For additionaldetails, see separate instruction [1].

BHEL, Haridwar

Turbogenerators

Inspection

2.5-4100-0500/10609 E

Insertion and Removal ofHydrogen Coolers

1 General

Each cooler section consists of a tube bundle, theupper and lower tubesheets and the inlet/outlet andreturn water channels. The upper tubesheet is largerthan the cooler well opening and used to fix the cooler.Gastight sealing of this tubesheet is done by a roundcord packing. The lower tubesheet is sealed but is freelymovable and capable of following the differentialmovement of the cooler due to the different thermalexpansions. Gastight sealing of the lower tubesheet isdone by a packing–type seal.

2 Checking the Generator

Prior to inserting a cooler section, the cooler wellshould be thoroughly checked for dirt or other foreignmatter. All compartments and surfaces in the well shouldbe subjected to a vacuum cleaner treatment. Never usecompressed air for this purpose, since the compressedair will only raise the dirt and carry it to inaccessiblelocations. The flange and sealing faces and the groovefor insertion of the round-cord packing should becleaned. Any burrs or compression marks should beremoved with a smooth-cut file.

3 Sealing the Cooler Section at the Upper HalfStator End Shield

The round-cord packing should be cementedtogether in accordance with the instructions givenelsewhere in this Manual [1], and then inserted into thegroove.

4 Inserting the Coolers

The cooler section to be inserted should be cleanedand suspended f rom the crane hook us ing thesuspension device of the return water channel. A secondwire rope should be attached to the nozzles of the inlet/outlet water channel and suspended from a secondcrane hook The cooler section should be brought in anupright position. With the cooler section in vertical

position, the lower wire rope should be removed andthe section positioned over the respective cooler wellopening.

If no second crane is available for bringing the coolersection in vertical position, the sections should be raisedby means of one crane hoist only, exercising utmostcare. To do this, suitable wooden supports should beplaced on the operating floor in order to protect thecooler sections against damage at the tilting edge andto ensure a firm footing of the section on the floor duringtilting.

The cooler section should be slowly inserted intothe cooler well, taking care that the resilient seal stripsbed against the gas baffle and that the round-cordpacking is correctly positioned in the groove.

The seal strips, which are resiliently mounted to theside walls of the cooler section, serve to seal the gapbetween the cooler section and the cooler well. In casethese seal strips fail to perform their function, hydrogencan flow past the cooler section without being cooled.For this section, the seal strips should be thoroughlychecked for proper functioning.

After the cooler section has been lowered intoposition, the wire ropes should be removed and analignment check performed at the lower tubesheet.There must be a uniform spacing between the tubesheetand the cooler well opening on all sides. The uppertubesheet should then be firmly bolted.

5 Seal ing the Cooler Sect ion at the LowerTubesheet

After alignment of the cooler section in the coolerwell and tightening of the flange bolts at the uppertubesheet, the hydrogen gasket should be inserted.

Note: During operation, the cooler section againstexpands in downward direction, requiring a gastightsliding contact between the tubesheet and the Veegasket over the distance due to thermal expansion.For this reason, the compression ring should not betightened excessively, as otherwise the sliding motionwill be impaired and/or excessive contact.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-5000-0500/10609 E

Bearings

The insulation resistance of insulated bearingsshould be measured prior to each inspection. Thebearings should then be dismantled and cleanedthoroughly. Bearing sleeves and shaft journals shouldbe checked for proper condition. If grooves are detectedthe manufacture should be asked for advice whether

the bearing may be used further. If a low insulationres is tance has been prev iously measured, therespective bearing should be inspected thoroughly forany damage by cathodic act ion. The inspect ionprocedure described above should be performed at allsleeve bearings of the turbine generator.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-6000-0500/10609 E

Shaft Seal

A differentiation is made between a minor, a mediumand a full-scale inspection. A minor inspection includesmeasurement of clearances and a visual examination. Amedium or full-scale inspection is automatically assumedif withdrawal of the rotor is required for which purposethe entire shaft seals will have to be dismantled andshould be subjected to a close inspection.

After dismantling, all shaft seal components should

be carefully and thoroughly cleaned. All points subjectsto natural wear should be inspected closely.

Reassembly of the shaft seals should be performedwith utmost care.

