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Joined: Jul 2004
Posts: 9,935 Likes: 34
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The real issue is the guy who drops a packaged spa on an existing concrete patio slab (no supplemental decking). The AHJs were requiring that they install a raised deck, nonconductive material, around the spa, out 3'. This was typically Trex or another plastic. This was to avoid tearing up the slab and putting in bonding. The spa stores have them as an accessory but I am guess the spa people thought, in tough times, it was hindering sales.
Greg Fretwell
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Joined: Feb 2003
Posts: 939
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That is instering and I think it should come standard package when they land it on slab but on decking it should not be a issue but the other hand is the deck stucture itself that should be well built to withstand the weight of spa when it get filled with water in there.
Merci. Marc
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
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Joined: Jul 2004
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The deck kits do no go under the tub, they just ring it about 8" high and extend 3 or 4 feet out from the tub. That usually relieves them from the "paved surface" problem.
Greg Fretwell
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Joined: Jun 2004
Posts: 613
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The 2005 NEC requires the perimeter bond under "paved surfaces"...2005 680.26(C)(3) requires #8 grid in a 12x12inch network
The 2008 NEC requires the perimeter bond under "unpaved surfaces" as well as "paved surfaces"... 2008 680.26(B)(2)(b) requires a #8 single conductor as an alternate means...
For 2011, the code has gone back to the 2005 method with the requirement of the grid style perimeter bond...2011 680.26(B)(1)(b)(3)
Does anyone have the 2011 ROP with regard to the change back to the grid pattern?
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Joined: Feb 2002
Posts: 2,233
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Why is it that the code making panels always have to mess with section 680 of the NEC? This seems like another good reason to have code making every 5 years instead of 3 years. Maybe the states should only adopt every other code change?
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Joined: Jan 2005
Posts: 5,445 Likes: 3
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Remember the Chevy Corvair? The car - the focus of 'unsafe at any speed' - had a stability issue that was solved by a rather plain change to the cars' unique suspension. Note that the change was needed only by that car, and was not applied to every car out there. Not even the crusading Ralph Nader advocated making that change to any car butthe Corvair.
This whole 'equipotential bond' ballyhoo has come about because of issues with ONE particular type of pool. The problem was not seen with any other pool typeor with spas. Yet, here we are, trying to find a 'one size fits all' solution.
The pool type involved is the factory-made, welded metal pool that is coated in PVC. Here's a thought: let'sapply the fix to that design alone- and leave everything else alone.
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Joined: Jun 2004
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I've looked at the ROP on the internet and I see nother regarding a 12x12inch network style grid for the perimeter bond for 2011. I made my statement from the article in the November issue of EC+M of code changes for the 2011 NEC.
I have not bought the 2011 NEC as I am waiting for the Massachusetts version.
Can anyone verify the 12x12inch grid for the perimeter in the 2011 NEC?
Thanks, shortcircuit
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Joined: Nov 2007
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The #8 solid copper conductor is still acceptable in the 2011 NEC for Perimeter Surfaces, 680.26[B],2,[b] Alternate Means.
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Joined: Feb 2002
Posts: 2,233
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Reno,
As I have been saying for awhile that the only pool I have ever seen problems with, are the pre-formed plastic/fiberglass pools. Only they seem to have stray voltage problems. Never seen stray voltage with concrete or steel pools.
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Joined: Jul 2004
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That is one unspecified advantage of the "paved surface" bonding. You are creating a Ufer ground electrode at the pool and that will mitigate most stray voltage problems by minimizing ground shift. I often wonder if these stray voltage problems at a plastic pool could have been fixed with a couple ground rods but when you bury that #8 solid you have just made a ground ring.
A concrete pool will always be your best ground electrode, like it or not. By the time you do all the required bonding on a typical "caged" pool, you have included your pool in the ground electrode system anyway.
Greg Fretwell
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Posts: 99
Joined: August 2003
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