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Equipotential bonding grid

Discussion in 'Pools, Spas, Hot Tubs' started by ICE, Apr 8, 2018.

  1. ICE

    ICE Sawhorse

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    I have a question. A pool is being built with an existing CMU fence located less than five feet from the waters edge. Is the wall steel required to be included in the equipotential bonding grid?

    I say yes. The standard approach is breaking into the footing and getting to the steel. I have caused it to happen many times as have other inspectors that I work with and also from other jurisdictions.

    Now I have been challenged by an inspector and an electrical engineer. The supposition is that because the steel can’t be touched it doesn’t need to be bonded.
     
  2. chris kennedy

    chris kennedy Sawhorse

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    I'm in that camp.Show me where in 680.26 that you would think its required.
     
    jar546 likes this.
  3. jar546

    jar546 *****istrator

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    The wall is less than 5' from the perimeter of the pool but not within 3' of the pool? Where is it exactly?
     
    Msradell likes this.
  4. ICE

    ICE Sawhorse

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

    I get the fact that this code section relates to pool shells and not a CMU fence. I am laying the ground work in an attempt to demonstrate how I got to where I am with bonding fences.

    680.26(B)(7) Fixed Metal Parts.
    All fixed metal parts shall be bonded including, but not limited to, metal-sheathed cables and raceways, metal piping, metal awnings, metal fences, and metal door and window frames.
    Exception No. 1: Those separated from the pool by a permanent barrier that prevents contact by a person shall not be required to be bonded.
    Exception No. 2: Those greater than 1.5 m (5 ft) horizontally from the inside walls of the pool shall not be required to be bonded.

    Re-bar in a block wall is a fixed metal part within a conductive material and if the CMU is less than 5' away from a pool wall it shall be bonded. There would be no argument if the fence was metal as opposed to CMU. Years ago it was determined that a CMU wall with steel re-bar is a metal fence within a conductive coating.

    Now this was not something I came up with.....it has been accepted policy for as long as I have been an inspector. If it changes I have nothing to say about that.
     
    jar546 likes this.
  5. jar546

    jar546 *****istrator

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    Now I have an issue with the part that says "fixed metal parts." You have an existing CMU wall that is not part of the pool, albeit within 5' of the pool edge. The walkway around the pool will be bonded. If it was new construction it would be an easy sell, not so much for existing that is not part of the pool assembly. JMHO
     
  6. steveray

    steveray Sawhorse

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    Under 250 whatever the heck, you get a pass on hitting a CEE when it is not "available".
    I don't know that you get the same pass on bonding for a new pool.....Interesting
    680.26B(7)?
     
  7. Rick18071

    Rick18071 Sawhorse

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    By this if a pool is less than 5' from a house would you make them break into the house footing to bond the rebar in the footing? Would you make them pay someone to see if there is rebar in the footing?
     
  8. ICE

    ICE Sawhorse

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    That has been the way it's done for as long as I have been here. But I think that will change to no bonding CMU walls and footing steel no matter how close to the pool. Surrounding jurisdictions may differ and keep the bonding requirement.
     
  9. Francis Vineyard

    Francis Vineyard Sawhorse

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    That rebar might be a UFER!
    250.52.jpg
     
  10. north star

    north star Sawhorse

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    ** = ** = **

    Soooooo, what is the verdict in **ICE**'s application ?......Is
    the bonding of the adjacent CMU wall; with structural steel
    [ of some sort ] in it, ..."required" by the Code sections that
    **ICE** provided ? :D


    ** = ** = **
     
  11. ICE

    ICE Sawhorse

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    250.52 (B) Not Permitted for Use as Grounding Electrodes.
    The following systems and materials shall not be used as grounding electrodes:
    (1) Metal underground gas piping systems
    (2) Aluminum

    680.26 (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 remote panelboards, service equipment, or electrodes.
     
  12. Rick18071

    Rick18071 Sawhorse

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    NEC 250.50 - All grounding electrodes as described in 250.52(A)(1)through (A)(7) that are present at each building or structure.......................
    Looks like the NEC calls at least 20' of rebar in a footing or foundation is a grounding electrode if it connected to the grounding system or not.
    So it looks to me that the pool would not be required to be bonded to the rebar in any footing or foundation.
     
  13. ICE

    ICE Sawhorse

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    That is the consensus.
     

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