scada hardware manual

8/8/2019 Scada Hardware Manual

1/99

meritHARDWARE MANUAL

TABLE OF CONTENTS

1.0 Introduction

1.1 Organization of the Manual

1.2 Who will get the best out of this manual

2.0 Overview of Traction Power Distribution

3.0 Overview of the Scada System

3.1 Remote Control Centre

3.2 Location of RCC equipment

3.3 Remote Terminal Unit ( RTU )

4.0 Functional Description of the SCADA System

4.1 General


4.3 Remote Terminal Unit

5.0 Technical description of Remote Terminal Unit

5.1 General

5.2 RTU at Traction Sub-station

5.3 RTU at sectioning and paralleling post

5.4 RTU at sub-sectioning and paralleling post

5.5 Functional description of Remote terminal Unit

5.5.1.0 Logic chassis

5.5.1.1 CPU module

5.5.1.1.1 Watch dog Timer

5.5.1.1.2 Interrupt Logic

5.5.1.1.3 Address Latch

5.5.1.1.6 Memory

5.5.1.2.0 Digital Output Module ( DOM )

5.5.1.2.1 Functional Description of DOM

5.5.1.2.2 Select Before Operation and Description

5.5.1.3.0. Digital Input Module ( DIM )

5.5.1.3.1 Interface Connection and Functional Description

Page No : 1


2/99


5.5.1.4.0 Analog Input Module ( POWER METER )

5.5.1.4.1 Functional Description of POWER METER

5.5.2.0 Interface Card Enclosure

5.5.2.4 Catanery Interface ( CIC )5.5.3.0 Modem

5.5.3.1 Overview of Modem

5.5.4.0 Power Supply Unit

5.5.4.1 Principle of Operation

5.5.4.2 Protection Features

5.5.4.2.1 Mains Supervision

5.5.4.2.2 Battery Supervision

5.5.4.3 Functional Description of LDA75F5.5.4.4 Functional Description of LDC30F

5.5.4.5 Overcurrent Protection

5.5.4.6 Overvoltage Protection

5.5.4.7 FoldBack Characteristics

5.5.6.0 Contactors / Relays

5.5.7.0 Terminal Block

5.6.0 Description of Telemetry at TSS

5.6.1 Under Voltage Tripping of Bridging Interruptors5.6.2 Scheme of Telemetry at SP

5.6.3 Scheme of Catenary Indication at SP

5.6.4 Closing of Bridging Interruptors

5.6.5 Under Voltage Tripping of Interruptors

5.6.6 Sequence of Operations of Under Voltage Tripping

5.6.7 Catenary Voltage Sensing at TSS

5.6.8 Scheme of Telemetry at TSS

5.6.9 Auto Re-closing Scheme at TSS

5.6.10 Field Wiring

Page No : 2


3/99


6.0 Maintenance of SCADA System

6.1 Maintenance philosophy

6.2 RTU Power Supply Unit

6.4 Table of Periodic Inspection and Maintenance6.5 Fault Finding and Rectification

6.6 Testing Equipment Requirement

6.7 Test Equipment

7.0 RTU Trouble Shooting Procedure

7.1 TeleSignal

7.2 Telemetry

7.3 Telecommand

7.4 Power supply Unit7.5 Trouble Shooting Chart for UPS

7.6 Trouble Shooting Procedure for Modem

7.7 TeleSignal Fault Finding Chart

7.8 TeleMetry Fault Finding Chart

7.9 TeleCommand Fault finding Chart

8.0 Downloading Program To Rtu Micro controller

9.0 Download Parameters to RTU

9.1 Testing the various parameters using MERITDIAG:

Page No : 3


4/99


CHAPTER - 1

1.0 INTRODUCTION

1.1 ORGANISATION OF THIS MANUAL

This document is the hardware manual of Remote Terminal Unit for Supervisory Control

and Data Acquisition (SCADA) System designed, manufactured and supplied by M/s

MERIT, Chennai. It contains the technical description, user procedures and maintenance

aspects of the system.

This manual helps the user to correctly install the system , use it effectively and maintain

properly.

The manual starts with an overview of traction distribution network and briefly introduces the

user to the SCADA system. Then the manual gives the technical description of the system

and the associated sub-systems. Finally, it deals with the maintenance aspects.

1.2 Who will get the best out of this manual ?

This manual is prepared for the use of the technical persons who are involved in using the

system and those who have the responsibility for maintaining it. The details contained in

this manual are highly technical in nature and hence the reader is expected to have a

basic understanding of electronics circuits and exposure to the latest state of art

technology.

The manual only covers basic trouble-shooting procedures and techniques. The reader is

advised to contact the technically trained engineers of SCADA system, before embarking

on component changes.

Page No : 4


5/99


CHAPTER - 2

2.0 OVERVIEW OF TRACTION POWER DISTRIBUTION

25KV AC, 50 Hz Single phase electric traction system is adopted for the electrified tracks.

Power is obtained from State Electricity Boards (SEBs) from their network at

220/132/110/66 KV at traction substations (TSS) and stepped down to 25 KV.

The high voltage winding of the single phase transformer is connected across two phases

and one terminal of the 25KV winding is connected to the rail and the other terminal to the

catenary system (Over Head Equipment (OHE)). The TSSs are spaced at a distance of

40 to 60 km.

The supply to the OHE from TSS is fed through interrupters located at feeding post (FP).

Adjacent TSSs normally supply power to the OHE on different phases to reduce

unbalance in the supply authorities grid.

To avoid the pantograph of a locomotive or electric multiple unit from bridging the supply

from different phases when it passes from one zone to another, a neutral section is

provided to separate the OHEs fed from different phases. The switching station provided

at neutral section is called "Sectioning and Paralleling post" (SP). At the SP in multi track

sections, the OHEs are also paralleled independently on either side of the neutral section

to reduce voltage drop. In an emergency, when a TSS is out of commission, feed from

adjacent TSSs on either side is extended up to the failed TSS by closing interrupters at

SP. The pantograph(s) of locomotive(s) or electric multiple unit is (are) lowered at the

failed TSS to avoid short circuiting the phases at the insulated overlap.

Between a TSS and adjacent neutral section, the OHE is divided into sub-sections for

isolating the faulty section for the purpose of maintenance and repairs.

The switching stations provided at such points are called "Sub-sectioning and paralleling

posts (SSP). The OHE of various tracks, in multiple track sections, are also paralleled at

the SSP to reduce voltage drop in OHE. The sub-sectors are further divided into

elementary sections by the use of manually operated isolators.

Page No : 5


6/99


At TSS, SP and SSP, equipment like power transformers, circuit breakers, interrupters,

single and double pole isolators, potential and current transformers, lightning arrestors, LT

supply transformers etc., are installed in a fenced enclosure which is locked up. A

masonry building is provided for housing the control panels, SCADA equipment, batteryand battery chargers, telephones and others.

All traction substations are manned and switching stations are normally unmanned. The

devices that are controlled from RCC through the SCADA equipment are circuit breakers,

interrupters and transformer tap changers. The tap changer of the transformer, circuit

breakers and interrupters can also be operated locally at the TSS, SP and SSP as the

case may be.

At the TSS, a local / remote changeover switch is provided on the control panel, as well as

in the mechanism box of the circuit breaker, interrupter and motor operated isolators. No

control panel exists for the interrupters at the SP and SSP and therefore the local / remote

changeover switch is provided on the mechanism box of the interrupter.

Page No : 6


7/99


CHAPTER 3

3.0 OVERVIEW OF THE SCADA SYSTEM

The SCADA system is designed to monitor the status and control of the 25KV electrified

traction system. It is a fully integrated hardware and software system with a central control

to monitor and control the field devices located at remote sites.

The SCADA system can be classified into two broad categories:

1. Remote Control Centre (RCC)

2. Remote Terminal Unit (RTU)


RCC is designed for monitoring different types of data like catenary indication, device statusand telemetry from various control stations. It also controls the field equipment like circuit

breakers, bridging interrupters, transformer tap position changing etc., RCC stores the

data regarding alarms, events, and telemetry to help the user to analyse the status of the

overhead equipment and switching stations. This data can be used for maintenance

purposes also. For example, RCC helps the user to easily identify the fault in OHE located

in various sections, for immediate rectification.

