Pool Light Change from 120v to 12v - Need help re-wiring (Electricians Needed)

[rheide]

Hi All,
I made the decision to swap out our 120v Pentair LED lights with newer 12v lights. It wasn't until after that did I realize it may not be as simple as I thought (or maybe it is). That's the point of this thread. Electricity is dangerous. My plan is to have an electrician come out and check everything once its done and before I ever provide power to the lights but I wanted to see if I could get some input on the best way to organize everything as I would like to learn and do some of the work myself.

My Questions:
1. Is it safe to have 12v DC and 120v inside the same conduit? I read a number of articles that said it was safe in most scenarios but google isn't a real electrician.

2. Assuming this isn't an issue, what is the proper way to wire things inside the EasyTouch when trying to keep low voltage and high voltage separate but having to send the wires down the same conduit? I'm under the assumption that its the connections that are most important to keep separate but again, what do I know.
In my diagram, how do I connect A with B? Should I use a conduit T so they don't join until outside the box? Does it matter?

Thanks so much in advance for all suggestions!


Current Wiring
Note: The conduit coming from poolside back to the EasyTouch panel contains BOTH the 120v Pool wires AND the 120v mains power.




And here is how the EasyTouch side of things look when the Transformer is added:

 

[kimkats]

I am not sure of the answer so here is a bump to get more eyes on this.

 

[drsipe]

It's never a good idea to mix different voltages within a conduit. You run the risk of what is called induced voltage, meaning the electrical current in the 120V wires can actually generate a voltage in your low voltage wiring. Without getting in to too much theory, your 120V AC (alternating current) is constantly having expanding and collapsing magnetic fields, and as these magnetic fields pass thru the low voltage wiring, they excite the copper in the low voltage wires and they generate voltage. It depends on the length of the wires as to how much voltage will be generated. This is the same reason that low voltage wiring in your house (phone, cable TV) should not be run parallel to you household wiring.

With that said, I have heard of people mixing voltage without issues, but I have also seen induced voltage and it can cause issues with low voltage wiring.

Induced Voltage Formula - Definition, Formula And Solved Examples

Electromagnetic induction is the procedure of producing emf (induced voltage) by exposing a conductor into a magnetic field. Learn more about induced voltage and solved examples.

byjus.com

Can you run high voltage and low voltage in the same conduit?

Running 0-10V dimming wires in the same conduit as line voltage is not recommended. The NEC does say that Class 1 and Class 2 wiring in the same conduit is NOT allowed, regardless of the insulation rating of the conductors. They need to be ran separately or at least separated by a continuous...

findanyanswer.com

I don't have any experience with the Pentair Easy Touch, but I hope this information helps you.

 

[rheide]

@drsipe I really appreciate it. I will check it out for sure!! Have a great one!

 

[jmastron]

Legal or not, I definitely wouldn't mix the 12V and 120V wires for a pool light. The safety benefits of 12V lights come both from being low voltage and from being completely isolated from the ground and rest of the electrical system. That's why there's no GFCI protection on the load side of the transformer -- because there's no fault to ground to detect or interrupt. You can't even get a 12V shock from touching *one* of the wires and being grounded (you can from touching both, of course).

You don't want to have your kids or grandkids in the pool when someone accidentally mows, digs, or kicks into one of the conduits or electrical boxes and shorts any of the 12V wires to the 120V wires.

I don't think you want 12V in the Easytouch box at all -- the ET relay should switch the 120V that goes to the listed pool light transformer, with the 12V transformer output going separately to those J-boxes in its own conduit. I've read of people wanting to switch the 12V instead so they can control lights separately, and technically the relay can do that, but I wouldn't do that for the same reason as above. Multiple transformers aren't that expensive if there's really a need.

 

[ImpalaSS]

As long as the low voltage wiring is rated as the same as the 120v wiring you will be fine running it in the same conduit, use THWN/THHN wire. The reason Pentair has the little low voltage side on the left of their control panels is that the 12v wiring is not rated to be with 120v wiring. You want to connect the line side of the transformer to the relay and the load wire to the lights. Make sure you use a GFCI breaker for the transformer. If possible try not to splice the 12v wiring in the control panel.