Short on 110V, but 12v works?

[Garyscamper]

I have a WFCO converter/ charger. I installed it myself, and it worked properly last year. This year whenever I plug it in to shore power it trips the 110v breakers. However it will still charge the battery. I'm thinking bad ground, but how do I test it?

[Thomas G.]

I'm confused.

If it trips the breaker when you plug it in, how do you know that it charges the battery?

[Byron Kinnaman]

Based on what you've said I'll make some assumptions, which could be wrong. My guess is that when you plug in the trailer the house circuit breaker pops, you reset the circuit and it works.
OR, at least one circuit breaker inside the trailer trips when you plug it, but not the one going to the converter.
First case, you probably have a defective circuit breaker.

Second case determine what the trailer circuit breaker powers that keeps tripping. Again it could be a defective breaker.

Ground problem, not likely unless the circuit breaker is a GFI breaker, then it's possible, still not likely.

[steve dunham]

Unplug your trailer from the receptacle that is supplying your trailer power.
Plug a load such as an electric heater (1500 watt) into the same receptacle and see if the breaker supplying that receptacle trips or if the receptacle gets warm. If the breaker trips or the receptacle gets warm the problem is probably in your house wiring, if not it is probably in the trailer wiring . If the problem is in the trailer ,shut of all the trailer circuit breakers, plug in the trailer into a power source and turn the trailer circuit breakers back on, one at a time starting with the 30 amp main breaker . See which or if a breaker trips in the trailer . Trouble shoot the tripping circuit . You may have a poor connection(s) at the trailer panel, in the supply cord cord cap ,in your converter (hot or Neutral) , shorted circuit wiring , a shorted or locked up appliance or a defective circuit breaker . Breakers that have been overloaded or short circuit tripped to excess will often nuisance trip Also if you are using an extension cord to feed the trailer ,examine the cord and the cord caps

[Garyscamper]

Originally Posted by Thomas G.

I'm confused.

If it trips the breaker when you plug it in, how do you know that it charges the battery?

I have a volt meter on the 12v circuit, so i can see it is charging.

Let me clarify. Whenever i plug in to shore current the main breaker trips. If I am plugged in to a 15 Amp house line I will trip the breaker in the house. If I am plugged in to a 30 amp house line I will trip the breaker in the Scamp. I have a GFCI outlet on one of the circuits, and that also trips, so I took it out of the loop, and the main breaker still trips.

I am going for ground, but how, other than trial and error do i test that? Can one test circuits without power?

[steve dunham]

Turn off all the circuit breakers in the Scamp - Plug the power cord from the Scamp into the 30 amp power source and see if your house circuit breaker trips -if the house breaker does not trip turn on the main 30 amp circuit breaker in your Scamp and see if a breaker trips (house or Scamp) - If either breaker trips check the trailer supply cord and the converter -(Also check to see if you have reversed polarity at the receptacle or in an extension cord or at the converter If some one has reversed the hot and neutral at any point in the circuit feeding your trailer you will trip the breaker (s)) If the 30 amp breakers do not trip , turn on each branch circuit breaker (one at a time) in your Scamp and see if you can isolate the faulted circuit - If you find a tripping circuit breaker(s) in the Scamp , unplug or shut off or disconnect all appliance , lights Etc .on that circuit and try to reset the tripping circuit breaker(s), if the breaker(s) still trips ,disconnect the hot and neutral conductors for that circuit at the Scamp converter and place an ohm meter across the black and white disconnected wires (Test wires for power before disconnecting or applying an ohm meter) If the ohm meter shows a low reading you have a short in the circuit - Also check or test from the black circuit conductor to the neutral bar or equipment ground bar and again if you have a low reading you have an unintended ground in the circuit. Isolate and repair the ground or short If the breakers hold with no loads connected you may have a shorted or an unintentional ground in a load or locked up motor in the A/C Smaller amperage circuit breakers should trip before larger amperage breakers but in the real world it doesn't work that way so the 30 amp breaker in the circuit may trip before the 15 amp breaker

[Thinh]

Originally Posted by Garyscamper

I have a volt meter on the 12v circuit, so i can see it is charging.

Let me clarify. Whenever i plug in to shore current the main breaker trips. If I am plugged in to a 15 Amp house line I will trip the breaker in the house. If I am plugged in to a 30 amp house line I will trip the breaker in the Scamp. I have a GFCI outlet on one of the circuits, and that also trips, so I took it out of the loop, and the main breaker still trips.

I am going for ground, but how, other than trial and error do i test that? Can one test circuits without power?

..Here is my guess for you, Buddy.
And my assumption only works IF the converter of your trailer having BRANCHES OF AC CIRCUIT. If that is the case(which your trailer 12VDC battery is still CHARGED)----> your branch AC circuit of your CONVERTER is defect. If this is correct, then go and check the AC fuses of your trailer converter(some models have these fuses INSIDE of the converter housing, you couldn't see it from outside). Before determine to dis-assemble the converter housing, using an OHM METER to measure those AC outputs of converter, you could tell they are SHORT or not. If they are NOT short, do not bother opening to check AC fuses, the problem must lie somewhere else. Hopefully it works....One more thing, Ohm measurement of the AC outputs of your trailer's converter must be in...COLD STATE, i.e...no power connection at all. Otherwise your meter fuse would be blown...

[stevebaz]

You only have 3 fixed sources of 110 volt power consumption. your Dc converter, your refrigerator and AC if you have it. I would disconnect each one and see if the short stops. Any other use is probably something random that is plugged in. I assume that a 12 volt DC frozen pump or fan could feed 12 volt to ground possibly tripping a gfi but I am not sure of that. Pulling your 12 volt fuses would isolate those. If your tripping a GFI taking it out of the loop solves nothing its there for your protection. I would really scrutinize that circuit.

[Carol H]

Originally Posted by steve dunham

Also check to see if you have reversed polarity at the receptacle or in an extension cord or at the converter If some one has reversed the hot and neutral at any point in the circuit feeding your trailer you will trip the breaker (s))

Steve would hooking up the battery backwards have an impact in this case. IE not having the positive to black? I know people sometimes assume the hook up is opposite to what it should be on a trailer.

[Garyscamper]

Interesting. The breaker that trips is attached to a GFCI outlet. When I get a chance I'll isolate it from the circuit and see if it still trips.

Assuming it is the GFCI outlet, and assuming I replace it and it still trips, how do I protect the circuit from ground faults. The outlet is close to the sink.

GQ

Originally Posted by Byron Kinnaman

Based on what you've said I'll make some assumptions, which could be wrong. My guess is that when you plug in the trailer the house circuit breaker pops, you reset the circuit and it works.
OR, at least one circuit breaker inside the trailer trips when you plug it, but not the one going to the converter.
First case, you probably have a defective circuit breaker.

Second case determine what the trailer circuit breaker powers that keeps tripping. Again it could be a defective breaker.

Ground problem, not likely unless the circuit breaker is a GFI breaker, then it's possible, still not likely.

[mary and bob]

I have seen a GFCI outlet go bad and trip a breaker. Don't know why or how but it did. Try that first maybe.