GP9-3-154                                                    TROUBLE SHOOTING

SECTION 3

LOCATION AND CORRECTION OF DIFFICULTIES ON-THE-ROAD

This section provides a check list calling the operator's attention to the troubles which are most frequently encountered on the road, and which can be quickly remedied thereby eliminating many delays.

No attempt is made to explain general operation and functions of equipment on the locomotive. For such information refer to the other sections of this manual.

300 GENERAL Safety devices automatically protect the equipment in case of the faulty operation of most any component. In general, this protection is obtained by unloading or preventing the loading of the Diesel engine so that the locomotive loses its pulling power. The locomotive can lose its power with the Diesel engine still running or stopped. An exception is a hot engine alarm which does not reduce the engine load or speed. The trouble shooting check chart, at the end of this section, pages 313-314, outlines the possible causes of trouble should the locomotive suddenly lose its power, with the Diesel engine running or stopped.

When trouble is experienced, the general location and type of difficulty is often indicated by the ringing of an alarm bell and the lighting of one or more signal lights in the troubled units. The signal lights, located on the rear cab wall, Fig. 3-1, and the engineman's control panel, Fig. 3-2, are as follows:

• a. Hot Engine - RED
• b. Boiler Stopped - GREEN (if used)
• c. Alternator Failure - BLUE
• d. Low Oil - YELLOW
• e. Ground Relay - WHITE
• f. PC Switch - WHITE

1. Alarm Lights	4. Engine Start	7. Headlight Control
2. Battery Ammeter	5. Engine Stop	8. Circuit Breakers
3. GPR Reset	6. Isolation Switch	9. Light Switches
	10. Water Temperature Gauge

Rear Wall Of Operating -- Cab Fig. 3-1

NOTE: All the circuit breaker switches, on the engineman's control panel, Fig. 3-2, trip open at 15-amperes; except the "Control And Fuel Pump", and "General Field", are 30-ampere circuit breakers.

The circuit breaker switches are ON (closed) when in the UP position; OFF-DOWN. If a circuit breaker is overloaded and trips open, service is restored by first placing switch fully OFF and then moving it to ON.

301 If Alarm Bells Ring An alarm signal light will be illuminated in the unit affected.

RED-Hot Engine Indicates the outlet engine water Engineman's temperature is about 208 degs F. A hot engine alarm does not reduce the engine load or speed. The alarm signal will not stop until temperature returns to normal.

Engineman's Control Panel -- Fig. 3-2

In case of hot engine alarm, proceed as follows:

1. Isolate engine; isolating the engine will not stop alarm bell; temperature must return to normal.

2. Check the engine cooling water tank for correct level, Fig. 3-3. If there is sufficient water in the system, allow the engine to run at IDLE speed.



Cooling Water Levels -- Fig. 3-3

3. AC cooling fan contactors must be closed, Fig. 3-4.

4. See that all shutters are open. If closed, check position of "shut off" valve in the air supply pipe to the shutter magnet valve.



AC Cooling Fan Contactors -- Fig. 3-4

5. The "Control and Fuel Pump" circuit breaker must be ON.

6. Check position of engineroom winterization hatch control damper. See Art. 404 Engineroom Winterization.

GREEN-Boiler Stopped Indicates steam generator has stopped. To stop alarm light and bell, turn boiler switch OFF, Fig. 3-5. Check overload relay, stack switch and coil blowdown valve.

Boiler Switch -- Fig. 3-5

BLUE-Alternator Failure This alarm signal indicates that the alternating current system has failed; traction otor blowers and radiator cooling fans have stopped; No Voltage Relay (NVR) is opened (de-energized), Fig. 3-6. The engine speed and load is autom atically reduced equivalent to No. 1 throttle position. The engine will STOP if the "AC" system fails with the throttle in Run 5 or 6. Placing the isolation switch in START stops the alarm signals.

