Retrofit bonding for existing pool

[trmiv]

I’ve got 32x16 vinyl liner pool that I’ve established is not bonded. The pool was originally built in the late 60’s or early 70’sI believe and has been upgraded at various times (liner was replaced in 2015), but no one ever did any bonding.

As far as metal parts it has two metal ladders, one of which goes into the water. Also has metal coping. Those are the only metal parts near the pool that I know of. The pool
has no light. It does have a concrete deck around it but I have no idea if there is rebar in the deck. I also don’t know what the support walls are made out of but I may be able to contact the company that replaced the liner to find out.

Anyway looking it it wouldn’t be difficult to attach a wire from each ladder to the coping and then from the coping run #8 wire in the separation joint of the concrete and then under the soil over to my equipment pad.

So is this worth doing? Does it make it any safer than nothing at all? or is leaving out the concrete deck and possible metal walls from bonding making the situation worse?

 

[atttech-2]

I don't think the possibility of metal side walls is much of a concern since without a light I am hard pressed to think how they could ever become energized. Even if the side wall did get energized as long as a person can't touch it then touch another conductor at a different potential there should not be a problem.

My concern would be the concrete I think without being able to bond it you may be better off with noting at all. The reason I say that is if you bond the ladders to the equipment pad and you have a electrical issue at the pad you have just created the potential for a voltage difference between the ladder and the concrete, a person could become the bridge between the two. I would only consider bonding the ladder to the equipment pad if there was an inconspicuous place that you could cut the concrete and see if there is some rebar or wire to bond as well.

The copper wire running in the expansion joint and between the earth and concrete may get you near equipotential to the concrete especially when damp or wet but not enough that I think it should be trusted as a bond.

Edit: It occurs to me this is too important to guess at I would check with a pool builder and/or an electrician familiar with pool bonding

 

[CJadamec]

I don't think the possibility of metal side walls is much of a concern since without a light I am hard pressed to think how they could ever become energized. Even if the side wall did get energized as long as a person can't touch it then touch another conductor at a different potential there should not be a problem.
QUOTE]

This is not a true statement about bonding. The wall, the coping, the deck, the water, and the pool equipment need to be bonded together. Anything made of a conductive material, with a surface are greater than 4 square inches, that is permanently installed within 5 feet of the pool wall must be connecter to the bonding loop. If you bond one thing you must bond them all. Skipping any part of the pool can actually make the situation more dangerous than if there is no bonding at all.

Bonding things brings everything to the same voltage so that current can not flow. If you skip part of the pool in the bonding loop you can potentially create a greater voltage difference than what would be there normally which would enhance current flow. That would be bad.

Retrofitting a bonding loop onto a pool that was not built with one is not an easy task. Unless you plan on ripping up the concrete deck and redoing it I would leave the pool as is.

The best thing you can do to increase the safety of a pool like this is to make sure all the electrical around the pool is protected by GFCI devices. Typically most pumps on older pools do not have GFCI breakers. Making this upgrade while not the same as a full bonding grid is a huge safety increase.

 

[trmiv]

Yea I had the electrical for the pump replaced when we bought the house. It was previously just on a branch 115v circuit running off the same breaker as the entire master bedroom believe it or not. It had a plugless GFCI wired in under the house that was wired wrong so it didn't even do anything. I had a dedicated circuit with a GFCI breaker in the main panel run so I could replace the old single speed pump with a variable speed pump that runs on 230v. I also added an Intermatic PS3000 surge protector myself to protect the pump. So all of that is all safe. That's the only electrical stuff involved with the pool, so it's pretty simple.

I wanted to address the bonding issue for safety but also because I want to add a saltwater system. Doesn't look like either of those are in the cards though. Not within any reasonable budget at the moment anyway.