RCC consists of the following equipment:

a) Main and standby Computerb) Operator Workstation computer

c) Communication Processors with Modems

d) Printer and Print Sharer Switch

e) Modem

f)UPS

g) Battery

3.2 Location of RCC equipment

These equipments are located in Traction Power Control (TPC) room. The UPS and

batteries are located in the UPS room and batteries room respectively. Main and Standby

Computers, Communication Processors, Modems Workstation Computers and Printers

are installed in the TPC Room. Supervisory console is installed at CTPC Room.

Page No : 7


8/99


System configuration

Page No : 8


9/99


3.3 Remote Terminal Unit (RTU) DESIGN AND MANUFACTURE BY M/S SANMAR

RTU is designed to control and monitor field equipment. It accepts digital and analog input

signals from the remote field equipment. It receives the control commands from the RCC.

RTU can be divided into the following four parts:

a) Logic Chassis

b) Interface Unit

c) Energy Meter

d) Modem

RTU accepts digital and analog input signals from the remote locations (TSS/SP/SSP) and

receives the control command from the RCC to perform the following tasks :

* Status input monitoring and change of status

* Control output operation

* Analog input monitoring

* Communication with RCC

RTU is designed to be flexible, modular and reliable making it easy to maintain and expand.

A highly integrated microprocessor based system, coupled with firmware programming

allows the RTU to perform sophisticated control and data acquisition functions.

RTU system can be configured for a wide variety of I/O mix, which can be configured and

expanded as required in the field. The configuration of an RTU is stored in non-volatile

memory and may be edited or expanded without hardware changes.

The RTU provides the following basic data acquisition functions:

* Data acquisition for status input and analog input

* Control outputs

* RTU / Master station communications

Implementation of the RTU capabilities is a combination of hardware logic and firmware

logic that is stored in Read Only Memory (ROM). This provides a convenient means to

alter and / or extend the capabilities of the RTU without significant hardware modification.

Page No : 9


10/99


Each TSS RTU will support,

* up to ninety six (96 ) Digital Input points

* up to Fourty Eight (48 ) Digital Output Points

* up to sixty four (8 ) analog input Points

Page No : 10


11/99


CHAPTER 4

4.0 FUNCTIONAL DESCRIPTION OF SCADA SYSTEM

4.1 General

The SCADA System, from RCC enables the Traction Power Controller (TPC) to control the

25 KV traction power supply to OHE. It also monitors and operates various equipments at

traction sub stations located enroute.

The SCADA System for Traction Power Control consists of two major parts:

a) Main and Standby Computers, Work station computers, Communication processors

are connected in the LAN set up and Powered through UPS with battery back up at

RCC

b) Remote Terminal Units (RTU) for acquisition of field parameters from the unmanned

control stations along the traction network.

The RCC and RTUs are connected in Wide Area Network (WAN).

The RCC Computers communicate with each RTU in a predefined sequence over the WAN

to acquire information regarding;

* Status of CB, interrupter, relays etc.

* Alarm condition in the controlled station

Measurand values


The Main and Standby Computers are Server Grade Pentium IV with 15" color monitor.The Main computer interacts between the Communication processor and Workstation

computers. It collects the formatted RTU information from Communication processor and

sends the processed information to the Operating Workstation (OWS) computers, which

enables the user to understand the field conditions.

The Main computer also responds to the requests of the OWS computer, which receives

commands from Traction power controller. Then, this information will be formatted and

sent to the communication processor.

The Main computer also updates available information with the slave computer, which

should have the same information. Whenever the Main computer fails, then the Slave will

become Main with updated information.

The Communication Processors (CP) are Server Grade Pentium IV Computers.

The Workstation Computers are Server Grade Pentium IIV with 21" color monitor

Page No : 11


12/99


4.3 Remote Terminal Unit (RTU)

RTU accepts digital and analog input signals, from the remote locations, TSS, SP and SSP.

It receives the control signals from the RCC. It performs the following tasks:

* Input status monitoring and recording the change of status

* Control output operation

* Analog input monitoring


RTU consists of the following five parts, namely (not shown in the block diagram),

* Power Supply Unit

* Logic Chassis

* Interface Unit

* Modem

* Termination Section

Power Supply unit Consists of two Parts, one for main 24V dc supply and the other is

(5v, 12v, -12v) for Modem and Interface card reference supply.

The Logic Chassis is the main part of RTU, and is based on microprocessor. It is used to

control and process all field signals. Each Logic Chassis supports 96 digital input, 48

digital output signals, 8 analog input signals.

The Interface Unit receives and controls the field signal devices. Energy Meter that is part

of the Interface Unit is used to convert the field analog signals like voltage and current.

Modem is used to convert the digital information to analog information suitable to for four

wire based communication cable and vice-versa in the FSK & PSK mode.

Termination Section is used to interconnect the field cables and RTU internal cables to

perform the control and supervisory operation at the field.

CHAPTER - 5

Page No : 12


13/99


5.0 TECHNICAL DESCRIPTION OF REMOTE TERMINAL UNIT

5.1 GENERAL

The Remote Terminal Unit (RTU) acts as the common interface between the field devices

and the Remote Control Centre of the system. The Remote Terminal Unit is designed

to be flexible, modular and reliable, making it easy to maintain and easy to expand. It is

highly integrated microprocessor based logic system, coupled with firmware

programming, which allows the Remote Terminal Unit to perform sophisticated control

and data acquisition functions.

RTU accepts digital and analog input signals from the Remote locations (TSS / SP / SSP)

and receives the Control command from the RCC to perform the following tasks:

* Status input monitoring and change of status

* Control Output operation

* Analog Input monitoring


5.2 RTU AT TRACTION SUB-STATION - TSS

This RTU is designed for the following capacity:

* 24 Telecommands

* 48 Telesignals

* 06 Telemetries

The term Tele command is used in railways to give output and sense the status feedback

for the particular device. Generally each Telecommand represents two digital outputs

and corresponding two digital inputs.

Page No : 13


14/99


RTU Block Diagram

The following are the Telecommands available in the TSS RTU:

1. 132 KV Circuit Breakers - 02

Page No : 14


15/99


2. 25 KV Circuit Breakers - 05

3. 25 KV Interrupters - 05

4. Auto Re-closure - 02

5. Tr. Tap Changer - 026. Interlock release - 01

The scheme of operating the sl.no.1, 2 & 3 is shown in the figure. This requires close and

open operations from the RTU and monitoring the status.

Auto reclosure is the facility available in the field. TSS control panel to close the feeder CB

automatically once whenever the CB trips and the scheme will become locked out

condition. The RTU is to sense the locked out signal and command is to be given to

release / reset the lock out.

Transformer, which is stepping down 132 KV to 30 KV, is having six steps of tapping

position. This TAP POSITION may be raised or lowered by giving RAISE or LOWER

commands and status of TAP POSITION (any one out of six) is to be monitored.

The following are the Telesignals to be sensed at TSS:

TYPE I Telesignals

* Transformer alarm - 2 nos

* Transformer fault - 2 nos

* Transformer Tap position - 12 nos

* 110V DC Fail for Tr. Trip - 2 nos

* 110V DC Fail for Tr. Alarm - 1 no

* W.P.C / D.P.R / O.C.R relay (FCB I) - 3 nos

* W.P.C / D.P.R / O.C.R relay (FCB II) - 3 nos

Using 110V DC from the field senses the above alarms.

Page No : 15


16/99


Block diagram of tss

Page No : 16


17/99


General scheme of TSS wiring

Page No : 17


18/99


Tss wiring 2 of 2

Page No : 18


19/99


G.A DIAGRAM OF TSS

TYPE II Telesignals

* 240V AC failure / PSU on DC - 1 no

* 25 KV feeder PT Fuse fail - 2 no

* Tr. Line Pt Fuse fail - 1 no

* 25 KV Shunt Cap. PT fuse fail - 1 no

In the above alarms are sensed by using availability of 240V AC and 110V AC from the

field.

TYPE III Telesignals

* 110V DC Low - 1 no

Page No : 19


20/99


In the above alarms are sensed by using availability of 110V DC from field batteries.

TYPE IV Telesignals

* Catenary indication - 4 nos.

In the above alarms are sensed by the availability of 120V AC from PTs connected to the

Overhead equipment.

The term Telemetry is used in railways to measure the current, voltage and Maximum

demand from the field. Each Telemetry will have one analog input from the field.