NVR Relay -- Fig. 3-6

Most "Alternator Failure" alarms are "false" since this alarm occurs if the engine is stopped for any reason while "on the line." With an "Alternator Failure" alarm and the engine stopped, ALWAYS isolate and check cause of engine stopping. Check (a) overspeed trip, (b) throttle must not be in STOP position, and (c) fuel flow through fuel return sight glass, Fig. 3-7, before trying to start engine that has shut down with no indication other than an "Alternator Failure." If other alarm indications are present with the "Alternator Failure" alarm, they must also be checked before starting the engine.

A "TRUE" AC failure is evident when the Blue light and alarm bell are ON with the engine running and the isolation switch in RUN. To correct a "TRUE" AC failure, proceed as follows:

• 1. Isolate engine.
• 2. Check "Auxiliary Generator Field" circuit breaker; must be ON, Fig. 3-8.
• 3. Check "Alternator Field" circuit breaker; must be ON, Fig. 3-8.
• 4. Auxiliary generator output fuse must be good, Fig. 3-9. To check, open auxiliary generator knife switch, remove fuse and test it on fuse test clips in electrical cabinet. If defective, insert good spare fuse and close auxiliary generator knife switch.

NOTE: If "Engine Run" circuit breaker is OFF, or PC light is ON (PC switch open) the "Alternator Failure" alarm signals are inoperative.

Overspeed Trip and Fuel Flow Check -- Fig. 3-7

YELLOW-Low Oil The tripping of the governor low oil alarm button, Fig. 3-10, due to engine low oil pressure or high oil suction, will always stop the engine and the yellow indicating light will flash ON. The alarm bell will also ring if the isolation switch is in the RUN position.

Circuit Breakers Electrical Cabinet -- Fig. 3-8

To correct, proceed as follows:

• 1. Place isolation switch in START.
• 2. Reset low oil trip button.
• 3. Check engine lubricating oil level on engine oil pan dipstick, Fig. 3-11.
  

  Battery Switch Panel -- Fig. 3-9

• 4. Check for broken or cracked
• 5. Restart engine. oil lines.
• 6. Check oil pressure (must be a minimum of 6 p.s.i. at IDLE).

NOTE: Do not repeatedly start engine if the LOW OIL button keeps shutting the engine down.

Lube Oil Button -- Fig. 3-10	Ground Relay -- Fig. 3-12
Engine Oil Pan Dipstick -- Fig. 3-11

WHITE-Ground Relay When the ground relay light on the engineman's control panel flashes ON, it indicates that the ground relay, Fig. 3-12, located in the electrical cabinet has tripped. The engine speed and load will automatically be reduced to IDLE, or to STOP if the throttle is in Run 5 or 6. When the ground relay trips, the white Ground Relay Light on the engineman's control panel, Fig. 3-2, will flash ON. The alarm bell will ring only if the isolation switch is in the "RUN" position, and the "Engine Run" circuit breaker is ON.

To correct: Isolate engine, reset ground relay, start engine if necessary and place engine "on the line." If the ground relay continues to trip, reset to stop the alarm, and leave engine isolated.

UNDER NO CONDITION OF REPEATED WHEEL SLIP ACTION OR GROUND RELAY ACTION SHOULD A UNIT BE ISOLATED AND ALLOWED TO REMAIN IN CONSIST UNLESS IT IS CERTAIN THAT ALL OF THE WHEELS ARE ROTATING FREELY.

ADDITIONAL SAFETY DEVICES

302 "PC" Switch Open The "PC" switch is an air operated electric switch that is tripped open by any "penalty" or "emergency" air brake application. When tripped, the white "PC light" on the engineman' s control panel, Fig. 3-2, will flash ON, but the alarm bell will not ring. The engine speed and load are automatically reduced equivalent to throttle position No. 1. If the PC switch tripped open with the throttle in Run 5 or 6, the engine would stop.

To automatically reset the PC switch.

• 1. Close throttle to IDLE.
• 2. Place automatic brake valve in LAP.
• 3. Place foot on safety control foot pedal (if used).
• 4. Wait until application pipe builds up to normal pressure. Listen for exhaust or watch PC switch light. If, after an emergency application, the PC switch does not reset itself with the automatic brake in LAP, move the brake valve to RUNNING. The PC switch is set when the light goes out.
• 5. Reset train control (if used).
• 6. Place automatic brake valve in RUNNING.

