GuangDong Wagna Power Technology Co.,Ltd

The cause and treatment of overvoltage / low fault of diesel generator set
- May 28, 2018 -

There are sometimes two extreme conditions in the use of diesel generators, one is the phenomenon of overvoltage, and the other is the low voltage phenomenon. The following are the solutions of the two phenomena:


Reasons for excessive voltage of diesel generator set and treatment measures:


1. Reason: The speed is too high.

Treatment: Descent speed.


2. Reason:the core air gap of the shunt reactor is too large.

Disposition: change the thickness of the core gasket of the reactor of the generator set, and adjust the air gap.


3. Reason: Short circuit of magnetic field rheostat; failure of pressure regulation.

    Treatment: Find the short-circuit point and eliminate it.



Reasons for the low voltage of the diesel generator set and its treatment methods:


1. The prime mover speed is too low.

     Remedy: Adjust the speed to the rated value.


2. The resistance of the excitation circuit is too large.

 Treatment: Reduce the resistance of the magnetic rheostat to increase the excitation current. For semiconductor excitation generator, check whether the additional winding connector is broken or wrong.


4. Some rectifier diodes are damaged

      Treatment: Review and replace the diode.


5. There is a short circuit or ground fault in the stator winding or field winding.

      Treatment: Check the fault and remove it.


6. Brush contact surface is too small, lack of pressure, poor contact.

Treatment: If the nominal value of the commutator is not caused, use an emery cloth to grind the name of the commutator or adjust the spring pressure at a low speed.