Grounding a 12v pool light

[Aquaman7]

Hello,
I installed a Pentair plastic wet niche in my inground polymer panel pool. The light fixture is 300w, 12v. Does the fixture have to be grounded? The light fixture itself is grounded and the niche is bonded.
Thanks.

 

[ajw22]

Yes, it needs to be grounded. See step L...

 

[Aquaman7]

No, plastic niche does not get grounded.

Even if it has a metal rim around the inside? Here is a picture of the niche.

 

[ajw22]

Yes, it needs to be grounded to the light junction box. See post 2.

Pool Light Junction Box.jpg

• ajw22
• Apr 25, 2020

 

[Aquaman7]

Yes, it needs to be grounded to the light junction box. See post 2.

Pool Light Junction Box.jpg

• ajw22
• Apr 25, 2020

Ok. Thank you aj.

 

[JamesW]

There are two connection points on the niche. The outer connection lug is the bonding lug. Since the niche contains metal, it has to be bonded. This bond lug is physically/electrically connected to the inside lug and to the metal strip in the niche. The metal strip creates a water bond.

The purpose of the inside lug is to create a connection point for a supplemental equipment grounding conductor between the niche, the light and the junction box. The supplemental grounding conductor can be metal conduit or a #8 green insulated grounding conductor in solid or stranded.

If you have a listed low voltage light that does not require a ground, the supplemental grounding conductor is not required. The supplemental equipment grounding conductor is also referred to as a “bonding jumper” because it bonds the niche to the junction box, but its purpose is grounding, not bonding.

The installation manual says to use the ground wire and it doesn’t seem to mention an exclusion for low voltage.

The code is confusing at best. In my opinion, the internal grounding conductor is not required for a listed low voltage light that does not require a ground.

Some inspectors might require it if they think that it’s required. So, you’re probably safer to include it. It will also give you the option to change to a 120 volt light later.

It looks like you already have the #8 wire in the conduit anyway. So, might as well use it.

Also, the internal connection needs to be sealed with an approved potting compound to isolate the connection from the water.

The light fixture itself is grounded

If it's a low voltage light, it won't usually have a ground. Are you sure that it has a ground?

If the light has a ground, then you do need the internal supplemental #8 green insulated equipment grounding conductor (bonding jumper) from the niche to the junction box.

If the conduit from the niche to the junction box is metal, the ground wire is not required in either case because the metal conduit is the grounding conductor.

Also, if the junction box has a bond lug on the bottom of the metal base, you should bond it with a bond wire to the bonding grid.

 

[jimmythegreek]

They want wet niche lights setup like 120v for the event in future someone replaces with a 120v. The bond lug goes back to the lug on outside with bond wire, the inside gets a potted #8 stranded to the ground bar in UL listed Jbox. You attach your green wire to the lug on the end of the metal skinny bar in pic. You potting compound to protect the wire amd lug from chlorine degradation. And best part is the hole for the wire wont fit without trimming the copper conductor it's usually a #12 hole. Just pot over all leaving mo copper or lug visible.

What are you using for a water bond?

 

[JamesW]

The metal strip in the niche is a water bond.

 

[Aquaman7]

The metal strip in the niche is a water bond.

O. Ok.

 

[Aquaman7]

They want wet niche lights setup like 120v for the event in future someone replaces with a 120v. The bond lug goes back to the lug on outside with bond wire, the inside gets a potted #8 stranded to the ground bar in UL listed Jbox. You attach your green wire to the lug on the end of the metal skinny bar in pic. You potting compound to protect the wire amd lug from chlorine degradation. And best part is the hole for the wire wont fit without trimming the copper conductor it's usually a #12 hole. Just pot over all leaving mo copper or lug visible.

What are you using for a water bond?

Thank you Jimmy. This is what I’m using for the water bond along with a bonded stainless steel ladder.

 

[JamesW]

Are you doing the project yourself or using a builder?

Will you be getting an electrical inspection?

 

[Aquaman7]

Are you doing the project yourself or using a builder?

Will you be getting an electrical inspection?

