Pop ) said...

Umm, no, they do NOT do that "sometimes" if everything
is installed correctly. Sorry, don't mean to sound
confrontational, but a GFCI tripping is an indication
that something went wrong whether it was water or
whatever that caused it to trip. They don't "just do
that" for no reason. They would be useless in such a
case.

Sorry to burst this bubble, but GFCIs can trip for what *appears*
to be "no reason", and this is why codes never make them manditory
for outlets used for refrigerators.

Transient noise on a power line can cause GFCIs to trip, however
I suspect it would be EXTREMELY rare for such noise to trip a
GFCI that did not have a load on it at the time. Since the original
poster mentioned lights that stopped working, it sounds to me that the
lights are downstream from the GFCIs and could possibly have been a
load on it when a transient (spike) hit it.

Transients are high frequency noise on the power line, and high frequencies
propogate slowly (relative to the speed of light) down a transmission line,
which the power line would serve as. GFCIs work by detecting a difference
in current between the line and neutral. The slow propogation of a spike
can lead to a sensitive GFCI to detect an imbalance long enough for it to
trip.

This would *appear* as a "no reason" trip, yet there is a reason. It
is just not a safety reason.

I once knew someone who had a pool pump on a GFCI and claimed that
every lightning storm his pool was "hit by lightning" because the GFCI
would trip. LOL -- if his pool was hit, his problem would be a lot
greater than just resetting the GFCI! The electrical storm was causing
transients on the power lines in the area that were the cause of the GFCI
tripping.

--
Calvin Henry-Cotnam
"Never ascribe to malice what can equally be explained by incompetence."
- Napoleon
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