Ground fault trips on shore power - Montana Owners Club

afzimm · 05-09-2011, 05:05 PM

I accidentally applied 50 amps to my shore power last fall. It fried some wires way in the back of my 30 foot Montana. I repaired the wires in the junction box, but when I hooked up the ground wire it would trip the ground fault breaker in my shops wall outlet. So I left the ground wire free. Today I hooked up and was getting ready to go camping this coming weekend, I hooked up shore power and now it trips the ground fault even with the ground unhooked? I disconnected all electrical appliances and I get the same thing happening can anyone shed some light on what the problem could be?

NCFischers · 05-09-2011, 10:54 PM

It would help if you would put the year, make and model of your trailer in your profile. The newer trailers are set up for 50 amp service so I don't understand how that relates to the problem.

afzimm · 05-10-2011, 04:46 AM

Nc it's a 2000 Montana 2950. 30 amp is the hookup. It had 50 amps accidentally hooked up briefly.
Now it trips the gfi thinking wires shorted somewhere. Or would the converter have gotten shorted?

dieselguy · 05-10-2011, 06:34 AM

Whew ... where to start here! Could you explain how you got 50 amps thru a 30 amp plug for starters? I used to own a 2000 2850RK, so I remember the shore power plug.

thor · 05-10-2011, 10:29 AM

the gfi plug may be bad

afzimm · 05-10-2011, 02:32 PM

I have tried 3 different circuits all with separate Gfi. Each one pops the moment I plug in the camper cord. I noticed some charring around the plug last fall when I bought this used rig. I replaced the plug. I plugged the camper into a welder 50 amp receptacle. I heard wire frying noises. Opened the junction box under the microwave ( rear kitchen) and found the red wire fried off. Repaired the wires plugged back into a 30 amp source and popped the gfi. Horsed around and finally found that if I left the ground wire unattached in the junction box, then power would remain on. As soon as I touched the ground wires together it would pop the gfi again. Now this spring it pops the gfi even with the ground wire unattached. I am thinking that I may have shorted the groung wire somewhere along the line. Or maybe damaged the converter?

noneck · 05-10-2011, 03:43 PM

Well, GFCI tripping is telling you there is current on ground leg, which is not good. Leaving that one you talk about floating was not the right thing to do but suggests a debug clue as problem is up stream. You say you heard frying, this might be so bad that the wire bundle is compromised. When I had a GFCI issue I ended up turning off Circuits until I was able to isolate to which one cause it to trip. Mine was a chafed neutral wire in the AC Unit on the roof rubbed on metal flange. Good Luck, be safe.

NCFischers · 05-10-2011, 04:39 PM

If you found one fried wire, you might have several more. Hearing that sizzling noise is not a good sign. You might have many more hours of troubleshooting ahead of you. When you replaced the plug, did you replace a 30 amp plug ( one hot wire, one neutral wire, one ground wire)with a 50 amp plug (TWO hot wires and one ground wire)and then plug into a 50 amp outlet (the welder outlet)? If the trailer was originally set up for 30 amp and you connected wires to the two hot leads on the new plug, you have probably caused a whole lot of damage. A friend of mine did that to his trailer and had to replace almost all the things that run on electric.

HamRad · 05-10-2011, 10:27 PM

I've got one of the older rigs and while it says it is 50 amp it really isn't. What it is it that it has a 30 amp circuit and then a separate 20 amp. You add them up and of course you get 50 amp. But my 30 amp circuit draws ONLY enough power that it can handle. Nothing burns or blows up when I connect to a 50 amp pedestal.

On Edit: I also thought that I'd read that power being supplied from a GFI from a pedestal or home type source that they would not be able to supply ongoing power. But my memory is not that great anymore.

So I too would like to know how the 30 amp circuit got 50 amps to it. Sure hope it does not happen again. Good luck in finding the problem and fixing it. Let us know so the rest of us won't make the same mistake. Thanks, Dennis

afzimm · 05-12-2011, 02:39 PM

Well I fixed the one wire that fried off in the junction box where the main power cord ties in. All appliances, including a/c work. All electrical outlets work. Yesterday I hooked up and moved the camper up by the house and plugged into a different gfi circuit. Everything works now. It did not trip this gfi. Tomorrow if it stops raining I will hook up that floating ground wire and maybe all my problems will be gone. Last night I touched some metal on the camper and I could feel a tingle of electricity. I guess I was the ground rod.

Phil P · 05-12-2011, 03:28 PM

Hi

If you felt a shock when you touched the trailer frame you have more problems than you think. From your post I would suggest you find an electrician to work on it.

Phil P

afzimm · 05-12-2011, 05:43 PM

Electrician was supposed to come today, but it rained 2" here again.
Tomorrow supposed to be dry, electrician coming to test ground wires. We will get to the bottom of this and make everything work properly. Thanks for all the input guys, nice forum here to tap into huge knowledge base. I'll keep you posted. AZ

afzimm · 05-13-2011, 08:09 AM

No rain today. Electrician came this morning. We found 2 problems.

1) hot and neutral wires in main cord plug in were reversed. This caused the frame and anything connected to it to become the ground path. Reversed the polarity and no more stray voltage.

2) Electrician took off cover to main fuse panel. He disconnected the hot and the neutral from their circuit breakers looking for anything out of the ordinary. He noticed one of the copper ground wires had made a loop and was just barely touching the buss bar where all of the Campers circuits are joined. He bent that wire away and untouching. That took care of the GFI popping every time I plugged in.
Good as new now, a load off my mind also. We are off to Two Rivers Rv park in north central Mn this weekend. Al Z

afzimm · 05-14-2011, 12:02 PM

We have been camping in an Arctic Fox 1150 pickup camper the past 3 seasons. Decided to try and sell the Fox last Fall. I put it on Craigs List and it sold the very next day! I thought I was just lucky, but as it turned out I wasn't asking enuff and I sold it way too cheap.
Upgreaded to this 2000 Montan 2950 model. This will be our first season using it and it seems like a palace with all the room compared to the pickup mounted model. Just wanted to add how much I like this forum. The friendliest folks seem to be on here and very eager to answer questions and help with problems. Hope to meet some of you guys out camping real soon. Al Z

http://www.facebook.com/media/set/?s...7&l=e963cf0870

MuddyPaws · 05-15-2011, 06:13 PM

We had the same sort of problem with our 2955, and the cause was the same. The previous owner of our house was a 'Power Systems Engineer' with IBM and a real SOB. He added dozens of plugs to the house and got ALL of them wrong! Once I fixed the polarity of the plug -- no more problems.

bill maietta · 05-16-2011, 10:51 AM

Just wondering if a surge guard would have detected a problem in the first place?

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