The New "4-Points" of E-Bonding

[George Stolz]

2008 ROC 680.26(B)(2) Perimeter Surfaces. The perimeter surface shall extend for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall include unpaved surfaces as well as poured concrete and other types of paving. Bonding to perimeter surfaces shall be provided as specified in 680.26(B)(2)(a) or 680.26(B)(2)(b), and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four (4) points uniformly spaced around the perimeter of the pool. For non-conductive pool shells, bonding at four points shall not be required.

I've been looking all over the place. Where is the proposal/substantiation for this "four points" concept?

 

[cpal]

George

I see the ROC has hit the street???

 

[George Stolz]

Sure has, click here to get there from here.

What, you sleep in?

 

[George Stolz]

Ahh...I see it now.

The TCC sent a proposal to "clarify" 680.26, Proposal 17-114a. It was hidden in there, there was no substantiation.

Interesting, we must technically substantiate everything regardless of how obvious it is, but they can up the requirements without proving one connection was not good enough...

 

[goodcode]

Look at 17-115. That is the base proposal. 17-114a ia a "panel proposal" which incorporated the intent of 17-115 as well as other proposals. The panel statement did not clearly explain that their action was based on "accept in principle" of several other proposals.

 

[George Stolz]

But I don't see the "4 points" of connection anywhere but 17-114a.

 

[bphgravity]

Hello George.

I have researched this pool bonding issue to death and have been in direct contact with CMP 17 chair Don Jhonson. I don't have all the numbers here with me at home, but the basic timeline and detail is as follows.

During the 2005 cycle, it was suggested as a comment that a FPN should be added to 680.26 recommending the inclusion of the pool's perimeter surface into the equipotential grid, thus a proposal was submitted by Mr. Jhonson himself. This was the first mention of the 4-point bonding. It was later agreed upon by the panel that a FPN would cause confusion and the requirement should be made into positive text. They based the wording and detail of the new "alternative means" in the pool deck area from a study on touch/step potentials and equipotential bonding at dairy farms. Finally, the 2005 was released and not much attention was paid to the section until Florida adopted the 2005 code.

The NFPA and other organizations were bombarded with questions, FI requests, and lots of hate mail from the pool and spa associations. Meanwhile, a group out of Australia began a study on the effectiveness of the equipotential bonding of a pool's perimeter surfaces. They concluded that a single #8 conductor placed around the perimeter of the pool or spa 18-24" into the walking surfaces and connected to the pool shell at four equal points along the perimeter of the pool was as effective as the alternative grid or use of structural steel in the deck surfaces. This resulted in a panel proposal for the 2008 NEC. Based on the ROC, the whole section will be rewritten and the alternative means well defined.

I will provide all the pertinent ROP and ROC numbers from the 05 and 08 code cycles on Monday when I get back in my office.

(On a side note, many jurisdictions in Florida are already permitting the use of the single ring bond in the deck as an alternative means based on the 2008 ROP/ROC.)

A long and drawn out discussion here in Florida can be found here:

http://www.iaeifl.org/cgi-bin/ubb/noncgi/ultimatebb.php?ubb=get_topic;f=26;t=000332

Editted inadvertent profane typo - George
(1 "s" in "as")

 

[infinity]

So correct me if I'm wrong, but this new proposal eliminates the need for hundreds of feet of rebar emanating from the pool wall out to 3' and replaces it with a single #8 conductor bonded at 4 points?

 

[George Stolz]

Bryan, thanks for the reply. (Thank you too, Trevor, but I'm not there yet and I haven't thought about your aspect. )

So, looking back at Proposal 17-124 (a proposal for an alternate means of creating e-bonding) leading to the 2005 NEC, I see a proposal containing the concept:

They shall take a path which brings them to points which divide the length of the waterline ring into four parts equal within 1 percent of the ring's overall length.

Substantiation:

For 680.27(5): The ring-bond conductors are intended to provide multiple-path bonding of the rings such that many connections could fail without affecting the effectiveness of the system. The 1% figure (IE: 1 foot in 100 feet) is to assure reasonably even installation.

From what I can see of this proposal, it was accepted without an overwhelming amount of technical information. Then the TCC said, simma down now.

In the 2005 ROC, I see Jhonson's proposal, with the four parts language struck through. I agree with his statements about applicability in the field. I read decently and I couldn't make heads or tails of what the stink the original proposal was describing without a picture.

I will provide all the pertinent ROP and ROC numbers from the 05 and 08 code cycles on Monday when I get back in my office.

