Electrical Problem with New Motorhome

Wyn · 07-28-2018, 01:52 AM

First a short backstory, in the past six years I have owned two travel trailers and one class C motorhome. All have been 30 amp units, and have been plugged into a 15 amp GFCI outlet in my garage using a 30 - 20 amp adapter plug. There have not been any issues with this set-up.

On Monday, I took delivery of a 2018 Chateau 24F motorhome, it too is a 30 amp unit. I plugged it into the GFCI outlet in my garage, and the GFCI tripped. I then tried another GFCI on another circuit and it too tripped. I then plugged the motorhome into a regular, non-GFCI outlet and everything was fine.

I checked the polarity in the motorhome with just the onboard generator running, and also while plugged into the non-GFCI outlet, everything checked out fine. I also checked the GFCI outlets in the house, and those also were good.

I took the motorhome back to the dealer, they plugged it into their outlets, and all was good, so they said 'problem must be your house'. I understand why they said that, but since the other RV's worked fine, I think the problem is in the Chateau.

Do you have any ideas as to what the problem might be and what I can do to fix it?

Thank you for your help.

Long & Winding road · 07-28-2018, 02:02 AM

I have heard of some GFI's being hyper sensitive. Try pushing in the test button on the GFI (to trip it and turn off power to the outlets) then plug RV in outlet (with everything off in the RV - so no power draw) the push the little button it on the GFI to power it up then turn the power on in the RV.

Dont know if this will help but that what I did one time whey I plug in at my moms house.

Let us know if it works. Maybe someone else can shed some light on this too.

Wyn · 07-28-2018, 02:12 AM

I did try that, unfortunately that didn't work either, once it tripped with the rig plugged in, the reset button would not reset. I tried this on both GFCI's which are on separate circuits.

I also turned off all the breakers in the motorhome, unfortunately, that didn't help either.

be happy · 07-28-2018, 09:00 AM

Just taking a stab at this, sounds like it could be a loose ground wire at the main panel. That would cause (I think) the system to work but would trip the GFI. I would go into the breaker box and tighten all of the connections.

A couple other things came to mind, maybe your 30amp cord is bad or your 30 to 110 adaptor. It does not take much to trip the GFI

TurnerFam · 07-28-2018, 01:56 PM

a loose wire is very suspect when it comes to 'sensitive' GFCI outlets... it can be aggravating, but it's probably not in your coach, but the outlet, or it's breaker panel that you are plugging into.

also, on GFCI coaches, sometimes the internal GFCI doesn't 'play well' with external GFCI outlets

Laco · 07-28-2018, 03:18 PM

I had the same problem with my former DP. Plugged into the GFI at storage, it tripped, plugged in virtually anywhere else, including any of the RV parks we stayed at it was fine. It turned out to be the refrigerator, which we could not run at storage. Never did solve that problem, we got rid of the DP, and with the Gemini we now have, no problem, even with the refrigerator running.

Beau388 · 07-28-2018, 04:11 PM

The usual cause for the coach tripping a GFCI and not tripping on a regular 120 V duplex receptacle is some where the ground and the neutral wire ate bonded (touching). You usually chase it by turning off all circuit breakers including the 30 amp main and plugging the coach in to a GFCI receptacle. If it trips, the the problem is in shore line or the entrance line to power panel. If it doesn't trip start turning-on each circuit breaker on one at a time (starting with the 30 amp) tying to find which circuit has the problem. In my coach, the problem was the stripped ground in a duplex plug was touching the neutral screw on a duplex receptacle. to fix, just bend the ground away from the screw and stuff the receptacle, carefully.

Bob Denman · 07-28-2018, 05:01 PM

I wonder if the O.P. has had a chance to check for loose wiring connections yet?

Trkyte@msn.com · 07-28-2018, 05:19 PM

Had a similar problem but my problem was the house GFCI would trip after a couple of hours. I plug in to cool the refrig before a trip and in the am I would find the refrig on propane. My trouble was the outside 120 plug had moisture inside the cover. That tripped the house GFCI but not the coach one. Traced my trouble using a VOM. Had high resistance between the hot leg and the ground leg.