Voltage

Current

Maximum demand

Voltage is measured from the 25 KV / 110 V Pts and Voltage changeover scheme connects

the higher side of the PT voltage to the Transducer.

Current is measured from the CTs whose ratings are given below

The Accuracy of the Voltage, Current, PF and MD is Class A Type (ie, 0.5%).

Dead Band : 0 to 255 ( 1 byte)

Resolution : 10 Bit

Normal value : 1000 Units.

Value of the LSB bit : 10 mv

(Resolution )

For 25 KV side

Primary side - Secondary side

1000A or 500A - 5A

1500A or 750A - 5A

For 132 KV side

Primary side - Secondary side

100A or 200A - 5A

The secondary side will be connected to the Energy Meter through Shorting terminals.

Page No : 20


21/99


Maximum demand is the parameter calculated from the measured Voltage and Current.

This will be done in the software at the Remote Control Center.

5.3 RTU AT SECTIONING AND PARALLELING POST - SP

The following is the design capacity of SP RTU :

Telecommands - 8 nos

Telesignals - 12 nos

Telemetry - 4 nos

The following are the Telecommands available in the SP RTU

25 KV interrupter - 4 nos

Spare - 4 nos

In general ,SP will have two nos of parallel interrupters which could be operated by issuing

open and close commands and another two nos of bridging interrupters which have to

meet the following Under voltage trip conditions :

Under-voltage Tripping

Under voltage tripping is the facility provided for bridging interrupters of SP. The two

different phases of 25 KV voltage are fed from the adjacent TSS to the Bridginginterrupter and it should not be closed when both sides of the voltages are high.

Whenever one side TSS fails, then RTU is able to close the Bridging interrupters to

extend the feed from one side to another side. After extending the feed, if both side

voltages are going low, then RTU should trip the bridging interrupters.

The following are the Telesignals to be sensed at SP :

TYPE I Telesignals

* Spare - 4 nos

The above alarms are sensed by the availability of 110V DC from the field.

TYPE II Telesignals


* Spare - 1 no

Page No : 21


22/99


In the above alarms are sensed by the availability of 240V AC.



* Spare - 1 no

In the above alarms are sensed by the availability of 110V DC from field batteries.

TYPE IV Telesignals

* Catenary Indication - 4 nos

(Inclusive of Under voltage tripping facility)

In the above alarms are sensed by the availability of 120V AC from PTs connected to the

Overhead equipment.

Block diagram of sp & ssp

Page No : 22


23/99


General scheme of sp/ssp wiring

Page No : 23


24/99


General scheme of sp / ssp wiring 2 of 2

Page No : 24


25/99


G.A DIAGRAM OF SP /SSP

Page No : 25


26/99


TELEMETRY

In SP, voltage is measured from the up and down line 30 KV / 120V PTs where thesecondary voltage of the PT is connected to the Energy Meter.

5.4 RTU AT SUB-SECTIONING AND PARALLELING POST - SSP

The following is the design capacity of SSP RTU :

Telecommands - 8 nos

Telesignals - 12 nos

Telemeter - 4 nos *

( * The above 4no Telemeters are spare. Hence Transducers will not be provided in the

RTU)

The following are the Telecommands available in the SSP RTU :

25 KV interrupter - 3 nos

Spare - 5 nos

The following are the Telesignals are to be sensed at SSP :

TYPE I Telesignals

* Spare - 8 nos

The above alarms are sensed by using availability of 110V DC from the field.

TYPE II Telesignals


* Spare - 1 no

The above alarms are sensed by using availability of 240V AC.


Page No : 26


27/99



* Spare - 1 no

The above alarms are sensed by using availability of 110V DC from the field batteries.

TYPE IV Telesignals ( Subject to the requirement )

* Catenary indication - 4 nos.

The above alarms are sensed by using availability of 120V AC from PTs connected to the

overhead equipment.

5.5 Functional Description of Remote Terminal Unit

Remote Terminal Unit is comprised of the following modular blocks

a) Logic Chassis

b) Interface Unit

c) Modem

d) Power Supply Unit

e) Transducer

f) Contactors / Relays

g) Terminal Block

Page No : 27


28/99


Signal flow diagram

5.5.1.0 Logic Chassis

A highly integrated microprocessor based logic system, coupled with firmware

programming, allows Logic Chassis to perform sophisticated control and data acquisition

functions. The Logic Chassis can be configured for a wide variety of I/O mix which can

be configured and expanded as required in the field. The configuration of an Logic

Chassis is stored in non-volatile memory and may be edited or expanded without

hardware changes

Page No : 28


29/99


30/99


Block diagram of logic chasis

5.5.1.1 CPU Module

CPU Module acts as the backbone to Logic Chassis. It is based on the microcontroller

Technology Philips micro-controller 80C669. The 80C669 is a highly integrated 16 bit

device with 33MHz speed which implements the following on-chip features

* Serial communication:

Page No : 30


31/99


In build in CPU and can support up to two serial ports on the

designed baud rate

* Number of DI, DO and AI can handle by a single CPU:

Digital Input and Digital Output: Maximum 1536

Analog input: Maximum 8

* Up to 16 Mbytes linear address space

* Five programmable chip selects

* Maximum of 56 interrupts

Block diagram of CPU

Page No : 31


32/99


Functional block diagram of CPU

These features combined with 33 MHz processor clock to perform many sophisticated

Page No : 32


33/99


data acquisition and control functions as software tasks. It contains the following function

blocks

* Watchdog timer

* Interrupt Logic

* Address Latch

* Modules Select Logic

* Module Address Data Bus

* Flash EPROM and RAM

* Dip Switches to set the address of Node

LED Indications

To display the operating status, the CPU module have four LED indications

INDICATION FUNCTION

PWR Supply Voltage Monitor

RUN CPU status and error display

TXI TX Status OF COM1

RXI RX Status OF COM1

TX2 TX Status OF COM2

RX2 RX Status OF COM2

Red ON Supply Voltage < 17V dc and Low

Battery

Details of RUN LED

LED STATUS MEANING

OFF Controller stopped / Fault

Page No : 33


34/99


Green blinking Controller Running

5.5.1.1.1 Watchdog Timer

The inbuilt function of the Micro controller monitors three vital conditions for the

Microcontroller, power supply and external reset.

First, a precision temperature compensated reference and comparator circuit is used to

monitor the status of +5V (VCC) power supply. When VCC falls below 4.65 V, the Chip

forces reset to the active state. When VCC returns to normal, i.e. greater than 4.65V,

then the reset signal is kept active for a minimum of 250ms to allow the power supply

and processor to stabilize. It has also additional feature of write protection for CMOSRAM or EPROM.

The watchdog timer continuously monitors the process of Microprocessor. The Watchdog

accomplishes this by activating the reset line, if the strobe input is not driven low before

the chips internal 500 ms timer has timed out. The strobe input is derived from the

microprocessor timer / counter output (TCO) which must be set from the software. If the

software does not reset the timer counter within the allotted time, a strobe pulse is not

generated and the reset line is forced to the active state. The reset is held momentarily

and then released, which causes the RTU to reinitialize and start execution from the

restart vector.

5.5.1.1.2 Interrupt Logic

The Logic Chassis is a real time device and therefore fully utilizes interrupts. There are two

external hardware sources from which an interrupt can originate. The first is initiated

when a change occurs at a status input. Status input modules contain the logic which

generate a signal any time their input values are changed, these signals are then sent toCPU and are input at data latches.

It should be noted that only odd numbered COS lines are input to data latch this is

because the even numbered modules pass their interrupts along to the odd numbered

Page No : 34


35/99


modules using the dedicated COS and COMPEN lines on the MOD bus and the odds in

turn pass the COS to data latch.

An active COS signal at the inputs to data latch acts to generate an active state at its output

and in turn at the 80C167C interrupt input. When the processor receives an interrupt, it

immediately enters service routine, which reads latch to determine which pair of Status

inputs signals (COS), caused the interrupt. Once the pair has been determined, the

processor reads the indicated module pair to determine the specific input or inputs, which

have changed.

5.5.1.1.3 Address Latch

The 89C669 utilizes a multiplexed Address data bus; therefore it is necessary to de

multiplex or latch the address information. The Address latch is comprised of D type

latches whose outputs are always enabled and clocked by the ALE (Address Latch

Enable) signal

5.5.1.1.6 Memory

The Memory is divided into 3 types

Processor RAM

External RAM

Processor RAM of 2KB is made available to the processor module to store the non-

alterable storage of program code. The ram may be accessed through 16bit word or Byte

segments.

