120V to 12V question

aquaN00b

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Jul 29, 2018
101
VA
Hello everyone! The switch for my pool light is aaaallllllllllll the way out at the pump equipment. I'm going to replace the switch with a Lutron Caseta smart switch with an accompanying Pico wireless switch at my back door for a second control. I'm also looking into replacing the aging pool light with an LED. Is there a good argument for getting an Intermatic transformer to step down the 120V feed to the pool light to 12V? I've heard you lose GFCI protection that way, and I've also read that you don't really gain any safety this way. The switch for the light is indeed fed from a GFCI outlet also at the pool enquipment, FYI. I'm fine keeping it all 120V, but if it's safer to do 12V then I have no problem getting the transformer.

EDIT: Just read the Intermatic unit I'm looking at has built-in circuit protection, so that's a mark in the "pro" column.


 
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chiefwej

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I just replaced my pool light bulbs with LEDS, then used hubless smart switches.
 

aquaN00b

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Jul 29, 2018
101
VA
120V with a GFCI is as safe as 12V from a transformer.
Oh yeah? I thought that might also be the case but then I saw some things about what if the GFCI outlet fails or something. With the 12V transformer, the same thing could happen and if the circuit protection fails, then you have the safety net of only 12 volts going to the pool. I know that you can still die from 12V (because amps is amps), but there's a reason the code mandates GFCI only if above 15V, right? Also, I thought there was a rule that if I were to swap out the switch, etc., I should just go with the 12V to "bring it up to today's code". So knowing all that, is it still pointless and unnecessary?
 
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jmastron

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Jul 21, 2014
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Sacramento, CA
My opinion -- 120V with GFCI, wired correctly and in good condition, is safe and meets code requirements in most places, and I wouldn't necessarily change it if so.

However, in my opinion 12V with a properly installed listed isolating transformer is safer. It's true that you there's no ground fault protection -- but that's because there's no path to ground in the first place, because of the isolating transformer. Touching either leg of the 12V while you are grounded (e.g. in the water) doesn't create a path through you at all. Touching the hot leg of 120V while you are grounded does create a path through your body -- you then hope the GFCI senses that, is functioning correctly, and trips quickly (which it *should*).

Touching both legs of the 12V (say one in each hand) DOES create a path through you -- but that is true of 120V also, and the GFCI won't trip in that case (if you're not grounded). And in that worst case 12V is a lot less likely to kill you than 120V.

A big issue in the past with 12V lights is the need for heavier gauge wiring, since wire is sized for current -- a 360 watt light at 120V draws 3 Amps, but a 360 watt light at 12V draws 30 Amps. However, LED bulbs are generally ~1/10th the wattage for the same light output, so the equivalent 12V LED also draws only 3 Amps.
 

aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
My opinion -- 120V with GFCI, wired correctly and in good condition, is safe and meets code requirements in most places, and I wouldn't necessarily change it if so.

However, in my opinion 12V with a properly installed listed isolating transformer is safer. It's true that you there's no ground fault protection -- but that's because there's no path to ground in the first place, because of the isolating transformer. Touching either leg of the 12V while you are grounded (e.g. in the water) doesn't create a path through you at all. Touching the hot leg of 120V while you are grounded does create a path through your body -- you then hope the GFCI senses that, is functioning correctly, and trips quickly (which it *should*).

Touching both legs of the 12V (say one in each hand) DOES create a path through you -- but that is true of 120V also, and the GFCI won't trip in that case (if you're not grounded). And in that worst case 12V is a lot less likely to kill you than 120V.

A big issue in the past with 12V lights is the need for heavier gauge wiring, since wire is sized for current -- a 360 watt light at 120V draws 3 Amps, but a 360 watt light at 12V draws 30 Amps. However, LED bulbs are generally ~1/10th the wattage for the same light output, so the equivalent 12V LED also draws only 3 Amps.
Even less! Looking at Inyo they have 12V/25W and 12V/5W lights, that's 2.08A and 0.42A respectively. Good point about the wire size, I will look into that, but yeah if it's drawing 0.42A then wire size is likely good.
 

aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
I just replaced my pool light bulbs with LEDS, then used hubless smart switches.
Thanks! Controlling from WiFi wasn't really that important to me, but now that I think about it, it might be cool to have. I was looking at going with Caseta because you can assign a Pico remote button directly to the smart switch, you don't need their hub. But if what you linked to can be used over WiFi AND have another switch connected to it as a three way config then I'll go for it
 

aquaN00b

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Jul 29, 2018
101
VA
Resurrecting this thread with some additional info/questions.

