instructions tm 138gpu 160 kva self propelled tm-138 chapter 1 operation section 2 - description and...

INSTRUCTIONS

OPERATIdN - MAINTbNANCE - OVERHAUL

TM 138

GROUND POWER UNIT - SELF PROPELLED 400 CYCLE 115/200 VOLT 160 KVA

with CUMMINS DIESEL ENGINE MODEL NT-310

(PRII$E MOVER)

SPECS 4982

MODEL 16OC17S

MOTOR GENERATOR DIVISION HOBART BROTHERS COMPANY

TROY, OHIO 45373 U.S.A.

SAFETY INSTRUCTIONS AND WARNINGS FOR ELECTRICAL POWER EQUIPMENT

ELECTRIC SHOCK can kill. Do not touch live electrical parts.

FUMES AND GASES can be fire and health hazards. Ventilate all fumes and exhaust gases to the outside.

ELECTRIC ARC FLASH can injure eyes, burn skin, cause equipment damage, and ignite combustible material. Do not

use power cables to break load and be sure tools don‘t cause short circuits.

IMPROPER PHASE CONNECTION, PARALLELING, OR USE can damage this and attached equipment.

MOVING PARTS can cause serious injury. Keep clear of moving parts.

IMPORTANT - Protect yourself and others. Read and understand all the instructions in this Operating/Instruction

A.

B.

Manual before installing, operating, or servicing this equipment. Keep this manual available for future use by all operators.

GENERAL Equipment that supplies electrical power can cause serious injury or death, or damage to other equipment or

property, if the operator does not strictly observe all safety rules and take precautionary actions. Safe practices

have developed from past experience in the use of power source equipment. Certain of the practices below apply to

engine driven equipment.

SHOCK PREVENTION

Bare conductors, or terminals in the output circuit, or ungrounded, electrically-live equipment can fatally shock a person. Have a competent electrician verify that the equipment is adequately grounded and learn what terminals

and parts are electrically HOT. Use proper safety clothing, procedures, and test equipment.

The electrical resistance of the body is decreased when wet, thus more easily permitting dangerous currents to flow

through it. When inspecting or servicing equipment, do not work in damp areas without being extremely careful.

Stand on dry rubber mat or dry wood, use insulating gloves that are effective when dampness or sweat cannot be avoided. Keep your clothing dry and never work alone.

1. Installation and Groundinq of Electrically Powered Equipment - Electrical equipment must be installed and maintained in accordance with the National Electrical Code, ANSI/NFPA 70, and other applicable codes. A power disconnect switch or circuit breaker must be located at the equipment. Check the nameplate for voltage,

frequency, and phase requirements. If only 3-phase power is available, connect any single-phase rated equipment to

only two wires of the 3-phase line. DO NOT CONNECT the equipment grounding conductor (lead) to the third live wire of the 3-phase line, as this makes the equipment frame electrically HOT, which can cause a fatal shock ---- --- ---*

Be sure to connect the grounding lead, if supplied in a power line cable, to the grounded switch box or building

ground. If not provided, use a separate grounding lead. Be certain that the current (amperage) capacity of the

grounding lead will be adequate for the worst fault current situation. Refer to the National Electrical Code ANSI/ NFPA 70 for details. Do not remove plug ground prongs. Use correct mating receptacles.

2. Output Cables and Terminals - Inspect cables often for damage to the insulation and the connectors. Replace

or repair cracked or worn cables immediately, Do not overload cables. Do not touch output terminal while equip-

ment is energized.

Instruction 910082

Nov 16182 Revised Page 1

C. FIRE AND EXPLOSION PREVENTION

Fire and explosion are caused by electrical short circuits, combustible material near engine exhaust piping, misuse

of batteries and fuel, or unsafe operating or fueling conditions.

1. Electrical Short Circuits and Overloads - Overloaded or shorted equipment can become hot enough to cause fires either by self destruction or causing nearby combustibles to ignite. Provide primary input protection to re-

move short circuited or heavily overloaded equipment from the line.

