I put a new GFI outlet in my basement for a sump pump. There was
already an outlet there, I just replaced it with a GFCI.
When I flipped the power back on there was a flash, and the GFCI
tripped. [I don't think the breaker did-- but I'm not sure.]
I took it apart & examined the GFCI. There was some carbon on one
end but I couldn't see anything that looked like it had arced.
Other than smoke residue I couldn't see anything wrong inside the
box-- so I wrote it off as a bad GFI & replaced it.
A few weeks later the GFCI tripped while I wasn't there. I reset it &
it was fine. . . until that night when it tripped again. It
tripped one more time in the next 24 hours-- so I bought yet another
GFI but it hasn't tripped again in several weeks.
Yesterday I unplugged the sump pump to do some work & noticed the
cheap clock radio that I was listening to go significantly noisier.
Plug in the sump, the radio clears up. It was repeatable several
times. Whether or not the pump is running doesn't matter. If it
is plugged in the radio quiets down. [the switch mechanism on the
pump is one of those diaphragm types that has no visible moving parts]
I've plugged one of those cheap circuit checkers [that plug in with
the 3 lights] & it didn't complain. I also had a Kill-O-Watt plugged
in to the outlet for a week or two & it wasn't indicating any leakage.
Any ideas what I'm looking for? Why would an appliance that is
[apparently] working properly and not running have any affect on a