I have two pool lights connected to a 15a Square D GFCI breaker. The breaker started tripping recently. After a bit of troubleshooting I've found that each light works individually but trips the breaker when both are connected.
- I removed both light enclosures from the water and verified the metal case is grounded.
- The inside appears to be dry, no sloshing water.
- checked resistance between each wire running to the fixture, resistance is zero
- Enclosures have LED lights installed about 2 years ago, clamp meter shows each draws about 36W
- The panel with breakers is outside, but dry and looks good inside.
Ideally, I'd like to open the fixtures and remove the bulbs but that would require me to buy new gaskets. I was trying to find a way to see which component may be bad without throwing money at it.
The lights had originally been setup with a standard 20a breaker, GFCI receptacle/switch and 500w lights. A few years ago, I wanted to add a smart switch for the lights so I replaced the breaker with the 15a GFCI, swapped the outlet/switch for the smart switch and added LED lights.
The breaker isn't that old, I don't think that's the issue, but I could return to the 20a and add a GFCI receptacle I have on hand and test that.
Any ideas or should I just order the gaskets and a new bulb?
I removed the GFCI breaker and added a standard 20a, tested with both lights and they both came on. In this doomsday configuration, the clamp measured no current on ground or with the hot and neutral clamped together. As suggested, the clamp is not sensitive enough.
I also added a GFCI receptacle in between and it also trips immediately.
I've restored the original GFCI and single light and will probably order a pair of gaskets so I can open the light housings.