What are typical causes of nuisance trips with two pole GFCI breakers with neutral (Not 240V)? What techniques can I use to diagnose them?
I put a two pole GFCI breaker on an MWBC circuit, as discussed here.
Currently, one of the legs "A" is connected to some existing room wiring. A few lights and outlets. The other leg "B" just has one 4W light bulb nutted directly to it for testing. (It's all temporary, the cables will be rerouted and each used for a single hard wired bathroom fixture).
In the current configuration, the breaker pops sometimes. It never pops randomly on its own. It popped several times when I turn on a light on leg A. For a while it would not reset, but when I removed the 4W bulb on leg B, it did reset .... then I replaced the bulb and it stayed on. Then I turned various lights on and off and it still stayed on and I removed and replaced the 4W bulb ... everything good.
I cannot identify a specific set of circumstances that reliably make it pop.
I'd like help with how to diagnose this. I'm concerned about the things I don't know about two pole GFCI breakers.