Bonding questions

[jspeacock1978]

I asked a PB a question if during my pool remodel the pool would be “bonded and grounded (new or existing)”. I put his response below. I figured bonding and grounding my pool was the PB’s job. Thoughts?

====PB’s response====
Pool must be bonded in a minimum of 4 places. We will provide a “ pig tale” wire attached to the back of the pool beam and it is the deck contractor responsibility to run a bond wire or bond grid. However, we can do it at minimum of $650.00 of $8.00 per ft which ever is more.

 

[Aquaman7]

Is the deck contractor separate from the pool builder?

 

[cowboycasey]

That 650 bucks is for the new bonding mesh 3 ft x 100 ft that gets installed under the deck

 

[jspeacock1978]

The PB and deck builder are separate companies.

 

[jspeacock1978]

I just spoke with one of the hardscape guys who said its usually done by the pool company. In this case my pool probably has one, but he said he'd raise red flags if he didn't see it. I just hope they don't trash it when they demo the deck but I'm not going to hold my breath. My guess is that I'll wind up paying the PB for a new bonding grid.

 

[PoolGate]

This really has to be done by the deck guys. It was with mine. It goes on top of the gravel substrate and under the concrete. If you demo a deck, I don't see any way that you'll save the bonding grid.

 

[sktn77a]

====PB’s response====
We will provide a “ pig tale” wire attached to the back of the pool beam.

Not sure what he means by this - shouldn't the pool be bonded to the shell rebar?

 

[jspeacock1978]

I’d like to think the he’s talking about running a wire from the rebar in the shell at each of the corners out a ways for someone to tie into. It was unclear how the bonding then makes it to the equipment pad.

I‘m also unclear about the difference between the bond grid or bond wire. I’ve ready a few posts where the “grid” was really a wire but others where a mesh was used. Anyone in California able to shine some light on this?

 

[jspeacock1978]

From:

https://www.contracosta.ca.gov/DocumentCenter/View/44645/RESIDENTIAL-POOL-AND-SPA-INSTALLATION

This part makes sense -
“All fixed metal parts, including underwater lighting, fittings, electrical equipment, piping, awnings, fences, etc. within 5 feet of the inside of the pool wall shall be bonded to the pool reinforcing steel with a #8AWG copper conductor. Bonding clamps for direct burial or concrete encasement shall be brass, copper, copper alloy, or other listed material.“

This part makes sense although I have no idea where you’d put this thing -
“Where none of the bonded parts is in direct connection with the pool water, the pool water shall be in direct contact with an approved corrosion-resistant conductive surface that exposes a minimum of nine square inches of surface area to the pool
water at all times. The conductive surface shall be located where it is not exposed to physical damage or dislodgement during usual pool activities and it shall be bonded as noted above. (CEC 680.26)”

I understand the idea, but how do you bond unpaved or paved surfaces. I think I understand concrete since I assume you’d bond to the rebar.
“The perimeter surface within 3 feet of the inside wall of the pool (including unpaved, paved, concrete surfaces, etc.) shall be bonded and attached to the pool reinforcing steel or copper conductor grid at a minimum of four points spaced uniformly around the pool. (CEC 680.26)”

Bonding an unpaved surface sounds like you’d need to drive a rod into the ground, but that seems like grounding not bonding. When it comes to a pool should my bonding grid be grounded as well or is that the point of that last part?

 

[cowboycasey]

This is what you use for the water https://smile.amazon.com/Burndy-Above-Ground-Bonding-BWB680AG

And these for under the deck weather it be concrete or pavers or whatever within 5 feet of the pool shell..

3′ WIDE X 100′ LONG COPPER EQUIPOTENTIAL BONDING GRID W/KIT <span> Case Qty. 1</span> - Consolidated Manufacturing

KIT INCLUDES 20 #8 SPLIT BOLTS, 16 METAL STAKES Case Qty. 1 AVAILABLE IN CUSTOM LENGTHS ; 50’. 125’, 150’, ETC.

www.cmiwebsite.com

#8 Bare Copper wire, 500′ rolls <span> Case Qty. 1</span> - Consolidated Manufacturing

Case Qty. 1

www.cmiwebsite.com

Hardware Kit for EB3100 <span> Case Qty. 1</span> - Consolidated Manufacturing

Case Qty. 1 Kit Includes: 20 #8 SPLIT BOLTS 16 METAL STAKES

www.cmiwebsite.com

So bonding and grounding are 2 completely different things and should never be connected to each other..

 

[jspeacock1978]

Thanks for the links @cowboycasey. I’ll accept that I can’t connect my ground and bonding grid, but isn’t ground just a path for current go to to the ground? If so, how is that different than a copper wire laying on the ground?

