GFCI and an Open Ground
Given: A 120 VAC GFCI supplying power to a 30 AMP RV. The RV has one problem, the 3rd Prong Ground wire at the 30 AMP plug is not making connection. (The RV chassis is floating because there are no ot...
Forum Discussion
BB_TX wrote:
OK, my head is starting to hurt. After all the reading I still cannot grasp how the circuit can detect a fault between the neutral and an open (not connected) ground. So I will just accept that it happens. I was a systems engineer with little experience at the circuit level, so that may be my weakness here.
If by open ground you mean a fault between neutral and ground inside an RV with no 3rd pin ground on the power cord and absolutely no path from the chassis to earth, it cannot dectect that.
What it can detect is if the LOAD side ground and neutral are shorted somewhere but only because the LINE side ground and neutral and bonded in the panel. If locations on both side of the GFCI have neutral and ground connected to each other, it forms a loop which can now flow current. It can do that with no loads plugged into the downstream receptacles, just the faulted wiring connected.
Feel free to PM me with specific questions. I’m not sure how else to describe it.