2. Battery - Batteries may explode and/or give off flammable hydrogen gas. The acid and arcing from a ruptured

battery can cause fires and additional failures. When servicing, do not smoke, causing sparking, or use open flame

near the battery.

3. Enqine Fuel - Use only approved fuel container or fueling system. Fires and explosions can occur if the fuel

tank is not grounded prior to and during fuel transfer. Shut unit DOWN before removing fuel tank cap. Do not

completely fill tank. Heat from the equipment may cause fuel expansion overflow. Remove all spilled fuel immediately including any that penetrates the unit. After cleanup, open equipment doors and blow fumes away with compressed air.

D.

E.

F.

TOXIC FUME PREVENTION Carbon Monoxide - Engine exhaust fumes can kill and cause health problems. Pipe or vent the exhaust fumes to a

suitable exhaust duct or outdoors. Never locate engine exhausts near intake ducts or air conditioners.

BODILY INJURY PREVENTION Serious injury can result from contact with fans, belts, and pulleys inside the equipment. Shut DOWN equipment

for inspection and routine maintenance. When equipment is in operation use extreme care in doing necessary troubleshooting and adjustment.

MEDICAL AND FIRST AID TREATMENT

First aid facilities and a qualified first aid person should be available for each shift for immediate treatment of all

injury victims. Electric shock victims should be checked by a physician and taken to a hospital immediately if any

abnormal signs are observed.

Call physician immediately. Seek additional assistance and use First Aid techniques recommended by American Red Cross until medical help arrives.

IF BREATHING IS DIFFICULT, give oxygen, if available, and have victim lie down. FOR ELEC-

TRICAL SHOCK, turn off power. Remove victim; if not breathing, begin artificial respiration, preferably mouth-to-mouth. If no detectable pulse, begin external heart massage. Call Emergency

Rescue Squad immediately.

G. EQUIPMENT PRECAUTIONARY LABELS

3. Service and Maintenance - This equipment must be maintained in good electrical and mechanical condition

to avoid hazards stemming from disrepair. Report any equipment defect or safety hazard to your supervisor and

discontinue use of the equipment until its safety has been assured. Repairs should be made by qualified personnel only. Shut OFF all power at the disconnecting switch or line breaker before inspecting or servicing the equipment. Lock switch OPEN (or remove line fuses) so that power cannot be turned ON accidentally. Disconnect power to equipment if it is out of service. If troubleshooting must be done with the unit energized, have present another per-

son trained in turning off the equipment and providing or calling for first aid.

EMERGENCY FIRST AID

Inspect all precautionary labels on the equipment monthly. Order and replace all labels that cannot be easily read.

Page 2 Instruction 910082 Revised Nov 16182

FOBART e

QD

$‘lOT& GENERATOR DIVISION f 2

z HOBART BROTHERS COMPANY

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GPU 160 KVA SELF PROPELLED TM-138

CHAPTER 1 DESCRIPTION AND OPERATION

SECTION 1 - INTRODUCTION

1. General

A. Scope

The purpose of these instructions is to inform the operator of the characteristics, capabilities, and limitations of this equipment and to assist maintenance personnel in installation, trouble shooting, and maintenance.

Best results will be obtained ONLY if the personnel responsible for this equipment have access to, and are familiar with, these instructions.

2. Supplementary Manuals

A. Supplementary manuals supplied with these instructions:

(1) The regulated static exciter manual covers theory of operation, line drop compensation, and maintenance of the static voltage regulator.

(2) Engine operator's manual outlines operation, inspection, and maintenance for the Cummins diesel engine, Model NT-310.

(3) Parts lists are provided for the power unit and the Cummins diesel

engine.

, Additional copies of the ground power unit manual and voltage regulator manual are available by writing to:


TROY, OHIO 45373

U.S.A.

giving the SPECS, SERIAL, and MODEL numbers of your equipment and the number of copies needed.

3. Terminology

A. Space relationships - "right", "left", etc., are determined by the driver's position.

B. The engine operator's manual will be abbreviated EOM, generally followed by a reference to the subject heading of the EOM.

