marine generator problem

the generator in question is tripping out in overvolts. the frequency is rising and so is the volts but the fuel actuator dosen't move on the engine ?. ive already tried a new avr, speed control unit, sync unit and load share unit.

 

You said:
The fuel actuator doesn’t move on the engine.

But is the RPM of the motor increasing?

The ressone I'm asking is it sounds mechanical. If the RPM is increasing, and causing the volts, Hz, so on to increase then it could be a bad bearing causing excessive slipping. In other words there is no friction on the motor, other then the generator, and it can run at a faster speed now. A lot of times when it is a bad bearing the opposite happens, and the motor would run hot, or stop. Until the overload trips. But if the bearing is not sticking then you have lost the friction it has on the motor shaft.

 

delboy some larger generator have a voltage sensing electronic unit that monitors the voltage output with a constant engine speed.

If you have a loose connection where the sensor is located between that sensor and the generator output windings then your sensor will get a false reading thinking it needs to increase voltage due to load etc.

Check for a loose or corroded connection around your voltage sensinig unit. Some of these are set at one voltage, some are infinite dial style that can compensate for voltage drop on long runs from the generator. The loose connection may be in the control panel of the generator also.

Hope this helps

Wg