That would be awesome, 'cause I'm still seeing a gap.

 

[George Stolz]

So correct me if I'm wrong, but this new proposal eliminates the need for hundreds of feet of rebar emanating from the pool wall out to 3' and replaces it with a single #8 conductor bonded at 4 points?

No. The basic premise is the same. If there is rebar, it's the first choice for the e-bonding grid.

2008 680.26 Equipotential Bonding. (A) Performance. The equipotential bonding required by this section shall be installed to reduce voltage gradients in the pool area as prescribed.

(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(7) shall be bonded together using solid copper conductors, insulated covered, or bare, not smaller than 8 AWG or with rigid metal conduit of brass or other identified corrosion-resistant metal. Connections to bonded parts shall be made in accordance with 250.8. An 8 AWG or larger solid copper bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to any remote panelboard, to service equipment, or electrodes.​

(1) Conductive Pool Shells. Bonding to conductive pool shells shall be provided as specified in 680.26(B)(1)(a) or 680.26(B)(1)(b). Poured concrete, pneumatically applied or sprayed concrete, and concrete block with painted or plastered coatings are shall all be considered conductive materials due to water permeability and porosity. Vinyl liners and fiberglass composite shells are shall be considered to be non-conductive materials.

a. Structural Reinforcing Steel. Unencapsulated structural reinforcing steel (rebar) shall be bonded together by steel tie wires or the equivalent. Where structural reinforcing steel is encapsulated in a nonconductive compound, a copper conductor grid shall be installed in accordance with 680.26(B)(1)(b).​

b. Copper Conductor Grid. A copper conductor grid shall be provided and shall comply with the following conditions:​

(1) Be constructed of minimum 8 AWG bare solid copper conductors bonded to each other at all points of crossing.​

(2) Conform to the contour of the pool and the pool deck.

(3) Be arranged in a 300 mm (12 in.) by 300 mm (12 in.) network of conductors in a uniformly spaced perpendicular grid pattern with a tolerance of 100 mm (4 in.).

(4) Be secured within or under the pool no more than 150 mm (6 in.) from the outer contour of the pool shell.​

​

​

(2) Perimeter Surfaces. The perimeter surface shall extends for 1 m (3 ft) horizontally beyond the inside walls of the pool. This shall include unpaved surfaces as well as poured concrete and other types of paving. Bonding to perimeter surfaces shall be provided as specified in 680.26(B)(2)(a) or 680.26(B)(2)(b), and shall be attached to the pool reinforcing steel or copper conductor grid at a minimum of four (4) points uniformly spaced around the perimeter of the pool. For non-conductive pool shells, bonding at four points shall not be required.​

(a) Structural Reinforcing Steel. Structural reinforcing steel shall be bonded in accordance with 680.26 (B)(1)(a).​

(b) Alternate Means. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, copper conductor(s) shall be utilized where the following conditions are met:

(1) At least one minimum 8 AWG bare solid copper conductor is shall be provided.
(2) The conductor(s) shall follow the contour of the perimeter surface.
(3) Only listed splices shall be permitted.
(4) The required conductor provided shall be 450 to 600 mm (18 to 24 in.) from the inside walls of the pool.
(5) The required conductor shall be secured within or under the perimeter surface 100 to 150 mm (4 to 6 in.) below the subgrade.

​

​

(3) Metallic Components....​

Bear in mind, some language may be goblidigook because what I quoted has strikethroughs that I wasn't overly concerned about deleting. I was trying to get the gist across.

 

[MIKEL WAYNE]

Orange County Florida Requires The Copper Equipotential Grid Be Covered With Plastic To Prevent Corrosion, Does This Not Act As An Insulator As There Is No Direct Contact From The Grid To The Deck?

 

[1sparks]

Non Conductive shells

Non Conductive shells

This code is written like crap and each inspector in Florida is interpreting it differently. I have been required to build a bonding grid of 3/8 rebar - 3' around a fiberglass pool by my city inspector. This is stupid if you asked me. We took an extremely safe, non conductive pool and surrounded it with metal, then boded the grid to the pool equipment and railing, creating an electrical magnet where none existed. Bonding is a very bad idea for non conductive pools IMO. It makes things more dangerous, not less. I hope the NEC authors are taking pool construction into consideration when revising codes. We have installed many 'glass pools in Highlands county since 2005 and not built a grid around them. Anyone else run into this problem with each locality interpreting the code to mean something different, and is there a consensus on what pool bonding requirements are for non conductive shells?

