Turning off fluorescent light trip GFCI on different ?

[Toller]

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 GFCI.

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.

Any ideas?

[Tazz]

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.

Reference.

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

[Toller]

But if the light is before the GFCI, it wouldn't matter what happened to the current going through the ballast since it wouldn't affect the GFCI. Would it?

[Tazz]

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?

[hallerb]

try replacing GFCI it may be overly sensitive. I tossed one that nuisance tripped too ofet, its replacement has been fine

[Myxylplyk]

ANY flux on the common leg of the curcuit will cause the GFCI to trip down stream, assuming you have them wired in series.