303 Engine Overspeed Trip If the engine speed should exceed approximately 910 RPM, an overspeed device, Fig. 3-13, located on the front end of the engine will trip and stop the engine by preventing the injectors from injecting fuel into the cylinders. The alarm bell and Blue light will come on if the engine is stopped in this manner while "on the line." The overtrip must be latched in the ù speed T position before the engine can be restarted.

Engine Overspeed Trip -- Fig. 3-13	Fuel Sight Glasses -- Fig.3-14
Emergency Fuel Cutoff Valve -- Fig. 3-15

304 Fuel Flow For proper operation, a good flow of fuel (clear and free of air bubbles) should be indicated by the fuel return sight glass, Fig. 3-14, located on the sintered bronze filter assembly.

If fuel is not flowing through return sight glass, check fuel pump motor. If motor is stopped, check (1) "Fuel Pump" circuit breaker in electrical cabinet must be ON, (2) "Control and Fuel Pump" circuit breaker must be ON, (3) Control knife switch and Main Battery Switch must be closed, and (4) for loose cable connections to motor. If pump is running but fuel is not pumped, check (1) fuel supply, (2) emergency fuel cutoff valve, (3) a suction leak in piping, (4) suctIon side of Dual Fuel filter (5) a slipping coupling at fuel pump.

305 Emergency Fuel Cut-off Valve Pulling any one of the three emergency fuel cutoff valve pull rings will shut off the fuel supply to the fuel pump (one is located on the rear cab wall behind the engineer, and one on each side of the locomotive near the fuel tank filler cap).

This valve is located inside a compartment on the lower front center of fuel tank. Action of the valveis as shown in Fig. 3-15. To reset, push in on the valve yoke "push rod" extension which can be reached from the right side of the unit. Pushing in on this push rod as far forward as possible will reopen the valve.

306 Motor Lock out Switches When used, motor lock-out switches of the type shown in Fig.3-16 permit cutting out one traction motor in the event that it is grounded and operation can continue on the remaining three motors. Always isolate unit before moving lock-out switch. Never cut out more than one traction motor.

CORRECTION OF DIFFICULTIES

307 If The Engine Goes to Idle

• 1. Ground relay might be tripped.
• 2. No voltage relay (NVR) might be open (Blue light will be ON).
• 3. PC switch might be tripped.
• 4. "Control And Fuel Pump" circuit breaker on the engineman's control panel might be "Off."
• 5. "Engine Run" circuit breaker on the engineman' s control panel might be "Off."
• 6. Isolation switch might be in START.

308 If The Engine Stops

• 1. Throttle might be in STOP position.
• 2. Low oil pressure button on the governor might be "out."
• 3. Engine overspeed device might have tripped.
• 4. No voltage relay (NVR) might have opened with throttle in RUN 5 or 6.
• 5. Ground relay might have tripped with the throttle in RUN 5 or 6.
• 6. "Engine Run" circuit breaker on the engineman's control panel might have been tripped "Off," with the throttle in Run 5 or 6.
• 7. PC switch might have tripped with throttle in Run 5 or 6.
• 8. "Fuel Pump" circuit breaker in the electrical cabinet might be "Off.
• 9. "Control and Fuel Pump" circuit breaker on the control panel might be "Off."
• 10. Emergency fuel cutoff valve under the locomotive might be tripped.

Motor Lock-Out Switch -- Fig. 3-16	Starting Engine -- Fig. 3-17

309 How To Start Engine (If it is deemed advisable, or upon recommendation of the Mechanical Department, the engine should be tested for possible liquid accumulations in the cylinders before starting, see Art. 316.)