I finally got around to taking out my Anderson pool light. It's in baaaaaad shape. Well, probably actually good shape considering it's the original light from the 70's when the pool was built and it works/does not leak. Anyway, the bulb snapped out, the rubber ring is deteriorating filling my hands with black tar, the electrical cord is deteriorating.........sooo time to replace completely! Apparently the Hayward Universal ColorLogic Pool Light 12V will fit my niche with no modifications needed, which is very desirable. So this puts me back to the 120V to 12V conversion to make this work.

My question: I'd like to put the light on a "smart switch". Does anyone think it's a problem to put the switch before the 120V/12V transformer? Or will a 120V rated smart switch (no neutral) work for switching the light after the transformer? Thanks for any insight.

P.S.--if anyone knows of another light besides the Hayward that will fit my niche, let me know. I know they make an adapter ring for Anderson lights but it looks like ill have to drill/bond it, etc. and I didn't want to drain the pool below the light (that's a LOT of water) to do all this

Thanks!.
 

aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
Check Florida Sunseeker. They may have a light system to fit.
Thank you! I'm just going to email their support and ask, probably faster that way to get an accurate answer. Do you have any idea if it's possible to use a 120V switch for a 12V light after the transformer? Amps shouldn't be an issue, the only thing on this circuit will be: GFCI > Transformer > Swtich > 1 Lights @ 12V/70W. Otherwise I could put the switch before the transformer, I just wasn't sure if switching the transformer would be good for it as the LED colors are changed by switching the light on and off at certain intervals of time.
 

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mknauss

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I believe the switch would be before the transformer, but check with the light manufacturer.
 

duckcmmndr

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Resurrecting this thread with some additional info/questions.

I finally got around to taking out my Anderson pool light. It's in baaaaaad shape. Well, probably actually good shape considering it's the original light from the 70's when the pool was built and it works/does not leak. Anyway, the bulb snapped out, the rubber ring is deteriorating filling my hands with black tar, the electrical cord is deteriorating.........sooo time to replace completely! Apparently the Hayward Universal ColorLogic Pool Light 12V will fit my niche with no modifications needed, which is very desirable. So this puts me back to the 120V to 12V conversion to make this work.

My question: I'd like to put the light on a "smart switch". Does anyone think it's a problem to put the switch before the 120V/12V transformer? Or will a 120V rated smart switch (no neutral) work for switching the light after the transformer? Thanks for any insight.

P.S.--if anyone knows of another light besides the Hayward that will fit my niche, let me know. I know they make an adapter ring for Anderson lights but it looks like ill have to drill/bond it, etc. and I didn't want to drain the pool below the light (that's a LOT of water) to do all this

Thanks!.
I would use a GFCI breaker that feeds your 120v smart switch that will power up the transformer. The Hayward Colorlogic lights can change colors by flashing power to the light (flipping the switch on/off a set number of times). They also make a controller for that does it. You can't use a 120V smart switch after the transformer.

At any rate...I would 100% feel better with 12v lighting->Transformer->Smart Switch->GFCI Breaker.
 

aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
I would use a GFCI breaker that feeds your 120v smart switch that will power up the transformer. The Hayward Colorlogic lights can change colors by flashing power to the light (flipping the switch on/off a set number of times). They also make a controller for that does it. You can't use a 120V smart switch after the transformer.

At any rate...I would 100% feel better with 12v lighting->Transformer->Smart Switch->GFCI Breaker.
Oh I forgot to mention--might not make any difference---the GFCI protection is from a GFCI outlet, not a breaker. Right now the circuit goes from panel > GFCI outlet > Switch > Light. Right now the light switch and GFCI outlet are in separate 1-gang exterior boxes and I was thinking of going combining them in a 2-gang box, then going to transformer, then to the light. So still keeping the direction panel > GFCI outlet > Smart Switch > Transformer > Light order.
 

aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
Ok pool light is in. I reached out to Florida Sunseeker and they sold me the light below + transformer. I have a couple questions if anyone here might have insight (i also emailed Florida Sunseeker but prob won't hear back till next week).