During each inspection, a check should be made toensure that the seal rings are still sufficiently insulatedfrom the stator frame.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7100-0500/10609 E

Seal Oil System

The work to be performed at an inspection is verydifficult to determine in advance. The scope of this workdepends on what defects were detected from the dateof the last inspection. The operating log should bechecked to determine which deficiencies should becorrected at the inspection.

The following inspection work should normally beperformed :

1 Seal Oil Filters

The filter to be cleaned should be taken out of serviceby changeover to the standby filter.

Remove cover of seal oil filter and complete screeninserts. Clean screen inserts with a solvent. To do this,drive out cotter pin and unscrew knurled unit. Base,fabric-lined supporting cylinder and screen ring cannow be pulled off the magnetic strainer unit. Rinse thescreen inserts with clean turbine oil to thoroughlyremove any solvent residue. Reassemble using newgaskets.

2 Differential Pressure Regulating Valves

Disconnect the signal pipes from the pressureregulating valves. Drain the seal oil from the signal pipes.Disassemble the valve head and valve yoke.

This work should be performed with utmost care soas to avoid damage to the sliding surfaces. Beforeremoving the valve yoke, unload the compression spring.

Remove the main bellows and the upper and lowersealing bellows. Check all sliding surfaces and valvecones for damage or wear. If damage or wear isdetected on the sliding surfaces, the bushings shouldbe replaced. Replace the main bellows and the upperand lower sealing bellows.

3 Pressure Equalizing Valves

Prior to disassembly of the pressure equalizingvalves, unload the compression springs, disconnect thesignal pipes and drain the oil. Check the sliding surfaces

for damage or wear. Replace the seals if they are wormor damaged.

4 Safety Valves

The safety valves should be removed and cleanedwith turbine oi l . Check safety valves for properper formance on pressure gauge panel pr ior toinstallation.

5 Shutoff Valves and Check Valves

Inspect shutoff valves and check valves for properoperation. If necessary, replace the valve inserts.

6 Pressure Measuring Points

The signal pipes to the pressure gauges should bedrained and flushed with clean turbine oil.

7 Seal Oil Tank and Float Valves

Remove the seal oil tank cover and check the floatvalve for free movement. If the performance of a floatvalve is unsatisfactory, the valve should be removedand replaced.

If sludge has accumulated, the seal oil tank shouldbe cleaned.

8 Thermostats and Contacts

Check thermostats, contacts of pressure gauges andpressure switches for proper operation.

All checking, cleaning and reconditioning workshould be performed with utmost care to ensure reliableoperation of the entire seal oil equipment for a prolongedperiod of time. When recommissioning the seal oilsystem, be sure that all status indications and alarmsfunction properly. All control gear, safety equipment,filters, coolers, signal and pressure sensing pipes shouldbe carefully vented at operating pressure.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7120-0500/10609 E

Seal Oil Pumps andBearing Vapour Exhausters

1 Electrical Motors of Seal Oil Pumps

At the manufacturer ’s works, the ant i f r ict ionbearings of the seal oil pump motors are packed withgrease sufficient to give troublefree service for a periodof two to three years. For this purpose, a grease onlithium-soap base with a drop point above 160°C is used.The period will be shorter under onerous serviceconditions or at high ambient temperatures. On expiryof this period, a thorough cleaning of the bearing interiorand an inspection for wear will be required. This worknecessitates a withdrawal of the armature, followedby washing the bearing shield bore, the bearings andthe bearing covers with light petroleum to which a smallquantity of oil was added, until the grease is completelyremoved. The bearings should then be packed withgrease of the same grade, taking care that both sidesof the cages are covered with grease so that aneffective seal is obtained against the ingress of foreignmatter. The unit can then be reassembled. Afterreassembly, a check should be made whether the shaftturns properly in the bearings.

Measure the carbon brush wear on dc motors. If thebrushes are heavily worn, new carbon brushes shouldbe installed.

Measure the insulation resistances between thewindings and ground with a 500 V megger. If theinsulation resistances does not comply with the relatedequipment manuals, the motors should be dried in anoven at approximately 70°C for several hours.

2 Seal Oil Pumps

Disassemble the seal oil pumps. Check whether thedummy pistons, the screws or the deep-groove ballbearing are worm. The passages in the casing insertand the sliding rings should also be checked. The sealrings and gaskets should be examined for tight sealingand replaced, if required.

