Breakers keeps tripping

[NevadaGeo]

Hmm, does the weather ever get damp or wet where you live? Dampness can get into a conduit and not come out unless you take it up to the dry desert. I bet if you surveyed folks, us desert rats have less problem with GFCI's than swamp dwellers.

[greyzeth]

This swamp dweller (yes, Portland OR is swamp land) checked all that.
This still won't explain why my A/S 20amp GFI would tripp when I'm plugged into the dedicated 30amp shore power and not the 20 amp non-dedicated shore power. both are in a dry garage.

[Rebee]

Try using a circuit tester in all outlets, If that proves fruitless look at A/C wiring. May need to check wiring to look for cracked or chaffed insulation.

Circuit Tester at Lowes: http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1

[HowieE]

There is little or no chance that anything on the shore power side will have any effect on the GFI in the trailer. If you want to test this just remove the wire from the GFI in the trailer panel and then set the GFI. My guess is it will not trip.

I would again suggest you go back to my above suggestion and try to isolate the problem within the trailer. Airstream, like almost all electricians will run a wire out from a panel and connect that wire to receptacles in a chain going away from the panel. Go to the receptacle farthest from the panel and begin removing thing at that point till you have a condition where by the GFI holds. That will define the point of the problem.

[Jammer]

Originally Posted by greyzeth

This swamp dweller (yes, Portland OR is swamp land) checked all that.
This still won't explain why my A/S 20amp GFI would tripp when I'm plugged into the dedicated 30amp shore power and not the 20 amp non-dedicated shore power. both are in a dry garage.

Probably because the 20 amp outlet isn't grounded the right way or the 30-to-20 amp adapter isn't grounded. Often that will mask the problem.

As Howie says, if you can't find the problem by inspection, you have to isolate it by disconnecting outlets from the string until you find the one that's causing the problem. If the problem is not due to moisture alone then it is probably because of a short between neutral (white) and ground somewhere.

[HowieE]

A GFI will only trip when there is an imbalance of current between the hot and neutral legs. It is designed to trip when some of the current is going through your body or any other path to ground. Now that said Jammer brings up a good point. If the 20 amp receptacle in your garage is not grounded, an open ground or a 2 prong adapter is being used to bypass the ground. Get a 3 prong tester and make sure the 20 amp receptacle is grounded. If it is then we are really at a loss.

[68 TWind]

Have you checked your outside 110 outlet. If there is water in there, it could cause your problem. i chased a gremlin for a week til TomW suggested I check the outside box. It was wet inside. I changed the outlet, the cover and a new gasket and problem solved.