  1. The light fixture fits and I can screw it in, but the outer ring is too large to both screw in at the top and catch the metal tab at the bottom of the niche. So even after screwing it in tight I can lift the bottom of the light ring away from the niche a tiny bit. Is this a problem? Or unsafe in any way? Is there some sort of fix I can do or just live with it? I'm fine living with it if all I need to do is tell the kids not to mess with the light
  2. Kicking myself for not taking a picture of this, but the cord wasn't pulling through so I figured there was likely something keeping it from coming through inside the niche. I hopped in the pool and sure enough there was a metal threaded fitting where the cord goes through the niche into the conduit. It looks like someone previously serviced this light and put a bunch of pool leak putty around it. I unscrewed it and the rubber washer was completely deteriorated. Not surprising on a 40 yo pool. Anyway, is this mostly to keep the cord from being loose? Or to actually keep water from getting in the conduit? I was going to buy a retrofit cord stopper or put pool putty on it---but also wondering if i can just leave it or if there's a safety issue with leaving it. Might have to go with putty as I think it's smaller than 3/4" and 3/4" is the smallest stopper I can find
  3. I'm reusing the wire from the pool pad to the J box under the diving board. Since the 12V transformer doesn't use a ground should I just leave the green ground wire from the pool pad to the J box unattached on both ends? Wire cap it?



Thanks!
 

ajw22

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Kicking myself for not taking a picture of this, but the cord wasn't pulling through so I figured there was likely something keeping it from coming through inside the niche. I hopped in the pool and sure enough there was a metal threaded fitting where the cord goes through the niche into the conduit. It looks like someone previously serviced this light and put a bunch of pool leak putty around it. I unscrewed it and the rubber washer was completely deteriorated. Not surprising on a 40 yo pool. Anyway, is this mostly to keep the cord from being loose? Or to actually keep water from getting in the conduit? I was going to buy a retrofit cord stopper or put pool putty on it---but also wondering if i can just leave it or if there's a safety issue with leaving it. Might have to go with putty as I think it's smaller than 3/4" and 3/4" is the smallest stopper I can find

Put some pool putty on the niche wire outlet. It is not a safety issue but that spot can be a source for a water leak.

I'm reusing the wire from the pool pad to the J box under the diving board. Since the 12V transformer doesn't use a ground should I just leave the green ground wire from the pool pad to the J box unattached on both ends? Wire cap it?

I wire cap spare lines to show they are purposely left disconnected.
 

aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
Put some pool putty on the niche wire outlet. It is not a safety issue but that spot can be a source for a water leak.



I wire cap spare lines to show they are purposely left disconnected.

Thanks! I was thinking how could it leak because the conduit goes back to a sealed J box, but I forgot the leak would be at that fitting and then leak behind the niche outside of that conduit. I'll seal it up!

So i've been reading up and im a little confused on the grounding/not grounding thing for a 12V light. Especially after reading about that Florida boy dying from a shock from the light, even when using a 12V one. The light's cord has a white, black, and green ground, just like a 120V light. I've read in forums that "they want you to still wire it like 120V in case in the future someone converts back to 120V". Ok no prob. So in the light's J box, I connected the light's black and white to the black and whites from the breaker box, and put the light's green wire on the J box metal like the previous light was connected. For the run going from the J box to the equipment pad, it's ground wire was also connected to the J box metal terminal. I left that alone. So back at the transformer, should I leave the ground disconnected and capped, or tie it into either the 120V ground that the transformer uses, or ground it to the metal transformer. I guess the question is, if there's a fault somewhere, could current be somehow sent to the light via the "unnecessary" ground connection im making? I can always consult an electrician, but it's hard to fine one that CORRECTLY understands "pool stuff" in this area. Heck I once had a licensed "master electrician" install my ceiling fan with an ordinary blue retro drywall box from home depot with those flimsy plastic tabs that pinch the drywall. Those aren't rated for even light fixtures let alone moving fans. Luckily I found out as I was servicing the fan and it literally fell out of the ceiling in my hands. Before I bought my house the previous owner had another licensed "master electrician" swap the house panel and the guy put the range and microwave on the same circuit and it kept blowing shortly after moving in. I just don't trust anyone to know anything anymore unless it's clear they are very knowledgeable and care about doing things 100% right. Hard to gauge that before they do the work.