Prior to recommissioning the seal oil system, add asmall quantity of turbine oil via the oil filling plugs on theseal oil pumps to ensure proper lubrication of the shaftseal and the necessary sealing of the screws for suction.

3 Bearing Vapor Exhausters

The antifriction bearings of the exhauster motorsnormally require no maintenance.

After approximately 8000 operating hours, thebearing vapor exhausters should be thoroughlyexamined. The motor should be disassembled and thebearings cleaned and packed with new high meltingpoint grease or replaced by new bearings. Remove theold grease from the regreasing device and check thepacking washer and seals for wear. If necessary,replace the packing washer and seals. Be sure toobserve the specified order of the spring washers andspacers when reassembl ing the uni t . Onrecommissioning of the unit, measure the vacuum in thebearing compartments.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7130-0500/10609 E

Seal Oil Coolers

Also refre to the following sections[1] TWA 57 905 Measures to Prevent Corrosion Damage

After isolation of the cooling water inlet and outlet,the upper water channels should be removed and theirposition marked. Use tube cleaning brushes to cleanthe tube interior.

Make sure that all deposits in the tubes and waterchannels are fully removed. Take care that the protectivecoating on the tube surfaces is not damaged duringcleaning, as this would promote corrosion. The drainand vent holes in the water channels should be checkedfor freedom from deposits and dirt. The vent and draincocks should be thoroughly cleaned and checked for

proper operation.If cleaning of the tube exterior should be required,

the tube bundle should be placed into a bath with asuitable cleaning fluid Cleaning by means of steam usingsolvents is also possible. After each cleaning procedure,the tube bundle should be well rinsed with turbine oilinside and around the tubes to remove the last tracesof the so lvent . Use only new gaskets whenreassembling the seal oil coolers.

For additional details, see separate instruction [1].

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7200-0500/10609 E

Gas System

Also refer to the following information[1] 2.5 – 0310 Leakage Tests

The work to be performed at an inspection is verydifficult to determine in advance. The scope of this workdepends on what defects were detected from the dateof the last inspection. The operating log should bechecked to determine which deficiencies should becorrected at the inspection.

The main purpose of an inspection of the gas systemis to restore a satisfactory gastightness. All pipeconnections of the gas system should be checked forleaks [1] before the unit is shut down. All leaks shouldbe marked and corrected during the inspection.

In addition, the scope of inspection work dependson the intervals between inspections, the scope of thework performed during the preceding inspection and onthe time available. During a full-scale inspection the partslisted under items a, b and c should always be replaced.Depending on the inspection conditions, the followingwork should normally be performed.

a) Remove and clean the dust filters in the CO2/H2 puritytransmitter. If required, insert a new sintered bronzefilter.The throttle element should be unscrewed, cleanedand reinserted.

b) Check and, if required, replace the pressure reducerdiaphragms.

c ) Check all valves of the gas system for leaks. Ifrequired, replace the diaphragms and valve inserts.

d) Check the gas dryer for leaks at the changeovervalve assembly and, if required, replace the gaskets.Perform functional check of the fan and heater.Replace the absorbent material of the dryer.

e) Drain the heat transfer liquid from the CO2 vaporiser.Disassemble the CO2vaporiser. Replace old gasketswith new ones and reassemble the CO2 vaporiser.

Fill the CO2 vaporiser with heat transfer liquid untilthe liquid level is observable in the riser of theexpansion vessel. Then functionally check the CO2vaporiser.

After completion of all inspection work on the gassystem, the gas system and generator should be leaktested. For this test, the main gas and measuring gaspipes at the generator should be closed. The waste gasvalves should then be closed, followed by filling thegas system, including the connected equipment, withhydrogen or air. During the filling procedure, the valvesat the gas valve rack (except for the waste gas valves)should be open cont inuously to ensure that a l lcomponents are included in the leakage test. The testpressure should correspond to the rated gas pressureof the generator. The air of gas supply should be shutof f when the test pressure has been reached.Subsequently, the pressure drop in the system shouldbe monitored for a period of 24 hours. The gas systemcan be considered sufficiently tight when the pressuredrop during a 24 hour test with compressed air doesnot exceed 0.15 bar. When this test is performed withhydrogen filling, the permissible pressure drop is 0.57bar. It should be noted, however, that these valuesexclusively apply to the gas valve rack and theconnected pipes up to the next shutoff valve. A checkby means of a leak detector should be performed whenhigher pressure drops are observed at the leakage test.On sealing of the leaks, the leakage test should berepeated until satisfactory results are obtained.

