I have a fluorescent light plugged into and outlet that comes BEFORE a GFCI
outlet on a circuit.
About 5% of the time I turn the light off (I have a switch leg going to that
outlet) the GFCI trips.
It only happens when I have an air filter turned on that is plugged into the
It is not clear to me why turning off the light would affect the GFCI coming
after it. (Yes, I do have the GFCI installed correctly; not backwards.)
Even if there was a ground fault, and I can't see why there should be one,
the GFCI wouldn't see it.
May have something to do with the starting on the ballast. Rapid start
or instant start. A ballast in a fixture is essentially a transformer.
A transformer with an inductive load.
What is nuisance tripping of a GFCI?
It takes only 5 mA (0.005 A) of current leakage from the hot wire to
the ground to cause a GFCI to trip. A small amount of leakage current
may be difficult to avoid in some normal circuits. Hand-held power
tools do not cause a tripping problem if the tool is maintained in
good condition. Some stationary motors, such as a bathroom vent fan or
fluorescent lighting fixtures, may produce enough leakage to cause
nuisance tripping. Another problem may be a long circuit with many
splices. If possible, keep GFCI circuits less than 100 feet long. To
avoid nuisance tripping, a GFCI should not supply:
Circuits longer than 100 feet
Fluorescent or other types of electric-discharge lighting fixtures
Permanently installed electric motors
I have seen it before.
Even having the lighting on the line side or anywhere in the circuit
it can cause the ground fault to trip
I would suspect loose wring or somewhere there is leakage from the
grouding and grounded conductor.
Are the light fixtures grounded?
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