Grounding a 12v pool light

[jamjam]

Though it sounds like Jimmythegreek answered your question here

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?

 

[aquaN00b]

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

It's labeled 12V 35W. I think they use the same housing and wire as the 120V lights to probably make things easier on them for manufacturing is what i was thinking.

 

[jamjam]

It's labeled 12V 35W. I think they use the same housing and wire as the 120V lights to probably make things easier on them for manufacturing is what i was thinking.

See my second post. Since this is a retrofit into a 120v wet niche sounds like Jimmy is saying they want you to wire it the same as 120v.

 

[aquaN00b]

Though it sounds like Jimmythegreek answered your question here

I wasn't totally sure what all he was referring to and that is for a plastic niche. My niche is old school metal with a metal conduit connecting it to the J box. in the J box is also a bonding wire attached to a grounding post in the box. I don't have a bonding lug external to the J box.

 

[aquaN00b]

See my second post. Since this is a retrofit into a 120v wet niche sounds like Jimmy is saying they want you to wire it the same as 120v.

Yeah I saw his post the other day. It could be right, but also, what about the scenario posted in the Mike Holt forum I linked to? Is it possible a 12V light, attached to a 12V isolating transformer, with an "unnecessary" ground could pose a risk if there's a ground fault in the house wiring? The guy on the Mike Holt forum explains the logic better than me.

 

[jamjam]

I wasn't totally sure what all he was referring to and that is for a plastic niche. My niche is old school metal with a metal conduit connecting it to the J box. in the J box is also a bonding wire attached to a grounding post in the box. I don't have a bonding lug external to the J box.

So modern niches have a grounding lug in the inside and a bonding lug on the outside. You run a separate ground to that lug. If you have metal conduit that is acting as your ground. I assume it is bonded from the outside, though maybe not.

to me it sounds like you would connect the integrated ground to the ground bar in your deck box. This would provide no more danger than a grounded 120v light.

 

[jamjam]

A ground fault from your house (if it makes it through the ground to the light) will travel through the ground bar in the deck box or at the niche to the bond grid (the deck box and light niche should be bonded) and you will have no isolation in the pool

 

[aquaN00b]

So modern niches have a grounding lug in the inside and a bonding lug on the outside. You run a separate ground to that lug. If you have metal conduit that is acting as your ground. I assume it is bonded from the outside, though maybe not.

Yeah that's pretty much what I gathered as well. I attached a pic. On the far left is a bare wire I assume is the bond, it goes into a metal conduit into the concrete under the diving board. In the middle is the old light connection, also in a (separate) metal conduit. On the right is the feed from the panel.

to me it sounds like you would connect the integrated ground to the ground bar in your deck box. This would provide no more danger than a grounded 120v light.

Yes that is what i've done so far. My question to Florida Sunseeker was, should I then also leave the ground on the right that's going back to the (now) transformer's grounding bar. This is the part that the post on Mike Holt was about. If this ground is tied in, could that introduce some kind of danger?

 

[jamjam]

Yeah that's pretty much what I gathered as well. I attached a pic. On the far left is a bare wire I assume is the bond, it goes into a metal conduit into the concrete under the diving board. In the middle is the old light connection, also in a (separate) metal conduit. On the right is the feed from the panel.



Yes that is what i've done so far. My question to Florida Sunseeker was, should I then also leave the ground on the right that's going back to the (now) transformer's grounding bar. This is the part that the post on Mike Holt was about. If this ground is tied in, could that introduce some kind of danger?

I’m not an expert but what you have here would be a continuous connection of all grounds which make their way back to the main bus in your service panel and to ground via grounding rod and connection to your water service (probably). The light niche and possibly your deck box are also tied to your bonding grid. If you are in the pool and it is energized you should be a bird on a wire (assuming everything is properly bonded). I think this setup would be the same level of safety as a 120v light that is properly grounded and bonded.

