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
Bobbo wrote:BB_TX wrote:Dutch_12078 wrote:
As has been stated, a GFCI trips when it detects an imbalance between the hot and neutral. The ground has nothing to do with it. ......
That part I understand and am not questioning the lack of a ground on the GFCI outlet itself. What I don’t understand is how you can have a ground fault in an ungrounded RV that would trip a GFCI outlet. To have a ground fault that would trip a GFCI outlet there must be some path for the errant current to drain to a ground source. Otherwise there would never be an imbalance in the individual currents thru the hot and neutral pins of the outlet.
The GFCI outlet has circuitry to detect a connection downstream from itself of a NEUTRAL/GROUND short even if no current is being used. It will trip. I have a BONDING PLUG for my Honda generator so it will work on my EMS-HW30C equipped trailer. If I plug that into a GFCI outlet, the outlet will trip instantly, even though the BONDING PLUG draws no current whatsoever so there can be no current imbalance.
When I looked at how they do this, I discovered that the GFCI simply induces current into the wires which in turn trips the very same current imbalance detector. So while no external current is flowing, there is some inside the device. Regardless, an RV without a ground path will not trip from current imbalance or shorted neutral & ground.