The Ground Power Unit will be abbreviated to read GPU.

Sept 20168

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Page 1


CHAPTER 1 OPERATION

SECTION 2 - DESCRIPTION AND DATA

1. Unit Assemblv

A. Description

The mounting frame carries a Cummins Model NT-310 diesel engine mounted at its forward end. A 400 cycle 160 KVA generator is attached to the flywheel housing of the engine. One end of the ac generator armature shaft is connected by a flexible coupling to the engine flywheel, the other end of the armature shaft is coupled to a 3 speed transmission and clutch. The rear axle reducing gears are connected to the transmission with a short drive shaft. The rear axle is mounted to the frame with leaf springs. A front axle with leaf springs and steering knuckles is hung under the frame at the engine end. The four wheels use 7:50 x 16 high pressure tires. Bumpers, fenders, running boards, a hood with side doors, and a seat are provided. The operators controls include the steering gear, clutch, brake, and accelerator pedals, a handbrake and a combined engine-generator control box. The hydraulic brakes apply at all four wheels.

2. Detailed Description of Major Components

A. Generator

(1) The generator is a revolving field, 3 phase alternating current generator. The rotor consists of the exciter armature, main generator revolving field, and a set of diodes to supply the excitation to the fields. The rotor also incorporates a fan for drawing cooling air through the windings. This air is discharged at the coupling end through a duct which carries the heated air outside the canopy. The output voltage is controlled by a transistorized voltage regulator. The generator output leads connect to two output receptacles in the output cable box for connecting the aircraft power supply cable.

B. Speed Regulation System

(1) This system includes a hydraulic governor (operation details in the

Cummins Engine Manual) and a foot throttle lock. The governor is so connected that when the engine speed is less than 1714 RPM and the GEN-DRIVE switch is in DRIVE position, the engine speed is controlled by the foot throttle even though the governor is in operation. For operation as a power unit, the GEN-DRIVE switch must be in GEN position and the foot throttle fully depressed, after which,

the governor will maintain constant speed.

Sept 20/68

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FOBART e f

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;YOTOR GENERATOR DIVISION

2 HOBART BRCITHERS COMPANY “c B . B ,+**


- C. Static Voltage Regulator

(1) The voltage regulator serves three purposes:

(a) It provides excitation voltage for the generator revolving fields.

(b) It provides 1% voltage regulation for all loads up to 100% of rated load at rated power factor. Regulation is achieved by varying the revolving field power of the alternator as required by load conditions. The maximum continuous rating of the regu-

lated static exciter is 150 volts dc.

(c) It provides line drop compensation by increasing the generator voltage in proportion to load increases to compensate for voltage drop in the cables to the aircraft.

D. Control Box

(1) The control box provides controls and instruments for both the engine and generator. The engine controls and instruments are mounted on the left side of the panel. When the panel is mounted on the GPLJ, the engine controls and instruments are directly forward of the operators seat. The generator output controls are mounted on the extreme right side of the panel. The generator instruments are mounted in the front panel of a sliding tray located between the engine and generator controls. Directly below the generator instrument tray is a second tray which contains the protective relays. Below the relay tray a third sliding tray contains the voltage regulator.

E. OutputCable Connections

(1) ,The output cables connect to receptacles located in the cable stor-

age box behind the drivers seat.

(2) The cable storage box extends behind the drivers seat and is provided with safety switches so arranged that the cables must be in the box and plugged in before the GPU may be driven.

F. Tabulated Data

(1) Performance

(a) Engine

Type ....................................... Diesel Make .............. . ........................ Cummins Model ...................................... NT-310 No. of Cylinders ........................... 6 HP ......................................... 275 @ 1714 RPM Displacement ............................... 855 cu. in.