Flash RAM (128 KB) is used by the RTU to store configuration variables and system

data, which require memory to be non-volatile, yet alterable without hardware changes or

replacement.

RAM (256KB) is used as a general-purpose area for the microcontroller to store data,

variables and operating information that are temporary in nature. Information stored in

this section area is volatile and will be lost in the event that power is removed from the

Logic Chassis. These devices also word are byte accessed using the select logic

provided by the processor control lines.

5.5.1.2.0 Digital output Module (DOM)

The Control output system for the RTU comprised of two basic types of components,

Page No : 35


36/99


control function modules (DOM) that are added in the Din rail and attached with the CPU

module to interface with the field equipments through potential free contactors. The

Digital output module (DOM) contains the logic and CPU interfaces hardware.

Each Digital output Module (DOT) has sixteen outputs and is designed to drive the

Contactors of 10A rate, which in turn activate the field equipments. These modules could

be plugged into the Din rail as and when required.

5.5.1.2.1 Functional Description of DOM

The Digital output function module (DOM) is comprised of group of data latches, which

act together write-read-execute sequence logic to provide secure control operations. All

control output operations are initiated and monitored by CPU module. A control operation

begins when CPU places a bit pattern and simultaneously strobe the new value into the

data latch of the Digital output module. Next the CPU reads back the data, verifies it by

strobing the data and reads back to latch. If the read data and already sent data are

same then the CPU issues an execute pulse to drive the Each module provides 8 digital

outputs at the rate of 24Vdc / 0.1 A and the Module requires the power supply is from

+18V to +30V dc with the power consumption of 200mW. Respective LEDs of Orange

color indicates present state of output signal. The Output from the Opto - isolator

operate the contactors.

Page No : 36


37/99


Connection details of dot

Page No : 37


38/99


Block Diagram of DOT

5.5.1.2.2 SBO ( Select Before Operation) Operation and Description :

1. Request: Selection Command

Whenever activation is enabled in Select Command packet, the selected digital

output point read by the CPU and simultaneously strobe the new data output point

into the data latch of the Digital output module.

2. Response: Select Confirmation

Once receiving the Select Command from RCC, the CPU module reads back the

data from data latch of DOT and compare the bit pattern of the digital output value. If

Page No : 38


39/99


bit pattern are matching and CPU sends the Selection Confirmation to RCC and If

RCC decides to cancel the selection, then the Select command is sent with a

deactivation and the CPU will disable the data latch value.

3. Request: Execute Command

Once RCC gets the Selection confirmation then it transmits the command message

with Execution packet. After getting the execution command, the CPU enables the

output channel in DOT that was already selected by the selection command. The

digital output channel enable time duration depend upon qualifier bit (10 ms to 2.55

Seconds (in single command record. The default enable time is one second.

4. Request: Execute Confirmation

Once the CPU executes the command and enable the selected digital output

channel, then the RTU responds with an activation termination to RCC to indicate

that the command has been successfully issued.

Page No : 39


40/99


Connection details of DIT

BLOCK DIAGRAM OF DIT

Page No : 40


41/99


5.5.1.3.0 Digital Input Module (DIM)

Each Digital input module has eight inputs and is designed to provide input points of

status information to the CPU module from the Input interface cards.

5.5.1.3.1 Interface Connection and Function Description

The Digital input Module (DIM) accepts the inputs from the field (110v DC) , the 16

Inputs and the which are multiplexed and Transferred to CPU. All the four inputs areelectrically isolated from the logic circuitry of the module and connected through terminal

block for input with reference to common 0V connection.

Basic circuit of Digital input module is shown. It describes the process of the input signal

with isolation and the LEDs connected to show the status of each signal. The modules

are designed for signal voltages up to 110V dc and used to collect the binary control

signals from the system and transmit them to the CPU. It may be easily exchanged in the

working condition without disconnecting the individual wire. Individual Green LEDs are

used to show the status of the system and the maximum power consumption is 100mW.

5.5.1.4.0 Analog Input module (AIT) POWER METER

The system comprises of a single 8 channel Analog input module with necessary Inbuilt

Page No : 41


42/99


Transducers. The Analog input module fixed in the Din rail and the system uses

multiplexing method which selects a specific termination channel read by the A to D

converter. The channels are read sequentially starting with channel 1 and proceeding to

the last channel configured in the system.

CONNECTION DETAILS OF AIT

Page No : 42


43/99


BLOCK DIAGRAM OF AIT

Page No : 43


44/99


The Analog input module accepts PT Voltage and Feeder Current and converts them to

proportional digital values. The module contains A to D converter, reference sources,

signal conditioning and multiplexing hardware required to select the correct signals from

the field. In this module we have the features to select the type of input is voltage orcurrent is based on the DIPswitch present at the backside of the module.

5.5.1.4.1 Functional Description of Power Meter

The Analog input values are received from the field in the form of PT voltage and Feeder

current. All the input channels are led to a common multiplexer and are galvanically

isolated. The time-multiplexed voltage is fed to the instrumentation amplifier where the

signal is converted from a differential mode to single ended signal. Analog source selectswitch is used to select between the +reference, - reference, ground or multiplexed field

inputs. The output of the power meter is been transmitted to the CPU module through

serial data bus.

.5.2.0 INTERFACE CARD ENCLOSURE

Interface card enclosure consists CIC INTERFACE to Monitor the Status Of

Catenary Input Signals

5.5.2.4 Catnery Interface Module ( CIC )

Page No : 44


45/99


The catenary indication, which is available in the range of 0-120V AC, from the field (25KV /

100V AC PT) is sensed using this circuit. This catenary indication is sensed with various

ranges to eliminate the effect of induced voltage from the adjacent OHE when the

sensing OHE is dead. The comparator circuits have been provided with potentiometerto adjust the drop-off and pickup of the relay as described below:

The 0-100V AC from PT is fed as an input to the Transformer. An MOV is provided across

this input to act as a surge arrestor. The stepped down output from the Transformer is

rectified through bridge rectifier and filtered of transients with capacitance filter C. The

interface supply (12V DC) is connected to this circuit for functioning of ICs and Relays

and same voltage is adjusted for comparator input reference voltage.

Two numbers of 8 way dip switches SW1 and SW2 are provided for pick up (high level) and

drop off (low level) voltage for catenary indication. The respective

setting range will be as follows :

Drop off : 48% to 70% (12 kV to 17.5 kV = 48V to 70V)

Pickup : 60% to 80% (15 kV to 20 kV = 60V to 80V)

The Dip switch settings will be in steps of 1 kV.

TYPE -IV

Page No : 45


46/99


COMPONENT LAYOUT

Page No : 46


47/99


The DC signal corresponding to AC ON input voltage would be stepped down using

suitable resistor path selected by DIP switch. This will be fed to input of the pick up

comparator and the trimpot is to be adjusted to make output high. Then the AC OFF

input voltage is to be set using suitable resistor path selected by DIP switch. This will be

fed to the input of Drop Off comparator and the respective trimpot is to be adjusted to

make output high.

Then the AC OFF input voltage is to be set using suitable resistor path selected by DIP

switch. This will be fed to the input of Drop Off comparator and the respective trim pot is

to be adjusted to make the output high.

Both of these comparator outputs ( U1-U3 ) are to be connected to input of the AND gate.

This energizes the output relay through driver transistor. The field signal input is

connected through 32 pin Half Euro connector. The output from this card goes to Digital

Input Function Module of Logic Chassis through Euro connector.

5.5.3.0 Modem

The word MODEM is an acronym for MOdulator and DEModulator. Modem is used to

transfer data between two computers located at a distant place by using a normal

telephone line.

Page No : 47


48/99


5.5.3.1 Overview of SCADA Modem

The basic configuration consists of one master modem and one or slave modems

connected. The transmit output of master modem is connected to transmit output of all

slave modems. The receive input of master modem is connected to transmit output of all

slave modems. Multi-drop Modem configuration can be either 2 wire or 4 wire

configuration. Our Railway SCADA Multi-drop modem configuration is 4-wire

configuration The mode of communication between master and slave modem is always

half duplex mode. At any given time either master modem will be transmitting data to

slave modem will be transmitting data to the master modem.

