Junction Box Confusion

[quinnstefanie]

Junction Box Confusion.

I bought a new house with a pool and I am tackling one project at a time and learning more every day. Yes forum has been great.

My latest question: There is a light in my spa and another one in my pool. Neither of them work. I have assumed that the problem is the bulbs. There is a switch next to my equipment pad and breaker that does nothing so I have assumed it turns on and off the lights (still thinking the bulbs are burnt out)

Today, I noticed on a 4 x 4 pole, there are these two junction boxes as shown in the picture. Underneath them is an exterior electrical outlet. This is located a distance away from the equipment pad and pool so I assumed that has nothing to do with the pool. Today, I googled the manufacture of this junction box and it is actually a pool part. Pentair makes these junction boxes. Now I am confused. What are they? Do they have something to do with the lights. If so, is it possible that the switch next to my equipment pad goes to something else and these have something to do with turning on the lights?

I know this is all very random but I am confused as to why these junction boxes exist and why they are in a separate location from the rest of my equipment pad and electrical and pool.

If anyone has any thoughts, please share.

 

[ajw22]

The pool and spa light wire runs to the junction boxes you found.

The wires connect at the junction box leading to the switches and circuit breakers.

The lights should be GFCI protected. If the CB do not have a GFCI then you may have a GFCI outlet the lights are wired through that is tripped.

 

[ajw22]

If you know how to use a multi meter and work around high voltage you can open the junction box and test if you have 120V at the box.

If you do then your problem is probably the light.

If you do not then you need to look upstream for a switch or GFCI.

 

[bradgray]

I am confused as to why these junction boxes exist

AFAIK, running a light circuit direct into the load center is against code (national? or just majority of local... I don't know) They also make install and service of pool lights much easier and safer. Easier to pull wire through, you can consolidate multiple lights into one HV run, creates an air gap and prevents moisture from getting to the load center. List goes on.

and why they are in a separate location from the rest of my equipment pad and electrical and pool.

Usually they are not too far, because an electrician will need to run another wet-rated conduit to the J-box. How far away is your equipment?

Allen made the best suggestion; check your GFI outlet or breaker. These trip easily, and are a sign the lights gaskets have failed.

 

[Dirk]

I know this is all very random but I am confused as to why these junction boxes exist and why they are in a separate location from the rest of my equipment pad and electrical and pool.

For each light:

The light bulb is located in a housing called a niche. The niche is full of pool water. It has a conduit coming out of the back of it, that is also full of pool water. The light bulb has a power cord sealed to it, that runs through this conduit. The conduit runs horizontally underground for some distance, then does a 90° upward and pops up in your yard. That conduit connects to one of those black junction boxes. From there, the light bulb power cord connects to the wires coming from the light switch.

The light bulb power cable, because it is underwater, needs to be one continuous piece, and well insulated, and permanently sealed to the bulb. So you don't "unscrew" a pool light bulb like you would a typical light bulb inside your home. The junction box exists so that that one continuous wire doesn't have to run all the way back to the light switch, which could be 100' away, or more, in some pools. When your bulb burns out, you have to change the bulb and the power cable, as one unit. Which means pulling the wire out of that conduit after disconnecting it inside that junction box. So you can see why the junction box is there, to facilitate both the electrical connection, and the changing of the bulb, without have to run that bulb wire any longer than necessary.

There are newer types of lights that work differently, but what I described is probably what you have, and is very typical in most pools.

 

[generessler]

When your bulb burns out, you have to change the bulb and the power cable, as one unit. Which means pulling the wire out of that conduit after disconnecting it inside that junction box.

All good stuff. Small thing though: it seems quite a few lights are set up for changing bulbs without replacing the fixture. Gaskets need to be replaced at the same time. All must be done perfectly to avoid leaks. Of course if the original failure was due to a leak other than the gasket, it will just fail again.

 

[Dirk]

All good stuff. Small thing though: it seems quite a few lights are set up for changing bulbs without replacing the fixture. Gaskets need to be replaced at the same time. All must be done perfectly to avoid leaks. Of course if the original failure was due to a leak other than the gasket, it will just fail again.

Yep, there are different systems, as I mentioned, I just described one of the more common ones. Step one is to figure out which one you have.

