As shown in Table 9: Generator Electrical Faults
| Fault Phenomenon | Causes | Handling Methods |
|---|---|---|
| No Power Generation or Abnormal Voltage | 1. Fuse blown | After confirming the circuit is normal, replace the fuse and then close the switch. |
| 2. Electrical meter damaged | Directly measure the generator terminal voltage with a multimeter voltage range. | |
| 3. Electrical meter inaccurate | Calibrate the meter regularly and replace it if necessary. | |
| 4. Poor contact of regulator pins | Check the regulator (50Hz, 60Hz) and whether the pins are loose. | |
| 5. Surge voltage suppressor short-circuited | Inspect the varistor winding to ensure no short-circuit phenomenon. | |
| 6. Rotating diode damaged | Remove the connection wire from the rotating rectifier to the main machine rotor field, measure the diode with a calibrated multimeter, and replace the tube if damaged. | |
| 7. Wiring error | Check in detail and correct according to the wiring diagram. | |
| 8. Open circuit of exciter field coil | Splice the broken wire with solder, wrap it with insulating material. | |
| 9. Loose wiring or poor contact | Clean the wiring and reconnect it properly. | |
| 10. Open circuit of generator armature coil | Locate the open-circuit point, re-solder and bind it. | |
| 11. Short circuit of generator armature coil | Short circuit will cause serious heating, so the coil should be replaced. | |
| 12. Open circuit or short circuit of exciter armature coil | Locate the fault point and replace the coil. | |
| 13. Abnormal speed | Check the generator speed with a tachometer or frequency meter. | |
| 14. Voltage regulator protection switch operates | Adjust after correcting according to the voltage regulator manual. | |
| 15. Voltage regulator failure | Replace the voltage regulator. | |
| Generator Voltage Fluctuation | 1. Incorrect speed | Check the tachometer and frequency meter to calculate the generator speed. |
| 2. Unstable speed | Verify the stability of the governor. | |
| 3. Poor stability of the voltage regulator | Refer to the regulator manual and adjust the voltage regulator stability. | |
| 4. Wiring fault or loose wiring terminal | Check all wiring for looseness or poor connection. | |
| 5. Faulty diode, surge voltage suppressor, or generator winding | Perform a separate excitation test on the generator (using a 12V battery). | |
| 6. Faulty remote voltage regulation potentiometer | Refer to the regulator manual and check the working status of the remote potentiometer. | |
| 7. Regulator fault | Refer to the regulator manual and replace the regulator. | |
| 8. Poor bearing or worn bearing support causing asymmetric air gap | Replace the used bearing, inspect the bearing support for wear, and replace if necessary. | |
| Motor Overheating | 1. Overload | Always pay attention to the ammeter to avoid overloading. |
| 2. Short circuit of AC armature coil | Replace the short-circuited coil. | |
| 3. Blocked ventilation | Thoroughly blow out the interior of the motor. | |
| 4. Short circuit of exciter armature coil | Replace the short-circuited coil. |
As shown in Table 10: Mechanical Failures of Generators
| Fault Category | Fault Phenomenon | Measures |
|---|---|---|
| Bearing | One or two bearings overheating (bearing temperature exceeds 80°C). With or without abnormal noise | If the bearing turns blue or the grease turns black, replace the bearing End cover is misaligned (boss not properly installed) |
| Abnormal Temperature | Generator base overheating (40°C higher than ambient temperature) | Blocked air passage (air inlet/outlet) or hot air recirculation between prime mover and generator Remove air passage blockages Generator operating temperature too high (over 105% rated voltage under load) Generator overload |
| Vibration | Excessive vibration | Misalignment (coupling) Improper installation with prime mover Unqualified rotor balance (prime mover-generator) |
| Obvious vibration and noticeable noise inside the motor | Generator single-phase operation (single-phase load, switch error or installation error) Stator short circuit |
|
| Noise | Generator is severely hit, followed by noise and vibration | System short circuit – possible result of wrong connection Coupling broken or damaged Shaft broken or damaged Rotor deformed or short-circuited Fan cracked or loose on shaft Irreparable damage to rotating diodes or AVR |
