pool light wiring

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bgelectric

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What size condutor would i need to use for a wet niche light in a pool.
I would like to locate the transformer 100' away from the pool. 120v to 12v 300w.
Seeing how its only 12v i would think the conductor needs to be larger than #10 for voltage drop.
 
Is the light rated at 300W or the transformer? I thought most LV pool lighting was much smaller than 300W. If the load is 300W at 12V, I think you need a new plan as you'll be over the #4 wire size and none of your boxes are going to have the clearance for that. What size is the conduit to the niche?
 
110.3(b) pops to mind.

The manufacturer often supplies the cord at the desired length;
30', 50', or 100' typically.
Lamp enclosure sealed, plastic or stainless.

The manufacturer will have had it listed for use with the designed cord length.

Are you getting the xfmr and cord/light assembly from the same company?
Are you bonding to the enclosure/housing with #8 solid Cu? Sealing/packing it?
 
Last edited:
Finite10 said:
110.3(b) pops to mind.

The manufacturer often supplies the cord at the desired length;
30', 50', or 100' typically.
Lamp enclosure sealed, plastic or stainless.

The manufacturer will have had it listed for use with the designed cord length.

Are you getting the xfmr and cord/light assembly from the same company?
Are you bonding to the enclosure/housing with #8 solid Cu? Sealing/packing it?
Click to expand...
The setup is existing. I'm not sure of the lamp wattage, just going off the xformer. Customer wants to relocate the xformer from under the diving board to outside the pool patio which will be below the 4"requirement as they want an inground box for it. So I thought my other option could be by the house where the conduit stubs up.
 
bgelectric said:
The setup is existing. I'm not sure of the lamp wattage, just going off the xformer. Customer wants to relocate the xformer from under the diving board to outside the pool patio which will be below the 4"requirement as they want an inground box for it. So I thought my other option could be by the house where the conduit stubs up.
Click to expand...

If you are not well versed on Art. 680, you may want to brush up on this. There are very specific requirements for pool lights. I'm assuming that this is a standard wet niche light. You have to have a listed pool light junction box somewhere between the light and the transformer-the conduit from the light can not extend directly to the transformer. Keep in mind that you need to order a light with enough cord to go from the J-box to the niche plus enough extra to coil up inside the niche so the light can be brought out of the water for relamping. Look closely at 680.23 and 680.24.
The pool light transformer will usually have taps so you can compensate some for long runs within reason. Just try to keep the voltage at the lamp to 12 volts or slightly less or you will have greatly reduced lamp life.
 
texie said:
If you are not well versed on Art. 680, you may want to brush up on this. There are very specific requirements for pool lights. I'm assuming that this is a standard wet niche light. You have to have a listed pool light junction box somewhere between the light and the transformer-the conduit from the light can not extend directly to the transformer. Keep in mind that you need to order a light with enough cord to go from the J-box to the niche plus enough extra to coil up inside the niche so the light can be brought out of the water for relamping. Look closely at 680.23 and 680.24.
The pool light transformer will usually have taps so you can compensate some for long runs within reason. Just try to keep the voltage at the lamp to 12 volts or slightly less or you will have greatly reduced lamp life.
Click to expand...

So your saying I cannot have the xformer inside the listed pool jbox?
 
texie said:
If you are not well versed on Art. 680, you may want to brush up on this. There are very specific requirements for pool lights. I'm assuming that this is a standard wet niche light. You have to have a listed pool light junction box somewhere between the light and the transformer-the conduit from the light can not extend directly to the transformer. Keep in mind that you need to order a light with enough cord to go from the J-box to the niche plus enough extra to coil up inside the niche so the light can be brought out of the water for relamping. Look closely at 680.23 and 680.24.
The pool light transformer will usually have taps so you can compensate some for long runs within reason. Just try to keep the voltage at the lamp to 12 volts or slightly less or you will have greatly reduced lamp life.
Click to expand...

After a few decades of this I am sometimes still a bit uncomfortable with pools so I may end up with egg on my face.. again ... but, as I read 680.24, if a transformer is involved the circuit (15 volts or less) can run directly to the transformer without a pool j box. The transformer must be a listed pool lighting transformer and as such will meet the requirements of 680.24(B).
 
augie47 said:
After a few decades of this I am sometimes still a bit uncomfortable with pools so I may end up with egg on my face.. again ... but, as I read 680.24, if a transformer is involved the circuit (15 volts or less) can run directly to the transformer without a pool j box. The transformer must be a listed pool lighting transformer and as such will meet the requirements of 680.24(B).
Click to expand...

