Pool GFI Revisited - test results! Pipedown?

Question

OK - I pulled off the top of the deck lamp junction box and isolated the wires going directly to the underwater bulb (recall that turning it on trips the GFI, which tests to be working correctly.

Between the two leads to the bulb (green and black) there is continuity. Between each of the individual leads and the pool ground (electrical junction box) there is also continuity. I think this is expected from the green (ground) lead --- but I'm guessing the fact that the black lamp lead is also grounded is what's causing the GFI to trip.

Is this right?

What's the next step in repair? Pulling the wire to the niche and replacing --- or is pulling the lamp housing up the surface for inspection next?

Thanks for ideas?

Duane Bozarth · Accepted Answer

Well, if the hot side is grounded there's a problem... :) But "continuity" is something else..if the bulb is intact, there will be continuity through the filament--but it shouldn't be a dead short.

I think b) is the next step...of course, I figured it was where you needed to look to begin with, too... :)

RBM · Answer

Now you've confirmed that you have a ground fault in the fixture/wiring. You have three choices: leave it disconnected and have no underwater light, somehow get the stuck screw out and "try" to replace the lamp if bad and the gasket(good luck) or spend a few hundred dollars and get an entire new sealed unit

Matt · Answer

Ron -Buy a new fixture. Don't attempt a repair.I'm not saying it can't be fixed... but do you really want to wonder ifyour fix is holding up every time you jump in the pool?Even if it's $1000; either buy a new fixture, or go without.Well, thats what I would do, anyway.

ron_windham · Answer

OK - My work is cut out: Hire an electrician!Thanks for the feedback - at least I"ll now what I'm up against.Cheers!

gfretwell · Answer

The next step is getting that screw out and getting the lamp out. Once you get it up on the deck you will know what is next. You can get a new lamp assembly for about $125-150 on the net. It may just be that the old one is full of water. The socket and wires are "potted" so it is not likely there is a problem there. If you do decide to pull out the light BE SURE you tie a piece of 1/4" nylon rope or similar to the cord securely and pull it through so you can pull the new cord back in. The "electrical" part is just to connect the 3 wires in the cord back to the junctions in the deck box.

Richard J Kinch · Answer

Check the fixture. Not a big job to remove and disassemble.

Regarding the wiring, wet niche lights are typically wired with just UF cable directly buried in the backfill. The via into the niche is just a

1/2 ID tube that is filled with caulk. If there's a problem inside the niche or the via, then you may fix it. If the problem is some buried wire, then oh-oh.

See my page at

formatting link

RBM · Answer

In the USA it is illegal to wire wet niche fixtures with UF cable. The PVC pipe feeding the niche will probably be 1" as it must contain a #8 solid bonding wire along with the fixture's feed cable

Richard J Kinch · Answer

Depends on the age of the pool and code in effect during construction.In that case, a problem is still typically repairable from the pool side.

RBM · Answer

If the pool was built in the US in the last thirty years, UF feeding wet niche fixtures was and is illegal. If the fixture is properly installed and wired it can either be repaired from the fixture end or the whole unit and attached rubber cord can be removed and replaced without digging or disturbing anything

gfretwell · Answer

Make that more like 50 years, long preceeding the invention of UF.

Pool GFI Revisited - test results! Pipedown?

Join the Discussion

Didn't find your answer?