14
OPM-142/D
SYMPTOM
CAUSE(S)
CORRECTIVE ACTION
No output voltage
1. Circuit breaker open
2. Defective frequency meter
3. Short circuit in the load
4. Defective receptacles
5. Loose (or broken) wires or
connections in control box
6. Defective rotating rectifier
7. Defective AVR
8. Shorted or open rotor
9. Shorted or open stator
1. Reset circuit breakers, replace if defective
2. Check output with another meter, replace meter if
defective.
3. Disconnect the load. Check voltage at receptacle cord
set. Check motors, appliances, and load leads for short
circuit. Repair short.
4. Remove panel cover and check for voltage to the
receptacles. Replace defective receptacles.
5. Remove panel cover and check all wiring and
connections.
Tighten and/or repair where necessary.
6. Test rectifier. Replace if defective.
7. Repair or replace as required.
8. Measure rotor resistance. Replace rotor if open or
shorted.
9. Measure between leads for open or short. Replaces
stator if defective.
High voltage
1. Engine speed too fast.
2. Defective or misadjusted AVR
1. Check engine speed for correct input RPM
2. Adjust, repair, or replace as required
Low voltage
1. Engine speed too slow
2. Generator overloaded
3. Inadequate engine horsepower.
4. Defective or misadjusted AVR
1. Check engine speed. Increase RPM if necessary.
2. Reduce load if it is higher than the rated capacity of
the generator. (see generator nameplate)
3. Generator requires 2 HP/1000 watt output. Obtain
larger engine if necessary.
4. Repair, adjust, or replace as required.
Output voltage
flickering or
fluctuation
1. Tumbling bar (shaft) misalignment
2. Engine governor may be worn or
improperly adjusted. Set or repair
defective governor.
3. Loose connection in field circuit
4. Tumbling bar U-Joints not
synchronized
1. Reduce tumbling bar misalignment to less than 15
degrees
2. Engine governor may be worn or improperly
adjusted. Set or repair defective governor.
3. Check and tighten connections.
4. Reassemble tumbling bar.
Excessive vibration
1. Power take-off misalignment
excessive
2. Loose mounting nuts and bolts or
hold down studs
3. Universal joints in coupling shaft
worn or dry.
4. Defective bearings
1. Correct misalignment. It should be less than 15
degrees.
2. Tighten mounting buts and bolts; repair hold down
stud mountings.
3. Repair or replace defective parts.
4. Check for possible causes. Replace defective bearings.
Generator
overheating
1. Poor ventilation
2. Generator overloaded
3. Shorted turns in field or stator
windings.
1. Clean ventilation and cooling fan screens.
2. Reduce load, then check voltage and current.
3. Replace defective components.
Oil Leak
1. Loose plug in gearcase
2. Defective seal, gasket, or plug in
geargase
1. Tighten plug.
2. Replace seal(s), gaskets or plugs. Maintain correct oil
level.
TROUBLE SHOOTING TABLES
