Grounding a 12v pool light

Aquaman7

Well-known member
Sep 15, 2019
374
NJ
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

Gold Supporter
TFP Guide
Jul 21, 2013
24,667
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Yes, it needs to be grounded. See step L...

B67766AA-924C-4C6D-B090-BD4054BDFBB8.png
 
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JamesW

TFP Expert
Mar 2, 2011
23,910
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.
 
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jimmythegreek

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
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Morris Cnty NJ
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?
 
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JamesW

TFP Expert
Mar 2, 2011
23,910
The metal strip in the niche is a water bond.

a2274213-9b1b-43b2-8bae-faf7d6f5e75a-jpeg.166899
 
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Aquaman7

Well-known member
Sep 15, 2019
374
NJ
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.
 

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JamesW

TFP Expert
Mar 2, 2011
23,910
Are you doing the project yourself or using a builder?

Will you be getting an electrical inspection?
 

Aquaman7

Well-known member
Sep 15, 2019
374
NJ
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

TFP Expert
Mar 2, 2011
23,910
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

Well-known member
Sep 15, 2019
374
NJ
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

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
3,515
Morris Cnty NJ
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

TFP Expert
Mar 2, 2011
23,910
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

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
3,515
Morris Cnty NJ
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
 
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