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[MOTOR GENERATOR DIVISION

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*c 8 4. B.11


(b) Power Generator

Volts ................................. 115/200

Amps .................................. 462 KVA ................................... 160

KW .................................... 128

PF .................................... 0.8 Phase ................................. 3

Cycles ................................ 400

RPM ................................... 1714 Duty Cycle ............................ 100%

(c) Capacities

Fuel Tank ............................. 100 gals. Cooling System (approximate) .......... 15 gals.

Crankcase (w/filters) ................. 10-l/2 gals.

Sept 20168

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Page 3

GENERATOR DIVISION HOBART BROTHERS COMPANY


(3) The preheater toggle switch (3) turns the preheater glow plug "ON" or "OFF" as required. When this switch is "ON", the preheater pilot light should also be "ON".

(4) The cold weather starting pump (4) is used with the preheat toggle switch to provide a cold weather starting system.

(5) The 'permissive start switch (5) by-passes the lube oil pressure safety switch until the oil pressure reaches 12 psi or more.

(6) The engine start switch (6), a pushbutton type, when pushed closes the circuit to the starting motor solenoid.

(7) The lube oil pressure gage (7) indicates the pressure of lubricating oil and should indicate approximately 30-50 psi during operation.

(8) The fuel oil pressure gage (8) will register only while the pre-

heater primer pump is in operation. Maintain 80-100 psi while crank- ing engine. This gage indicates pressure only during the cold weather starting procedure.

(9) The water temperature gage (9) registers the temperature of engine coolant.

(10) The battery charging ammeter (10) indicates the rate at which the battery is being charged or discharged.

(11) The Gen-Drive switch (11) must be thrown to GEN or DRIVE, depending

upon the requirement at hand. To operate the unit as a mobile unit the switch must be in DRIVE position and the output cable plugs must be inserted in their respective micro-switch boxes. To operate as a power unit, the gearshift must be in neutral and the GEN-DRIVE switch must be thrown to GEN. A micro-switch on the gearshift will shut the engine down if the unit is in gear while the GEN-DRIVE switch is in GEN.

(12) The engine hour meter (12) registers the accumulated number of hours the engine has been in operation.

(13) The panel light switch (13) turns the panel lights and marker lights "ON" or "OFF" as required.

(14) The headlight switch (14) turns the headlights, panel lights, marker lights "ON" or "OFF" as required.

(15) The 20A fuses (15) protect the headlight and panel light circuit.

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Page 2

(16) The fuel gage (16) indicates fuel level in the tank.

Sept 20/68



E. Relay Tray (See Figure 5)

1. Overvoltage Relay 6. Overload Relay

2. Undervoltage Relay 7. Test Bank Switch 3. Time Delay Relay 8. Resistor 100 ohm 25 watt

4. Underfrequency Relay 9. Resistor 250 ohm 100 watt

5. Plug Interlock Relay 10. Receptacle

. Figure 5 - Relay Tray

(1) If the voltage of Qny phase exceeds 130 volts line to.neutral, the

c,ontacts of the overvoltage relay (1) open, opening the load contactors.

(2) The undervoltage relay (2) contacts close when the voltage of any phase.drops below 103 volts. This starts the undervoltage timer which, after timing out, opens the load contactors.

(3) The undervoltage time delay relay (3) after being actuated by the

undervoltage relay, and after a 5-second delay, opens the load contactors.

(4) The underfrequency relay (4) actuates to open the load contactors when a condition of underfrequency (375 cycles or under), exists.

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Page 6 Sept 20168



F. Regulator Tray (See Figure 6)

(1) The regulator tray contains the static voltage regulator and is so connected that by disengaging one connector the regulator can be removed for maintenance by simply sliding the tray out of the control box.

(2) A valtage regulator rheostat is included in the regulator tray. Rotating the rheostat knob to the right (clockwise) increases the alternator voltage. Rotating the knob left (counterclockwise) will decrease the alternator voltage. The regulator will regulate the voltage as set by the rheostat.

