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Posted By: George Little Bonding grid- Swimming pool - 03/24/04 02:21 AM
If I have a totally non metallic inground swimming pool, with no metallic parts within five feet of the water's edge, am I required to install a bonding grid in the area of the pool and run a #8 solid coperr conductor back to the water circulating pump? Note: This is very common to have a large bathtub type fiberglass tub and no metallic parts. And to make maters even more interesting, thay add a double insulated motor with no requirements for bonding.
Posted By: Yoopersup Re: Bonding grid- Swimming pool - 03/24/04 05:50 PM
Try 680.26 (4)
Where a double -insulated water -pump is installed ect ect
Where there is no connection between the swiming pool bonding grid and ect ect

Thats the closest I can come.
Posted By: PCBelarge Re: Bonding grid- Swimming pool - 03/24/04 05:58 PM
Hello George
Is there no rebar supporting the pool?

If not this presents an interesting situation.
My opinion - the bonding at pools is for creating an 'equipotential grid'. Without all of the 'normal' stuff around a pool it would seem that no equipotential grid would be required. My thoughts are that there can still be step potential around the pool (due to the potential stray current) and maybe some kind of bonding conductor could be installed around the pools edge - I don't really know, I was thinking outloud [Linked Image]

Pierre
Posted By: HotLine1 Re: Bonding grid- Swimming pool - 03/24/04 07:42 PM
George:
If you have nothing to bond.....then the bond is not required.

Now, that said, are there any pool ladders??, diving board?? Heater?? Pool Cover?? If yes to any accessories, then if it's metalic, and 4 sq in. or larger it must be bonded.

Also, how about a in-pool light??

John
Posted By: Ryan_J Re: Bonding grid- Swimming pool - 03/25/04 12:45 AM
Hi George. I wasn't going to give my two cents about this, because I think it is a very important and very delicate matter. When we read about pool shock/electrocution, it seems as though it could have been prevented by bonding somehthing to something else to eliminate a voltage gradient. I guess the bottom line is just what Jon said, bonding requires to two objects of a different potential to be connected together. If you don't have those two items, there is nothing to bond.

I called IAEI about this once, and that is basically what they told me. Scary stuff...I hate being an inspector when things like this come up.
Posted By: kody wilson Re: Bonding grid- Swimming pool - 03/25/04 05:04 AM
what is IAEI?
Posted By: Ryan_J Re: Bonding grid- Swimming pool - 03/25/04 02:04 PM
Hi Kody. IAEI is the International Association of Electrical Inspectors.

www.iaei.org
Posted By: George Little Re: Bonding grid- Swimming pool - 03/25/04 04:32 PM
Thanks Ryan for your comments and your support for IAEI. I to am an IAEI member and Past President of the Michigan Chapter. When I had E-mail with IAEI on this question there was no definitive answer. I have concluded that there should be a grid, if nothing more than a #8 solid around the pool and run back to the motor location and tied to the bonding lug or EGC of the motor. Here's my reasoning. Since the code is silent on this specific senerio, and is vocal on similar thing. They talk about voltage gradients and no one can argue that there are no voltage gradients in the earth. One post here goes so far as to mention step potential. So I'm going to "suggest" that a bonding grid be installed. It's safer with it than without it IMHO.
Posted By: HotLine1 Re: Bonding grid- Swimming pool - 03/26/04 02:42 AM
George:
Now, I'll inject a personal note on this subject.

IF I was the EC, I would install a 'bond' as you stated. If there was a concrete decking around the pool, I would bond the reinforcing mesh.

The NEC requirements are the minimum, which seems to be difficult for some guys to understand, although as an AHJ, it's ALL I can enforce.

NJ has a State required Ground/Bond testing & Certification for all pools except 1 family houses (Test/Cert valid for 5 yrs, or time as stated by testing co) and a annual visual electrical inspection.

A few areas here in NJ have a 'stray' voltage problem from the local utility. Blamed on SWER system, and utility neutral/ground issues, and it's been around for a few years.

John
Posted By: Bomzin Re: Bonding grid- Swimming pool - 03/28/04 04:42 PM
How big is this pool? We do a number of installs for various companys. No light? No Rails? What about the pool cover rails and motor ? All need a to be bonded!Continuously?

Having a big plastic tub of water that cannot be grounded to the rest of the system I think would be dangerous. In just grounding the concrete around it I could see a differance in polarity building under the right circumstances.

Neil
Posted By: mvrandazzo Re: Bonding grid- Swimming pool - 03/29/04 10:45 PM
Interesting thread.
I agree that some kind of bonding grid should be installed if nothing exsists to bond to. But how? Would it be enough to place a ring of #8 solid around the pool or would you install a ramp around the pool like you do in barns? (Please, No inusult intended comparing humans to barn animals) In other words installing ground rods driven at a 45 degree angle at regular intervals around the pool to reduce the step potential.

Blessings.
Mark
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