 

[vermaraj]

They are connected, but they are separate systems. The load panel is bonded on the outside and grounded (bus bar) on the inside. As the inside and outside are the same piece of steel, they are in fact connected. But for the purposes of code, they are separate.

Such is the smoke and mirrors nature of electrical engineering.

Which I am allowed to say as an electrical engineer and a PE.

 

[cowboycasey]

your "electrical ground" is is for electricity and your bonding is so you do not get electrocuted in your pool... bonding keeps the same exact electrical current within that 5 feet of the pool... so if you reach out of the pool and grab a ball you do not get electrocuted because that 5 feet is at the same equipotential... the link below will teach you more than I ever could.. It took me a long time to understand all this also...

Mike Holt Enterprises - The Leader in Electrical Training.

Mike Holt worked his way up through the electrical trade from apprentice electrician through electrical contractor, to become one of the most recognized experts in the world as it relates to electrical power installations. He was a Journeyman Electrician, Master Electrician, and Electrical...

www.mikeholt.com

 

[Dirk]

your "electrical ground" is is for electricity and your bonding is so you do not get electrocuted in your pool... bonding keeps the same exact electrical current within that 5 feet of the pool... so if you reach out of the pool and grab a ball you do not get electrocuted because that 5 feet is at the same equipotential... the link below will teach you more than I ever could.. It took me a long time to understand all this also...

Mike Holt Enterprises - The Leader in Electrical Training.

Mike Holt worked his way up through the electrical trade from apprentice electrician through electrical contractor, to become one of the most recognized experts in the world as it relates to electrical power installations. He was a Journeyman Electrician, Master Electrician, and Electrical...

www.mikeholt.com

I think I can get a bit closer (though NO kind of expert on this topic). Without bonding, you'll get shocked in a pool if you touch two things that have a different voltage potential between them. Like the water you're in and, say, the ladder you grab. You could ground both of those two things independently, but the voltage potential could still exist, because the two would only be connected together by dirt, which of course is not a great conductor. If there is enough of a difference in potiential, you feel the shock because you are a better conductor than the dirt. By connecting everything together with a big, fat copper bond wire, whether it's grounded or not, you wouldn't feel the shock because there is no longer a different voltage potential between the two objects. And if some stray voltage is introduced somewhere, the copper wire is so much the better conductor than you, that you don't feel anything. Er suppin' like dat dar.

That's why they are considered separate systems, even though they will be connected together somewhere along the way. They both have to exist for the pool to be completely safe.

 

[Dirk]

I said "completely safe" when I really should have written "safe-ish." I didn't read your link, Casey, but I watched one of the authors videos a while back. He seems to know his stuff. He was demonstrating with his own pool, and the most interesting part of the demo was the fact that Holt won't put anything electrical in or near his pool. So no light! Pretty telling when even a respected expert in the field doesn't trust these safety systems 100%! Best, I think, to always wear a rubber suit when swimming. It's the only way to be sure!!

 

[cowboycasey]

Dirk, he really knows some stuff, made many of the recommendations for bonding to the NEC... I like 12 volt as it is way safer than 120v

 

[vermaraj]

Bonding in the electrical code is defined as creating a continuous interconnected path such that there can be no voltage difference between the components. In theory this could happen at any voltage but, in realty this can only happen at zero voltage which is ground.

Ground is an electrical level created by burying wire or steel in moist soil such that it could conduct small amounts of charge (electricity). Thereby creating a reference plane that can be used for fault current interrupts (circuit breakers) like GFCIs.

As mentioned before if they both separately connect to the same steel box, they are connected.

In fact, your steel reinforced concrete pool that sits in hundreds of square feet of moist soil is one of the best grounds available. The only better ground is a steel well casing that extends into bedrock. A concrete encased electrode or "UFER" is the preferred method of grounding new construction. It is a 20' length of rebar in the concrete foundation footing.

There are instances in factories where a system is bonded but not grounded, or in electrical power distribution where a system is neither bonded nor grounded. But none of these conditions exist in a house.

 

[jspeacock1978]

@cowboycasey - Thanks for the link. Mike is crazy and brave for getting into a swimming pool energized with 110volts and while I'd NEVER try that, he does a great job of describing and demonstrating the importance of the pool bonding system. I've never thought about concrete as a conductor of electricity but he shows it obviously is and dangerously so.

@vermaraj - Your comment about the pool bond and the grounding systems being "...connected. But for the purposes of code, they are separate.." made perfect sense. I'm not an electrical expert at all but when you run a wire touching the ground, seems like an electrical path to ground to me.

Now that I understand the bond better, I understand why the PB says he bonds to the pool and doesn't do the deck and why the decking contractor says the PB "bonds the pool". I'm going to call the decking contractor back and get clarification on bonding under the deck.