Pool lighting gfci problem


I was troubleshooting a pool with 4 lights in in and when I put the gfci load that was through a time to each light they individually worked, but when I tied all of them together it would trip. There was one light that needed a gasket to be sealed behind it and was thinking that maybe it was looosing or gaining some type of induction to the other lights through the water, which was causing it to trip. I checked for continuity between the neutral and ground of every light and between all of them and nothing. The timer had to be changed due to malfunction and I also switched out the breaker and was getting the same thing. Can someone please help me understand why this is happening.

Dennis Alwon

Staff member
Are these line voltage or low voltage lights? If they are 120v then perhaps the wattage is too high. What size breaker? What is the total wattage? If there are 4 lights at 500 watts each that may be an issue.

I would switch out to a new breaker and if it still tripped then try a regular breaker. This will let you know if there is a gfci issue or an overload issue. If the original gfci is weak and you try a reg. breaker first then that will not give you a true diagnosis


It was a 20a breaker so even at 500w your looking at roughly 17 a and that isn’t enough to throw that right away, I did switch out the breaker but not to a regular because it held with the gfci breaker individually but not as a whole.

this thread ended up in the wrong category


Electron manager
GFCI trips around 4-6mA of leakage.

If you have 1.5mA leakage per light, a single light doesn't leak enough to trip the GFCI, but four of them puts you at 6mA, right at the upper end of trip threshold.

Leakage doesn't have to be a damage or defect, could just be capacitive leakage, longer the circuit the more capacitance it will have.