Above ground pool bonding (metal wall)

[JKB121]

Well, it's not quite pool time here, so the best I can do is log on and read about them... LOL. So I haven't seen anything very recent about bonding the steel wall panel on an above ground pool. I see mostly the concept of running a #8 copper wire around the entire perimeter of the pool, connected at 4 points. I also see some say 1 point where the wall is joined is also acceptable. Based on what a pool installer told me at the time of purchase 2 years ago, I went with the 1 location at the wall seam. I was wondering if this post on here from 2014 is still an accepted procedure. "The 4 equally spaced connections does not apply to most AGP with a solid metal wall. They only require a single bonding connection. The 4 equally spaced connectors apply to pools with rebar or copper grids. Your inspector may see it differently. If you have a resin pool shell with metal supports, each support must be bonded, not just 4. NEC 680.26 (B) (4) Read ALL of 680.26!"

Everything in my system is bonded and the water is bonded through the titanium heat exchanger, (per HP manual).

Thoughts??

@ajw22

 

[mknauss]

It sounds like you are following the right path. Also be sure the bond wire connects to the pump, heater, SWCG, etc.

 

[ajw22]

I was wondering if this post on here from 2014 is still an accepted procedure. "The 4 equally spaced connections does not apply to most AGP with a solid metal wall. They only require a single bonding connection. The 4 equally spaced connectors apply to pools with rebar or copper grids. Your inspector may see it differently. If you have a resin pool shell with metal supports, each support must be bonded, not just 4. NEC 680.26 (B) (4) Read ALL of 680.26!"

I don't see where NEC 680.26 allows a single bonding point on a solid metal wall pool. While that 2014 post makes the claim he does not cite what in the NEC allows it.

If your pool bonding will be inspected then check with the inspector on what he will accept.

Everything in my system is bonded and the water is bonded through the titanium heat exchanger, (per HP manual).

I would not rely on the HP to provide the water bond. If the HP is removed or bypassed you will compromise your bonding.

 

[JKB121]

Thanks Guys! I appreciate the help.

I live in a very rural area. Wouldn't have it any other way. Permits are not required, and there is no residential inspector. (just perfect). That said, I always strive to do things right. I stumbled upon some of those old posts looking at other threads, and it got me thinking.

This pool was like so many others, a COVID pool. I bought the pool from a big National pool store. Their installers were booked into the next year, so I did it myself. One of their installers was at the store at the time and I asked him about bonding in 4 locations. He said he only does 1 location (at the seam) and mentioned some pools have a plastic bottom track which cannot be used for bonding. Mine does not, and I never heard of such a thing, but he is an installer.

So at this point I have the wall bonded at a top bolt and a bottom bolt at the seam. 1 piece of bare #8 copper runs from there to the pump, then to the HP. Currently every piece of equipment is bonded. I will need to include the new SWG in the spring.

That said, and preferring to do things right, is a complete loop of #8 necessary? It would not be the easiest thing to bury on the back side of the pool at this point with a deck there now. Not impossible, just difficult. The deck is framed of pressure treated lumber and covered with plastic decking. Plastic steps into the water.

What is the concept of a loop 18 inches away from the base of the pool? Would 4 equal points that is not a loop work? Like a big "C".

 

[JKB121]

I just found this recent thread on Mike Holts Forum. It is my understanding that Mike Holt's Forum is a well respected source for electric information. I'm still curious as to why some bury a complete loop of copper.

Q: Does the 4 point bonding described in 680.26(B)(2) apply to all vinyl lined above ground pools? If the pool has a continuous metal wall that bolts together at one point, isn’t one connection from this wall splice point to the perimeter bonding conductor sufficient?

A: If it's continuous, up to the joining point, that's all you can bond to on the pool itself. Of course, you still need the water & equipment bond.

A: (From an inspector) I been getting a lot of above ground pools this year and was also struggling to understand the four points of grounding' where they bolt together at one point. I have been requiring to only bond the pool wall at this seam of the wall by adding a lug to one of the bolts.

A: I do a lot of above ground pool jobs in Ohio. Every resin pool I have done the inspector is fine with bonding the shell with one point at the seam, along with water and pump bonding. I had one pool installer drill four holes in the bottom of the shell and place 1/4 20 bolts through it where I could put lugs. Other than that I just bond the one point at the seam.

