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.
In the context of a 30 AMP RV there will normally be the EARTH GROUND present even though the RV Chassis may be floating. The floating VAC will typically be somewhere less then 115/2 = 57 VAC, depending on the (V)AC current paths from chassis to earth. If a person contacts the 115 AC from the RV while providing a conductive current path to EARTH the GFCI will trip even though the ground wire to the RV is open.
So, that begs the question, will the GFCI trip IF the person standing on EARTH touches the floating RV chassis (the famous tingle)? My guess, probably not.