 

[Porten1134]

pool rebar extending 3 feet

pool rebar extending 3 feet

i am an inspector in slc utah and have come across a matter that needs some clarification.680.26 (c) states you can use the pool rebar and extend it out 3' to meet the intend of the code.now 680.26(c)3 a-c states alternate means,basicly allowing a 12"x12" mesh of #8 copper. my extrapolation of this is the intent of the code is that basicly a 12"x12" mesh of #8 copper or rebar is required around the edge of the pool.
now if the rebar spacing of the pool is considerably tighter(say #3 rebar @ 4" O.C.) does that mean that my bonding grid (680.26(c)1)is required to maintain the same spacing, unless using the alternate means? if a rebar mesh is bonded using a #8 copper wire but is 3'x3' does it meet the intent of the code under 2005 N.E.C (or 2008).It seems to me that the intent of the code is to get at least a 12"x12" mat of copper or rebar under the walking surface of the pool(including the coping stones)even if the rebar in the pool is spaced at greater intervals.
in my case the pool contractor has rebar in the pool @6" O.C. both directions.He does not want to continue the rebar out of the pool onto the deck to provide a little wiggle room for expansion and contraction and ground heaving in the winter.He has bonded a 3'x3' grid of rebar to the pool rebar via a #8 rebar.He has stated that he has met the intent of 680.26(c)1 because the spacing of the rebar is not specified.Has he?

 

[infinity]

Now if the rebar spacing of the pool is considerably tighter(say #3 rebar @ 4" O.C.) does that mean that my bonding grid (680.26(c)1)is required to maintain the same spacing, unless using the alternate means?

IMO, yes. 680.26(C) tells us that the EBG can be achieved by one or more of the three methods listed in 680.26(C)(1),(2) or (3). Since the structural reinforcing steel of the pool is permitted to satisfy this requirement it is required to extend out 3' horizontally under the paved walking surface. If the pool design allows for this rebar to be spaced at wider intervals, that rebar spacing may continue out under the walking surface and still satisfy the requirement. IMO the reverse would apply if the spacing were tighter.

When using an Alternate Means as outlined in 680.26(C)(3) then that specific grid patterned spacing must be followed.

 

[bphgravity]

For you Florida guys, see this bill in legislation at this very moment. If and when it is signed by the Govenor, pool bonding requirements at pools will look much like the proposed 2008 version of 680.26 of the NEC.

Go here:

http://www.flsenate.gov/cgi-bin/vi...tory=session/2007/Senate/bills/billtext/html/

 

[ryan_618]

Interesting, we must technically substantiate everything regardless of how obvious it is, but they can up the requirements without proving one connection was not good enough...

George, it seems to me that CMP's can change anything without technical substantiation. Take a look at the CMP's proposal to chagne the defintion of dwelling unit. They were going to make evey hotel/motel with a microwave a dwelling. I (or maybe I submitted it under Mike) made a comment to reject because of a lack of technical substanation. The panel rejected the comment. It wasn't until I talked to the TCC that it got overruled by the TCC, not the CMP.

 

[Pierre C Belarge]

i am an inspector in slc utah and have come across a matter that needs some clarification.
It seems to me that the intent of the code is to get at least a 12"x12" mat of copper or rebar under the walking surface of the pool(including the coping stones)even if the rebar in the pool is spaced at greater intervals.
He has bonded a 3'x3' grid of rebar to the pool rebar via a #8 rebar.He has stated that he has met the intent of 680.26(c)1 because the spacing of the rebar is not specified.Has he?

Hello Porten and welcome to the site.

I am not sure if I understand your post, so I will ask some questions first.

1. What code cycle and revisions if any is your jurisdiction referencing?

2. By "3'x3' grid of rebar", do you mean rebar, or are you talking about the 'rollout' we see installed for stability of walking areas, such as sidewalks? Rollout is not rebar, it is a mesh that the metallic portion is usually much smaller in diameter that the actual pieces of rebar.



These are pics of "rollout", not rebar.

 

[Jomaul]

This method is not new, in Pinellas county Fl back in the 70's we had to run an unbroken #8 completely around the pool, and back to the pump. every 10' we had to tie the #8 to a piece of rebar from the shell with a country clamp. all the cups for the ladders or handrails had to be tied to the same unbroken #8.

 

[Pierre C Belarge]

I wonder if that was a written change to the code... as would be required. Meaning the jurisdiction is required to have the codes in writing.