Rust from pool light ground wire

[Hosertx]

I had new Hayward Pool Light (non LED) installed last year. Shortly after, I noticed a streak of rust stains appearing above the light. The streak is easily cleaned with Vitamin C powder in a sock and being doing that every two - three weeks. I finally removed the light from the Niche to see what was going on behind the light. I noticed that there is an extra thick black wire that ends in what looks like a rusted terminal that is covered with a blob of some type of hard white compound. The terminal is not connected to anything. It's just floating free within the niche. The rust is definitely coming from this terminal which is partially protruding from the white compound.

I'm going to call the pool repair company that installed the light, but before I do, want to make sure I understand what is normal and how this wire is supposed to be configured in the niche. I'm also wondering if the rust is due to some electrical current running through this extra wire.

Any thoughts on what is going on and how this should have been set-up?

Thanks!

 

[Hosertx]

Adding pictures.

 

[Dirk]

Where's is PoolguyinCT when we need him? Is that the bond wire come loose?

No matter, the pool repair company is the right call, unless they don't know what it is, then you need a better pool repair company! They may have sent a guy out that was experienced enough to install the light, but not enough to address that wire. Lights can be replaced without even getting in the pool, so maybe he just didn't see it.

It's not something to mess with yourself: pool water and electricity and all...

If it is the bond wire, it's possible your pool could be unsafe until it is reconnected correctly. I'm not sure you or anybody else should be in the water until you know what's up.

 

[JohnT]

Rapid rusting is generally a consequence of an electrical issue. If they can't tell you what the wire is, I'd be very concerned. My guess is that it is the bond wire from the niche. There should be a box somewhere 5ft or so from the edge of the pool behind the light. It will stand up a foot or so out of the ground. Shut off the power and take the cover off the box and see where that wire goes.

Even if this is the bond wire that has become disconnected, I'm concerned that there is an electrical current flowing in your pool causing the rapid corrosion. Your pool company is unlikely to help much sadly.

 

[Dirk]

Your pool company is unlikely to help much sadly.

And there's the rub!

I know from watching him work, and cleaning up after him, that my pool guy didn't know all he should have about bonding. And not too long ago I was having a chat about pool bonding with an electrician at a trade show, who clearly didn't understand the subject either.

And we're the consumers! We're not supposed to have to know about bonding!! So who are we supposed to call, and how are we supposed to know that who we end up with knows enough about pool bonding to make our pools safe?!?

 

[Hosertx]

Thanks. I'm glad I asked and kicking myself for not looking into this sooner. Since it's been over a year, I'm afraid the pool company that installed the light will not offer to help. If there is some small current causing the rusting, could that contribute to rising PH or dropping Alkalanity? I've been fighting that even after 1 year since the pool was replastered.

 

[ajw22]

If there is some small current causing the rusting, could that contribute to rising PH or dropping Alkalanity? .

No. Rising PH is a byproduct of new plaster curing plus maybe SWG or water features.

Dropping alkalinity comes from the MA you are adding to reduce the PH and the way you are adding it.

What PH are you looking to maintain? When do you add MA?

 

[Dirk]

My pool has no water features, almost-one-year-old pebble, an SWG and high-TA fill water. It is still very thirsty for MA...

 

[JamesW]

There is a bond lug on the outside of the light niche where the solid #8 bare bond wire goes.

There is also a bonding connection inside the niche where a #8 solid or stranded, insulated bonding jumper can be connected.

When the conduit from the junction box to the light is non-metallic, you install the #8 solid or stranded, insulated wire in the conduit with the pool light cord. This is called a bonding jumper.

Inside the niche, you connect the bonding jumper to the internal connection and the other end connects to the bond/ground lug inside the junction box.

The connection inside the niche is supposed to be covered with a listed potting compound that is supposed to protect the connection from corrosion. That's what the white compound is.

The terminal can corrode and break off, which is what looks like has happened.

If the connector is corroded off, getting the wire reconnected won't be easy.

Can you get a picture of inside the niche so that we can see if the internal connection is still usable or completely gone?

Hopefully, the external bond wire is still in place.

 

[Dirk]

James, thank you! Almost every line of your post is an answer to a question I've had!

 

[Hosertx]

James Thanks. I called the pool company and they did also feel that the repair may not be easy and referred me to another pool company who has an expert in this area. They pointed out that the bonding wire could have been been jarred and broken during the plastering of the pool. The light was installed a few days prior to the plastering of the pool, and the pool niche was likely exposed during plastering, which explains the blue plaster on part of the wire.

It's also possible that the rusting has more to do with my low alkalinty than a stray current in the wire. My alkalinity has remained between 30-50, only because it continues to drop even when I bring it up to 80-90. I've been battling rising PH since the install, and it hasn't seemed to slow down. The PH and Alkalinity keep moving in opposite directions. (target PH 7.6, Alkalinity 50 to slow the rising PH). The pool company said I should target 120 for my alkalinity.

Can someone explain the concerns or danger of this light not being bonded? Should we stay out of the pool? Obviously the new light has an internal ground within the wire. Is the bonding wire intended to be an additional safety net for light electrical issues or for any electrical current that hits the pool?

