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#187991 07/16/09 02:01 PM
Joined: Jan 2004
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G
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Okay gang- I rarely see a permanently installed swimming pool that is installed above ground. Here's the picture, vinyl liner, and steel wall with support members around the perimeter. The question that come up is: do I need a "Perimeter Surface grid" extending out 3 feet from the pool. If I do, what would be acceptable? If I understand correctly, and that might be the problem, the purpose of the perimeter surface grid is for the people setting on the edge of the pool and dangling their feet in the water exposing their bod to a difference of potential. Pretty hard to do with an above ground pool.

Greg- What do they do in the bikini State?

680.26(B)(2)

Last edited by George Little; 07/16/09 02:02 PM.

George Little
2017 / 2014 NEC & Related Books and Study Guides
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George:

An above ground pool under '05 requires the grid...IF there is conductive materials around the pool. Grass & dirt don't count. (That's DCA, not my opinion)

If cement/concrete then steel rebar/welded wire mesh/copper 12x12. If 'pavers' then Cu 12x12 on top of sub-base only, or a 'rough' concrete sub-base with the grid in that.

So, if it's wood, Trex, dirt/sand nothing.

When we go to '08 (October 1, 2009 mandatory date) the '08 version of the equipotential grid will be required.

PS: I have not seen an AG pool with a grid yet. AS to your 'hanging off', I think it's more for standing an 'grade' and reaching in.

Don't forget the TR/WR/GFI protected, Bubble covered general purpose receptacle.

That's the 'Jersey Way'


John
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I haven't seen an above ground pool without a deck and we are just dabbling with the 08 but ...

The comment from the handbook

Quote
The requirement for bonding perimeter surfaces now applies to paved and unpaved surfaces. An example of an unpaved perimeter surface would be the lawn surrounding a permanently installed aboveground swimming pool.


So it looks like an 8ga copper, tied to the pool shell 4 places equally spaced around the pool.


Greg Fretwell
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Here the AHJ has understood the easing of the grid requirements (from 05 to 08) to mean that the grid need not be copper, that ordinary steel reinforcing mesh is enough - even if there's no concrete, just pavers of grass.

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John,


The last talk I had with Suzanne, she said that under the '08 code, you will still need the bonding grid even if it is just dirt/grass. Now granted under the '08 it doesn't have to be that 12" X 12" copper grid. A single #8 cu wire will be OK.

The last above ground pool I looked at had NO metal parts. The upper and lower track, and uprights, etc. were all made of plastic. NOW is that bonding ring required?

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Harold the answer is in the last line of 680.26(B)(2)

Quote
For nonconductive pool shells, bonding at four points shall not be required.


The only thing you don't need is the radials to the pool shell. You still need the ring of #8 tied to the rest of the bonded items.


Greg Fretwell
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Ironically, the problem is CAUSED by non-conductive pool shells. Specifically, the PVC molded, and PVC-coated steel shells.

It is the insulating nature of the shell that allows a voltage potential to develop. What it seems we are trying to accomplish is the bonding of the pool water to the ground around the shell.

Harold, I think you mis-read my post. I did not say the grid was not required ... I said it was no longer required to be made of #8 copper. You can use ordinary steel reinforcing mesh to make the grid.

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Regular steel mesh in the dirt around here wouldn't last more than a couple years.


Greg Fretwell
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Perhaps, Greg ... but that is one issue code does not address.

I did such a pool last Spring; my fear of corrosion was why I used a copper mesh for the area near the pool equipment, and steel for under the rest of the pavers.

The inspector was surprised; he had never seen a copper grid.

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Harold:

Last I heard is/was 'not required on dirt/grass'.

What I posted above was from the last conversation with her. Nothing in writing.

Now, that I read Greg's post.....hmmm.



John
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