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.
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
#87602 - 03/24/0403:42 PMRe: Bonding grid- Swimming pool
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.
Ryan Jackson, Salt Lake City
#87604 - 03/25/0401:04 AMRe: Bonding grid- Swimming pool
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.
#87607 - 03/25/0410:42 PMRe: Bonding grid- Swimming pool
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.