Yes. I installed it myself. I have the final electrical inspection tomorrow. I already ran the ground wire, was just asking because I thought 12v didn’t need it. I read from Mike Holt that if you have a short in the house it can transfer to the pool via a ground wire

 

[JamesW]

I already ran the ground wire, was just asking because I thought 12v didn’t need it. I read from Mike Holt that if you have a short in the house it can transfer to the pool via a ground wire

Does the light cord have a ground wire or is there a ground wire from the power supply to the junction box?

With low voltage lighting, I don't think that you will have those grounds.

If there is no ground in the light cord and no ground from the power supply to the junction box, you probably don't need the ground wire from the niche to the junction box.

Your local code might require the ground wire or the inspector might require it if the code says to follow the installation instructions from the manufacturer.

In any case, the niche should be bonded from the back to the equipment, which is also grounded, which connects the bond grid to the grounding system.

So, either way, the light is grounded.

 

[Aquaman7]

Are you doing the project yourself or using a builder?

Will you be getting an electrical inspection?

Yes. myself. I have the final electrical inspection tomorrow. I already ran the ground wire, was just asking because I thought 12v didn’t need it. I read from Mike Holt that if you have a short in the house it can transfer to the pool via a ground wire

 

[jimmythegreek]

Sounds like you got it covered. If you pulled the permit yourself he will be thorough and nit pick. Make sure any outlets nearby even on house exterior are gfci. I asked about the water bond because every inspector I've encountered in NJ specs minimum size area for the water bond and pentair niches dont make it. Haywards do sometimes. They really bust chops here in NJ and make their own rules at times

 

[JamesW]

It looks like there is enough surface area of metal in the niche to qualify as a water bond.

It looks like a strip and a ring.

 

[jimmythegreek]

I agree James. These guys here in NJ have their own way. This is the land where they were making guys use $2k copper bonding mesh under pavers for a few years for nothing. Now that's faded away and were back to a simple loop with 4 attach points. Electrical is the biggest pain when building a pool. Worst when your in a big town and you get 2 different inspectors from same office that want something different or additional over the first guy

 

[Aquaman7]

Thanks guys for the help.

 

[aquaN00b]

Does the light cord have a ground wire or is there a ground wire from the power supply to the junction box?
With low voltage lighting, I don't think that you will have those grounds.
If there is no ground in the light cord and no ground from the power supply to the junction box, you probably don't need the ground wire from the niche to the junction box.
Your local code might require the ground wire or the inspector might require it if the code says to follow the installation instructions from the manufacturer.
In any case, the niche should be bonded from the back to the equipment, which is also grounded, which connects the bond grid to the grounding system.
So, either way, the light is grounded.

Hello, I'm in the same boat. Bought a new 12V/35W LED light to replace an ancient 120V/500W light. I bought an Intermatic PX50 transformer. AJW22 helped me on another thread but the fact that this new light has a ground in its cord just has me scratching my head. Why would they do that? And I also read on the Mike Holt forum the same thing about a ground fault in the home possibly making its way to the pool via an "unnecessary" ground. In fact I think that's how the boy in Florida Calder Sloan died from his pool's 12V light. I can't find a lot of details on the case, but i do believe i read that they had poor grounding in the house and a fault made its way to the pool light and he touched it.

Anyway, I bought the light from Florida Sunseeker on their recommendation to fit my old-school niche and emailed their support about the grounding and got.....a response. My main question was that I am re-using the existing 120V wiring for the 12V run from the transformer to the light's JBox and was wondering if i should just use the ground included in that to tie in the ground coming off the light cord. Their response: "I talked to our electrician about the ground. He explained that the ground from the light should be pulled over the 120volt side thorough a hole near the bottom, and then connected to that old ground wire from the equipment pad, the wire connector can go in the 120volt side of the transformer. Your electrician should say the same thing, it should be no different with the pool stuff."

It just makes no sense to me why this should be done. I would ask electricians and pool folks here where I live but it feels like a 1 in a million chance to find someone that would actually know the answer to this.

EGC on a 12V pool light

I've spent the evening looking at a few hundred posts on low-voltage pool light grounding (not bonding), and can't seem to find a satisfactory answer to this, even though the topic of pool lights has been covered extensively. I'm looking at a 12V pool light, and the cable from the lumiere...

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[jamjam]

You sure you didn’t get the 120v version of the light?