Mystery Trip - 3.0A Breaker on NL M673L.3 Genset

[Dreaming Yachtsman]

Recently while I was off the boat, the generator was running to power air conditioning. The wife noticed that the A/C was no longer working so she shut down the genset. When I got back to the boat, I found the 3.0A circuit on the control panel tripped. That breaker supplies the Automatic Voltage Regulator (AVR). I reset the breaker and restarted the generator, which has worked normally since.

My question is: What could cause this breaker to trip?
Is this a situation that will come back to bite me?

[model 10]

Originally Posted by Dreaming Yachtsman

My question is: What could cause this breaker to trip?
Is this a situation that will come back to bite me?

I don't think you can ever go on just 1 trip unless it's the first time you turn it on or it's a spaceship. 2 trips, then you have something.

[a64pilot]

Unless or until it starts tripping again, your faced with the trouble shooters dilemma, I can't fix what ain't broke


Sent from my iPad Pro using Cruisers Sailing Forum

[transmitterdan]

These small breakers are usually the thermal type. They can gradually reduce their tripping current over time. Also, high heat in the genset compartment can make them trip. Vibration is also something that can cause degradation.

Recommend you get a spare breaker and keep it on hand then I would just continue to watch the old one. I might even try to measure the current in the old breaker to see if it is close to 3A (like 2.5A). But it isn't always easy to make that measurement. If it trips again and you are on site check the temperature around the genset. It could be some air passage has become blocked with debris or possibly some insect has built a nest. If the air temperature is normal then I would replace the breaker and hold the old one as a spare. If the new one trips then you have to do some more troubleshooting.

[Dreaming Yachtsman]

Thanks for the responses. The generator was operating in unusually warm conditions so it is entirely possible that the ambient heat contributed to its trip. Now I need to figure out how to get a replacement breaker.

[svlamorocha]

Originally Posted by Dreaming Yachtsman

Recently while I was off the boat, the generator was running to power air conditioning. The wife noticed that the A/C was no longer working so she shut down the genset. When I got back to the boat, I found the 3.0A circuit on the control panel tripped. That breaker supplies the Automatic Voltage Regulator (AVR). I reset the breaker and restarted the generator, which has worked normally since.

My question is: What could cause this breaker to trip?
Is this a situation that will come back to bite me?

You are not the first one. According to some literature from NL the "AVR circuit breaker protects your generator from overload damage." Therefore it is fair to assume that there was an overload event.