Things that I have had trip a GFCI.
1. The phone charger (Hard to believe, but it did even tho a 2 prong)
2. Power Converter
3. Miswire at the main circuit breaker panel
4. Burnt/melted wires at the Main Breaker panel
5. miswire of receptacles downstream of the GFCI
6. miswire of the GFCI
7. Bad/charred relay at the 50 amp transfer box
8. Appliances (non RV) plugged into GFCI controlled receptacles
I turn off all the breakers and if the pole GFCI does not trip, I then turn on each breaker until I find the circuit that trips the GFCI. Then you have to trace that branch circuit down, disconnecting/inspecting items until you find the source. Doug