I also find this confusing, here is the installation sheet for a PX300 -http://www.intermatic.com/~/media/Intermatic/Documentation/Pool%20and%20Spa/Specialty%20Controls/PX%20Series/PX300%20and%20PX300S.ashx

It clearly states "Suitable for direct connection to underwater lights and for Indoor/Outdoor installations except in CANADA"
but, the PX300 does not meet any of the criteria (2008 code) of 680.24(B)(1)1-4
Incidentally there is a misprint in Mike Holt?s Guide to 680 http://www.mikeholt.com/mojonewsarchive/NEC-HTML/HTML/SwimmingPoolInstallations~20021227.htm number 3 is skipped)
and as Mike has commented: There are no listed enclosures for transformers or GFCI protection devices that meet the above requirement. This requirement should stop the practice of terminating the conduit that extends directly from the underwater light to a panelboard or low-voltage transformer.

Now we have the 2011 version below:

680.24(B) Other enclosures. An enclosure for a transformer, ground-fault circuit interrupter, or a similar device connected to a conduit that extends directly to a forming shell or mounting bracket of a no-niche fixture shall be as follows:
1. Construction. The enclosure shall be listed and labeled for the purpose and meet the following requirements:

1. Equipped with threaded entries or hubs or nonmetallic hub.

2. Comprised of copper, brass, suitable plastic, or other approved corrosion resistant material.

3. Provided with an approved seal, such as duct seal at the conduit connection, that prevents circulation of air between the conduit and the enclosures;

4.Provided with electrical continuity between every connected metal conduit and the grounding terminals by means of copper, brass, or other approved corrosion-resistant metal that is integral with the box.

It appears that if it is a wet niche fixture, that 680.24(B) does not matter in the 2011 code.
and you can therfore pipe directly into the transformer.

I too am sure I am off base, please correct my misinterpretation.
 
I have never install a 12v light in a pool but all the 120V lines come with a cord attached to the light. I suspect that will be the case. The longer cords will have a heavier gauge.
 
For 240 watts you will have a .272 VD for each 10' linear feet of #8 wire. so for 100' you would have a 2.7v drop at 240 watts
 
Intermatic has a series of pool distribution (example part #T20004R) control panels with built in time-clocks and also has provisions for circuit breakers and can be connected directly to pool lights with additional kit such as intermatic part #156PA13715A

This panel has a transformer built into it for direct connection to a pool light...

http://www.intermatic.com/~/media/I...rols/Transformer Series/T400000RT Series.ashx
 
shortcircuit2 said:
Intermatic has a series of pool distribution (example part #T20004R) control panels with built in time-clocks and also has provisions for circuit breakers and can be connected directly to pool lights with additional kit such as intermatic part #156PA13715A

This panel has a transformer built into it for direct connection to a pool light...

http://www.intermatic.com/~/media/I...rols/Transformer Series/T400000RT Series.ashx
Click to expand...

As I see it, the problem with these is they do not meet the criteria of 2008 NEC 680.24(B)(1)1-3:
but maybe it is OK with 2011? as long as it is not a no-niche fixture? someone please set me straight.

2008 NEC 680.24(B)(1)1-3
(B) Transformer or GFCI Enclosure.
Where the enclosure for a transformer or GFCI is connected to a conduit that extends directly to an underwater permanently installed pool, outdoor spa, or outdoor hot tub luminaire forming shell, the enclosure must comply with the following:
(1) Construction. The enclosure must be listed and labeled for the purpose, and be:
(1) Equipped with threaded entries or a nonmetallic hub,
(2) Constructed of copper, brass, or corrosion-resistant material approved by the authority having jurisdiction, and
(3) Provided with electrical continuity between all metal raceways and grounding terminals of the enclosure.
 
cpinetree said:
As I see it, the problem with these is they do not meet the criteria of 2008 NEC 680.24(B)(1)1-3:
but maybe it is OK with 2011? as long as it is not a no-niche fixture? someone please set me straight.

2008 NEC 680.24(B)(1)1-3
(B) Transformer or GFCI Enclosure.
Where the enclosure for a transformer or GFCI is connected to a conduit that extends directly to an underwater permanently installed pool, outdoor spa, or outdoor hot tub luminaire forming shell, the enclosure must comply with the following:
(1) Construction. The enclosure must be listed and labeled for the purpose, and be:
(1) Equipped with threaded entries or a nonmetallic hub,
(2) Constructed of copper, brass, or corrosion-resistant material approved by the authority having jurisdiction, and
(3) Provided with electrical continuity between all metal raceways and grounding terminals of the enclosure.
Click to expand...

I don't see the problem... 680.24(B)(1) 2008 and 2011 are the same word for word. These products are listed for direct connection to pool lights.
 
pool

pool

Back to my original question,
I wanted to extend the xformer from inside the diving board to the outside of the pool to an inground box. From what ive gathered i cant do this because its below the water level outside the patio.
The light is 12 volts so i can go directly to the xformer but it still needs to be above the water level.
I dont think I can achieve this without replacing the niche light with one that has a longer cord attached to it. exp 100' one. (Right now its only about 10')
Then i can mount the transformer further away from the pool and run the cord through the conduit to it.
Does this sound about right to anyone?
 
Take a look at 680.24(2)(c). On a 12 v system it appears you can use a flush deck box (with requirements).
 
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