Electrical Pool Lights wiring question...

[Wayne 962]

I posted this on www.electriciantalk.com but those parsimonious twits said, "hire a professional" and then deleted / locked my post. What aholes.

So maybe someone here can give me some feedback on this. I do actually want to hire a "professional", but I don't trust anyone these days, particularly when "professionals" make mistakes that kill kids (as seen in Florida).

Thanks in advance.

Thanks in advance for input. My experience level is very high (mechanical engineer), but not to the level of a professional. I've done light switch replacements and simple fixes around houses / buildings.

My question is on the topic of 120-volt pool lights - an inherently dangerous design where there are many points of failure that could lead to issue, especially as equipment (in a salt pool environment) ages and deteriorates.

I would like to upgrade my 120-volt pool lights to 12-volt. I know that I need an external, electrically isolated 120V AC to 12V DC transformer to power the new lights. However, I have some questions on the wiring and wiring safety:

1- The new lights are 12V DC, but for some odd reason, they still include a green grounding wire (some of them, the Pentair ones do - not sure about all of them). On "pool forums" people have been like "who cares, it's an extra wire, and it's probably there as a requirement so that if someone goes back to 120-volts in the future, then it's safe." Good thinking on the surface, but there is at least one incident where this green grounding wire was not connected to anything (because one doesn't need it on a DC circuit), and then the loose "grounding wire" became looser and contacted a 120-volt hot spot in the junction box and then energized the pool light housing and killed some kid in Florida. Very sad case: Google "Calder Sloan Swimming Pool" for more info (I'm not allowed to post links yet).

2- With that in mind, I think that it would be best (or code) to not mix the 12-volt wiring and 120-volt wiring in the same junction box? Right now, there is a big junction box with five "outputs" - three pool lights, a 120-volt outlet, and I think the fifth one powers the pool cover (not sure). If I don't update this myself, I'm thinking that I should insist that the electrician separate all of the 120-volt from the 12-volt physically with separate junction boxes? Is this code? It would seem like it would be for pool lights.

Thoughts would be appreciated - the typical Google search didn't produce anything useful or definitive.

-Wayne

[greglepore]

Personally, I think that's overkill - so long as you don't terminate the 12v wiring inside the j box. All of the dc wiring should run thru the box to the xformer in its original sheathed cable, and the sheathing doesn't get removed until its clear of the 120v stuff. Your conduit to the lights likely terminates in the existing j box, so to completely separate out the wiring you'd need to put s bends in the conduit to relocate its termination.
Having the sheathed cable pass thru the existing box to an external location for the xformer is safe enough for me. This assume appropriate gfci and pool bonding, which is necessary regardless.
Not a pro, but I've done a fair amount of pool and spa maint...

[Wayne 962]

Hmm. This gives some good thoughts - I should post a pic. Separating the 12 v from the 120 junction box shouldn’t be too difficult - there are individual conduit pipes coming up from the ground. I can just tap on to the existing conduit and then run the 12 directly to the transformer or to an additional “12 v only” junction box.


Wayne

[Cajundaddy]

Retired from the swimming pool industry and never made a transition from 120VAC lighting to 12vdc lighting but... Best practices with lighting, audio, and machinery always suggest physical separation of 120VAC and 12vdc circuits. I would not connect them in the same J-box but I would still have a bond wire from the underwater fixture connected to everything else (bond wire is different than green ground wire).

This is the current Florida Code for submerged luminaries and it appears that a bond or ground is not required. The J-box for 12vdc does require separation from 120VAC circuits. I hope this is helpful. Pentair tech support line also used to be very helpful when you hit a snag like this.
Cheers!

https://floridabuilding.org/fbc/thecode/2017_Code_Development/2017_Resources/Swimming%20Pool%20Electrical%20Safety%20-%20fact%20sheet%20-%202016-06-30.pdf

[greglepore]

Yeah, I agree that separating them isn't all that difficult, but once you do that you'll have a 90 or worse an s bend in the conduit - if and when you replace something you have to pull the cable thru that, which while doable isn't fun or optimal. A pic would help, but I'm envisioning that you have a large 120v box with 3 120v light cables tied to one 120v switch source for the lighting, and a separate 120v switched feed tied to the cable running to your power cover. So 5 or 6 conduits - one or two for the 120v in 4 for the 120v out to lights and motor?
As above, the bond is important and different, don't disturb it when you working in the light niches. It should be number 8 copper tied to anything metal in or around the pool-its to ground out stray current that can exist independent of the pool circuitry .

[greglepore]

Now that I think about it the 12v cable is likely much small dia. than the 120 so probably very easy to pull thru a bend....
The place to ask for sure is troublefreepool. Its the Pelican of diy pool sites, and a fair number of pros post.

[Wayne 962]

[Wayne 962]

Sorry, the iPhone got confused. I'm not at the house right now, so I can't take a "real" photo.

I think if i simply cut the conduit for the pool lamps short, then I can can simply add on a flexible conduit and run it over to the wall where the 12V transformer will be? That way, the 12V wires and the 120V wires will never be in the same junction box, and never have a chance to "commingle".

I know that a few of you said that if I simply run the 12V through the box and do not terminate in the box, then I should be okay, but if there is a deterioration of the sheath or something odd (like a mouse chewing stuff), then there is indeed a chance that they can connect. Very slim, but we're not talking about blown equipment - we're talking about pool lights which can easily kill people?

-Wayne

[Wayne 962]

Originally Posted by greglepore

Yeah, I agree that separating them isn't all that difficult, but once you do that you'll have a 90 or worse an s bend in the conduit - if and when you replace something you have to pull the cable thru that, which while doable isn't fun or optimal.

Well, I can simply cut the conduit and run the 12V wires without any conduit right to the transformer? Or use some small flexible conduit that can just attach on to where it exits the ground?

-Wayne

[Cajundaddy]

Originally Posted by Wayne 962

Well, I can simply cut the conduit and run the 12V wires without any conduit right to the transformer? Or use some small flexible conduit that can just attach on to where it exits the ground?

-Wayne

Without getting a good look at the situation it is tough to advise. The light conduits should be wet below the waterline so normally you would keep them continuous until 18" above grade, otherwise there will be flooding. I would take some pics with measurements and contact Pentair tech support for advice. I am sure they have seen hundreds of these retrofits by now and have a well-established protocol.

What about just separating into two J-boxes. One for low voltage and one for 120VAC so they are completely discrete? It might take an hour to separate them but you will be 100% certain of the result. This should also keep the inspector happy while cutting the conduit may not.

Best wishes!

[Tishabet]

I am not going to be of any help re: your actual question. But, I believe I recall you (pretty sure it was you Wayne but possible I am misremembering) having a thread several years back where you were sealing up your swimming pool with a flush wooden deck. If I am not misrembering, is this the same pool/how did it all go recommissioning the pool/any regrets or lessons learned from the deck approach?