Interestingly enough would the bond grid then not supply the same path to that “ground” that the Mike Holt forum was concerned about since the bond grid is connected to ground at the sub panel and at the J Box (and at the light niche)?
Grounding a 12v pool light
- Thread starter Aquaman7
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Kind of interesting that Calder Sloan's family (the Florida boy electrocuted) lodged a lawsuit against Pentair in June 2014 and Pentair's last version of this manual was updated October 2014. I would have to assume they made extra sure it's correct
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Yeah that's why I posted it since it's in black and white writing. Sorry, didn't mean to jack your thread, I actually have a thread of my own, but my light is a 12V/35W 3-wire light and that Mike Holt forum had me wondering too.
No problem about jacking the thread. We all learn from each other especially when it comes to safety. Like you I also read the Mike Holts thread and was concerned.
You make a good point about Pentair and their 2014 revision. Are you going to connect the ground wire that’s included in your light?
You make a good point about Pentair and their 2014 revision. Are you going to connect the ground wire that’s included in your light?
Yeah I'm going to. And then part of my questions around this project was, do I leave the "old" ground from the 120V feed to the Jbox connected, or disconnect that now that the 12V isolating transformer doesn't include or require it? I'm going to leave that one disconnected. That way my setup matches the Pentair diagram. The transformer will itself will be grounded with its 120V feed from a self-testing GFCI receptacle. I'm also swapping my pump's 20A breaker with a 20A GFCI breaker since that's in the 2017 NEC code update. I'm already in there, may as well do it.
I think you have it right. Everything downstream of the transformer is not directly grounded. The J box is now a low voltage box and the ground wire in the light is basically unnecessary but is acting as a bond. This all makes sense in my mind.
If your going to leave the existing ground disconnected from the Jbox then what’s grounding your niche? The metal conduit terminates at the Jbox.
he has an old metal niche with no ground lug - also his conduit is metal. He said his niche is bonded but never had an independent ground wire. I assume with the niche still bonded and the light now low voltage he is fine.
I'll go find it, but I thought the NEC code says the metal conduit grounds the niche to the J box and the J box is connected to the bonding grid as well. I know bonding does not equal grounding, but it also mentions a bond to ground jumper that happens in the Jbox, right?
Haven't seen one in a while but the Jbox is the split of the system. Towards the panel its 120 transformer back, and towards pool its standard pool wiring for a light. With metal the conduit is the wire, how you proceed depends on what the conduit is doing, ie ground/bond. I've seen them both ways. Usually metal piped is older and doesnt have a bond wire. Are you sure you have a continuous bond thru the system back to equipment and handrails etc?
Sorry Jimmy, I didn't realize you replied. Here's a pic of the jbox with the bond wire on the left. Jbox has two metal conduits and one PVC conduit. PVC conduit carries the 120v wires from the panel, middle metal conduit carries the pool light wiring to the niche, and second metal conduit, I assume, carries the bonding wire. Pool was built in the 70's.
I don't know for certain if all the metal around the pool is in the continuous bond, but I have no reason to think it's not. I am certainly willing to break out some wire and my multimeter to check. Back in the pump area, a bond wire does come up out of the ground and bonds the pump and heater to it.
Keep in mind when this was built they didnt bond pools. The bonding was added later and I've never seen it in a conduit. I would grab a roll of wire or am extension cord and tone it out for continuity to be sure it's all connected. Be sure the PVC has a ground wire and that transfers over to the metal conduit if it doesnt have a seperate ground wire and you end up using the metal for the ground.
Ok, so in the PVC are the brown, white, and green wires from the existing 120v feed. I was going to use the brown and white to now carry the 12v from the transformer. As you can see, the green ground is attached to the jbox grounding terminals on the right there. So then should I just leave that and attach the other end to the grounding terminal back on the transformer? I was going back and forth on doing that because the 12v didn't call for a ground connection from the transformer. So if I go ahead and connect it, would that achieve what you're talking about here?
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