Hello,

I have a 6KW generator. It now has a low voltage problem. It sometimes give full 220V and can support some loads but if I put a heavy load on it, the voltage drops under 100V.

Right now, it is showing a 100V voltage without any load. I have checked the brushes, they look fine. The resistance in stator main winding is around 12 ohms. Without the AVR, the voltage is 6.8V.

Generator's RPM is ok.

The output voltage from the stator that goes to the AVR seems to be very low. It is around 5V AC. The voltage from AVR to brushes is around 8V DC.

I have no idea what to check next.

Thank you for any suggestions

 

I would suspect the AVR is faulty, could be faulty solder joints on the main reg transistor like this one. Gave similar problems.

 

The problem was the AVR

Thank you