JWRoberts wrote:
Voltage measurements will not help you diagnose this problem.
It will if there is a voltage difference between the neutral and ground. That pretty much is the definition of a ground fault.
IF.....with nothing plugged into the circuit, or with the breaker OFF, there is no voltage between neutral and ground BUT when a device is plugged in or the breaker is turned ON there is a voltage difference there......then there is a ground fault in the device in question. There is some current flowing through the ground wire, which never should happen. But better for the stray current to flow on that safety wire than through YOU if you touch the device in question.
As someone else said, there is a remote chance that there is a REALLY BAD connection on the neutral wire (white) but more likely the device itself has an internal partial short to ground.......which is exactly what the GFI is supposed to detect.
