GFI opens

[two sailors]

I had a 30 amp. coach that plug in to a 15 amp gfi without a problem. I now have a 50 amp coach that always causes a GFI outlet to open.
Anybody have any idea what the cause would be?

Brad

[Gary RVRoamer]

Something in the coach is using the ground instead oif the neutral or has a neutral that is hsorted to ground. Either one will trip the GFCI. Start out with all the circuit breakers in the coach turned off, even the mains, and plug into shore power. If the GFCI trips , the problem is in the coach shore power wiring or transfer switch. If it does not, start turning breakers on one at a time until the GFCI trips. That will tell you what circuit has the problem. On that circuit, unplug or disconnect everything and then reconnect one at a time to identify which item is causing the GFCI trip.

[RV Wizard]

I have found heating elements that have the filament slightly shorted to ground to cause GFCI's to trip. It is not enough of a short to trip the main breaker and works fine on non GFCI 30 or 50 amp circuits. Check the water heater and refrigerator circuits. Let us know what you find.

[RVThere]

Do you have a surge protector installed in the new motorhome?

I found that after I installed my MH surge protector, the house GFI plug would trip.

["007"]

The Wizard is correct I have one electric element of two for refridgerator 1200 after it heats up will trip my ground fault 110 GFI at house move service line to non-GFI and it works fine. The same element does not trip my Surge Protector when using 50 amp shore line. Both elements do work to operate refridge without a problem.