My barn has three 20 amp circuits for recptacles, each with GFCI breakers, and two 15 amp circuits for fluorescent lights, neither GFCI protected; each of these circuits are totally separate from each other, except that they are all fed from a single panel. I originally wired this about 19 years ago, and everything has worked fine until now.
Last night, I replaced an old magnetic ballast in one of the fixtures with a new electronic ballast, and now, when I turn on the switch for that set of lights, the light comes on, and that breaker does not trip, but one of the GFGI breakers for my receptacle trips. I repeated this process about a dozen times; each time, the same GFCI tripped, but each time I could rest the GFCI, and both the lights and the receptacles remained on.
So, my plan is to unplug the light, and check both the receptacle and the plug, to make sure that I do not have anything crossed there, although I do not expect that to be the case, simply because I double checked everything as I went, and the breaker for the light circuit does not trip.
Next, I plan to remove the panel cover, and check that all of my wires are secure, including the gounds and neutrals, although, again, I do not expect to find a problem there, only because I do inspect my panels, etc. periodically, and did so within about the past 6 months.
If nothing else shows up, I plan to switch the affected GFCI with one of the other ones, and, assuming I find it to be the culprit, repace it.
I welcome, and thank you for, any other thoughts or suggestions.