On completion of the inspection work, the electricalpurity meter system should be calibrated with pure CO2and H2.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7300-0500/10609 E



[1] 2.4 – 4740 Primary Water Filters[2] 2.3 – 9782 Conductivity in Primary Water System

The work to be performed at an inspection is verydifficult to determine in advance. The operating logshould be checked to determine what faults need to becorrected.

The following inspection work should normally beperformed after draining of the primary water circuit :

1 Primary Water Filters

1.1 Main FilterOpen the filter housing and remove the insert. The

magnet bars should be taken out of the filter insert.The filter insert should be brushed and rinsed with a

suitable cleaning agent, using a brush of mediumhardness. After cleaning, blow out the strainer withcompressed air from the clean side for removal of thedirt retained in the filter cloth.

As filter cleaning agent, only fully demineralizedwater, condensate or air should be used, since thesecleaners will not contaminate the primary water.

After cleaning of the individual components of thefilter insert and filter housing, install the insert with newseals and insert the magnet bars. Reinstall the filtercover, making sure that the filter insert is tightly seatedand that the cover gasket is properly positioned.

1.2 Fine FilterThe cartridge in the filter should be replaced at each

overhaul[1].

2 Ion Exchanger

Depending on the condition of the ion exchanger

resins, they should be replaced by new or reactivatedresins. The replacement of the resins should be done inaccordance with a separate instruction [2].

3 Valves

Inspect all valves for proper operation.During a large-scale inspection, the packings of the

valves should be replaced.

4 Level Monitoring System

The probe rods in the primary water tank should beremoved, cleaned and reinstalled using new seals.


At each inspect ion, the t ransmi t ters of theconductivity meter system should be removed, cleanedaccording to a separate instruction [2] and reinstalledusing new seals.

6 Controllers and Contacts

Check the thermostats and pressure switches forproper operation.

All checking, cleaning and reconditioning workshould be performed with utmost care to ensure reliableoperation of the entire primary water system for aprolonged period of time. After recommissioning of theprimary water system, all control and alarm equipmentshould be subjected to a functional test.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7320-0500/10609 E

Primary Water Pumps

1 Electric Motors for Primary Water Pumps

After 8,000 operating hours, the bearings of theelectric motors should be removed, cleaned and packedwith high melting point grease. Worn bearing should bereplaced by new ones.

Measure the installation resistance between thewindings and ground with a 500 V megger. If theinsulation resistances do not comply with the relatedequipment manuals, the motors should be dried forseveral hours in an oven at approx. 70°C (160°F).

Check the coupling between motor and pump andreplace worn parts.

2 Primary Water Pumps

2.1 BearingsThe pr imary water pumps are equipped with

lubricated bearings. The oil level in the bearings can bechecked at an oil slight glass. After approx. 3000 hoursof operation, the oil should be changed. For this purpose,only a good quality oil (SAE 20/30) should be used.

During intermediate inspections, the bearings shouldbe checked. Worn out bearings should be replaced.When replacing the bearings, the seal rings should alsobe replaced. The bearing caps should be remountedusing new gaskets (0.1 mm = 0.0004 in. thick).

2.2 Sliding Ring GlandDuring minor and major inspections, the sliding ring

gland should be replaced. For this purpose, the pumpimpeller must be pulled off.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7330-0500/10609 E



[1] 2.3 – 5003 Hints for Cooler Operation

The upper water channels should be removed andtheir location marked after the cooling water inlet andoutlet valves are closed. The tube bundles should bewithdrawn and the tubes cleaned internally usingspecial brushes [1]. Deposits on the primary water sideof the tubes should be removed with a water jet. Careshould be taken that all deposits on the tubes and waterchannels are completely removed. Take care that theprotective coating on the tubes is not damaged duringcleaning, as this would promote corrosion. If corrosionor damage to the protective coating is detected, theeffected area should be cleaned and protective coating

reconditioned or replaced. The drain and vent ports inthe water channels should be inspected for freedomfrom deposits and dirt. The vent and drain should becleaned thoroughly and checked for operation.

