# Existing pool... is some bonding better than none?



## 220/221 (Sep 25, 2007)

How can you see the bonding lugs on the niche? Aren't they on the outside, encased in gunite?


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## Honestly (Feb 3, 2011)

The pool is temporarily drained. The bonding lugs are on the forming shell (I think its called). The homeowner just wants me to check everything out and replace bulbs and gaskets. I don't know whether I should bring up the bonding issue or just let it go. I just don't want to have my name tied to it if unsafe. I will make sure that everything is properly gfi protected, just wanted someone more informed's opinion on the bonding issue.


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## Honestly (Feb 3, 2011)

That probably didn't answer your question- when I took out the lights, I could see the lugs on the back on a metal part of the shell


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## heel600 (Oct 31, 2007)

Honestly said:


> Inground pool installed probably 15 years ago. Two wet niche lights with bonding lugs, but no wire  I just briefly looked it over, haven't checked pool equipment yet, but I suspect nothing is bonded. So the question for someone who really understands pool bonding (not me)... is it better just to leave it as is, or bond what is accessible: possibly the lights (and water) and pump. The perimeter is poured concrete with tile on top. I don't know how I would bond this.



Bonding can't hurt anything, it can only help. There is nothing in the NEC that prohibits bonding anything (pool related anyway)

I would bond as much as possible.

Niche to deck-box
Pool shell to pump to deck

I would recommend putting the pump on a GFCI too.


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## Honestly (Feb 3, 2011)

That's kinda what I was thinking. I know how to do it more than why to do it, and I didn't know if bonding only SOME of the normally required things would somehow create a higher voltage gradient with those that were not bonded (like the pool perimeter)


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## Magnettica (Jan 23, 2007)

Honestly said:


> The pool is temporarily drained. The bonding lugs are on the forming shell (I think its called). The homeowner just wants me to check everything out and replace bulbs and gaskets. I don't know whether I should bring up the bonding issue or just let it go. *I just don't want to have my name tied to it if unsafe.* I will make sure that everything is properly gfi protected, just wanted someone more informed's opinion on the bonding issue.




Then maybe you should walk away and let a licensed guy come in and do the job the right way. You'll never get a license if you go and kill someone in pool because you didn't know what the hell you were doing and some poor person drowns because of your inexperience.


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## Honestly (Feb 3, 2011)

I remember reading a post from someone claiming that bonding only certain conductive materials in a pool would create more of a hazard than no bond at all. Didn't know if this had any merit. Till know, all my pool experience has been books.


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## macmikeman (Jan 23, 2007)

What is the voltage rating of the pool light fixtures? listed low voltage lighting fixtures do not require bonding to the grid. Go have a look at the pool motors, if you don't see any bonding connections to them and they are not double insulated motors, then what I do is haul my ass right out of there pronto, or send them to a company that specializes in tearing up pool coping and installing bonding grids to existing pools.


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## Honestly (Feb 3, 2011)

macmikeman said:


> What is the voltage rating of the pool light fixtures? listed low voltage lighting fixtures do not require bonding to the grid. Go have a look at the pool motors, if you don't see any bonding connections to them and they are not double insulated motors, then what I do is haul my ass right out of there pronto, or send them to a company that specializes in tearing up pool coping and installing bonding grids to existing pools.


120v wet niche fixtures. I am going to look at the rest of it today. I think you are right. If I don't see ANYthing bonded, I will probably take my hands off and put it in writing on my next invoice that I recommend she has someone come in, tear up the perimeter, and install a bonding grid. Thanks


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## oliquir (Jan 13, 2011)

if everything is gfci protected it is not so bad, i have an old inground pool (70s pool) and nothing is bonded, water is isolated via liner or plastic parts and tubing, the only thing that is bonded that is not isolated to water is the pump


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## LK1 (May 7, 2011)

oliquir said:


> if everything is gfci protected it is not so bad, i have an old inground pool (70s pool) and nothing is bonded, water is isolated via liner or plastic parts and tubing, the only thing that is bonded that is not isolated to water is the pump


What about all the real killer problems, like stray voltages, isolation does not prevent dangerous stay current from doing it's damage.


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## Honestly (Feb 3, 2011)

As suspected, pumps not bonded. The only semblance of a bond I see is this #8 on a ground rod, running over about 4 ft, and down into the concrete. No pool liner, metal ladder


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## oliquir (Jan 13, 2011)

LK1 said:


> What about all the real killer problems, like stray voltages, isolation does not prevent dangerous stay current from doing it's damage.


yes i know it is not 100% safe i was just telling how it was made back in the 70s here


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## Honestly (Feb 3, 2011)

More


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## Honestly (Feb 3, 2011)

"deck box".


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## kwired (Dec 20, 2009)

Honestly said:


> That's kinda what I was thinking. I know how to do it more than why to do it, and I didn't know if bonding only SOME of the normally required things would somehow create a higher voltage gradient with those that were not bonded (like the pool perimeter)


 
By bringing a solidly grounded conductor or conductive object close enough for people to reach something that is earth grounded only you do increase the risk of someone being subject to any voltage potential between these objects.

The tough call on this is it is nearly impossible to predict what voltage may be imposed on something. Bonding it all together brings it all to the same potential even if it is a voltage above some other reference. The idea is to minimize the potential between points that a person can come into contact with more so than achieving zero volts to earth ground.


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## CraigV (May 12, 2011)

Since the entire premise of bonding is to create equal potential in *all *conductive surfaces and objects, "some" is definitely not better than "none". This is why water and patio/decking were added to the bonding requirements, whereas in the past only metal objects were required to be bonded. I have serious doubts/reservations about the effectiveness of trying to bond concrete, dirt, water, etc, as their resistance is high and variable as compared with most metals. But it's not my call...