5.5.4.0 POWER SUPPLY UNIT

5.5.4.1 Principle of Operation

The RTU Power supply consists of two parts , one for main 24 v dc Supply and the other

is (5v, 12v,-12v) for Modem and interface card reference supply.

Supervisory Module

The function of this card is to monitor the presence of the input AC voltage and change

over to battery whenever the input AC voltage crosses beyond the specified limits which

is less than 155 V or greater than 290 V.

The Supervisory module monitors the input voltage to check the High/Low value.

The relay circuitry is used to control the AC/DC Supply switch over.

The DC LOW, and AC Fail Status also be provided by this module to Digital

Input Module

5.5.4.2 PROTECTION FEATURES

5.5.4.2.1 Mains supervision : When AC Mains voltage is between 155V AC to 290V AC as

specified in the RDSO document then AC Mains will be connected to the DC-DC

Page No : 48


49/99


converter, otherwise 110V DC battery voltage will be connected.

5.5.4.2.2 Battery supervision : When battery voltage is between 99V DC to 140V DC as

specified in the RDSO document then Battery voltage will be connected to the DC-DC

converter. Protection of electronics from surges and noises are taken care by using

transient voltage suppressors and line filters. Transient voltage suppressor will prevent

the abnormal rise of AC input voltage. Line filters will provide filtering of electrical noises

of DC supply given to the SMPS.

Page No : 49


50/99


Block diagram of Power supply

PWER SUPPLY WIRING DIAGRAM

Page No : 50


51/99


Block diagram of psu of LDA75f

Page No : 51


52/99


component layout of LDA

Page No : 52


53/99


Ckt of psu LDC 30F

Page No : 53


54/99


component layout of lLDC 30f

This power supply unit is to work with 240V AC from MAINS. If this voltage goes below

155V AC, then the input will be cut off and it has to reach 175V AC to become normal. If

the AC input goes above 290V AC, then it will be cut off. Whenever AC is cut off due to

high or low level, then the 110V DC input voltage from Battery is to be connected. If this

Page No : 54


55/99


voltage goes below 80V DC, then it has to reach 95V DC to become normal. If it goes to

140V DC and above it will be cut off.

5.5.4.3 Functional Description of LDA75FThe DC input voltage is provided through Molex connector at the line and neutral points.

A 3Amps fuse isolates the power, which is filtered by spike noise suppression capacitor

C11. A damper discharge resistance bleeder for this capacitor is formed by resistor

network. The leakage and mutually inductive coupled input is fed to the rectifier bridge.

The Negative output is AC Grounded to flame grounded before feeding through inrush

limiting thermistor to tank capacitors. A LC filter combination will filter the rectified output

to feed a steady current into primary of transformer.

The primary winding of transformer are current switched by MOSFET TR31 at 140 KHz

to generate an average input current of 3.3 Amps at 200v AC. Auxiliary winding pin

provide for soft start control with capacitor. The PWM (Pulse Width Modulation) control

has pulse modulated between primary winding of the transformer. The output terminals

of the transformer operate a common cathode dual diode in the feed forward mode

through inductances. The output is RC damped and LC filtered. Any over/under shoots

are damped by bleeder resistor network. The output voltage is crowbar clamped with

zener diode and optically coupled.

The voltage control is affected by programmable IC, which has comparator resistors

network for output setting. The Positive/Negative terminals of output are floating with

respect to ground. The Output Voltage of LDA75F is +24 V DC (3.2 Amps).

5.5.4.4 Functional Description of LDC30F

The DC input voltage is provided through Molex connector at the line and neutral points.

A 3Amps fuse isolates the power, which is filtered by spike noise suppression capacitorC11. A damper discharge resistance bleeder for this capacitor is formed by resistor

network. The leakage and mutually inductive coupled input is fed to the rectifier bridge.

The Negative output is AC Grounded to flame grounded before feeding through inrush

limiting thermistor to tank capacitors. A LC filter combination will filter the rectified output

to feed a steady current into primary of transformer.

Page No : 55


56/99


The primary winding of transformer are current switched by MOSFET TR31 at 140 KHz

to generate an average input current of 1.3 Amps at 200v AC. Auxiliary winding pin

provide for soft start control with capacitor. The PWM (Pulse Width Modulation) controlhas pulse modulated between primary winding of the transformer. The output terminals

of the transformer operate a common cathode dual diode in the feed forward mode

through inductances. The output is RC damped and LC filtered. Any over/under shoots

are damped by bleeder resistor network. The output voltage is crowbar clamped with

zener diode and optically coupled.

The voltage control is affected by programmable IC, which has comparator resistors

network for output setting. The Positive/Negative terminals of output are floating withrespect to ground. The output Voltage of LDC30F is +5V (3.0 Amps), +12V(1.2Amps)

and 12V(0.3 Amps).

5.5.4.5 Over current Protection

Over current protection circuit is built-in to be operated over 120% of the rated current.

This function works to protect against short circuit and over current condition, which is less

than 20 seconds, when cause of activation of over current protection is removed, theoutput will be automatically recovered.

Page No : 56


57/99


Supervisory 1 OF 2

Supervisory 2 OF 2

Page No : 57


58/99


PCB LAYOUT OF SUPERVISORY

5.5.4.6 Over Voltage Protection

Over Voltage Protection is builtin and will be operated at 290 of the rated input Voltage.

When this function operates, input should be shut off. Output Voltage will be recovered

Page No : 58


59/99


whenever the input supply becomes Normal.

5.5.4.7 Fold Back Characteristics

INPUT Pick up Drop off

A.C Input Voltage

(High Range)

270V AC 290V AC

A.C Input Voltage

(Lower range)

155V AC 135V AC

Hysterisis: 20 V AC for both Higher and Lower range.The output voltages are as follows:

1. Logic Chassis

+24 v DC with respect to GND

2. Modem

+12V DC

-12V DC

+5V DC with respect to GND

3. Contactors

24V DC with respect to GND

4. Interface Cards

+12V DC with respect to GND

5.5.6.0 Contactors / Relays

The Contactors are used to activate the field devices such as Circuit breakers, Interruptors,

Transformer TAP positions and Autoreclosure lockouts. The rating of these contactors is

as follows

Make - C & S

Page No : 59


60/99


Coil voltage - 24V DC

Contactor rating - 10A

No. Of contacts for CB / BM - 3 NO + I NC

No. Of contacts for Auto reclosure - 2 NO + 2 NC

These contactors are suitable for DIN rail mounting as well as screw mounting. DIN rail

mounting offers ease of assembly in the panels.

These are made of flame retardant thermoplastic material. These are very strong, compact

and light in weight. Mounting space is saved due to its compact design.

Enclosed contacts and shrouded terminals ensure protection against accidental touch. Due

to modular design, replacement of coil is very easy without disturbing the power

connections. Accessibility for change of coil is from the front. The terminals have self

propelling washers for easy connections, bounce free contact system and high contact

pressure makes the contactor suitable for high making and breaking currents.

The Relays are used in the Interlocking circuit and under voltage circuit.

Make : OEN / 4R Series

Type : 4R Series

No. of contacts : 3 Changeover

Coil voltage : 24V DC

Contact rating : 2A

Page No : 60


61/99


Schematic for tele command

Page No : 61


62/99


Schematic for hv cb tele command

TAP POSITION

Page No : 62


63/99


5.5.7.0 Terminal Block

Terminal Block is used to interconnect the field cables and RTU internal cables to

perform the control and supervisory operation at the field. Interconnection between RTU

and field terminal block is done in the switching stations to collect the Status / Alarms and

control the Field equipment. The RTU terminal block section is designed in such a way

that separate terminal sections are arranged for Tele commands, Tele signals and

Telemetry.

Note : Please Refer Annexure I & II for Terminal Block Connection Details.

5.6.0 DESCRIPTION OF TELEMETRY SYSTEM AT TSS

5.6.1 Under-voltage Tripping of Bridging Interrupters

Page No : 63


64/99


This scheme is applicable only under extended feed condition. The arrangement is such

that the bridging interrupters at SP can be closed only when OHE is dead on one side of

neutral section. The under voltage scheme becomes operative only after the bridging

interrupter is closed. When the undervoltage scheme is in active condition and if OHEvoltage goes below the set level, then the bridging interrupter will be tripped by the under

voltage circuit. The logic program is designed such that if both the catenaries are low as

per the set value then the respective Bridging BM open command will be executed at

RTU level.