 

[JamesW]

It's called a bonding jumper but it's not the bond wire for the light niche.

The bond wire for the niche connects to the outside of the niche. So, the light niche should be bonded.

The purpose of the wire is to bond the niche to the junction box, but I don't know the specific reason.

Some references refer to the wire as a ground. The wire is sometimes green insulated wire, so that makes sense.

The purpose might be to extend the bonding grid to the junction box or it might be for grounding. I'm not sure.

Either way, it's required by code, so I can't tell you that you don't need it.

I don't think that it got broken off during plaster because it is a strong heavy wire connected to a metal connection.

You would have to pull with over 100 lbs of force to break it loose. And, it should be tucked in the niche out of the way.

It probably corroded off. It might have been 99% corroded and got knocked off during service.

There should be a connector in the niche where the wire connects. If it's in good shape, you can cut off the end of the wire where the white compound is and strip to clean copper and reconnect to the connection.

You can replace the wire if necessary. The other end is in the light junction box.

If the connector is corroded off, that's going to make a fix much harder.

You would need to be able to make a new connector or replace the niche or replace the conduit with metal conduit.

You can look up inside the niche to see if the connector is still usable or not.

You can use a dive mask and get in the water or a mirror or an underwater camera to get a good look at the connection point.

Don't raise the TA. A pH of 7.8 and a TA of 60 is usually a good choice.

Maintain the CSI at about -0.3 to 0.0 and that should help.

 

[Dirk]

I cannot for the life of me find the thread that I was just in, seems like very recently, that has a pic that clearly shows the heavy gauge stranded wire in the junction box that James is describing. There's a grounding bar in the junction box (similar to what you'd find in a breaker box), and the bond wire along with other ground wires are all attached to it. The bond wire runs into the same conduit that the light cable does.

Anybody remember that thread?

Anyway, glad to hear that a niche is bonded on the outside as well as the inside. Seems reasonable to assume that if the original PB installed that stranded bond on the inside, with the glob of corrosion stuff and all, that he would have installed the solid one on the outside. (But an assumption just the same.)

Hopefully restoring the inner bond will not be too bad...

 

[JamesW]

Junction Box Conduit Help

Pool light junction box help

Problem installing new pool light!!

 

[Dirk]

Not any of those (thanks for trying!), but "Pool light junction box help" has a pic of a very similar j-box, including the ground bar I was describing, with both the stranded bond wire (or whatever it is) and all the romex solid ground wires all connected together. That setup is different in that the heavy-gauge stranded wire (green jacket) continues on into the other conduit. In the one I was referring to it's all connected up the same, except there's only one stranded wire, and it leads to the niche.

I guess there are many ways to do it.

 

[Dirk]

I've been trying to imagine how I might reconnect the wire to the niche if the lug corroded off the original connection. Especially while underwater! Yikes.

Is a niche part of the watertight "membrane?" If you just drill a hole in it to screw on another bonding lug, would that then be a leak point? If you tightened it up well and then covered it in some sort of goo (epoxy?), would that be a reliable fix? That's all I can think of.

That, or try to locate the #8 solid copper bond wire on the outside of the niche, and connect a new bond wire to that, and run that to the j-box, and abandon the stranded one. Have no idea if that's code or not. And surely that would be some major digging, with no guarantee of finding the thing. It could all be embedded in the gunite, right?

Sorry, not much help...

 

[JamesW]

In the picture with two #8 green wires, I think that the junction box goes to two different lights.

One #8 green goes to one light niche and one #8 goes to a different light niche.

The base of the junction box is metal and has connections for the #8 bond/ground wire and different connections for the ground wires but all are connected by the metal base.

Connecting the bond wire to the junction box base might be an acceptable fix, but it's not what the code requires.

The bond wire is available at the equipment pad. So, maybe it can be run to the junction box.

To be considered code compliant, I would think that you would need to have an electrician or electrical engineer certify the modification and apply for an exception or variance to the local authority having jurisdiction and get it approved.

The niche is part of the membrane and you can't just drill through. Trying to fix a corroded off connection would not be easy.

 

[Dirk]

Gotcha. It kinka looks like that j-box is back by the pad. Could the OP abandon the broken wire in the niche and instead pull a #8 stranded wire from the pad to the j-box, and connect the j-box to the bonding grid that way? Or, by code, does there have to be a wire direct from the niche to the box?

Actually, did the OP say where the light's j-box is located?

 

[JamesW]

I think that the code requires the bonding jumper to be in the conduit to connect the junction box directly to the niche.

I think that the modification would be equivalent, but it would probably need to be certified by a qualified professional and approved by the authority having jurisdiction.

 

[Dirk]

Any thoughts about screwing a new lug right into the niche and sealing it up with epoxy?

I'm just picturing the OP's electrician taking one look and saying "I can't fix that!"

- - - Updated - - -

If he had to replace the niche, that would mean digging out the back side, right? All the way to the j-box? Or can you connect a new niche to an existing conduit from the pool side somehow?