Convert 120v Light to 12v Low Voltage Using Existing Wiring?

[tim5055]

I agree with danpik. The photo seems clear that the two sets of wires at the pool junction box are both solid conductor wire. The cord from the light will be stranded so it is very flexible. So, again as danpik states somewhere between the light niche and the junction box someone has made an illegal splice.

I would advise two things-

* Turn the breaker off to that circuit and do not use it until the splice can be located and corrected.

* Hire an electrician versed in pool electrical work. It is a unique sub-set of electrical skills because of the unique situation of water and electricity being close together (like the flooded conduit).

While it appears you do have an understanding of normal electrical circuits, when you add in the need to understand grounding, bonding and making sure everything in/around the pool is at the same potential you really need specialized knowledge.

 

[balderdashian]

I have stayed out of this one untill now. Looking at the picture you posted kind of confirmed a suspicion I had about the problem you are having. Usually if a pool light is tripping a GFCI it is because the lamp housing has failed and water was getting inside. The other failure point can be in the wiring but it is rare as the cable assembly is rated for underwater use. If the cable gets damaged it can be the source of the problem. Your cable problem seems to be a splice somewhere in the conduit that has failed. Untill you dig it up and find the splice it is any guess as th where it is and how they did it. My best guess is there is a buried junction box that the wires are clamped to. This may be the reason why you can not pull the cable/wires out.

Thanks. I'm in 100% agreement. I'm certain there is a buried j-box or the cable is clamped down somewhere.

Thanks everyone else too for the advice. Barring discovery of a wireless controlled battery powered pool/spa light, I'm going to have to go without a spa light until I have the entire patio redone. I'm going to try and get the city to pay for it since the root is from a tree on the street.

I am going to replace the working pool light bulb with a 12V one and feed it 12V to the J-box from a isolation transformer. Bulb and transformer retrofit kits are available for sale and specifically meant for this purpose. I'm totally convinced it is not only safe, but far safer than any 120V light going to the pool no matter how properly installed it is.

 

[tim5055]

Thanks. I'm in 100% agreement. I'm certain there is a buried j-box or the cable is clamped down somewhere.

Thanks everyone else too for the advice. Barring discovery of a wireless controlled battery powered pool/spa light, I'm going to have to go without a spa light until I have the entire patio redone. I'm going to try and get the city to pay for it since the root is from a tree on the street.

I am going to replace the working pool light bulb with a 12V one and feed it 12V to the J-box from a isolation transformer. Bulb and transformer retrofit kits are available for sale and specifically meant for this purpose. I'm totally convinced it is not only safe, but far safer than any 120V light going to the pool no matter how properly installed it is.

It's not the voltage that kills, it's the amps, or maybe mA. As little as 500 Ma at 12V DC are given as possibly capable of inducing fibrillation in the heart.

I really do stand by the comment that until the fault in the wire can be located that circuit should be turned off and not utilized.

 

[bradj]

Just so everyone is aware, 12V pool lights being powered by a transformer are not "DC". Discussions about 12V car batteries are sort of irrelevant to this discussion. 12V can be just as deadly as 120V assuming a few ideal conditions, specifically internal body resistance.

It sounds like you've probably isolated out the fault in the circuit running to the spa. For my friends & family I'd just discontinue the use of lighting(wire nut off conductors at breaker) until I had the wiring corrected. Seeing that you have solid conductor THHN coming into the junction box your installation isn't up to code. If you modify this electrical system and do not bring it up to code you will be have a legal liability if someone was to get injured. Considering you have documented your plans here on the internet makes it even worse.

Good luck!

 

[balderdashian]

It's not the voltage that kills, it's the amps, or maybe mA. As little as 500 Ma at 12V DC are given as possibly capable of inducing fibrillation in the heart.

I really do stand by the comment that until the fault in the wire can be located that circuit should be turned off and not utilized.

It has been found, it's the wire between the spa and the j-box.

 

[balderdashian]

Just so everyone is aware, 12V pool lights being powered by a transformer are not "DC". Discussions about 12V car batteries are sort of irrelevant to this discussion. 12V can be just as deadly as 120V assuming a few ideal conditions, specifically internal body resistance.

It sounds like you've probably isolated out the fault in the circuit running to the spa. For my friends & family I'd just discontinue the use of lighting(wire nut off conductors at breaker) until I had the wiring corrected. Seeing that you have solid conductor THHN coming into the junction box your installation isn't up to code. If you modify this electrical system and do not bring it up to code you will be have a legal liability if someone was to get injured. Considering you have documented your plans here on the internet makes it even worse.

Good luck!

I didn't install it. The house came with it. I know it's a long thread and it's easy for people to skim over, but I'm kind of sick of repeating it. I am not reconnecting the spa light. It is to remain disconnected and capped off. The J-box you see with those unsheathed wiring is to the spa light, which again, will not ever be reconnected to any lead.

Because of how mother nature damaged my spa light and could have caused injury, I will be turning my POOL light (which works just fine) into 12V. If the same shoddy wiring exists in my pool light J-box, I wouldn't know.

 

[borjis]

The copper wire you are referring to may be the bond wire which should be an insulated stranded #8 copper wire. There should be no bare copper wires in the pool light niche or conduit.

Is that even allowed? (running bond wire through the light conduit)

I thought the bond wire comes through the floor of the equipment pad only, and the light niche is connected to the pool bonding grid.

 

[gwegan]

Borjis is correct. Bdavis is confusing the bond wire which attaches to the inside of the niche, usually to a nine inch square metal plate to bond the pool water and the ground wire which attaches to the niche but the connection is covered with putty. The bond wire then attaches to the pool rebar.

See the diagram in this thread: Relamping - use long light cable instead of junction box