5.6.2 Scheme of Telemetry at SP

The arrangement is such that a Power Meter is used to measure the voltage of either up

line or down line. In case of failure of any one line, the Power Meter will be connected to

the other line through the PT changeover circuitry. The changeover will be effective

based on the settings on catenary indication circuit.

5.6.3 Scheme of Catenary Indication at SP

The arrangement is such that the catenary indication is available at the pick up voltage and

will go off at the drop off voltage selected and set by the user.

The pick up voltage selection range is available from 60% to 80% of PT voltage and drop off

voltage is available from 50% to 70% of PT voltage. The pick up and drop off settings

have been provided to take effect of induced voltage in adjacent OHE which otherwise

may give false indication of OHE live, even after section has actually been de-energised.

The arrangement of these settings programmed in the CPU card.

Page No : 64


65/99


SCHEME OF TELEMETRY AT TSS

5.6.4 Closing of Bridging Interrupter

When OHE is dead on one side of SP, then the bridging interrupter can be closed. This is

Page No : 65


66/99


achieved for BM1 as given below. One end to close command contactor (NT) coil is

permanently connected with +24V and the other end is controlled by a command driven

by a Digital output module. The respective output of the Digital output module is

programmed to give command when any one of the catenary values becomes low whichis sensed from the respective Transducer connected to the Analog input module.

5.6.5 Under voltage Tripping of Interrupter

When under voltage circuit is in active condition, if OHE voltage becomes low below the set

level due to any fault, then the bridging interrupter is to be tripped.

To achieve this function, one end of the trip command contactor (FT) coil is connected +24V

DC, and the other end is connected to the Digital output module. Whenever both theadjacent catenaries are going low then the respective Digital output channel will enable

the FT coil to trip the Bridging BM.

Note : The Software is designed such a way that the bridging interruptors can be

closed only when the section on one side of neutral section is dead and the under

voltage circuit become operative only after the bridging interrupter is closed.

5.6.6 Sequence of operations of under voltage Tripping

1. When OHE voltage is available on both sides of SP, then the close command should

not be executed.

2. When OHE is dead in any one side of the SP (i.e. PT1 or PT2), the operator will be able

to close the bridging interrupter by energizing NT coil.

3. When both the PT fails under the feed extended condition, then the respective Digital

output module will initiate the command to trip the Bridging BM without Operators action.

Page No : 66


67/99


Hardware Schematic

Page No : 67


68/99


Hardware schematic

5.6.7 Catenary Voltage Sensing at TSS

The secondary of 25 KV / 100V PT is fed to the catenary indicator, under voltage

tripping and telemetry circuit. This voltage is stepped down by the Transformer,

rectified through a bridge rectifier and filtered of transients with capacitance

filter C. An MOV (Metal Oxide varistor) is provided across the input to act as

surge arrestor.

For catenary indication, 2 nos of 8 way dip switches SW1 and SW2 are provided for

Page No : 68


69/99


selecting pick-up (high level) and drop off (low level) voltage. The respective setting

range will be as follows :

Drop off : 48% to 70% (12 KV to 17.5 KV = 48V to 70V)

Pick up : 60% to 80% (15 KV to 20 KV = 60V to 80V)

The Dip switch settings will be in steps of 1 KV.

WARNING

IT IS TO BE ENSURED THAT THE DROP OFF VOLTAGE SETTING IS ALWAYS

LESSER THAN PICK-UP VOLTAGE SETTING FOR PROPER OPERATION OF

SCHEME

5.6.8 Scheme of Telemetry at TSS

The arrangement is such that a POWER METER is used to measure the voltage of either

up line or down line. In case of failure of any one line, the Transducer will be connected

to the other line through the PT changeover circuitry. The changeover will be effective

based on the settings on catenary indication circuit.

5.6.9 Auto Re-Closing scheme at TSS

In case of tripping of the feeder circuit breaker on fault at TSS, a single shot auto-reclosing

scheme re-closes that breaker automatically only once after a pre-set time delay. In the

event of any fault on OHE presisting the feeder circiut breaker trips again and and

autoreclosing scheme gets automatically locked out to prevent reclosing of the breaker a

second time. The locked out condition is telesignalled to RCC. The operator releases the

locked-out condition when a telecommand is initiated through the keyboard console.

5.6.10 Field Wiring

Page No : 69


70/99


Interconnection between RTU and field terminal block is done in the switching stations to

collect the Status / Alarms and control the Field equipment. The RTU terminal block

section is designed in such a way that separates terminal sections are arranged for Tele

commands, Tele signals and Telemetry.

Field termination cables are used with different thickness to meet the current carrying

capacity of the field equipment. Different color cables are used for easy identification of

the signals in the field. Cable terminations are numbered using the ferrules for the

traceability of the signals. Signal cables, Power cables and Communication cables are

routed in different PVC pipes from RTU to field terminal block.

Auto reclosing

CHAPTER 6

Page No : 70


71/99


6.0 MAINTENANCE OF SCADA SYSTEM

6.1 Maintenance philosophy

In the event of failure of the system, it is recommended to identify the faulty printed circuit

card and replace the card with a working card. The recommendation is based on the

complexity of trouble shooting and technology used for mounting of component as

explained below:

1. The system is based on the microcontroller technology where almost every

component has a very high level of integration. The components perform multiple

functions, as the level of integration is high.

Therefore, the component has to be tested for all its intended functions to

conclude whether it is faulty. The testing engineer should know each and every

function of the component under test and the testing methods. Hence, component

level troubleshooting needs a specialist with special tools.

2. The components are soldered to the Printed circuit card with surface

mounting technology. Removal of faulty components from the card and soldering of

a new component on to it also needs a skilled person with special and expensive

tools. These tools are generally used only in a production centre.

Maintenance of SCADA system may be classified into two as preventive and corrective

maintenance. Preventive maintenance is to reduce the number of failures and corrective

maintenance to put back the failed system into operation.

6.2 RTU Power Supply Unit

1. Switch off the RTU and check the Power Supply Gently for any loose contact if so tight the same.

2. Switch On Both AC & DC Supply. Check AC to DC Changeover during the violation of set limit for

input voltage. Also Check DC to AC Changeover and observe the AC Fail & DC low indication onRTU.

3. During Changeover observe any disturbance in CPU Module.

4. To Measure the Ripple Voltage in D.C

Page No : 71


72/99


5. Measure the Output Voltage of RTU power Supply of MCB and ensure that the deviation is with in

the limit as indicated in the below. If any voltage falls beyond its limit then replace the related

Module.

Input Limit

240V AC ( 155 to 290 V)

110 V DC ( 100 to 130 V)

+24V DC (+/- 2 VDC)

+5 V DC (+ 1 V / - 0.1VDC)

+12 V DC (+/- 1 VDC)

-12 V DC (+/ - 1 VDC)

6.3 UPS SYSTEM

The UPS System is conservatively designed. It is completely static with all advanced

digital circuits. This system will provide many years of trouble-free service with minimum

maintenance. However a regular periodic maintenance program should be followed.

Table given below provides the schedule maintenance procedure in detail.

WARNING

HIGH VOLTAGE IS USED IN THE OPERATION OF THE SYSTEM. HENCE EXTREME CARE

SHOULD BE TAKEN WHEN PERFORMING MAINTENANCE TASK OF TROUBLE SHOOTING

THIS SYSTEM, TO PREVENT ACCIDENTAL ELECTRIC SHOCK

Page No : 72


73/99


TABLE - 1

6.4 TABLE OF PERIODIC INSPECTION AND MAINTENANCE

Sl No ITEMS INSPECTION PERIOD PROCEDURE

1 Ventilation

& opening

Daily Daily Check that intake and exhaust air

openings are not obstructed.

2 Chassis

Assemblies

Weekly Weekly Remove dust & foreign particles within

& Battery the chassis & battery bank

using compressed air or blower. Check

mounting bolts and terminals for

looseness, tighten them, keep the

battery terminals clean.

3 Cabinet 3 Months 3 Months Inspect the transformers, chokes for

evidence of heating, damaged

insulation, loose mounting of screws.

Correct any malfunctioning before

operating the unit. Tighten any loose

screws or nuts, clean electrical

contacts with a cloth dampened with

carbon tetrachloride. Do not use

cleaning solvent on electrical contacts.

Replace if found defective.

4 Controls 3 Months 3 Months Controls 3 Months Check all indicator

lamps

5 Controls 6 Months 6 Months Check all the controls for operability.

Check the operation of meters.