Wyn · 08-02-2018, 03:47 AM

Update, I checked the wires in the house breaker panel, and all were tight, and polarity was correct. My RV dealer sent a tech to my house to try to fix the problem, he also checked the house wiring, changed the GFCI outlet, bypassed the GFCI outlet in the motorhome and still the house GFCI outlet tripped as soon as the MH was plugged in. After two hours of testing and isolating circuits, he cried "uncle", he could not figure out what the problem is. All the tests of both the house electric and the MH electric checked out fine, but for some reason the house GFCI still trips immediately upon plugging in. The dealer is going to consult with an electrician and try to get to the bottom of the problem. The MH operates normally when plugged into a non GFCI outlet in the house and also when running off the onboard generator.

**16ACE27** · 08-02-2018, 11:07 AM

Have you checked the heating element in the water heater?

The Gritz Carlton · 08-02-2018, 11:30 AM

"The MH operates normally when plugged into a non GFCI outlet in the house"

There's your answer!

**16ACE27** · 08-02-2018, 12:06 PM

Quote:

Originally Posted by The Gritz Carlton

"The MH operates normally when plugged into a non GFCI outlet in the house"

There's your answer!

The answer to what?

schreinertms · 08-02-2018, 02:06 PM

Had the same issue at my house. Turned out to be a flaky GFCI receptacle. Seems the more you spend for a GFCI (brand especially) the better the result.

Wyn · 08-02-2018, 07:32 PM

The dealers tech did change one of the GFI receptacles at the house to see if that was the problem, unfortunately it was not. We also tested the electric element in the water heater, no problems with it either. This is very frustrating, but fortunately my dealer is working to investigate and resolve the issue.

**16ACE27** · 08-02-2018, 07:43 PM

Well the GFCI will trip when the current on the hot leg and the current on the neutral leg have a difference of a few milliamps. So if it instantly trips when you plug your MH into it then there is a "leak" of AC current in your MH, hopefully to ground. As I understand it, your ground and neutral in your MH are not supposed to be tied together (except when the generator is supplying power); but if they were, for instance if the automatic transfer switch were improperly wired, then that would cause the GFCI to trip. Have you done a continuity check between ground and neutral on your MH?

Beau388 · 08-02-2018, 08:35 PM

I am all for GFCI and CAFCi circuit breakers. For 18 years we traveled in an all aluminum coach (UltraVan). The first time I reached to open the door with a wet hand and suddenly found I was neutral of a 30 amp coach, I replaced all four circuit breakers in the power center with GFCI breakers. I bought an EPS by PI and digital line monitor to test the pedestals BEFORE plugging-in.

Wyn · 08-02-2018, 10:01 PM

Tfryman, I just tested for continuity between the neutral and ground on the MH outlets with the electricity shut off. I do have continuity between neutral and ground. From what you said, this should not be, so any suggestions on tracking down the source and fixing it? Thanks very much for your help with this.

Bob Denman · 08-02-2018, 10:25 PM

(This is coming from an admitted electrical fool...

)
What if you were to just plug into a non-GFCI plug: with a surge protector in between your house, and your RV?

Beau388 · 08-02-2018, 10:56 PM

Quote:

Originally Posted by Wyn

Tfryman, I just tested for continuity between the neutral and ground on the MH outlets with the electricity shut off. I do have continuity between neutral and ground. From what you said, this should not be, so any suggestions on tracking down the source and fixing it? Thanks very much for your help with this.

The ground wire system and the neutral wire system are two separate wire systems. By code, they are to be connected together at ONE point and only one point. If there is more than one bonding point in the wiring system, you can create ground faults, circulating currents and possibly prevent a breaker from tripping if there is a short circuit. If there is no bond, it is also possible that a breaker will not trip.
The breaker panel in your RV is classified as a sub-panel. As such there is NO bond in the panel and the neutral/ground wiring systems in your RV are NOT connected to each other anywhere in the RV. This is because when you plug in your shore power cord, you become part of the campground electrical system which IS bonded, again, at ONE point in the entire campground, generally at the campground main breaker panel.

If you have a generator that is permanently installed in your RV, such as is typical in Class A motorhomes, the generator has a bond between the neutral and the ground, such that when the transfer switch switches, the isolated neutral and ground systems get connected together. Thus the generator becomes the ONE bond point for the RV.

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