12v pool light conversion using existing 120v wiring and fixtures

[dariushd]

Is this a bad idea to convert to a 12v system using my existing 120v wiring and pentair fixtures in my under water lamps? I read that gfi is useless at 12v, so that makes going to 12v dangerous or against code?
i recently replaced my bulb and a new silicone gasket and I noticed a little water getting into the housing. Im
buying a new gasket (not silicone this time) to try again and thought maybe going 12v would be safer? Also I was told not to put silicone on these gaskets, just confirming this as well.

 

[mechanikmike]

I actually have the exact same question as you, my bulb just burnt out and my fiance does not like the 120v since the pool guy says our ground is missing. As far as the GFCI goes that depends on where your transformer is located, as far as protecting the equipment goes inside your basement by the breaker panel is best, but 12V does not like to travel long distances so by the time you reach the light it probably won't work, and I don't know your local code but here in MA it's against code to run high voltage(120V+) and low voltage(anything under 50V) in the same conduit. If you add a sealed cabinet out by the pool with the transformer then the GFCI breaker will protect the transformer and wiring up to the transformer, but not after the transformer up to your light, and then your 12V will only have to go the short distance from the cabinet to the light. The thing I am not sure on is if the 12V lights are AC or DC, if DC you will either need a special transformer or a properly rated voltage rectifier. Either way you will have to set up separate protection for the 12V side of the circuit, in compliance with local code, circuit breakers for that are easy, they sell weathertight push button reset 12V breakers, I would have to check if there is a 12V GFCI.I am curious to hear other people's thoughts on this, I am brand new to pools but not to electrical and was thinking about the swap myself, without buying a complete assembly.

 

[mechanikmike]

I did some checking as far as the low voltage side and NEC regulations state that a GFCI is not required on any circuit under 15V, so you wouldn't need one after the transformer, but it also states that any transformer used in pool or spa lights for underwater lights must be rated specifically for pools and spas and be grounded inside a listed enclosure that is also grounded. If you do this you will want to have a 120V switch to be able to shut off the transformer in case of emergencies, and also a switch for the 12V side because switching the transformer on and off rapidly will trip the GFCI. In case you buy a bulb where the color is changed by switching the power on and off. Hopefully this helps? And hopefully someone with more pool specific experience can let both of us know if it is cost effective to do this or just replace the complete assembly?

 

[dariushd]

I know I have a spa and a pool light both on two light switches at the pool equipment on the same breaker about 20 feet away. There is a GFI junction box right there at the pool equipment as well, not sure if right before or right after the switches (assume it is before switches), but it's a matter of a couple feet between the switches and the GFI box. Then, I assume straight line from each switch to each light. I would not want to drag new wiring and new fixtures into this. I have 120V LED lights waiting to get installed, but I'm wondering if I should return them for 12V versions and get the transformer to install after the GFI and before the switches.

 

[mechanikmike]

I would say you definitely have to kill all the power out there and do some digging, sometimes people do strange things to save money and they share neutrals to everything, if they have a neutral spliced off of the pool or spa light to something else, like the pump, then you would definitely have to pull some wire, and it shouldn't be in the same pipe as the lighting wiring because then you risk reintroducing 120V to the pool or spa in the event that a wire burns up and melts inside the conduit. Also I would definitely have a switch, not just the breaker, but a regular switch for the transformer so when you are done in the pool you can shut it off. If you leave the power at the transformer it will eat up any savings you create with LED's since a transformer always consumes power.

 

[dariushd]

I think then I should stay at 120v as everything is under concrete, and I could not be sure there are no shenanigans as you mentioned. :-|