Replace if any damage or mal-

functioning is observed.

6 Controls 12 Months 12 Months Check the cable for input and output

power and internal wiring to

components. Check for cracks or

broken insulation. Replace as

indicated.

7 12 Months 12 Months Inspect the general conditions of

PCBs. Check the components for

Page No : 73


74/99


evidence of over heating, cracks

orpeeling. Repair or replace board, if

necessary.

8 12 Months 12 Months Inspect diodes and silicon Controlled

rectifiers and their heat dissipators for

loose mounting or defective electrical

connections. Tighten screws and nuts.

9 12 Months 12 Months Inspect PCB, sockets for loose

components electrical connections.

Tighten the mounting screws & replace

defective sockets, if any.

10 12 Months 12 Months Inspect terminal boards for breakage or

dry joints. Replace if necessary thedefective TB. Tighten mounting screws

if necessary.

11 Inspect the electric wiring for broken

solder connections or peeled insulation

and general deterioration. Repair or

replace wiring. Use carbon

tetrachloride in well ventilated areas.

Do not breathe fumes.

6.5 FAULT FINDING AND RECTIFICATION

When replacing the components, observe the following :

Page No : 74

CAUTION

FUSE REPLACEMENT MUST BE MADE ONLY WITH TYPES SPECIFIED IN THE

PARTS LIST


75/99


1. When soldering avoid excessive heat which may damage associated

components.

2. Be careful while making all soldering joints, as a poorly soldered joint can

cause further trouble and is one of the most difficult faults to locate.3. Do not drop drips of solder or hardware into the chassis.

4. Do not damage leads of other components by pushing or them aside.

5. Maintain a log of all repairs and adjustments. Comprehensive notes and an

accurate log, make it possible to reverse the procedure or to facilitate the

communications regarding repair procedure.

6. When detaching wires from components, mark the wire with tape to ensure

correct re-wiring.

7. Always place the component in the exact position occupied original.8. Whenever one or more components have been replaced, testing and

readjustment of appropriate circuit is necessary.

6.6 TESTING EQUIPMENT REQUIREMENT

Whenever it becomes necessary to replace any of the components in the UPS, re-

adjustment of the appropriate circuits may be necessary. Familiarity with the Systems

and judgement must be exercised when determining, which component effect re-

adjustment. Following Table lists the test equipment required for reforming adjustment

servicing :

6.7 TEST EQUIPMENT

EQUIPMENT WITH MODEL / TYPE QTY Mfr

Oscilloscope with Dual Channel 1 no. APLAB

Page No : 75


76/99


Voltage Probes into 10 Model 2 nos APLAB

Digital Multimeter Type 1 no. NIL

Distortion Meter 1 no. APLAB

Decade Resistance 1 no. APLAB

Card Servicing Unit 1 no. Numeric

CHAPTER 7

7.0 RTU TROUBLE SHOOTING PROCEDURE

7.1 TELESIGNAL

The problems in the field equipment can be classified into three types

a). Telecommand (BM/CB) not operating

Page No : 76


77/99


b). Telesignal (BM/CB status and Alarms) not coming

c). Telemetry (Voltage/Current) not received from the post

1. Check the 110 V DC at respective RTU terminal block as per the Field

Termination Chart or the Wiring Diagram where this voltage comes from the field

devices. If there is no voltage at RTU terminal block then the problem is not with

RTU. Check the field equipment side and the cable continuity. If the voltage is

available then follow the next step.

2. Replace the respective DIM d as per the wiring diagram or Field termination

Chart and check respective LED indication at DIM card.

.

7.2 TELEMETRY

1. Check the respective PT/CT secondary at RTU terminal block as per the wiring diagram

or the Field Termination Chart.

2. If there is no required minimum Voltage or Current then the problem is not in the RTU

side. Check the field devices and the interconnecting cables.

Page No : 77


78/99


3. Check the POWER METER input Voltage or Current. If there is no Voltage or Current

then check the cable between the RTU terminal block and Power Meter input.

4. Check the power Meyer output, if there is no serial output with respect to input voltage

or current then replace the Power meter check the value at RCC.

5. Replace the flat cable and check the value at RCC.

7.3 TELE COMMAND

Page No : 78


79/99


1. Check the Selected channel enable and indication is proper. If channel does not

glow, the problem may be resolved by changing the following items one after

another.

Change the DOM card.

a. If the problem is not resolved, then change the cable termination.

b. If the channel glows, then check the contactor operates. Otherwise check for 24

V DC across coil; if voltage is available, then replace the contactor.

c. If the coil voltage is not available, then check the 24 V DC Supply at terminal

block TB1.

d. If the contactor operates, then check the NO contact for input and output

voltages; if available, then problem is in the Field devices side.

e. If the 110 V DC is not available on the input side then the problem is again on

the railway terminal board. If voltage is available on the input side but not

available on the output side then change the contactor.

7.4 Power Supply Unit :

( If output voltages are not coming)

Page No : 79


80/99


1. Check the input voltage of the LDA (OR) LDC Module at Molex connector CN1. (if the

Voltage is available go to step-7

2. If the Input Voltage is not present ,Check the output voltage Supervisory Module

at Molex Connector JP4.

3. If the supervisory card input voltage is not present , then check the A/C input voltage at

connector JP1.

4. If the A/c Input voltage is not present then check the MCB-1 input & Output. ( The

Voltage Must be less than 290v and greater than 155v )

5. If the D/C Input voltage is not present then check the fuse (F3) and MCB-2 Input and

Output.( The Voltage must be less than 140v and greater than 90v DC)

6. If the Fuse (F3) blown up, then replace the 2A fuse (20mm)

7. If the the LDA /LDC input voltage is present at connector CN1 ,

Then check the module fuse (F1).

8. Check the Output voltage at connector (JP3) for +5v/+12v/-12v.

( Check the Molex pin connection and crimping )

9. Check the Output voltage at Connector (JP5) for 24v/DC.

( Check the Molex pin connection and crimping )

7.5 TROUBLESHOOTING CHART FOR UPS

NO FAULT SYSTEM REASON REMARKS1 System working on mains but

not working on batteryBattery fuse blown Check the battery polarity and

replace the fuse.

Page No : 80


81/99


2 Charger not coming ON whenswitched ON

Mains input fuse failed ormains MCB tripped

Check the rating of the fuse.If itis of lower rating, replace withproper fuse.

Input fuse of the chargerblown

Check the battery polarity and

connection. Correct if it iswrong. Replace the fuse

Contactor not coming ON Check the input supply. If

present, check the wiring of

Contactor & rectify it. Check the

coil. Replace if faulty.3 Mains Input Fuse Failure Very low input

voltageProvide rated input voltage.

Input cable capacityis less

Replace the wiring with correctly

rated cable.

Loose contact in theinput wiring

Tighten the connections.

4 DC Under Voltage indica tioncomes on even when DCvoltage is nominal and theInverter Trips.

Inverter Fuse blown Replace the fuse

5 DC under Voltage comesimmediately after the Inverter isswitched on (NO LOAD) andInverter Trips

Mains input cable is lessthan rated capacity

Replace the cable from D.B.

with correctly rated capacity.

6 DC under voltage indicationcomes on while working onBattery (in the absence ofmains) and Inverter trips.

Battery is dischargedBattery cable of lessercapacity less than ratedLoad surge.

Keep the battery in charged

condition Replace the cable with

a correctly rated cable.7 Overload Indication comes on

while the load is switched ONVoltage reaches 230V Switch on the loads one by

one .

7.6 Trouble Shooting Procedure for Modem :

Page No : 81


82/99


Team link SCADA modem is designed in such a way that it requires just plug in the modem

for normal operation. In case the polling operation does not take place the following points

will facilitate the first line maintenance of the card.

Check for correct ness of the jumper setting.

A) Ensure all the modems involved are powered on.

1. Make sure that the power card is kept correctly, 230v, AC in case of master modem,

DC voltage in case of Slave modem.

2. Verify that the modem is powered on by observing the MR led glowing on the front

panel.

B) Ensure that the modem to RTU /MTU connections are proper.

1. Verify that the RTU/ MTU signals are coming properly at the RS-232C cable coming

from RTU/ MTU. Verify the following signals are in the range of 3v to 15v at the RS-

232 C Cable coming from RTU/ MTU.

-Transmit Data (TXD) at Pin No. 2 of RS-232C cable coming from RTU/

MTU .

