GFI tripping when plugging in to charge batteries

[Haines1959]

Help! Took delivery of a Grand Design 28g 2019 new toy hauler last month. Whenever I plug in to GFI outlet when reducing from 30 amp to 15 amp it trips the GFI plug. I used this same plug to charge the batteries in our last 5th wheel for 4 years with no issues. I have tried other GFI outlets and the same thing happens but yet others can plug in with no problem. Took it back to dealer and they said it must me plugged into 30 amp outlet per Grand Design instructions. I asked if they called the manufacturer for this info and they said yes. But when I called the manufacturer they seemed perplexed and I was told they would have to look into it. I have been an RVer for 18 years and never had this issue. I did have the dealer install 2 6 volt batteries before I took delivery as I was told they are so much better. I like to plug in before a trip to start my frig and make sure batteries are topped off but unable to do so. Thanks for your help. Steve

[Flute_Man]

ScottG wrote:
I could not disagree more with the above. Your trailer should not trip a GFCI and if you ignore it, you can easily end up with a hot-skin issue and someone could get hurt or worse. The problem is fixable.
(Retired EE)

X2. Another retired EE

[mapguy]

arkidog wrote:
Not a link but you can find it here:
Grand Design Owners Forum / General Tech / Electrical / Shore Power Gfci Issues
Page 3 (#38) dated 02/22/2020 10:43 AM

https://www.mygrandrv.com/forum/showthread.php/28159-Shore-Power-Gfci-issues

[arkidog]

Not a link but you can find it here:
Grand Design Owners Forum / General Tech / Electrical / Shore Power Gfci Issues
Page 3 (#38) dated 02/22/2020 10:43 AM

[dedmiston]

arkidog wrote:
I also own a GD 21G that will trip any ground fault plug that I plug into. From reading on the Grand Design Forum it seems that every GD with an installed generator has this same problem. One member reported that GD told him the problem was that the neutrals for the RV and the generator were bonded together at the generator transfer switch causing the problem and gave him a fix. I will not try to restate that fix here. The fix should come from GD and be done by dealer / service tech.

How about a link?

I'm typically not a fan of links to other forums & social media, but linking to the solution would help the OP so he doesn't have to start from square one when he calls the factory.

[ScottG]

wopachop wrote:
Is there any chance his water heater, fridge, lights and converter are simply pulling over 15 amps? Like mentioned above turn off all the RV breakers and try again.

Also make sure you water heater is filled with water. You probably know that after 18 years though.

Good question but a GFCI is not a circuit breaker and wont trip just because one pulls more than 15A from that size of circuit.
But a defective water heater, fridge or converter can cause a ground fault.

[wopachop]

Is there any chance his water heater, fridge, lights and converter are simply pulling over 15 amps? Like mentioned above turn off all the RV breakers and try again.

Also make sure you water heater is filled with water. You probably know that after 18 years though.

[arkidog]

I also own a GD 21G that will trip any ground fault plug that I plug into. From reading on the Grand Design Forum it seems that every GD with an installed generator has this same problem. One member reported that GD told him the problem was that the neutrals for the RV and the generator were bonded together at the generator transfer switch causing the problem and gave him a fix. I will not try to restate that fix here. The fix should come from GD and be done by dealer / service tech.

[ScottG]

I could not disagree more with the above. Your trailer should not trip a GFCI and if you ignore it, you can easily end up with a hot-skin issue and someone could get hurt or worse. The problem is fixable.
(Retired EE)

[cavie]

There is nothing wrong with your trailer. There is no ground fault. There is 2 ways to fix your problem. Dealer not required.

Your trailer has a GFI circuit in it. Sometimes 2 GFI's in series don't play nice. One way is to turn off your GFI 120 volt circuit breaker in the breaker box of your Trailer. Not the outlet in the bath. Everything will work except any outlets within 6' of a water source.

Option #2 is to plug into a non-gfi circuit at the house.

[wra]

I have worked on "new" RV's with the same problem. Somewhere the green "ground" wire is shorted to the white "common" wire inside of your RV. It usually happens when the manufacture wires in the converter. Have your repair person use an ohm meter to see if there is a short between the ground and common of the RV plug. (the plug must be unplugged, of course. Follow the connections from the other end of the cord until you find where the ground and commons are connected together. Separate them, and tie the whites to whites, and ground to grounds. A wire nut will usually do the job to connect the same color wires.

[time2roll]

Start by turning ALL breakers in the RV off. Plug in and see if it still trips. Then turn on the main and one branch circuit at a time and see if the issue can be isolated.

Has it been raining? Could be water in the exterior outlet. Next would possibly be the water heater or fridge. Both these have heating elements that can leak to ground. Long shot would be a defective converter or a crossed connection. Hopefully the breaker with lead you to the branch circuit with trouble.

Ultimately the circuits will need to be separated to isolate the issue.

[Lwiddis]

X2, mobile tech.

[Flute_Man]

I agree that it needs to be fixed. I would trust a mobile tech before I trusted the dealer. I can help you over the phone if you will call me.

[KD4UPL]

Your RV has a ground fault. It needs to be fixed. Your dealer is full of it. Tell him so. Or, find another dealer.