16
OPM-136/D
SYMPTOM
POSSIBLE CAUSE
CORRECTIVE ACTION
Low Output Voltage
1. Engine speed too slow.
2. Generator overloaded.
3. Inadequate engine horse power.
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 2.0 HP/1000 Watt output. Obtain
larger engine if necessary.
4. Adjust, repair, or replace as required
High Output 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
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°.
2.Tighten mounting nuts and bolts; repair hold-down
stud mountings.
3. Repair or replace defective parts.
4. Check for possible causes. Replace defective bearings.
No Output Voltage
1. Circuit breaker open.
2. Short circuit in the load.
3. Defective receptacles.
4. Loose (or broken) wires or connections in
control box.
5. Defective rotating rectifier.
6. Defective AVR
7. Shorted or open rotor.
8. Shorted or open stator.
1. Reset circuit breakers, replace if defective.
2. Disconnect the load. Check voltage at receptacle
cord set. Check motors, appliances, and load leads for
short circuit, repair short..
3. Remove panel cover and check for voltage to the
receptacles. Replace defective receptacles..
4. Remove panel cover and check all wiring and
connections. Tighten and/or replace where
necessary.
5. Test rectifier. Replace if defective.
6. Repair or replace as required
7. Measure rotor resistance. Replace rotor if open or
shorted.
8. Measure between leads for open or short. Replace
stator if defective.
Output Voltage Flickering or
Fluctuating
1. Tumbling bar (shaft) misalignment
2. Engine governor may be worn or improperly
adjusted.
3. Loose connection in field circuit
4. Tumbling bar u-joints not synchronized.
1. Reduce tumbling bar misalignment to less than 15
degrees.
2. Set or repair defective governor.
3. Check and tighten connections.
4. Reassemble tumbling bar.
Generator Overheating
1. Poor ventilation.
2. Generator overloaded.
3. Shorted turns in field or armature 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 gearcase.
1. Tighten plug.
2. Replaces seal(s), gasket or plugs. Maintain correct oil
level.
TROUBLE SHOOTING TABLE