 

[aquaN00b]

I’m not an expert

And I'm an Aqua Noob

 

[jamjam]

I did do all my own electric and bonding for my pool so I was you reading every forum possible. But unlike you I have a modern light niche. I think the boy in FL died not from a simple ground fault from the house but an improperly installed or faulty transformer (which is ironic because had they had a 120v light he would be alive).

 

[aquaN00b]

I did do all my own electric and bonding for my pool so I was you reading every forum possible. But unlike you I have a modern light niche. I think the boy in FL died not from a simple ground fault from the house but an improperly installed or faulty transformer (which is ironic because had they had a 120v light he would be alive).

Yeah I have two kids 3 and 6, so that story scared the living poop outa me. I could easily call a pool pro or electrician to check my work, not sure they would "sign off" due to liability tho. I could get them to do the work but I've had such a bad run of contractors where i live. My dad was a union electrician so I picked up some things from him, but like most kids I didn't listen to him all the times I should have. I paid a licensed "master electrician" to install a couple ceiling fans because I didn't feel like spending all day running wire/etc. The guy installed an ordinary "old work" box with the flimsy plastic tabs that clamp to drywall. They aren't even rated for lights let alone moving fans. I went to change the fan's light and the whole thing fell out of the ceiling in my hand. I had to go get a proper retro fan box with the joist bar and fix both of them. At least I got out of running the wire and got my money back from him. I was livid. Another master electrician swapped the house panel before we bought the house and put the range and microwave on the same circuit and it kept popping. I just don't trust anyone around here lol.

 

[jamjam]

I found lamp cord buried in my ceiling and no box for my ceiling fan. As long as your niche is bonded and you transformer is grounded I think you are fine. I have small kids as well so I triple checked my work and also got it underwritten (you could get an inspector out to check).

 

[aquaN00b]

I found lamp cord buried in my ceiling and no box for my ceiling fan.

Wow small world, our first home the inspector found a twist connected (no nuts) lamp cord running in the attic through the blown insulation into the master bedroom ceiling fan. Good inspector.

As long as your niche is bonded and you transformer is grounded I think you are fine.

So as in, proceed grounding the light like it's 120V or leaving the extraneous grounds capped and disconnected? Possibly either might be fine I'm thinking.

and also got it underwritten (you could get an inspector out to check).

That's a really good idea, I actually thought of that the other day and wasn't sure if I could have an inspector out. Do I have to pull a permit first?

 

[jamjam]

Wow small world, our first home the inspector found a twist connected (no nuts) lamp cord running in the attic through the blown insulation into the master bedroom ceiling fan. Good inspector.



So as in, proceed grounding the light like it's 120V or leaving the extraneous grounds capped and disconnected? Possibly either might be fine I'm thinking.


That's a really good idea, I actually thought of that the other day and wasn't sure if I could have an inspector out. Do I have to pull a permit first?

if it were me I would be inclined to connect all grounds. But I agree that keeping the light ungrounded on the low voltage side is probably safe.

Look up electrical inspector in google for your area (in my area all electric inspections are done by private inspectors). I assume you can find a private inspector without actually opening a permit.

 

[aquaN00b]

Found this today on pentair's website for the Amerilite product which is exactly the same as my light. Don't know why I didn't check sooner. I'm just going to attach the ground to the j box from the light, then leave the ground off from the j box to the transformer.

 

[jamjam]

Curious as to what the green ground from the light to the J box is actually doing here since there is no ground between the jBox and the transformer

 

[ajw22]

Curious as to what the green ground from the light to the J box is actually doing here since there is no ground between the jBox and the transformer

Belts and suspenders. Lots of things in the electrical system have conservative redundancies for safety. That ground wire may help and can't hurt.

 

[aquaN00b]

Curious as to what the green ground from the light to the J box is actually doing here since there is no ground between the jBox and the transformer

Tying into the bonding grid maybe? In the j box the bond and ground wires are all electrically connected because they bolt into the jbox steel

 

[jamjam]

Yeah there is that.