Yet another question about 120v to 12v conversion

May 12, 2011
13
#1
I've been reading topics all over the internet about converting a 120v incandescent pool light to 12v and I just can't seem to get a good feeling about it. Every thread I've read seems to have complications about shorted wiring, tripping GFCI, damaged conduit, etc... and seem to go off on a myriad of reasons not to do it. I would like to believe my situation is different, so I'm posting - yet another - 120v to 12v conversion thread.

I have an older pool with a Pentair 120v niche housing directly running back to my equipment pad. No above ground conduit or junction boxes till you get to the pad. The control center is a Polaris EOS and is about 5' above water level. The 120v light has worked for years, but I do have to replace the bulb every couple of years due to heavy use. We run the lighting a lot since we do most of our swimming at night due to the heat in Texas. I want to convert to 12v LED lighting for both the lower operating cost, longer bulb life, color changing features, and perceived safer operating voltage. I considered replacing the housing, cable and conduit, but the expense is huge due to it running under concrete deck and pool house. I had a contractor look into it when I had the pool refinished 5 years ago and they said the cable was stuck in the conduit and it would they would have to dig up the entire conduit run at a cost of about $5000.

In this situation, why couldn't I disconnect the lighting wire running at the control box on the pad, hook it to a 12v transformer, and replace the 120v incandescent bulb with a 12v LED bulb? On the surface, it would seem to be a simple task. I'm just sending 12v through the existing cable rated for 120v to the housing in the pool where a 12v LED bulb sits, right? The transformer would be plugged into GFCI at my equipment pad. It seems like this solution would get me the results I want, for about $500

What am I overlooking here?
 

JamesW

TFP Expert
Mar 2, 2011
12,837
#2
Pool lights should not be modified in any way. It's a safety issue. Any safety ratings are as originally manufactured. When you change the volts and amps, things might not work correctly.
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,216
East Texas
#3
But doesn't a normal thermostat in a house run off a 12 volt transformer from a 110 circuit?

I'm kinda thinking that if the house hasn't burned down then the pool won't blow up! Admittedly I know nothing about water and electricity.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,550
Bedford, TX
#6
mon,

Since you can't get the cable out, but it still works, another option would be to install a color changing LED bulb that works off of 115 VAC.

I have never used one and have no idea how bright they would be compared to a standard pool light bulb.

Jim R.
 

JamesW

TFP Expert
Mar 2, 2011
12,837
#7
But doesn't a normal thermostat in a house run off a 12 volt transformer from a 110 circuit?

I'm kinda thinking that if the house hasn't burned down then the pool won't blow up! Admittedly I know nothing about water and electricity.
Many thermostats run on 24 volts AC. That is the voltage that they are designed to use.
Electrical design considers many factors including voltage, amps etc. The specifications for insulation, wire size etc depends on these factors.

Any modification to a product like a pool light should only be done under the supervision of a qualified engineer.