• 1. Place throttle in Idle and reverse lever in Neutral.
• 2. Place isolation switch in the START position.
• 3. Place the "Auxiliary Generator Field," "Alternator Field" and "Fuel Pump" circuit breakers in the electrical cabinet in the "ON" position.
• 4. Close all knife switches in the electrical cabinet.
• 5. At the engineman' s control panel place the "Control And Fuel Pump" circuit breaker in "ON" position.
• 6. After allowing a few seconds for fuel to flow through the return sight glass, Fig. 3-14, solidly press the START button and hold until the engine starts, Fig.3-17. If engine fails to start after 15 seconds of rotation, check possible troubles listed under Arts. 310-311 before again trying to start engine.
• 7. After allowing time for the lube oil pressure to build up, place isolation switch in the RUN position.
• 8. Place "Engine Run" circuit breaker at engine man' s control panel in ON position.

310 If The Engine Does Not Rotate When "Start" Button is Pressed

• 1. "Control And Fuel Pump" circuit breaker on the engineman's control panel must be ON.
• 2. Isolation switch must be in the START position.
• 3. 400-ampere starting fuse must be good.
• 4. Main battery switch and the. Control knife switch in the electrical cabinet must be closed.

311 If The Engine Rotates But Does Not Start When "Start" Button is Pressed

• 1. Low oil pressure button on the governor must be pressed "IN."
• 2. Engine Overspeed trip must be "Set".
• 3. "Fuel Pump circuit breaker in the electrical cabinet must be ON.
• 4. Emergency fuel cutoff valve must not be tripped.
• 5. See that fuel oil supply is adequate.

312 If The Engine Does Not Speed Up When Throttle is Opened

• 1. "Control and Fuel Pump" circuit breaker on the engineman's control panel must be ON.
• 2. "Engine Run" circuit breaker on engineman's control panel must be ON.
• 3. Isolation switch must be in RUN position.
• 4. PC switch must not be tripped.
• 5. Ground relay must not be tripped.
• 6. No voltage relay (NVR) must not be open.
• 7. Control knife switch in electrical cabinet must be closed.

313 Engine Speeds Up But Locomotive Does Not Move When Throttle is Opened

• 1. Reverse lever must be in either "Forward" or "Reverse" position.
• 2. Generator Field (Gen. Fld.) circuit breaker on engineman' s control panel must be "ON."
• 3. Selector lever must be in No. 1 position.
• 4. Battery field fuse (80 amp.) must be good and in place. 5. Hand brakes and air brakes must be released.

314 Battery Ammeter Shows Continual Discharge See Fig. 3-18

• 1. Battery charging contactor located in the electrical cabinet must be closed.
• 2. 150 or 250-ampere auxiliary generator (battery charging) fuse must be good.
• 3. The "Auxiliary Generator Field" circuit breaker in the electrical cabinet must be ON.
• 4. The auxiliary generator knife switch in the electrical cabinet must be closed.

315 Compressor Control The air compressor is automatically governed and will normally keep the main reservoir pressure at 130-140 p.s.i. Incase of trouble, the normal position of either of the valves, Fig. 3-19, may be changed as shown to manually load or unload the air compressor.

Battery Ammeter -- Fig. 3-18	Compressor Unloader Valve -- Fig. 3-19	Cylinder Test Valves -- Fig. 3-20

316 Cylinder Test Valves Each cylinder is equipped with a test valve, Fig. 3-20, used for relieving cylinder compression during certain maintenance operations and tests. They can also be used, when deemed necessary, to test for possible liquid accumulations in the cylinders prior to starting an engine after prolonged shutdown, as follows:

• 1. Remove 400 ampere starting fuse.
• 2. Open all engine cylinder test valves (3 full turns).
• 3. Rotate engine at least one complete revolution using engine turning jack. Observe test valves for liquid discharge.
• 4. If liquid is discharged from any test valve, engine should not be started until cause of accumulation has been determined and either corrective steps taken or authority to proceed given.
• 5. Close cylinder test valves.
• 6. Replace 400 ampere starting fuse.

If the engine is running and any cylinder test valve is heard to be leaking, the engine should be stopped, and the valve(s) should be tightened.

GP9 TROUBLE SHOOTING CHECK CHART

GP9 TROUBLE SHOOTING CHECK CHART