For reassembling the tube exterior, the tube bundleshould be immersed in a suitable cleaning agent.Cleaning by means of steam, with solvent added, isalso possible. The tube interior and exterior should bewell rinsed with water and dried after each cleaning.Only new gaskets and packings should be used forreassembly.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7381-0500/10609 E

Treatment and Cleaning of Pipesin Primary Water Circuit

1 General

The pipes of corrosion-resistant resistant chrome-nickel steel used in the primary water circuit of water-cooled generators are welded according to the TIGmethod with SAS 2/G, using argon (99.9 %) as shieldinggas.

Any required pipe bends should be made only bycold bending on the pipe bending machine or pipe elbowsshould be welded in.

2 Treatment of welds

After welding, the welds should be treated asfollows:

Fusion check(surface penetrant test)The fusion check to be carried out on each weldaccording to the surface penetrant method.Mechanical treatment or cleaning of pipes tarnishedby welding.Even when using a shielding gas, the pipes tarnish

up to 20 mm from the weld. On completion of thewelding work, the tarnished portions of the pipesshould be cleaned mechanically on the outside andas far as accessible, on the inside, too. Use onlybrushes of corrosion resistant chrome-nickel steelfor such mechanical cleaning work. For grindingwork use only new grinding wheels or wheels thathave been in contact with corrosion-resistantmaterials only.Flushing the pipes welded at the power plant.Prior to assembly, all pipes welded at the powerplant should be flushed with hot water at 80°C orwith Chlorothene NU at ambient temperature.Following this, all parts should be dried by blowingthem out with water and oil-free compressed air. Allpipe lines not required for immediate service shouldbe closed at the ends.

3 Flushing the Complete Piping System

Prior to commissioning the complete piping systemshould be flushed in completely assembled condition.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7382-0500/10609 E

Flushing External Part ofPrimary Water Circuit

Also refer to the following information[1] 2.5 – 7381 Treatment and Cleaning of Pipes in Primary

Water Circuit[2] 2.5 – 7384 Leakage Test of External Primary Water

Circuit.

1 General

Prior to startup of the turbine-generator, the completepiping system should be flushed. Any dirty and dustparticles in the system in spite of the extreme care takenin the installation will thus be retained in the main filter.

It is assumed that all pipework is in clean conditionand that all pipe sections replaced during the inspectionhave been subjected to the treatments and checksspecified elsewhere in this manual [1].

2 Preparatory Work

Prior to flushing, the following work should beperformed:

Install bypass pipes between inlet and outlet of

stator windingterminal bushings.generator main leads (if provided).generator main circuit breaker (if provided).

Close above components by fitting closure discs.

Close all equalizing valve assemblies upstream ofvolume flow measuring devices.Remove all orifices and screens, if provided.Ensure that tank MKF60BB001 is not filled with resinsand has been drained.Remove filter element from filters MKF60BT001.Isolate N2 supply line and vent gas line by closingshutoff valves MKF91AA502 and MKF91AA506.

Check to ensure that primary water pumps are readyfor operation. Heat water by simultaneously placingboth primary water pumps in operation after fillingof primary water circuit.

3 Flushing the Complete Piping System

Fill system with cold or hot deionate (up to 50°C) viathe filler valve in accordance with the instructions forfilling the primary water circuit.

Ensure that pressure in primary water tank does notexceed the ful l -scale value of pressure gauges(MKF91CP001 and MKF91CP501. For this reason, keepdrain valve MKF91AA505 open during filling and flushingprocedures and adjust the filling rate accordingly.

Initial flushing should be performed for 8 to 12 hoursat a water temperature of 45 to 50°C. Vibrate all pipingand welds to facilitate removal of dirt.

Then drain all flushing water from the circuit. Open,clean and reassemble main filter.

Repeat flushing procedure until no dirt particles arecollected in the filter.

4 Preparing Primary Water Circuit for LeakageTest

After the last flushing procedure and filter check, allfilters should be reassembled using new gaskets.

Reinstall orifices and screens prior to performingthe leakage test. Remove bypass pipes.

Perform leakage test according to the instructionsgiven in the turbogenerator manual [2].

BHEL, Haridwar

Turbogenerators

Inspection

2.5-7384-0500/10609 E

Leakage Test of ExternalPrimary Water Circuit

Also refer to the following information[1] 2.5 – 7382 Flushing External Primary Water Circuit.