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## Honestly (Feb 3, 2011)

The way I see it now, the decking is the real problem. I could bond the pumps, lights (and water), and ladder, but effectively bonding the decking without removing it all (tile and concrete), has me stumped. There is no permit out, but I may meet up with the inspector in the morning to get his thoughts. Thanks for the input.


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## kwired (Dec 20, 2009)

CraigV said:


> Since the entire premise of bonding is to create equal potential in *all *conductive surfaces and objects, "some" is definitely not better than "none". This is why water and patio/decking were added to the bonding requirements, whereas in the past only metal objects were required to be bonded. I have serious doubts/reservations about the effectiveness of trying to bond concrete, dirt, water, etc, as their resistance is high and variable as compared with most metals. But it's not my call...


You do not bond concrete you place conductive objects in it and bond them to the electrical grounding system. There will be voltage 'zones' around these bonded conductive objects in the concrete, dirt and water so you will want to put several conductive objects within the concrete in close enough proximity to minimize the voltage by making the 'zones' overlap.


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## CraigV (May 12, 2011)

kwired said:


> You do not bond concrete you place conductive objects in it and bond them to the electrical grounding system. There will be voltage 'zones' around these bonded conductive objects in the concrete, dirt and water so you will want to put several conductive objects within the concrete in close enough proximity to minimize the voltage by making the 'zones' overlap.


Forgive me for soapboxing:
I understand the method and the theory/reasoning behind it. But the contact surfaces which are intended to be protected by a grid and water bond are of too-high and too variable resistance for this method to be considered consistently safer than not bonding, _in my opinion_. There is too much potential for installation error, material corrosion and material failure. This isn't like a GES that is simply intended to clear faults, its intention is human protection. It needs to have, and maintain, a potential small enough to not pass lethal or dangerous voltage through human bodies. That's a very small number.

Let's put it this way; It's 20 years into a pool install. If someone told you there was a direct fault to a pool grid and the 20 y/o gfci has failed, would you feel comfortable putting your wet hands on the step rail while standing on the patio in wet bare feet? That's the litmus of confidence in a system, _in my opinion_.
[/soapbox]


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## kwired (Dec 20, 2009)

CraigV said:


> Forgive me for soapboxing:
> I understand the method and the theory/reasoning behind it. But the contact surfaces which are intended to be protected by a grid and water bond are of too-high and too variable resistance for this method to be considered consistently safer than not bonding, _in my opinion_. There is too much potential for installation error, material corrosion and material failure. This isn't like a GES that is simply intended to clear faults, its intention is human protection. It needs to have, and maintain, a potential small enough to not pass lethal or dangerous voltage through human bodies. That's a very small number.
> 
> Let's put it this way; It's 20 years into a pool install. If someone told you there was a direct fault to a pool grid and the 20 y/o gfci has failed, would you feel comfortable putting your wet hands on the step rail while standing on the patio in wet bare feet? That's the litmus of confidence in a system, _in my opinion_.
> [/soapbox]


A GES is not installed for clearing faults it is there to provide a ground reference and bleed off surges, lightning, etc. An EGC is for clearing faults. Drive a ground rod and attach an ungrounded conductor to it and see how much current it draws. In most cases would probably not even blow a 5 amp fuse.

What is going to fault to the pool grid? The potential for shock in a pool does not typically come from a faulting pool pump - in those cases if proper EGC is installed the fault causes the overcurrent device to open and there is no more shock hazard. The biggest problem is stray voltage. It usually will come from voltage drop on the POCO primary neutral. Earth and everything on it like concrete and water tend to remain at one potential. Now bring an EGC from electrical system that even though is earthed at the service as well as the supply transformer is also bonded to the POCO primary neutral. Since the conductors used for the service neutral and EGC are much lower resistance than earth Most of voltage measured between primary neutral and earth at a point several blocks away is about same at the pool also. You are not bonding everything to get rid of the voltage potential you are bonding to bring everything in close proximity to each other to the same potential.

If you have a pool that has all metal well bonded and a good bond to rebar you likely could still drive a ground rod 50 -100 feet away and be able to read some voltage between the rod and the bonded pool equipment. That is no different than bringing the service ground rod closer to the pool via equipment grounding conductors for any pool equipment.


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## Honestly (Feb 3, 2011)

Great info! By the way, the inspectors advice was the same as macmikeman's- RUN. And refer them to a company that specializes in adding equipotential bonding grids to existing pools.


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## RIVETER (Sep 26, 2009)

Honestly said:


> Inground pool installed probably 15 years ago. Two wet niche lights with bonding lugs, but no wire  I just briefly looked it over, haven't checked pool equipment yet, but I suspect nothing is bonded. So the question for someone who really understands pool bonding (not me)... is it better just to leave it as is, or bond what is accessible: possibly the lights (and water) and pump. The perimeter is poured concrete with tile on top. I don't know how I would bond this.


Being an electrician, if you are qualified, means that it is your responsibility to inform the owner of the problems. If they refuse to pay for the mitigation then you are clear. If you take the job knowing that you are leaving it possibly unsafe...the courts will find you liable if something happens.


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## macmikeman (Jan 23, 2007)

RIVETER said:


> Being an electrician, if you are qualified, means that it is your responsibility to inform the owner of the problems. If they refuse to pay for the mitigation then you are clear. If you take the job knowing that you are leaving it possibly unsafe...the courts will find you liable if something happens.


B.S. At my shop I have a sign. It says we reserve the right to refuse service to anyone. Same like restaurants have, actually thats how I got it. 
You are not forced to disclose anything until you start working on it, you can walk from a firetrap for no better reason than you are just not interested...


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