circuit breaker keeps tripping AC main power

[bob veltre]

The AC main power continues to shut down when only the battery charger and a space heater are in use. Marina tested for pull on 15 and 20 amp service and found nothing wrong. What could cause this? It does not shut down right away but after in use for maybe10 to 12 hrs.

 

[Steve Dion]

My guess

Bob:My guess is that when you arrive at the boat the batteries are fully charged. You get on the boat and fire up the space heater, which is the real problem. Then you are using lights and other DC accessories which starts to drain the batteries. Now the battery charger kicks in. The additional load of the battery charger is tripping the circuit.We cannot run a coffee pot and the space heater at the same time. When we make coffee we get a little chilly until the coffee is done, then we flip the heater back on. What size circuit breaker do you have on the main?

 

[Peter Albright]

Check for heat

If the breaker has a thermal/magnetic trip, it's rating is temperature dependant.After 8 hours, disconnect shore power, and feel the breaker and all the terminal connections. If you find any hot spots, check for corrosion and loose connections.If everything is cool, you may need a new breaker.Pete Albrights/v Nancy Ross '77 H30