We have experienced this problem a few times now. Have replaced a few carbon brushes and replaced AVR but after a few days it trips again.

 

What kind of exciter do you have? Basically what is happening is you have some sort of instability in your field excitation. Depending on what type of exciter you're using, I might be able to help point you in the right direction.

 

Leslie... please provide more than name, rank, serial number!

Is the genset operating in parallel with another? With others? Connected to a grid? Is it stable at one load? Are there problems with the prime mover? Is it big? Little? Is it old? New? Etc? Etc?

Phil Corso