pool bonding

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  #1  
Old 09-09-06, 06:48 AM
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Question pool bonding

Ok, judging from helpful responses, I am going to jackhammer a hole in the side of my concrete block pool (that is ready to have liner and filled) to expose a piece of the rebar of the grid, since I do not have enough #8 wires to go to my 2 12 volt lights, pump, heater, ladder, future diving board, etc.(thought I could connect them all in series before) So my question is now, since I am only having brick in sand patio around edge of pool and supposedly need a wire preformed mesh for 3ft from pool water out under my brick to create another part of the grid, then how many points of it do I need to connect with #8 wire to the rebar in the wall of pool? one? corners? (I'll have to cut hole in wall at each point! ) Also how deep or shallow must it be under the brick? thanks for help.
 
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  #2  
Old 09-09-06, 08:46 AM
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Equi-potential bonding and grounding of a swimming pool and related equipment is probably over the head of most DIY'ers.
I suggest that you study NEC article 680 for reference and use a electrician for consultation.
IT MUST be grounded and bonded properly. The well-being of your family, friends and pets may depend on it.
steve
 
  #3  
Old 09-09-06, 12:22 PM
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What I suggest is you buy a prefabricated copper mesh for this purpose. You bond that mesh together where ever you cut it going around the pool under the brick with a listed connector for direct burial. You only need to bond it to the rebar in one place. Not at every corner. There is no depth requirement for the mesh just next to the earth and put your sand over it.There has been a lot written on revisions in this area into the code book in the last year. There a few tia's (amendments) being looked at by the cmp (write the code) guys.
In my opinion you need to visit with your inspector with what your plan is, after doing your home work on what is required. Then get him to commit to its approval. The inspector isnt going to elaborate on how to do anything but he will or should approve any plan of yours to address his concerns.
One of the concerns by the cmp's was exactly what you are stating that if you use brick for the walkway.... is the wire mesh grid required. The 2005 code isnt very specific in what the walkway contruction needs to be in order to define if a grid in it or under it is required. It eludes to poured concrete walkways around the pool perimeter. However in my area if the surface is considered conductive (a brick walkway is in my locale) it requires the mesh and the tentative vote of the cmp was that brick requires the equipotential grid mesh. So again it may be a local call on this if you use brick. I would want the mesh under the brick. No one is real happy with these added costs in the industry... it has caused some very heated debate in our area of the planet.
If your interested I can spend a little time and find some of the companies that provide this mesh and post that info for your discretion.
Your inspecter told you you couldnt splice a #8 bonding conductor running from the rebar grid to metal parts or circulating equipment. That is the same requirement in my area with some exceptions for existing pools. Like Speedy said there is no code reference to not allow you to splice these wires. But your inspector will not let you... so outside of trying to prove to him you can splice you will have to comply. For what it is worth your not the first person that has had to knock a hole to get to the rebar. Some of your problem is this is new construction and a few of the exceptions that an inspector may allow are hard for him to justify.

Roger
 
  #4  
Old 09-11-06, 06:28 AM
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Originally Posted by POOLMAN
Ok, judging from helpful responses, I am going to jackhammer a hole in the side of my concrete block pool (that is ready to have liner and filled) to expose a piece of the rebar of the grid, since I do not have enough #8 wires to go to my 2 12 volt lights, pump, heater, ladder, future diving board, etc.(thought I could connect them all in series before) So my question is now, since I am only having brick in sand patio around edge of pool and supposedly need a wire preformed mesh for 3ft from pool water out under my brick to create another part of the grid, then how many points of it do I need to connect with #8 wire to the rebar in the wall of pool? one? corners? (I'll have to cut hole in wall at each point! ) Also how deep or shallow must it be under the brick? thanks for help.
To answer this question fully in the answer you want it is important to know which NEC cycle your are under in your area. The 2002 NEC is slightly different than the 2005 NEC in regards to a little detail about the layout of the grid mat.

I know you state the "GRID" which would leave me to believe you are under the 2005 NEC.....but it is important to know because the 2002 does not require the mat process.
 
  #5  
Old 09-12-06, 09:22 PM
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I have to ask (not to get off topic), what is the purpose of the pool bonding? The term, "equi-potential bonding" says that it's to help ensure there aren't potential differences between different pool components - I would assume much the same as bonding cable tv, antennas, phone, electrical service, etc. together.

Why is such a complex bonding scheme required? With all the conductive materials, concrete, water, I would think less bonding would be necessary.

Just curious and looking to learn more.

Thanks!
 
  #6  
Old 09-13-06, 04:17 AM
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Here is the best I can come up with. It is the NEC Handbook commentary:

It is important to understand the difference between the terms bonding and grounding as they apply to Article 680. As defined in Article 100, bonding is ``the permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.'' As described in 680.26(A), the function of equipotential bonding differs from the function of bonding to meet the requirements of Article 250 in that providing a path for ground fault current is not the function of the equipotential bonding grid and associated bonding conductors.
Creating an electrically safe environment in and around permanently installed swimming pools requires the installation of a bonding system with the sole function of establishing equal electrical potential (voltage) in the vicinity of the swimming pool. A person who is immersed in a pool or who is dripping wet, has a large amount of exposed skin, and is lying or walking on a concrete deck is extremely susceptible to any differences in electrical potential that may be present in the pool area.
The primary purpose of bonding in and around swimming pools is to ensure that voltage gradients in the pool area are not present. The fine print note explains that the 8 AWG conductor's only function is equipotential bonding to eliminate the voltage gradient in the pool area.
The reason for connecting metal parts (ladders, handrails, water-circulating equipment, forming shells, diving boards, etc.) to a common bonding grid [pool reinforcing steel, pool metal wall, or an alternative bonding grid as described in 680.26(C)(3)] is to ensure that all such metal parts are at the same electrical potential. The grid reduces possible injurious or disabling shock hazards created by stray currents in the ground or piping connected to the swimming pool. Stray currents can also exist in nonmetallic piping because of the low resistivity of chlorinated water.
 
  #7  
Old 09-13-06, 04:33 AM
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If you were EQ. bonded, you would not receive a static shock.
Thats why you wear a stactic strap when working on electronics. Thats the stray voltage/potential they speak of.

Explained correctly?
 
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