GFCI Circuit with Dimmer Switch

[ChrisRO528]

Recently renovated a covered back porch for a customer. Used 12/2 wire on a single 20 amp breaker. The first fixture was a gfci, then a switch (controls 2 ceiling fans), then another receptacle, then a long run to the other side of the porch, about 40 ft. Halfway across that run I spliced in a another switch that controls 5 recessed lights.
Customer called back and wants a dimmer switch to control the recessed lights. I’m hesitant as I don’t know if the dimmer would affect the gfci. Has anyone run into this before?

 

[Lucien Nunes]

It should work OK. There is a small caveat that dimming creates more ground leakage from fixtures and wiring, due to the modified AC waveform. So long runs of wiring beyond the dimmer (over 100 feet especially in conduit or MC) and some types of higher-output lighting fixtures and drivers can start to create enough ground leakage to contribute to nuisance tripping. But for a few small LED lights and 50 feet of cable it's unlikely to make any difference.