Pool Bonding

[Sparky1981]

I am working on an existing Recreation Center that has an existing lap pool. This lap pool is 40 years old and does not contain the equipotential grid. We are adding a large wing to the aquatics to include a new leisure pool, water slide, hot tub and therapeutic pool. Of course all these pools were designed with an equipotential grid that all metal parts to these pools will bond to.

My question is the AHJ is considering making the contractor provide this grid for the existing pool. To me this is a huge cost. With this pool not in scope I did not include it on my plans. Two questions

1. Is there an exception anywhere in the 2011 NEC I am missing for an existing pool?
2. Assuming we need to provide this has anybody had to do this on an existing pool? How did you do it? I am thinking of things like the metal drain at the bottom of the pool, how the heck to you bond that to a grid in an existing deck.

Thanks in advance.

 

[Dennis Alwon]

A lot of communities are making rec centers or town owned facilities to bring their pools up to date. Doing the pool drain would not be practical so I would do the equipotential bonding and the pool water and whatever else is realistic.

The nec is silence on this issue

 

[macmikeman]

This is where proper contracting comes in. I write into any proposal or contract "any work whatsoever to the existing pool is excluded". Then if it still becomes a requirement due to inspectors or such, change order time. $$$$$

 

[bkelly]

Scope letters

Scope letters

This is where proper contracting comes in. I write into any proposal or contract "any work whatsoever to the existing pool is excluded". Then if it still becomes a requirement due to inspectors or such, change order time. $$$$$

This is the #2 most important thing I tell new contractors. Number #1 is pay your taxes, and # 2 is proper scope letters. I spent years developing a scope letter to avoid thing such as this.

 

[packersparky]

I am working on an existing Recreation Center that has an existing lap pool. This lap pool is 40 years old and does not contain the equipotential grid. We are adding a large wing to the aquatics to include a new leisure pool, water slide, hot tub and therapeutic pool. Of course all these pools were designed with an equipotential grid that all metal parts to these pools will bond to.

My question is the AHJ is considering making the contractor provide this grid for the existing pool. To me this is a huge cost. With this pool not in scope I did not include it on my plans. Two questions

1. Is there an exception anywhere in the 2011 NEC I am missing for an existing pool?
2. Assuming we need to provide this has anybody had to do this on an existing pool? How did you do it? I am thinking of things like the metal drain at the bottom of the pool, how the heck to you bond that to a grid in an existing deck.

Thanks in advance.

The 1975 NEC required a "common bonding grid" around the pool. Not that you are responsible to install it.

 

[MasterTheNEC]

I am working on an existing Recreation Center that has an existing lap pool. This lap pool is 40 years old and does not contain the equipotential grid. We are adding a large wing to the aquatics to include a new leisure pool, water slide, hot tub and therapeutic pool. Of course all these pools were designed with an equipotential grid that all metal parts to these pools will bond to.

My question is the AHJ is considering making the contractor provide this grid for the existing pool. To me this is a huge cost. With this pool not in scope I did not include it on my plans. Two questions

1. Is there an exception anywhere in the 2011 NEC I am missing for an existing pool?
2. Assuming we need to provide this has anybody had to do this on an existing pool? How did you do it? I am thinking of things like the metal drain at the bottom of the pool, how the heck to you bond that to a grid in an existing deck.

Thanks in advance.

Greetings,

I wont read the other responses because quite frankly I dont care what they say.

1) I sit in CMP 17 and i can tell you if the pool is existing then nothing within the NEC, even as we sit today after the 2020 First Draft that would require a retrofit of an existing pool situation. There was an effort being back the "grid" around the pools in 2020 NEC but it fell short of getting the votes.

2) Thats your problem. If you attempted to do it then you simply will end up having to get local exception allowances by the AHJ which again is far overreaching by the local body. If it was me I would ensure GFCI on every possible circuit to this pool and i would recommend a rubber or similar perimeter mat system around the existing pool and as a suggestion to the owners a change of all rails and ladders to fiberglass or coated components.

The more complex response is if the AHJ makes you do the existing pool then appeal it unless you just want to do it.

 

[Sparky1981]

Thanks for the input. Although the AHJ has not officially directed us to do this we have shared our concerns, many of which are reflected in your comments. I find nothing in the NEC that requires us to bond an existing pool not in the scope of the project.

We are waiting to see what they come back.

If they make us do this I am hoping all parties can be practical and have an open discussion on bonding the pool shell, ladders, diving board and other more readily available metal components. Getting to the bottom of a 12' diving well in the middle of the pool to bond the drain would just be nuts.

 

[kwired]

I don't know how you could do it properly with concrete shell/deck pool without basically starting over.

Introducing a bond just to what is easy to get to may do more harm then good also.