Simple really..
Oh, you wanted the simpler version!
Yes certainly you can be screwed up with 120VAC leakage and GFI breakers.
Current passes in other ways then just directly conducted thru metal wire. With a transformer, power is conferred without a direct connection. Same thing happens when you have a conductor passing very closely to another conductor. You can have a little power transferred because of the capacitance. With the correct situation you can get enough of this capacitive "leakage" to actually trip GFIs.
You can get a heck of a tingle out this leakage.
I had a refrigerator that would jolt the hell outta us if we touched it an anything grounded at the same time. It is common with motor like devices because they can have a large amount of wire running near metal. In a refrigerator all those windings in a metal case.
You can have that problem with a long cable with a ground in it. You may have some coupling to the ground from the power conductors. This conducted power is frowned upon by the GFI as it is seen as a fault.
With capacitive systems in general you may have a GFI problem because the inrush or non-symmetrical discharge of the device's energy during turn on or off can cause a brief imbalance that trips the GFIs.
A book.. Dang sorry. It is more like just the rules of a capacitor. Two conductors separated by distance and having areas. The transmitted(leaked) current is then a function of the voltage and the frequency.
Keith Cress
Flamin Systems, Inc.-