AC Main Circuit Breaker

[EggHrbrGuy]

My main circuit breaker for the AC shore power has started to trip off every now and then for no reason. Only load is auto bilge pump which rarely runs. The boat is an '87 Tartan 28. I also must admit the "on" light for main breaker has not worked for awhile. Any thoughts?

[Sailmonkey]

The breaker is going bad.......
Roughly how old is it?


Sent from my iPhone using Cruisers Sailing Forum

[EggHrbrGuy]

original equipment

[DeepFrz]

Probably the breaker but not knowing how close it is to the shore power inlet check your shore power connector at the boat. That is a big source of heat and boat fires. It could also be a loose connection at the breaker causing heat buildup.

[EggHrbrGuy]

Thanks DeepFrz

[exMaggieDrum]

You should definitely get it fixed. I would replace the breaker as a first step as suggested above. It could be a loose connection as well I guess but if you replace it you will know one way or the other. I always keep spare breakers on hand as they do go bad sometimes. Just be sure and replace yours with the same rating. I'm assuming it is already a double pole breaker. If not you should install one that breaks both the hot and the neutral - and it should break both automatically - i.e. not two separate breakers.

[hellosailor]

You have an AC bilge pump wired to the AC shore power?? OK.


But in any case if the shore power system is that simple, start at the inlet, install a proper GFI device, run a new wire to the new breaker, and you're done. Cheaper than trying to get someone to test and troubleshoot it.


And AC with "mysteries" can easily burn down the boat, not unreasonable to just replace it sometimes.

[boeing1]

yes, suggest first check your shore power cord and connections for condition, if ok look at the circuit breaker. your bilge pump should be DC.

[CC45]

I had a similar experience. My circuits and some times the main will trip. I checked every thing except for the power inlet. So when i unhooked it, i seen some browning to the wires. I replaced it, snipped off 1" of old wire, striped and re-installed, Had no problems since.
Oh yea, those screws that held the wires in place were loose, so the build up of heat would shut it down.

[One Chance]

You could have a very serious problem! Start right at your shore power & trace/verify each connection is tight & not corroded. I just did this on my boat & found almost all connections to be substandard. After many years in a caustic environment electrical connections need constant maintenance. I would replace anything which was not 100%. Use marine electrical grease on all connections. VERIFY ALL IS GROUNDED PROPERLY!

[TacomaSailor]

Had a similar problem several years ago. The AC main breaker was 18-years old. I could not figure out why the breaker was tripping because it seemed to test well. Then I looked a little more closely at the 30 amp AC lead from the shore power connector. The AC power lead was in a wire bundle wrapped in spiral wrap and was not easily visible.

The attached picture was that AC power lead where it connected to the back of the circuit breaker. There was a lot of corrosion on the filaments and they were developing high resistance and heating up when, during the winter, we plugged in a 1500 watt electric heater and ran the 750 watt water heater while doing the winter evening liveaboard things. I measured 2.5 Kw thru the lead after I replaced all the wiring between the shore power connection and the AC breaker. That is a lot of heat!

I was very lucky the AC panel had not burst into flames.

[Nicholson58]

Originally Posted by Jon Wachs

original equipment

replace it & carry a spare. They do get old & fail.

Our 60-amp 240 is hard to find. Recently, it was destroyed by lightning so I Re-wired & carry two spares.