Tripping gfi in garage when plugging into garage

sometimes there is something else on the same line inside the house. We had a problem at a friends house whenever their freezer in their basement kicked on. turns out it was on the same line as the garage outlet we were using.

In our house the garage gfi is also part of the master bath gfi circuit. Wife drys here hair while I am using power tools in the garage and click goes the breaker. Would love to separate it out but just not worth the cost. Maybe one of these days. Could the water heater have fried and causing an excessive draw?

got to make sure all three lines are being used all the way from the 120VAC receptacle to the trailer shore power cable. Might be no ground wired to your receptacle in the garage also....

Pick up one of those 120VAC circuit testers. This will tell you if the proper circuit connections are present...


In my case it is usually the other way around. MfyGFCI in the trailer trips haha...

Roy Ken

Trip all circuits in motorhome to off. Plug in motorhome to garage gfi. Turn on and then back off each motorhome circuit until gfi trips. You now know what circuit in the motorhome may have a ground fault or has a appliance on with a greater than 15 amp draw such as the AC, Water Heater, microwave, etc. If none of the circuits trip the GFI by themselves then turn on one and then the next until you overload the gfi. At least you may be able to isolate the cause somewhat this way.

The strange thing is that it was working for over a week. Had ac and microwave circuit breaker off to try and isolate. Even removed one of the leads to water water but still tripped. Water heater does not appear to be fried. It works on the generator with no problem. I was thinking the same thing that is why I tried it on the generator. Even tried a different outlet on the house which was not in the garage.

The other funny thing is that it does not trip right away. Takes a couple of minutes, but I have nothing on, no frig. , hot water heater , micro wave so can't tell the draw. The end shows 126 h, 0 amp and ems shows ok.

Good possability you burned up the WH hearing element and now it is shorting, tripping the breaker.

I always thought GFCI's tripped with a faulty ground NOT current overload which would trip the circuit breaker in the main C/B box.

I was thinking it was the heater but have it shut off and even had one of the power. Disconnected to rule that out.

It is possible the GFCI outlet has started to fail. It does have a sensitive circuit to compare current flow thru the hot and neutral lines, compare the two, and trip if there is even a very small difference between the two. Before I got too far into checking every individual circuit, I would replace the GFCI outlet. Inexpensive and easy to replace.