Figure 6 - Regulator Tray

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FOBART B f

QD

;MOTOR GENERATOR DIVISION

“c z HOBART BROTHERS COMPANY

a . B A,,~*+


SECTION 4 - OPERATION

1. Preparation For Use (See engine operator's manual)

A. Servicing

(1) Inspect the unit thoroughly to be sure it is in proper working order. Check all fuel and wire connections to be certain they are secure. Tighten any loose screws, nuts, or bolts.

(2) Fill crankcase with 10-l/2 gallons of oil (see EOM).

(3) Be sure oil pan drain plug is closed.

(4) Perform all lubrication specified in lubrication section of EOM.

(5) Clean entire unit; be certain that all radiator air passages and fins are free from foreign matter.

(6) Fill the fuel tank with a good grade of fuel that is free from water and other foreign matter. Make sure the air vent to the fuel tank is open.

(7) Fill radiator to the top of the overflow tube with clean soft water. Be sure the drain cocks on the radiator and on the engine block are closed. If the unit is to be operated in freezing weather, protect

the cooling system with a suitable permanent type anti-freeze.

NOTE: The unit should be operated in as near a normal horizontal position as possible and never at a tilt greater than 15' from horizontal.

B. Preparation For Starting

(1) Make sure servicing instructions have been carried out, see paragraph A. ~~ .~~ ~~~. ~~~~~

(2) Open fuel line valve.

(3) Insert plug of 400 cycle output cable into plug box.

(4) Place gearshift lever in NEUTRAL position.

(5) Place GEN-DRIVE switch in DRIVE position.

2. Starting the Engine

A. Normal Starting

(1) Close the permissive start switch to START position and hold. The fuel valve solenoid will open the fuel valve allowing fuel to flow.

(2) While holding the permissive start switch in the START position,

press the starter pushbutton.

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Sept 20/68 Page 1

TROUBLE

Engine speed drops

excessively under load

Engine "hunts", speed

surges up and down

No voltmeter reading normal voltage into contactor

No voltmeter reading no voltage into contactor

Voltage too high,

Voltage too low, regulator rheostat will not control

Voltage oscillates

Voltage drops as load is applied

FOBART e

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gMOTOR GENERATOR DIVISION f s

2 HOBART BROTHERS COMPANY “c

B . B ,+**


POSSIBLE CAUSE

Improper governor setting

Too sensitive governor setting

GENERATOR EXCITER AND REGULATOR

Faulty voltmeter

Faulty meter selector switch

Loose connection

Rotary exciter not building up:

a> Loss of residual magnetism

b) Open in static regulator starting circuit

4 Defective revolving diodes

Open revolving fields

Excitation de-energizing relay faulty

Loose connection to Rl, R2, or R3 (see connection diagram)

Defective regulator rheostat

Defective static regulator

Defective damping circuit in regulator

Too long output cable

Line drop compensation set too low, or turned off

REMEDY

See data in governor

manual

See governor setting

in governor manual

Check, replace if required

Check switch

Repair

Remagnetize exciter field with separate 12V dc source

Repair or replace

Replace defective diode

Repair or replace

Repair or replace

Resolder connection if at rheostat, or tighten screw if at terminal strip

Replace

Repair or replace

Adjust per regulator manual

Shorten output cable

Adjust per regulator manual

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Page 2 Sept 20168

TROUBLE

Overheats

Unbalanced output


Cannot close output contactor

Contactor will not stay closed - opens up immediately


GENERATOR

POSSIBLE CAUSE

Improper ventilation

Overload

Loose connection

Short in stator

Open or shorted phase

Loose connect&on

GENERATOR CONTROLS

AC voltage too low

Loose connections or dirty contacts at "ON" button

Faulty rectifier supplying dc to contactor coil or defective 2 amp. fuse

Open contactor coil

Overvoltage relay tripped

Test Bank Switch in

wrong position

Cable interlock relay is defective

Underfrequency relay tripped

100 ohm 25 watt resistor defective

REMEDY

Provide adequate ventilation

Remove overload

Tighten connection

Replace stator

Correct open

Tighten connection

Check voltmeter

Repair or clean

Replace fuse or replace rectifier

Replace

Check for proper voltage, if okay, replace relay

Should be in OFF

position unless aircraft has no provision for 24

volts return on E and F leads

Replace relay

Check for proper frequency, if okay, replace relay

Replace

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Sept 20/68 Page 3

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ZMOTOR GENERATOR DIVISION 3 HOBART BROTHERS COMPANY

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C. Canopy

(1) Disassembly (See Figure 1)

(4

(b)

cc>

Cd)

(e>

Open doors, depress the spring loaded guide both top and bottom and disengage doors from tracks.

