Lately, I have had an issue where sometime during the night the main GFCI breaker would trip.
The only thing different on the nights that this happened was that one of the nights was (1) extremely cold, and the other night was (2) extremely foggy.
Circuit Design & Load: Not all receptacles on the circuit are GFCI, as some are located inside an enclosed outbuilding. The entire circuit is very lightly loaded with a few LED lights and IP cameras, drawing at most 7 amps.
Why GFCI Receptacles on GFCI Circuit? The entire circuit is on a GFCI breaker at the main panel that also serves a pool sub-panel. Installing GFCI receptacles was purely in preparation for offloading those structures to a new service in the near future.
Further examination identified that the GFCI main breaker was tripped, however, none of the individual GFCI receptacles were tripped nor was the standard 15A breaker in the subpanel that serves the outbuildings.
Is it possible that the extreme cold or higher moisture content contributed to the main GFCI breaker tripping, or furthermore that the dual layer of GFCIs are causing conflict in this environment?
Update: There is also an APC BackUPS that is on one of the non-GFCI receptacles. I cannot rule out that it is doing a self-test when the GFCI breaker trips.