I have an off grid system: PV, charge controllers, inverters, and batteries. I want to add a 120V grid input from a GFCI outlet through an extension cord directly into the inverter AC input. However, the GFCI trips when the AC input connects. But only if the ground from the extension cord is connected. Is it necessary to have the ground of the extension cord connected??
I could see an issue where the hot could touch the case of the inverter but the case would have no path back to trip the outlet's breaker. But wouldn't the GFCI protect it?