There are potentially severe consequences for working on a pool light (as in deadly). If you're not 100% confident in what you are doing, get a pro to do it. And/or consider replacing whatever you've got with a low-voltage solution. Or both. I have a 120V light, but wish I didn't. Once it goes I'll move to low voltage for my own pool.

The notion of a 120V potential lurking in my pool is pretty creepy, when I think about it. There's a method for testing a pool's electrical system for leaks. At the very least you should know how to do that. If you don't, it would be prudent to get someone to your pool that does. Don't trust that the previous owner did everything correctly.

Testing the GFCI would be job one. Ever done that?

 

[1poolman1]

For each light:

The light bulb is located in a housing called a niche. The niche is full of pool water. It has a conduit coming out of the back of it, that is also full of pool water. The light bulb has a power cord sealed to it, that runs through this conduit. The conduit runs horizontally underground for some distance, then does a 90° upward and pops up in your yard. That conduit connects to one of those black junction boxes. From there, the light bulb power cord connects to the wires coming from the light switch.

The light bulb power cable, because it is underwater, needs to be one continuous piece, and well insulated, and permanently sealed to the bulb. So you don't "unscrew" a pool light bulb like you would a typical light bulb inside your home. The junction box exists so that that one continuous wire doesn't have to run all the way back to the light switch, which could be 100' away, or more, in some pools. When your bulb burns out, you have to change the bulb and the power cable, as one unit. Which means pulling the wire out of that conduit after disconnecting it inside that junction box. So you can see why the junction box is there, to facilitate both the electrical connection, and the changing of the bulb, without have to run that bulb wire any longer than necessary.

There are newer types of lights that work differently, but what I described is probably what you have, and is very typical in most pools.

For a standard pool light.

 

[Dirk]

@1poolman1, which do you feel is more reliable/safer: the kind where you can change the bulb, or the kind that has the power cable integrated and sealed so that you have to change both as one unit?

I shouldn't have written that the latter type is "typical in most pools," as I don't actually know which type is most often found.

 

[JamesW]

The light bulb is located in a housing called a niche.

The light bulb is in a sealed light housing and the housing goes in the niche.

So you don't "unscrew" a pool light bulb like you would a typical light bulb inside your home.

You remove the housing from the niche and then you open the sealed light housing and then you unscrew the bulb to replace it.

You reseal the housing and reinstall the housing in the niche.

 

[ajw22]

@1poolman1, which do you feel is more reliable/safer: the kind where you can change the bulb, or the kind that has the power cable integrated and sealed so that you have to change both as one unit?

I shouldn't have written that the latter type is "typical in most pools," as I don't actually know which type is most often found.

They are both equally safe when connected to a GFCI.

Replacing a bulb costs $25. Replacing a sealed light that is not serviceable costs hundreds of dollars.

 

[bradgray]

They are both equally safe when connected to a GFCI.

Replacing a bulb costs $25. Replacing a sealed light that is not serviceable costs hundreds of dollars.

+1.

We use this argument often for clients building pools in a rental.

 

[quinnstefanie]

For a standard pool light.

Very helpful. I will update you once I embark on this project.

 

[quinnstefanie]

The pool and spa light wire runs to the junction boxes you found.

The wires connect at the junction box leading to the switches and circuit breakers.

The lights should be GFCI protected. If the CB do not have a GFCI then you may have a GFCI outlet the lights are wired through that is tripped.

If you know how to use a multi meter and work around high voltage you can open the junction box and test if you have 120V at the box.

If you do then your problem is probably the light.

If you do not then you need to look upstream for a switch or GFCI.

Thank you. I will run this test before proceeding. Very helpful

 

[quinnstefanie]

Yep, there are different systems, as I mentioned, I just described one of the more common ones. Step one is to figure out which one you have.

There are potentially severe consequences for working on a pool light (as in deadly). If you're not 100% confident in what you are doing, get a pro to do it. And/or consider replacing whatever you've got with a low-voltage solution. Or both. I have a 120V light, but wish I didn't. Once it goes I'll move to low voltage for my own pool.

The notion of a 120V potential lurking in my pool is pretty creepy, when I think about it. There's a method for testing a pool's electrical system for leaks. At the very least you should know how to do that. If you don't, it would be prudent to get someone to your pool that does. Don't trust that the previous owner did everything correctly.

Testing the GFCI would be job one. Ever done that?

Yes. The GFCI works at the switch and I believe the breaker box to the pool has a special GFCI breaker also