- Request to send (RTS) at Pin No. 4 of RS-232C cable coming from RTU/

MTU

- If the voltages are not present then check for the continuity of the cable.

- If the signals are present ensure that the RS-232 Cable is mating properly

with corresponding Connector of the modem end.

C) Ensure that the Modem to Modem connection are proper.

Page No : 82


83/99


1. Ensure that the connection from the Master modem are properly connected

to Slave modems.

2. Check the continuity of the Communication Line.

D). Ensure that the Modems are operating properly

Check for MR led on the modem, if MR is glowing put the Analog loop back switch in to

On position and send data and check, if data is not correct modem could be faulty. If

data is correct then connect the modem with any one of the Remote modems and ask

them to put in to Digital Loop back switch in to ON position, send data and receive,

check for correctness. If the data is not correct check for communication cable. If thedata is correct then,

Start the polling cycle and observe the following

1. Master Modem:

- CTS led should always be glowing.

- TD and RD led should blink

2) Slave Modem:- DCD led should glow, if not check for the communication cable.

- RD led should blink, if not check the following

- Check the RS-232 cable from RTU.

- Check whether RTU is responding for the polling.

If still the problem persists then replace the modem .

7.7 TELESIGNAL FAULT FINDING CHART

Page No : 83


84/99


Page No : 84

CHECK THE RTU TERMINAL BLOCK FOR110V FOR FIELD INPUT

110V AT

TB

NOT A RC PROBLEM

REPLACE DIM

DIM LED

IS

GLOWING

REPLACE DIM

MODULE

NO

YES

YES

YES

NO

NO

PROBLEM SOLVED


85/99


7.8 TELEMETRY FAULT FINDIING CHART

Page No : 85

CHECK THE RTU TERMINAL BLOCK FOR

FIELD INPUT

FIELD

INPUT NOT A RCPROBLEM

CHECK FUSE &CABLE FOUND

FAULTYREPLACE IT.

REPLACE THE

Power Meter

NO

YES

YES

YES

NO

NO

CHECKPOWER Meter

INPUT &

Supply

CHECK

POWER

METER

OUTPUT

PROBLEM SOLVED


86/99


7.9 TELECOMMAND FAULT FINDING CHART

8.0 DOWNLOADING PROGRAM TO RTU MICROCONTROLLER:

Procedure:

Page No : 86

CHECK THE RESPECTIVE CHANNEL LED IS

ENABLED

LED

ENABLE

D

REPLACE DOTMODULE

CHECK THEO/P

VOLTAGE

AT TB

PROBLEM SOLVED

NO

YES

YES

YES NOCONTACTOR IS

OPERATING

CHECKVOLTAGE

ACROSS COIL

REPLACE THE CABLE

YES

REPLACE THECONTACTOR

CHECK THE WIRING FOR LOSSE

CONNECTION. ANY DAMAGE REPLACE IT

NO

NO


87/99


1. Set the jumper J2 of CPU to download mode. Connect the serial-port-1 of CPU tosystem serial port.

2. Software used for Download Program: C:\SCSI\BIN\SPJTERM.EXE

The preloaded SPJTERM.EXE is the programming tool of the micro controller used in theRTU.

3. After opening the program click Settings to set the communication Settings.

4. Set the parameters as shown below.

5. After setting the port parameters click port open to initialize the serial port.

Page No : 87


88/99


The window will appear as shown below.

6. Click the In System Programming in File menu.

RTU is now ready for download and the communication is now initialized with theController.

7. Set all the parameters as shown below.

Page No : 88


89/99


8.Click Full Chip Erase to clear the buffers of Micro controller.

9. Click Browse and select the .HEX file of RTU download file. The path and name of the filewill be appearing on the band HEX file to download.

10. Click Program to start the downloading.

Page No : 89


90/99


The above shown window will disappear after download is completed. Switch off the RTUand set the jumper J2 of CPU to normal position and Switch ON. RTU is now ready fornormal working.

9.0 Download Parameters to RTU

Procedure :

1. Software used for Download Program: C:\ADRA\MERITDIAG.EXE

The preloaded MERITDIAG.EXE is the downloading tool of the Merit RTU.

2. Click Baud Rate and set the speed of serial communication. Default-600.

Page No : 90


91/99


3. Click Comm Port and set the serial port to witch the RTU is connected. Default-Comm 1.

Page No : 91


92/99


4.Click Setup and set the parameters to download to the RTU.

5. After setting the parameters click Download & Update button to set the RTU parameters.

Note: Before Clicking Download & Update make sure that the Digital Input Modules and the

Digital Output Modules selected must match the actual modules inserted in the RTU. While

setting the slot for Digital Output modules the RTU will start from the number of digital input

modules and the slots will be allocated automatically after the Digital Input modules. If amismatch occurs while download, the modules will gets damaged and may cause serious

damages to the whole unit.

Setting of Analog Input Channels:

SSP - 0

SP - 2

Page No : 92


93/99


TSS/FP - 8

Now the RTU is ready for communication and operation. All the DI, DO and AI channels can

be checked through MERITDIAG.

6. The RTU running memory buffers can be cleared by clicking Reset RTU Database.

7. The RTU real time clock can be set by clicking Set RTU Time.

9.1 Testing the various parameters using MERITDIAG:

1. Click Scan Digital Inputs. The window will appear as shown below. All the DI channels

can be tested and viewed.

Page No : 93


94/99


2. Click Scan Output Status. The window will appear as shown below. All the DO

channels can be tested and viewed

Testing Procedure: Click on the channel to be tested.

Press space bar once. On will appear.

Page No : 94


95/99


Click on Set Outputs. The particular channel will be made On by RTU.

Press space bar again. On will get disappeared.

Click on Set Outputs. The particular channel will be made off by RTU.

Press space bar twice. Timd will appear.

Click on Set Outputs. The particular channel will be made On and Off by RTU.

3. Click Scan Analog Inputs. The window will appear as shown below. Analog count ,

percentage and unit against all the AI channels can be viewed here.

Page No : 95


96/99


LIST OF ABBREVIATIONS

Page No : 96


97/99


A Amperes

AC Alternating Current

AIT Analog Input Termination

BM Bridging interrupter

CAN Controller Area Network

CB Circuit Breaker

CD Carrier Detect

CP Communication Processor

CPU Central Processor Unit

CT Current Transformer

CTA Cable Termination Module

DDC Bus Coupler Module

DC Direct Current

DIFM Digital Input Functional Module

DIT Digital Input Termination

DIP Dual-In-line Package

DMA Direct Memory Access

DOT Digital Output Termination

DRAM Dynamic Random Access Memory

EMF Electro Motive Force

EPROM Electrically Programmable Read Only Memory

FP Feeding Post

FSK Frequency Shift Keying

Hz Hertz

IBM PC International Business Machines Personal Computer

IC Integrated CircuitIDE Integrated Drive Electronics

IRQ Interrupt Request

LAN Local Area Network

LC Logic Chassis

Page No : 97


98/99


LED Light Emitting Diode

MB Mega Byte

MOBI Mod Bus Interface

MODEM Modulator Demodulator

MOSFET Metal Oxide Semiconductor Field Effect Transistor

MOV Metal Oxide Varistor

NC Normally Closed

NO Normally Open

NVRAM Non-volatile Read Only Memory

OHE Overhead Equipment

PC Personal Computer

PCB Printed Circuit Board

PCS Peripheral Chip Select

POST Power ON Self Test

PWM Pulse Width Modulation

RCC Remote Control Centre

RD Receive Data

RF Radio Frequency

RLA Relay

ROM Read Only Memory

RTS Request to Send

RTU Remote Terminal Unit

SCADA Supervisory Control and Data Acquisition

SCR Silicon Controlled Rectifier

SEB State Electricity Board

SH ShuntSIMM Single-in-line Memory Module

SP Sectioning and Paralleling Post

SSP Sub-sectioning and Paralleling Post

SVGA Super Video Graphic Accelerator

SW Switch

Page No : 98


99/99


TB Terminal Block

TCO Timer Counter Output

TD Transmit Data

TPC Traction Power ControlTSS Traction Sub-station

UPS Uninterrupted Power Supply

V Volts

VGA Video Graphic Accelerator

WAN Wide Area Network

scada hardware manual

Documents