Light conduit size

trivetman

Bronze Supporter
Jul 14, 2017
736
Jenkintown, PA
Pool Size
24000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Is there a standard size for pvc conduit to a light niche, and what is it?

Im thinking about replacing my light which is shorted out and has been disconnected for a couple years. I am going to have to break off this putty around the cord. I want to be prepared with the right size rubber stoppers in case that putty was put there for a reason.

If it matters, gunite pool circa 1980’s. Light is I think a pretty standard model. INYO telle me Pentair Amerlite is the replacement.
 

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Not so sure there is just one standard size. 3/4 to one inch is what I generally see here on the forum. Some pools have even larger conduits than 1". One inch seems to match the size of most standard niche hubs. The conduit size may also be driven by what the builder had available at the time, amount of bends required, and distance from pool to pad for ease of wire pull..
 
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Get some tapered plugs of various sizes and you should be set for whatever size it ends up being.

Tapered rubber winter expansion plugs with a wingnut to tighten come in various sizes:

  • 0 - 1/2" pipe tapered
  • 1 - 1/2" pipe
  • 2 - 3/4" tube tapered
  • 3 - 3/4" pipe
  • 4 - 3/4" and 1" pipe
  • 5 - 1" pipe
  • 6 - 1" fitting
  • 7 - 1 1/4" pipe tapered
  • 8 - 1 1/2" pipe tapered
  • 9 - 1 1/2" pipe and 1 1/4" fitting tapered
  • 10 - 1 1/2" fitting tapered
  • 11 - 2" pipe

Rubber_Expansion_plug.jpg
 
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Thanks guys. One more question for you.

I am leaning towards keeping this as a 120V fixture. Retrofitting to 12V is looking complicated and expensive in terms of installing the transformer and possibly needing to rewire. My current wiring is probably 60 feet from switch to jbox and either 12 or 14 gauge, so pushing the limit at best in terms of voltage drop.

Anyway, assuming I stay 120, the current gfi protection is at an outlet only. I am thinking it might be wise to add gfi at the breaker as well. Is there any reason having redundant gfi protection would cause problems?
 
I am leaning towards keeping this as a 120V fixture. Retrofitting to 12V is looking complicated and expensive in terms of installing the transformer and possibly needing to rewire. My current wiring is probably 60 feet from switch to jbox and either 12 or 14 gauge, so pushing the limit at best in terms of voltage drop.

12 volt lights work fine with 100' cords. You use the 14 Volt tap on the transformer so there is 12 V at the light.

Anyway, assuming I stay 120, the current gfi protection is at an outlet only. I am thinking it might be wise to add gfi at the breaker as well. Is there any reason having redundant gfi protection would cause problems?

No benefit. The GFCI on the outlet is as good as on the CB. They are designed to fail open and recent outlet GFCIs have a self test monitoring circuit. I have about half a dozen of them outside around the house and am replacing them regularly when they give up and don't provide power anymore.
 
12 volt lights work fine with 100' cords. You use the 14 Volt tap on the transformer so there is 12 V at the light.

No benefit. The GFCI on the outlet is as good as on the CB. They are designed to fail open and recent outlet GFCIs have a self test monitoring circuit. I have about half a dozen of them outside around the house and am replacing them regularly when they give up and don't provide power anymore.

Thanks. I did not consider that a gfi failure would fail in the open position.

The documentation on the transformer indicates the voltage drop is a little more restrictive with 12 and 14 gauge. Am I reading it correctly? Or perhaps actual operation does exceed the documented tolerances as is often the case.

Even if I don’t need to rewire conduit to the jbox behind the niche, staying 120V is going to be an easier and much less expensive way to go. Still on the fence.
 

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This table does not show using the 14V tap.

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This table does not show using the 14V tap.

I see. I wonder why they only went to 13V?

Last question - is there a way to test/verify the bonding to the niche is intact? Am I right in thinking all bonding connections are behind the niche and inaccessible without major digging?

I’ve never had any issues that make me think its not intact.
 
Does the light wire run to a pool light junction box?

Do you have a bare #8 copper bond wire at the junction box?
 
Yes light wire goes to j box behind pool. This jbox is 50-60 feet from equipment pad where light switch is.

Its been a while since ive opened that box to disconnect the light which was shorting.

There is no bare wire in the ground around the jbox.

If you meant possible bare copper within the jbox, I don’t remember one but memory may be bad. Itll be a couple days before I can investigate, but even if bond wire ran to that jbox, it wouldn’t connect to anything as I am sure bond wire does NOT run from switch to the jbox. Ground wire (insulated green) does run from switch to jbox within conduit but not bond wire.
 
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This wire circles red looks like a bonding wire, correct? Its not bare copper but looks 8awg or close to it.

Is there a proper material to seal this box up when the work is done? The sealant on there is some sort of sticky almost roofing tar substance
 

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It's called a bonding jumper, but it is a supplemental ground.

Bond lugs are usually on the outside of an enclosure.

Ground lugs are on the inside.

If there is no external bond lug, it does not need to be bonded.

The niche is already bonded on the outside and the ground connects to the inside lug, which is directly connected to the outside lug.

The gasket is a regular rubber gasket.

If there is something sticky, it is not the correct gasket.

7a71f84d-4fbd-4c7f-9ba1-62bbbac37a1f-jpeg.482834
 
This wire circles red looks like a bonding wire, correct? Its not bare copper but looks 8awg or close to it.

Is there a proper material to seal this box up when the work is done? The sealant on there is some sort of sticky almost roofing tar substance
Looks like the original gasket material deteriorated or was lost and some black silicone sealant was used.
 
Well, I just went in the freezing half empty pool and was able to chisel out the putty without much problem.

The J box is maybe 5-6 feet from the pool. I haven't measured exactly. It's definitely more than 4. Could be less than 5.

I had been planning on using a 'cordstopper' with the new light to protect against possible leaks in the wiring conduit. The supplemental ground wire is making me rethink those plans. Chiseling out the putty within the niche revealed the supplemental ground wire. I couldn't see how it was attached terribly well, but it seemed like some sort of welded lug, not just a screw attachment. However, there looked to be an unused screw fitting into the lug. Is this possibly for reattachment of the wire should it be needed?

Anyways, I won't be able to use a cordstopper without disconnecting the ground wire. I don't want to disconnect the ground wire unless there's a foolproof way to reattach it. Also, there is definitely some amount of copper now exposed without the putty there. Does this need to be covered up so not to put copper into the pool.

I think my best bet is to reinstall pool putty over the new wiring as well as the ground wire connection once I get the new fixture installed.

Thoughts?
 
Butyl Tape for the conduit seal and Aquabond for sealing the ground wire seems to be the way to go.


 
Any suggestions for getting the old cord to move? Its pretty stuck somewhere deep in the conduit. Both ends are loose but won’t move more than an inch?

Any lube which is safe to throw down the conduit? A jet of compressed air or water to loosen things up? I still have a pool half full of water so dish soap isn’t ideal

Is the only possible solution digging?
 
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