NL 9KW

[Dixie Life]

No one has been able to tell me what is going on with my genny. It starts and runs fine, after starting it will only put out about 30v per leg. But if I flip the toggle switch breaker on the junction box it will put out 120/240. I tried re-exciting the windings. No change. This is the second VR board I have installed. Any guesses?

 

[twistedtree]

By the "toggle switch breaker", do you mean the 120/240V output breaker?

If so, measure the voltage on the input side of the breaker before you toggle it. Is it 30V per leg or 120V? I'm thinking it's a marginal breaker.

 

[Dixie Life]

No, there’s 2 breakers mounted on the junction box mounted on the generator. A small round push button and a toggle just below it. I even tried jumping it out in case it was going bad. Same results.

 

[CaptTom]

I don't understand that part about toggling a breaker. But I do know that my generator at home will put out low voltage like that when the capacitor fails, at 2:30 in the morning, during a raging storm, and a 2-day power outage. Don't ask me how I know.

I don't know if marine generators even uses a capacitor, but I figured I'd through that out just in case.

 

[twistedtree]

No, there’s 2 breakers mounted on the junction box mounted on the generator. A small round push button and a toggle just below it. I even tried jumping it out in case it was going bad. Same results.

OK, I see that the push button breaker is for the gen DC controls, and the toggle is for the AC sense feed to the AVR. If the gen starts and keeps running as yours does, then the pushbutton breaker if fine.

Did you also jumper across the toggle breaker? If so, I would then trace the wires on both sides of that breaker and check carefully for chafing, bad connects, etc. It looks like there are one or more plugs involved which might have corroded contacts.

 

[SteveK]

30V? Recently I overloaded my GEN and the panel voltage dropped to 30V. I went to the GEN and turned the main breaker back on for 120V. Have not given this more thought until this thread.

 

[Dixie Life]

The AC breaker is the one I jumped out thinking the contacts may be dirty. I also traced the wires to one of the safety relays. Got desperate and replaced it with a new one. Same result. Checked wiring for loose connections but didn’t check for corrosion. I’ll try that tomorrow. Thanks Tree.

 

[Dixie Life]

Tried everything still no change

 

[twistedtree]

Tried everything still no change

This is indeed a strange one. I can think of a few things you might test/measure in hopes of gaining some insight. The only thing we know is that something changes when you open and re-close that breaker, but we don't know what. So trying to find what's changing seems like a good path to explore.

- Start the generator with the breaker open. You would expect no gen output. Then close the breaker and see if you get output. This will tell us if the significant step is closing the breaker, or the initial opening of the breaker.

- With the breaker closed, start the gen. With a meter, measure the voltage between ground/neutral and each of the 4 poles on the tandem breaker. You would expect it to be the same on both poles of each breaker. Then open the breaker, and measure again. Then close the breaker and measure again. Hopefully something will change in the process and give some clue.