Need electrician's input on GFI breaker...

[S10xGN]

I could use some electrical "genius" diagnosing my pool light. The GFI breaker is in constant trip and will not reset. I have lifted the wires marked "A" which are for the light, and the breaker will reset. I can plug a 1/2" drill in the outlet, the breaker stays in, and the drill motor runs. However, when I lift the wires marked "B" (only the light wires connected), the breaker stays tripped.

It's the light, right? Well, maybe not... I removed the wire nuts in the junction box, wired a pigtail to the light, and plugged it into a non-GFI outlet elsewhere. The light comes on and stays lit. After removing the pigtail, I megged across the terminals and got 75 ohms from white to black, 28k ohms from black to green and 28k ohms from white to green. I"m thinking the resistance from ground to the black and white leads should not be there (infinity) and that's what's causing the breaker to trip. I pulled out the light and there's no indication of any "problem". Could the sheathing be bad? In the past, replacing the GFI breaker "fixed" the problem, but this will be my 4th GFI breaker @ $50 in 20 years and I'm beginning to smell a rat. Don't they normally last longer? I'd hate to have to pull 50 ft of 1/2" diameter cable to replace the lamp

assembly.

 

[John Larkin]

Is that a sub-panel or your main panel? Is the coiled wire from the gfi breaker connected to the buss bar?

 

[regan j]

I'm not an electrician but why can you not put in a GFCI Receptacle in where it is needed instead of the breaker?

 

[whitehot84]

According to your diagram you are switching the neutral on the light. Run your white to the light directly from the panel and make sure the pigtail is on the neutral bar. Then run your hot through the switch to your light. When you drop the neutral the breaker senses it and turns off.

 

[gnxtc2]

Few things

- The pool light and it's enclosure (called a niche) is inside the water. The niche has a pipe that goes to the deck box (in your pic the junction box). When the pool was first installed, the pipe that enters the niche, should have had potting compound installed to prevent water from entering the pipe. Now if does not, that pipe fills with chlorine or saline water. The pipe should be either brass or PVC. The J-Box should above the water line of the pool. The cord that attaches to the fixture is in this pipe. The water could of over the years attacked the conductors/insulation hence giving your ground fault.

- Water could be entering the cord connection at the fixture.

- According to your diagram, it appears it's wired wrong. The hot leg should be on the switch not the neutral. The white wire coming off the breaker should be on the neutral bus. The neutral wire coming from the light/switch goes on the neutral lug on the breaker. Also the hot leg goes on the breaker.

Is the pool above or below ground?

Let me know how you make out.

Billy T.
gnxtc2@aol.com

 

[turbonut85]

Few things

- The pool light and it's enclosure (called a niche) is inside the water. The niche has a pipe that goes to the deck box (in your pic the junction box). When the pool was first installed, the pipe that enters the niche, should have had potting compound installed to prevent water from entering the pipe. Now if does not, that pipe fills with chlorine or saline water. The pipe should be either brass or PVC. The J-Box should above the water line of the pool. The cord that attaches to the fixture is in this pipe. The water could of over the years attacked the conductors/insulation hence giving your ground fault.

- Water could be entering the cord connection at the fixture.

- According to your diagram, it appears it's wired wrong. The hot leg should be on the switch not the neutral. The white wire coming off the breaker should be on the neutral bus. The neutral wire coming from the light/switch goes on the neutral lug on the breaker. Also the hot leg goes on the breaker.

Is the pool above or below ground?

Let me know how you make out.

Billy T.
gnxtc2@aol.com

x2

 

[S10xGN]

I can't seem to "multi-quote" posts any more, so here goes:

John, it's a sub panel and yes the coiled pigtail is connected, I just didn't bother drawing it in.

Regan, the light is wired direct through a switch, not plugged in (at least, not normally). I only plugged it into a non-GFI circuit as a test.

Billy (and white hot), I wired this up myself, but the city inspector did sign off on it before the sheathing and plaster work. Because it's been like this for 20 years, I'm gonna have to leave it like it is because I cannot justify tearing out my walls to fix it. Are you saying it will be a hazard?

My lamp has PVC conduit as you described, but I'm hoping that there is no "potting" material in there because if I end up pulling that cable out, it'll prolly break and then I'll just quit and do without a light.

My brother's son-in-law gave me something to try. He thinks there may some moisture or corrosion in the bulb socket so I'm leaving the light on overnight to see if it'll dry out enough to be hooked back up the GFI circuit. I'm inclined to think that may be it, as in the past this was rectified by putting a new GFI breaker in (which may have been more fault tolerant by nature of being "new"). If I can't get it to work, next step will be trying to pull the old cable out. If it comes out, I spring for a new 12v LED lamp that does not require GFI protection...

 

[TexasT]

Used to be the NEC required the neutral and ground buses to be separated in a sub panel, and it had to have its own driven ground rod. Stray voltage does mean things. Been a while since I cracked open an NEC code book.

 

[whitehot84]

The code requires that you use a 4 wire system. The separate grounds can have different potential. The ground must come from the source now.

 

[S10xGN]

Used to be the NEC required the neutral and ground buses to be separated in a sub panel, and it had to have its own driven ground rod. Stray voltage does mean things. Been a while since I cracked open an NEC code book.

The code requires that you use a 4 wire system. The separate grounds can have different potential. The ground must come from the source now.

I guess my inspector overlooked these, or they weren't in effect at that time, or he didn't think it was too big a deal.

Anyways, problem solved! After leaving the lamp on overnight, I rewired the leads back into the GFI breaker and was then able to reset it. Thanks to all for pointing out my wiring errors, I may just swap the "blacks and whites" at the breaker and stick a note in the box explaining why...