 

[JoyfulNoise]

In an idealized, aka theoretical, situation, a continuous sheet of metal, no matter how twisted or formed, would only need one point of contact to be electrically bonded to another metallic object. Do you live in a theoretical universe or the real world? Engineers set specification based on what happens in the real world and base those specification from the starting point of the theoretical. But, as every engineer is taught on day one in college, everything that is designed needs to be fault tolerant because Señor Murphy has a law … anything that can wrong will go wrong. So 4 bonding points on the shell ensures that you do not create something that has a single point of failure. If 2 or 3 bonding points is all you can do easily then do that. The cost of the extra #8 conductor you’d have to purchase is nothing compared to the agony you’d feel if someone you love gets hurt ….

 

[JKB121]

In an idealized, aka theoretical, situation, a continuous sheet of metal, no matter how twisted or formed, would only need one point of contact to be electrically bonded to another metallic object. Do you live in a theoretical universe or the real world? Engineers set specification based on what happens in the real world and base those specification from the starting point of the theoretical. But, as every engineer is taught on day one in college, everything that is designed needs to be fault tolerant because Señor Murphy has a law … anything that can wrong will go wrong. So 4 bonding points on the shell ensures that you do not create something that has a single point of failure. If 2 or 3 bonding points is all you can do easily then do that. The cost of the extra #8 conductor you’d have to purchase is nothing compared to the agony you’d feel if someone you love gets hurt ….

Agreed. I'm trying to figure out "why" some say to bury the loop between 12 and 24 inches outside the wall. In the event someone might be adjusting a solar cover from outside the pool standing on the ground, would it not be safer if the loop was 3 or 4 feet outside the pool wall so the person would be inside the loop? The cost or difficulty is not the issue. I'm trying to understand the logic. Make sense?

 

[JoyfulNoise]

Agreed. I'm trying to figure out "why" some say to bury the loop between 12 and 24 inches outside the wall. In the event someone might be adjusting a solar cover from outside the pool standing on the ground, would it not be safer if the loop was 3 or 4 feet outside the pool wall so the person would be inside the loop? The cost or difficulty is not the issue. I'm trying to understand the logic. Make sense?

12-24" is about where a person's feet would land if their arm is reaching over the side and in the water. Soil isn't really a great conductor of electricity so you want the conductor to be as close as possible to where a person might reasonably be standing. If you want to do two rings of conductor, then place the second one a few feet out. The better option would be to use a buried copper mesh that's a foot or two wide and runs all around the pool perimeter. That would give excellent coverage.

This isn't an exact scientific problem, it's risk mitigation. SO there's lots of different ways to create an equipotential grid and the code is simply trying to give a person the most straightforward way to do it that is likely to have the greatest chance at averting injury. There's many ways to do it, pick one that works best for your situation. As you said, there is no inspector in your area so you are basically free to do whatever you want ... and you assume all the risk for that luxury

 

[JKB121]

it's risk mitigation.

Exactly. At least I have the rest of the winter to plan and execute the additional safety measures...

I never heard of the copper mesh..... looking now!

 

[JKB121]

This is a lot of knowledge in a very long video.

 

[JoyfulNoise]

Mike Holt makes excellent videos and is a great instructor. He’s one of those rare individuals that cares both about the detailed science and the practical implementation. And he’s articulate and engaging as well … a natural and talented teacher.

 

[JKB121]

Mike Holt makes excellent videos and is a great instructor. He’s one of those rare individuals that cares both about the detailed science and the practical implementation. And he’s articulate and engaging as well … a natural and talented teacher.

So many things to check before pool opening, but I'll feel MUCH safer afterwards.

 

[cruiser310]

This thread has been very informative for my situation also, but the one question that wasn't really addressed yet was 'why does the perimeter loop need to extend underneath the deck area when no one can physically be standing under the deck and touching the water at the same time'. In this case would the 'C" type configuration the original poster referred to work? Or does that go back to the theory of only 1 point of failure in case the bond wire was broke or damaged, then there would be a backup path to the other equipment?, assuming it is only broke in 1 place.
I am asking because my pool has a wooden deck around half of the pool much like the original poster and no one will be able to be under the deck and touching the water at the same time.

Thanks everyone, I am enjoying the valuable information from everyone in this post.