Mechanical Faults
| Symptom | Repair |
|---|---|
| Excessive overheating of one or both of the bearings | If the bearing has turned blue or the bearing grease has turned black, replace the bearing. |
| The bearing is not fully locked in the bearing cage. | |
| The end shields are incorrectly aligned. | |
| Excessive overheating of the generator frame | Air flow is partially blocked or air is being recirculated from the generator or the engine. |
| The generator is operating at a voltage that is too high. | |
| The generator is overloaded. | |
| Excessive vibration | Misalignment of the coupling |
| The rotor is not balanced correctly. | |
| Excessive vibration and a humming noise from the machine is present | The phases of the generator have unbalanced loads. |
| The stator has a short circuit. |
Electrical Faults
No Voltage
- Connect a 12 V battery to terminals "E+" and "E-" on the voltage regulator for 2 to 3 seconds. Connect the "+" battery terminal to the "E+" terminal on the voltage regulator and connect the "-" battery terminal to the "E-" terminal on the voltage regulator.
Expected Result: The generator builds up voltage and the voltage remains correct when the battery is removed.
Results:
OK - The generator builds up voltage and the voltage remains correct when the battery is removed. There was a lack of residual magnetism. Reconnect the wires of the generator to the "E+" and "E-" terminals on the voltage regulator. STOP.
NOT OK - The generator builds up voltage but the voltage does not reach the rated value. Check for the following problems:
- The connections for the voltage reference on the voltage regulator are incorrect.
- There is a faulty diode.
- The armature has a short circuit.
STOP.
NOT OK - The generator builds up voltage but the voltage decreases when the battery is removed. Check for the following problems:
- The voltage regulator is faulty.
- The exciter stator has an open circuit.
- The main stator has an open circuit.
STOP.
- The connections for the voltage reference on the voltage regulator are incorrect.
Low Voltage
- Check the engine speed.
Expected Results: The engine speed is correct.
Results:
OK - The engine speed is correct. Go to step 2.
NOT OK - The engine speed is not correct. Increase the engine speed until the speed is correct. STOP.
- Check the connections of the voltage regulator.
Expected Results: The connections of the voltage regulator are incorrect.
Results:
OK - The connections of the voltage regulator are incorrect. Correct the connections of the voltage regulator. STOP.
NOT OK - The connections of the voltage regulator are correct. Check for the following problems:
- The voltage regulator is faulty.
- There is a faulty diode.
- The main stator has a short circuit.
- The voltage regulator is faulty.
High Voltage
- Adjust the voltage adjust potentiometer on the voltage regulator.
Expected Results: The voltage can be adjusted to the rated value.
Results:
OK - The voltage is adjusted to the rated value. STOP.
NOT OK - The adjustment is not effective. Replace the voltage regulator. STOP.
The Voltage is Unstable
- Adjust the stability potentiometer on the voltage regulator.
Expected Results: The voltage can be stabilized by adjusting the stability potentiometer.
Results:
OK - The voltage is stabilized. STOP.
NOT OK - The adjustment is not effective. Check for the following problems:
- The engine speed is incorrect.
- The connections on the voltage regulator are loose.
- The voltage regulator is faulty.
- The engine speed is incorrect.