Faulty GFCI Load

Question

I have a pool side GFCI outlet. I am sure that the LOAD from GFCI goes to pool light switch.

I have connected the backyard string light to this outlet. However since connecting string lights, the GFCI keeps tripping as soon as I connect light to this outlet.

I changed the 15A GFCI receptacle but still same issue.

What I saw was that the “hot” wire from LOAD goes to the pool light switch from GFCI receptacle. So, I removed this hot wire from LOAD and now string lights are working and GFCI receptacle is NOT tripping.

What do you think is the problem? Just the hot wire going from LOAD to pool switch or it could be a bad pool light switch?

Is it ok to operate GFCI receptacle for outdoor string light with LOAD wire removed from GFCI to pool light and capped? Will there be any issue with pool electric shock hazard as the pool light is inside pool water and not connected to GFCI receptacle?

Answer 1

If there is no hot line going to the pool light, there is no electrocution danger there, however there is no pool light either. (I would disconnect the Neutral too, just in case).

Are the string lights LED by chance? That could explain why adding them made the pool light circuit trip. The pool light circuit had a small amount of leakage to ground, as in under 4mA, so not enough to trip the GFCI by itself. But if the string lights are LED, the "drivers" that make the LEDs work also have a tiny amount of leakage and combined with the tiny amount in the pool light, added up to be over the threshold for the GFCI detection circuit. If you need the pool light to work, you likely need to change the wiring out to that switch, maybe other components as well.