Ground fault plug in shop trips

Mike3393 · 05-07-2018, 08:34 PM

I have a friend who call me to help him track down a problem. When he plugs his camper into a ground fault reception at his house it trips the circuit. It was working then it stoped. I disconnect everything it all will work until you connect the bare ground in the camper load center, any ideas what is happening?

**wmtire** · 05-07-2018, 08:39 PM

It has been noted many times that two gfci's do not always play well together, since you have gfci outlets in your RV...as well as the one you are plugging into at the house.

It also is sometimes a problem with the adapter and/or extension cord you are using to connect to the household outlet.

Sometimes can be a bad electric heating element in the water heater too.

**Flybob** · 05-07-2018, 08:40 PM

Some GFCI's do not like being connected in series, Try plugging the TT into a non GFCI outlet.

Mike3393 · 05-08-2018, 07:47 AM

We disconnected the gfi in TT and had every breaker off. Started turning on one at a time everything works until connect solid ground in TT load center. Even took converter loose as battery was weak and making sure not related to load from charging. Charger ran everything held until connected solid ground.

**Flybob** · 05-08-2018, 08:04 AM

Please explain in more detail. "Connect the solid ground in the load center"

clr · 05-08-2018, 08:10 AM

Sounds like you have done a lot of hard work trying to get to the bottom of this problem.

The bottom line is that RV's do not play well with GFCI outlets. There are many reasons for this but the explanations are long and technical. You may well be chasing a problem that does not exist.

GFCI must see the current back on the neutral within about 5ms so the tolerances are very tight. Many switching type power supplies such as used in the RV converter actually delay the current flowing back into the neutral by more than 5ms, so they will never work on a GFCI.

If this was me I would plug the RV into a NON GFCI outlet for testing and ensure that the RV does not have a hard electrical fault. If the breaker does not trip you have found your problem.

llr · 05-08-2018, 08:11 AM

what ground are you connecting and disconnecting? If you are disconnecting the main ground to the camper be very careful as you probably have a hot skin condition when it is disconnected.

Have you tried it with all the breakers in the panel off?

Do you have a voltmeter? If so with AC power disconnected and all breakers off set the meter to the lowest resistance range and measure between ground and common and between ground and the hot side.

Please add detailed photos of the power panel, especially showing the ground and common bus bars

ScottBrownstein · 05-08-2018, 08:24 AM

Well, simply stated, unless you are electrocuting someone, you can't have a ground fault without a ground. Agree with others, GFI's in series is a bad idea as they are notoriously intolerant of all kinds of things.

Mike3393 · 05-08-2018, 04:30 PM

After reading what all ya’ll had posted and doing little more research, I told him to connect the bare wire ground coming from plug to the circuit breaker ground lug. Then plug into a non gfi recept. It works, he is leaving Thursday am on a camping trip so he disconnect the ground to be able to plug in in the shop and keep refrig cold. He and I will run a non gfi after he’s home. Thanks for all the help!!!!

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