GFCI tripping

If nothing is attached to it at the time it may be moisture . It is possible something on the load side of the device has an intermittent ground fault

IMHO:

If you have no other factors, like heavy applicances which you didn't mention, then I would guess since the GFCI fails safe, that line voltages could fluctuate and cause the GFCI to trip.

GFCI's nusance tripping is understood, and very well accepted, so once every several months could be something very tolerated by many. Remember to follow manufacture's instructions for regular testing.

later,

tom @

How does a line voltage fluctuation cause a current imbalance in the legs? The real culprit must be something such as a chafed wire, a mouse biting a wire, etc.

OK. Finally yesterday (Thanksgiving) the GFCI triiped off completely and it was not reset. The GFCI is the only receptacle on 20 A circuit and powers D/W in kitchen. It is on Edison circuit and shares neutral wire with another 20 A circuit that powers garbage disposer. The garbage disposer circuit has also one GFCI with switch and it is in the same double box as D/W GFCI. Grabage disposer GFCI worked just fine. Today I removed faulty GFCI ( I had to remove garbage disposer to remove GFCI so it took me several hours). I checked voltage on GFCI screws between hot and neutral and between hot and ground. Both were

I used to have one that did that, before it failed (tripping instantly after reset) completely. The problem was ants (this was inside, but on an outside wall). Too much ant feces all over inside that electrical box.

Well... If *I* was having occasional tripping of GFCI device, my first thought would be that it was caused by a ground fault, but that's just me....

It it was a ground fault, then I would suspect that an applicance, or other plugged in item, was causing. Then it wouldn't occur every several months, but everytime the item was used. This would create an immediate patern, and no NG post would have happened. :p

tom

IMHO:

Wait let me explain, we always have voltage fluctations. I am not talking about lightening strikes, or cars hitting poles. The quality of many home electric system sources is always in question. This is why we install ground rods to help keep the neutral bus a base 0. Since the quality of the electrity, the wave formation is a little off, this effects electronic equipment. Some more than others.

This is what was explained why some of my computer power supplies died early, and why GFCI's trip with nothing plugged in them, but reset easy. If it was a physcal cause like wires damaged, or chaffed wires, the GFCI would trip and not reset.

Just working on what made sense to me, not a GFCI expert. :D

later,

tom @