Remove screws from door hinges and remove the doors.

Disengage fasteners at each end of canopy top and remove the canopy top.

Remove radiator cap, disconnect clearance light wiring, remove attaching screws and remove radiator hood.

Disconnect all engine controls and all generator control wiring from the combined engine and generator control box.

Remove attaching screws and remove the floorboards.

Remove attaching screws from superstructure and from steering column brace. Lift the superstructure with hoist and remove it complete with generator control box.

ylgure 1 - Canopy Disassembly Sept 20/68



(7) Remove the pull wires and solder connector lugs to the ends of the leads.

(8) Connect the generator field leads to the diode studs.

(9) Wrap 4 to 5 turns of linen tape around the shaft to cover the leads between the exciter armature and the diode mounting plate. Coat the tape with insulation varnish.

2. 7-- ~.-

Reassemble GPU

A. Generator

(1) Tilt engine as shown in 3-1 figure 5.

(2) Lift generator with hoist and lower carefully into place on frame.

(3) Attach generator housing to engine casting, 12 screws.

(4) Insert screws through fan and flex coupling into the engine flywheel, tighten securely.

(5) Reinstall fan guard.

(6) Lift engine and remove blocks, then lower engine and generator onto frame.

(7) Secure generator to frame with six screws and tighten the bolts.

(8) Secure engine to frame with mounting screws.

(9) Remove hoist from generator housing.

B ., Transmission and Clutch

(1) Lift the transmission and clutch assembly with a hoist and lower it into place in the GPU.

CAUTION: THE TRANSMISSION MUST BE GUIDED VERY CAREFULLY WHEN LOWERING TO AVOID DAMAGE TO SURROUNDING EQUIPMENT.

(2) Use the hoist to hold the transmission in approximate position and carefully move the housing with your hands until the drive shaft splines are engaged. Secure the transmission housing to the generator housing with screws.

(3) Reassemble the clutch pedal hardware and the drive shaft universal joint.

C. Cooling System (See 3-l Figures 2 & 2A)

(1) Lift the radiator into place with hoist, attach to frame.

(2) Install fan guard and radiator shrouds.

Sept 20168

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Page 5

FOBART e s

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iMOTOR GENERATOR DIVISION HOEIART BROTHERS COMPANY

“c 2 b . a ,,I~“’


(3) Attach radiator hoses and pipes.

(4) Fill radiator with distilled or mineral free water, (approximately 15 gallons).

D. Canopy

(1) Remove radiator cap.

(2) Lift canopy with hoist and lower it carefully into place on the GPU.

(3) Install all attaching hardware on canopy and end panels.

(4) Attach and connect clearance lights.

(5) Replace the radiator cap.

(6) Install and latch canopy doors.

E. Operational Check

(1) Start the engine, (Ref. l-4, paragraph 2A).

(2) Check generator operation.

(a) Ref. 1-4, paragraph 3A.

(b) After the engine warms up and the generator output shows normal in step (a), connect 24 volt leads from engine battery or any 24 volt DC source to terminal posts E and F on the Output Terminal Plug. The system is a negative ground type, connect ground lead from battery to the GPU frame. Plug output cable into a load bank and simulate a normal load, all meters and

equipment should operate as noted in l-5, paragraph 3.

(c) If the unit does not operate normally, trouble shoot as shown in Chapter 2, Section 2.

3-2

Page 6 Sept 20168

instructions tm 138gpu 160 kva self propelled tm-138 chapter 1 operation section 2 - description and...

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