Thanks for the help guys. This 40 year old pool is a bear to deal with sometimes. Luckily the original owner replaced all the stone and coping a few years ago. The next thing i want to look at it resurfacing because the gunite is super rough. How much did your 2017 resurface cost?
 
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ajw22

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I've read in forums that "they want you to still wire it like 120V in case in the future someone converts back to 120V". Ok no prob.

I am not sure I buy into that. It should be enough to leave the ground wire capped off. If someone converts back to a 120V light they will need to got into the J box and change the wiring and should know enough to connect the capped off ground wire.

So in the light's J box, I connected the light's black and white to the black and whites from the breaker box, and put the light's green wire on the J box metal like the previous light was connected. For the run going from the J box to the equipment pad, it's ground wire was also connected to the J box metal terminal. I left that alone.

Where is that wire connected to at the equipment pad?

I wonder if we are discussing a true ground wire running into the ground bus of the electrical panel or a bonding wire?

So back at the transformer, should I leave the ground disconnected and capped, or tie it into either the 120V ground that the transformer uses, or ground it to the metal transformer.

What transformer are you using?

Is this ground connection on the 120V aide of the transformer or the 12V side?

I guess the question is, if there's a fault somewhere, could current be somehow sent to the light via the "unnecessary" ground connection im making?

I think that is a valid concern if the electrical ground gets energized it can backfeed voltage to the pool.
 

aquaN00b

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Jul 29, 2018
101
VA
I am not sure I buy into that. It should be enough to leave the ground wire capped off. If someone converts back to a 120V light they will need to got into the J box and change the wiring and should know enough to connect the capped off ground wire.

Where is that wire connected to at the equipment pad?

I wonder if we are discussing a true ground wire running into the ground bus of the electrical panel or a bonding wire?

What transformer are you using?

Is this ground connection on the 120V aide of the transformer or the 12V side?

I think that is a valid concern if the electrical ground gets energized it can backfeed voltage to the pool.
Sorry, I could have been a little more clear from the start. I don't have the transformer yet, but I ordered an Intermatic PX50. The ground running from the pool light junction box to the equipment pad does tie into the ground bus of the sub-panel eventually. In the pool light junction box is also a separate bonding wire. I'm not sure where it goes, I had assumed it went to the niche, but now that I think about it, it probably goes into the bonding grid and is bonding the J box itself. The conduit from the niche is metal, so that probably takes care of the bonding the actual niche. The conduit for the mystery bonding wire is also metal. The conduit from the equipment pad to the J box is plastic. I attached some pics to help make sense of it. The middle wire is from the old light, the wire on the right is from the equipment pad, and the wire on the left is the bond. I didn't take a pic of the new light but it's the exact same, the new light also has a green ground wire in it's bundle that put in the same place on the J box as the old box.

*I left the switch off these diagrams. It's between the GFCI and pool light. I will be replacing it with a new smart switch between the GFCI and transformer
*Blue line represents white neutral
 

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ajw22

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The question is where your pool gets its water bond from. The conduit from the niche is not an acceptable bond connection. For the niche to be the water bond there should be a bare #8 wire from the niche to the J Box.

I would connect the ground wire from the pool light to the J-box, It may be a satisfactory substitute for your lack of a bonding wire to the niche.
 
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aquaN00b

Gold Supporter
Jul 29, 2018
101
VA
The question is where your pool gets its water bond from. The conduit from the niche is not an acceptable bond connection. For the niche to be the water bond there should be a bare #8 wire from the niche to the J Box.

Well, that bare wire on the left of the photo is definitely a bond wire--question is where does it go. I'm thinking it goes into that conduit and joins with something from the niche and then joins the pool grid. That would then bind the J box, the niche, and the water bond, right? There are some schematics for this pool, i can check them out. I might call the local pool company as well as I'm sure there are lots of these brand pools they service from the same era.

I would connect the ground wire from the pool light tot he J-box, It may be a satisfactory substitute for your lack of a bonding wire to the niche.

Yup, that's already done. Question is, do I go with option 1, 2, or 3 for the existing wiring im using to power the 12V light from the breakerbox/gfci.
 

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