1 General

A leakage test of the external primary water circuitis required after a major overhaul of the unit. This testserves to inspect all components of the system for leaks.

2 Preparatory Work

The external primary water circuit is normally cleanedbefore the leakage test is performed [1]. Since the testis restricted to the external circuit, the stator windingand the terminal bushings with the phase connectorsshould be and must remain isolated from the externalprimary water circuit by means of closure discs.

During the leakage test, pressure gauge MKF91CP501in the waste gas pipe should be replaced by a pressuregauge of accuracy class 0.6 with a range of not lessthan 10 bar.

All other pressure gauges and pressure transmitterswith a range of less than 10 bar should be isolated fromthe primary water circuit by cleaning the respectivevalves.

All shutoff and gas valves in the primary watercircuit should be opened.

3 Filling the Circuit

The circuit should be filled with deionate via thefiller line (shutoff valve MKF60AA504) and properlyvented, making sure that all drain valves have beenclosed prior to filling.

Observe water level I the primary water tank duringthe filling procedure. Water level in primary water tankshould be approximately 300 mm. Ensure that all waterlines connecting to the primary water tank are filled

with water.

4 Applying the Test Pressure

Admit nitrogen at a gauge pressure of 10 bar toprovide a gas cushion above the water level in theprimary water tank. The test pressure is to be appliedfrom a nitrogen bottle connected to the gas pipe to theprimary water tank via a pressure reducer. Beforeapply ing the test pressure, c lose shutof f valveMKF91AA508 and open shutoff valve MKF91AA502.Pressure rise in circuit can be read at pressure gaugeMKF91CP501. Close shutoff valve MKF91AA502 whengauge pressure in circuit amounts to 10 bar.

5 Leak Detection

Inspect all flanged, bottle and welded joints in primarywater circuit as well as the respective shutoff valvesfor leaks while maintaining constant pressure. Repairany leaks detected and repeat the leakage test.

6 Terminating the Leakage Test

The primary water circuit may be considered assufficiently tight when no leaks are detected by visualexamination and when no pressure drop is observed atpressure gauge MKF91CP501 during a test period of 10minutes (after thermal equilibrium has been reached).Drain external primary water circuit after completion ofthe leakage test, remove all closure discs and promptlyreasonable the primary water circuit.

Place primary water system in operation immediatelyafter the system has been restored to its previouscondition.

BHEL, Haridwar

Turbogenerators

Inspection

2.5-9000-0500/10609 E

Excitation SystemExciter

1 General

The scope of work to be performed during aninspection depends mainly on the equipment on whichdefects have been detected since the last inspection. Itwill therefore be necessary to extract from the operatinglog all deficiencies to be corrected during the inspection.

In accordance with the inspection schedule [1], thefollowing inspection work should be performed.

2 Hydrogen Leakage Test

Prior to removing the hydrogen gas from thegenerator casing, the dc field connections should beleak tested.

To do this, check the coupling between the generatorand exciter and the terminal bolts between the rectifierwheels with a potable leak detector.

3 Dismantling and Cleaning the Exciter

Remove exciter rotor. The coupling flange at the rotorshould be checked both at the guide flange and at thecoupling bolt holes. Check coupling bolts for propercondition and take dimensions.

Check field connection for gas tightness. To do this,a cover with top-mounted pressure gauge should beattached to the coupling flange and sealed gas tight.The space inside the cover should then be pressurizedat a gauge pressure of 6 bar via the compressed airconnection. With gas tight lead, no pressure drop ispermissible within a period of about six hours.

Any accumulations of dirt in the ventilating air ductsof the rotor, at the diodes, fuses and heat sinks must beremoved. Cleaning should be done very carefully to avoiddamage to the numerous insulated parts. It is, therefore,recommended to remove these contaminations with abrush, cloth (non-l inting) and a vacuum cleaner.Particular care should be exercised when cleaning theporcelain bodies of the diodes.

4 Measuring the Insulation Resistances of theWindings

Disconnect cables at stator terminal boards of thepilot and main exciters.

Remove measuring brushes of ground fault detectionsystem from slip rings.

The insulation resistances to ground of the individualwindings should be measured with a megger. For details,

see the respective instructions [2].

