Generator overspeed fault

[woodchopper]

What causes a generator overspeed fault ?

[beso]

The engine governor.

They usually work by centrifugal force acting on rotating weights pushing against a spring that holds the throttle open. When the weights are moving fast enough the throttle is pushed close.

Wear in the throttle butterfly valve spindle can prevent it shutting properly. Or the mechanism may simply be jammed.

Some cheap engines use the pressure of the air from the cooling fan instead of the rotating weights. Restricting the air flow will make it overspeed. However this system is only normally used on engines where precise speed control is not important.

[Disco Fever]

Well said, I look after a few generators and they do this once in a while so I just reset them and turn the guvnor down slightly so as long as I get the right frequency, 50 Hz, then all is ok....