Electrical problem

[dennislanier]

Just returned from a short trip of 4 nights. The second night, I woke up about 3 AM and the power was off. I had been running the AC and also the electric water heater. When I got up the next morning the breaker was tripped AT THE PEDESTAL, not inside the MH. This had happened before at another campground earlier this year. My question is, why would it trip the breaker at the pedestal and not inside the MH? Any ideas? How would I go about checking for potential problems?

[enblethen]

NEC does not specify wire size feeding the sub-panel. There is some language to calculate loads, but allows for derating of loads.

[tenbear]

Dusty R wrote:
NEC allows that when a panel has no more than 6 breakers to not have a main.

Dusty

I don't know much about NEC. Does it say what the wire size feeding the 6 or less breakers must be? Seems to me it should be large enough to handle the current for all 6 breakers at max rating, ie, 4 x 15A breakers should be wired with wire capable of handling 60A, #8 AWG, or is it #6.

[Dusty_R]

NEC allows that when a panel has no more than 6 breakers to not have a main.

Dusty

[tenbear]

IMHO very few builders would depend on the pedestal to limit the current to 30A. Some RVers use a 50A to 30A adapter. Without a 30A breaker in the RV there is no protection in that case.

[enblethen]

Some 30 amp rigs do not have a main breaker, so the combined branch breaker loads can be above 30 ampere.
OP: Does your rig have a main breaker?

[tenbear]

When 2 circuit breakers with the same rating are on the same circuit, one of them will open first. It could be either one. As others have said, the pedestal breakers get a lot of use so they may have weakened.

[dennislanier]

Thanks for all the great information. From now on, I will turn off the water heater when not using it, at night for sure. I will also take a look inside the breaker box and check connections etc. I try not to use too many electrical items and one time but forgot about the water heater-air conditioner combo.

[Dusty_R]

Pedestal receptacles get worn and a little loose, and can cause a voltage drop/power loss, right there.

Dusty

[dan-nickie]

Turn off the electric water heater at night.
Only turn it on when you are expecting to need hot water.
YOu can typically turn on electric and gas for a fast heat up.

[I_am_still_wayn]

You do not have an electric problem. You just use more electricity (amps) than your 30 amp service is designed for.

Water heater 1200 watts
Air conditioner 1250 watts
Refrigerator 500 watts
Converter 250 watts
Your running amps load is 27 amps at 120 volts or 29 amps at 110 volts. When the air conditioner starts up it will draw 2400 watts momentarily. A worn circuit breaker at the pedestal cannot handle the load you put on it.

[WyoTraveler]

With both A/Cs on I can't run much else even on 50 amp breaker.These RVs are maxed out.

[enblethen]

It overloaded for some reason.
I would suggest going through your 120 volt ac electrical panel. Turn off all 120 AC power. Look closely and tighten all electrical connections. Pay special attention to the neutrals(white wires) on the terminal block in the back of the panel. Look for any discolored or melted insulation.
A joint that isn't tight enough or is corroded can increase the resistance on the circuit.

[rv2go]

None of the RV circuits were over loaded, but the combined load was more than the Pedestal circuit breaker was rated for.

[workhardplayha1]

I had the same thing happen when running. I don't think there is any problem with my unit.