5 Drying the Windings

After a prolonged shutdown of the exciter, areduction of the insulation resistance may be causedby the formation of a moisture film on the surface of thewinding. Such a moisture film can be removed by dryingthe main exciter rotor. This should be done by placingan air dryer into operation, which was installed asadditional precaution against corrosion.

6 Checking the Diodes, Fuses and Rectif ierWheels

For details, see the respective instruction [3].

7 Emergency Cooling and Makeup Air Filters

The drive motors of the actuators for the emergencycooling f laps should be subjected to a thoroughfunctional test. The drive motors of the actuators forthe emergency cooling flaps should be subjected to athorough functional test. Perform the maintenance workin accordance with manufacturer’s special instructions.

The filter mats of the makeup air filters should becleaned or replaced. To enable their reuse, slightlycontaminated f i l ter mats should be beaten out.Otherwise, the filter mats should be washed in cold tolukewarm (30°C maximum) suds (e.g. Pril). When placingthe filter mats in the suds, make sure that the air inletside points downward. After washing, the filter matsshould be rinsed with clean water.

8 Bearing and Labyrinth Rings

Check the insulation of the bearing, pipe connectionsand, labyrinth rings. For details see the respectiveinstruction [4].

If the bearing babbitt is found grooved, our erectionengineer should be consulted regarding further use ofthe bearing.

The strips of the labyrinth rings should be checkedfor proper condition and replaced, if required.

9 Checking the Contact Pins and Plug-In SocketStrips

The contact pins and plug-in socket strips should bechecked for proper mechanical condition. If the silver

Also refer to the Following Information

[1] 2.5 – 1090 Inspection Schedule – Excitation System[2] 2.5 – 3300 Insulation Resistance Measure-ments on

Rotor and Exciter Windings[3] 2.5 – 9010 Checking the Rectifier Bridge Circuit[4] 2.5 – 0300 Checking the Bearing and Shaft Seal

Insulation2.5-9000-0500/2

plating of the contact pins shows signs of arc erosion,the contact pins require reconditioning and re-plating. Acheck should be made to ensure that the projectingcontacts of the plug-in socket str ips are spiral lydistributed on the entire circumference of the contactsleeve.

10 Checking the Condition and Performance ofthe Ground Fault Detection System

It is recommended to replace the carbon brushes ofthe ground fault detection system at each inspection.Ensure to insert the carbon brushes of the specifiedgrade which match the slip ring contour. After completeassembly of the exciter, the complete ground faultdetection system should be subjected to a functionaltest.

11 Cleaning the Exciter Coolers

Remove the coolers and perform the same cleaningprocedure as described for the hydrogen cooler.

1 Insulation2 Contact sleeve3 Plug-in contact strip

Fig. 3 Section Through Contact Sleeve

BHEL, Haridwar

Turbogenerators

Inspection

2.5-9010-0500/10609 E

Excitation SystemChecking the Insulation Resistanceof Heat Sink Insulation

Also refer to the following information[1] 2.5 – 9011 Checking the Insulation at Rectifier

Wheels

Regular inspection work should include checking theinsulating sections, between the diode heat sinks andrectifier wheels [1]. Leakage paths may be formed atthese points as a result of dirt deposits, rendering thefuses connected after the diodes ineffective in the eventof a failure.

In the event of a diode losing its blocking capability,an interruption of the respective bridge arm by the fuse

would then no longer be ensured, resulting in a phase-to-phase fault in the main exciter circuit.

After removal of the fuses, the insulation resistancebetween points a and b or a1 and b1 respectively, canbe measured by means of a megger, applying a voltageof 500 to 1000V. The insulation resistance between theheat sink and rectifier wheel should not be less than 10M .

BHEL, Haridwar

Turbogenerators

Inspection

2.5-9011-0500/10609 E

Excitation SystemChecking the Insulation at Rectifier Wheels

Detail X

4,8

2

1 Fuse 2 Heat sink 3 Diode 4 Rectifier wheel (-ve polarity) 5 Terminal bolt 6 Tension bolt 7 Hot air outlet 8 Rectifier wheel (+ve polarity) 9 AC lead10 DC lead

3 1 9

10 1 2 3 4 5 6 7 8 9

Current path

om manual for 500 mw gen-bhel

Documents

cooling system

rotor grounding system

primary water inlet

mechanical dataseal

generator bearings generator

rotor end winding

seal oil pumpsseal oil

generator cooling gas