Bonding with a ground rod

[EVChargeGuy]

Moderator Note - this side discussion moved out of this thread: IG pump plugged into outlet - Page 2


RE: can’t find existing Bonding?

We’re installing a SS Stair Railing via boring holes in the pavers to install the rail anchors, which need to be bonded.
Not being sure if we’re going to be near the grid the Electrician will be driving a long rod into the ground to create a new bonded site for the Rail/anchors etc. If you need to bond the pump etc and cant find existing Bonding, have an Electrician do the same.
When it comes to the electric needs of the house we always have a licensed Electrician ether sign off on the job or do the job. This way the insurance company has no issues if something goes amiss!

 

[DeadAquaRite]

Re: IG pump plugged into outlet

the Electrician will be driving a long rod into the ground to create a new bonded site for the Rail/anchors etc. If you need to bond the pump etc and cant find existing Bonding, have an Electrician do the same.

I'm not an electrician, but based on what I know I'm really surprised that is the advice of an electrician. What he's installing is a ground rod. A ground is not a bond. Two grounds at different locations on the property can be at different electrical potentials. The purpose of bonding is to create a single electrical potential, eliminating the possibility of current flow.

For those interested, this is a good video on pool bonding:
Swimming Pool Equipotential Bonding 2 of 3, NEC 2014 - 680.26, (19min:50sec) - YouTube

 

[EVChargeGuy]

Re: IG pump plugged into outlet

I'm not an electrician, but based on what I know I'm really surprised that is the advice of an electrician. What he's installing is a ground rod. A ground is not a bond. Two grounds at different locations on the property can be at different electrical potentials. The purpose of bonding is to create a single electrical potential, eliminating the possibility of current flow.

For those interested, this is a good video on pool bonding:
Swimming Pool Equipotential Bonding 2 of 3, NEC 2014 - 680.26, (19min:50sec) - YouTube

It was not the advice of an electrician, it was my thought with the cavet of having a licensed Electrician do the work. I would think that licensed Electrician would know what method is sound?

In my case we’re using this method for a freestanding SS handrail and even the rail manufacturer can use confusing language:
“is provided with a 1/4-20 UNC brass ground screw for bonding”

 

[DeadAquaRite]

Re: IG pump plugged into outlet

It was not the advice of an electrician, it was my thought with the cavet of having a licensed Electrician do the work. I would think that licensed Electrician would know what method is sound?

Gotcha. My guess is that your electrician will veto the idea. Although, as Tim noted electricians are often unfamiliar with pool bonding.

With respect to bonding, always remember that the purpose of a bond is to make all surfaces the same potential so that when you bridge them with your body there is no current flow. For example: If your water is bonded at the niche and your ladder is grounded but not bonded, touching the ladder above the water line could make your body the shortest path from water to ground. In that case it would actually be safer (but not approved) to not bond the ladder at all.

I am assuming installing a bonding grid would take a lot of digging? What parts of the pool would you have to access?

Here is where you really need to consult a professional. Not only because this is a complex project, but also because ANY modification may cause the AHJ to require you to bring the whole pool up to code. Definitely don't start a $200 project and end up being forced into a $20,000 project

 

[tim5055]

DAR is correct, ground rods are not used in a bonding grid and his description of the possibility of making the pool more dangerous with this method may be possible. I will yield to Gordon on this issue.

 

[gwegan]

Yea, the idea of a bonding grid or system is to have all surfaces that may be conductive around a pool have the same electrical potential. That way a person in contact with two conductive surfaces does not become a conductor between them.

So the bonding system is not, in a US pool, connected with the equipment grounding conductor. At the main panel the equipment grounding conductor is connected to a ground rod. That ground rod serves an entirely different purpose.

In a bonding system you want to connect all the potentially conducting surfaces (plus the water) together so if one becomes energized, then all become energized. They have the same electrical potential. A ground rod adds nothing to that process because the ground will generally have resistance so it will not cause to surfaces to have the same resistance. So in a bonding system a ground rod isn't bad it just doesn't really do anything.

Finding a good electrician who understands pool bonding and Article 680 of the NEC is not easy. Most electricians, or at least residential electricians, don't do much bonding. The most important thing you can have is a good water bond, deck bond and anything metal witin reach of the pool. Make sure they are all bonded together. in and out of the pool is the danger zone.

 

[atttech-2]

Question in newer construction how is the water bond accomplished, is it because the pump(s) are bonded and they are in contact with the water or is it because the water is to some degree saturating the gunite and the structural steal is bonded? If that is the case what do they do with liners and fiberglass is there an anode somewhere in the pool to accomplish the bond?

Just curious.

 

[tim5055]

Question in newer construction how is the water bond accomplished, is it because the pump(s) are bonded and they are in contact with the water or is it because the water is to some degree saturating the gunite and the structural steal is bonded? If that is the case what do they do with liners and fiberglass is there an anode somewhere in the pool to accomplish the bond?

Just curious.

They can do it several ways. If there are metal ladders then a bonded ladder in the water counts as long as it has more than 9 square inches of surface space. Metal light niches can count also, again needs to be more than 9 sq inches. There are water bonds that go in the plumbing and some that are installed in the skimmer like this Amazon.com: Burndy Waterbug Pool Water Bonding Kit Ul: Kitchen Dining

 

[gwegan]

In my area most new pool are boned with a small plate in the light niche. The code requires nine square inches of contact. One reason I suspect the inspectors like the plate in the niche is because it's a location that is least subject to change. Heaters can be removed, ladders changed out but an incispicuious plate in the niche will stick around.

 

[atttech-2]

Interesting, I have nicheless led lights and no metal ladders and I know they did not put a waterbug in the skimmer. I do have a conduit that goes to an overflow built into the auto fill so I guess if I ever develop a problem I could extend the bonding wire down that conduit into the auto fill and install a waterbug in there.

 

[gwegan]

Atttech I'd call your contractor and ask where he did put the water bond. It's just a small metal plate. Did you look in the auto fill.

As I recall you live in Tracy, their inspectors would not miss that. When I delt with them years ago they seemed very competent.

 

[atttech-2]

I will call them and ask and take a look but I have videos and photos of the whole build and I did not see it or recall the inspector looking for or at it. I was there for all but one correction inspection. The bonding wire is accessible at several points around the pool so if it is not there should be an easy fix through the auto fill.

As for their inspectors not missing it one guy that was there 2 of the 4 times was not a city employee some sort of outsourcing due to high volume of building going on. I had to point out to him that the neutral should not be bonded in the sub panel and he had to go check with his shop steward because "He is more up on the electrical stuff than I am"

 

[gwegan]

In Tracy? That's scary. We almost always used independent inspectors. And while I generally think independent inspectors do a good job my then employer built seven massive buildings over two years where our crews really screwed up the roofs. The inspectors they saw nothing real. We spent millions fixing those roofs.