grounding vs. bonding in swimming pool question

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Michael Kennedy

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In the post... "Grounding Vs. Bonding" by George Stolz it is pointed out that ?grounding is a connection to earth and bonding is the connection of items to each other?. It has been clearly stated by many contributors to this forum and hundreds of articles written else where that equipotential bonding has nothing to do with earth and I recognize the reason behind it.

Mike Holt has provided a .pdf free download of Article 680 which is regard to the installations of swimming pools....... the link to it is given at the end of this post.

My first question is why in Article 680 is there the continuous use of the words ?equipment grounding (bonding)? ? Why not "equipment grounding" and "equipotential bonding" ?

Secondly why in Figure 680-20 of Article 680 are the green 8 AWG wires connected to the "wet-niche luminaire "light can" marked as ?to equpotential bonding grid? connected to the junction box and then on to transformer box and panelboard where it is marked as ?grounding (bonding) conductor? ? Also if one were to use a copper or brass conduit from the light can (as many are made) to the metal junction box ?(deck box)? as required by Article 680.24 (A) (2) and the metal light box is tied to the rebar in the pool as required by Article 680 as part of the equipotential bonding requirements you have tied the ?grounding (bonding) conductor and equipotential bonding together. It is stated in 680.24 (A) (3) that this metal junction box will be ?provided with electrical continuity between all metal conduit and the grounding (bonding) terminal within the junction box.?. Also if one were to run the metal conduit from the light can directly to an approved swimming pool GFCI enclosure (see 680.24 (B) (4) you would have the same result. In addition the brass conduit connected to the metal GFCI enclosure is buried in the earth and tied to the light can and rebar in the pool so that makes for a nice grounding rod in itself and yet these are parts of the equipotential bonding loop?

Could you please explain this to me as I must be missing something?

For convenience use the link below to quickly get to Mike Holt?s .pdf free download of Article 680. The Figure 680-20 is on page 23 of the .pdf file.

Thank you,

Michael Kennedy


http://www.mikeholt.com/files/PDF/Pooldownload.pdf
 
Michael Kennedy said:
My first question is why in Article 680 is there the continuous use of the words ?equipment grounding (bonding)? ? Why not "equipment grounding" and "equipotential bonding" ?
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That originally confused me too. I think the reason is to illuminate the fact that the author was referring to his opinion (which I share) that the term is technically wrong.

Secondly why in Figure 680-20 of Article 680 are the green 8 AWG wires connected to the "wet-niche luminaire "light can" marked as ?to equpotential bonding grid? connected to the junction box and then on to transformer box and panelboard where it is marked as ?grounding (bonding) conductor? ?
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To help out your discussion, I'm pasting just the figure here:
View attachment 3000

I'd say it's because the conductor marked "equipment grounding (bonding) conductor" is an EGC, designed to be used in the event of a ground fault. It is not related to equipotential bonding.

Could you please explain this to me as I must be missing something?
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I don't understand your question, but I'm also short on time now. I'll come back and look closer later. :)
 
Figure 680-20

Figure 680-20

George....Thank you for your response. My question is why in Figure 680-20 does the equipotential bond get tied to the ground (bonding)? I understand from articles that you and Mike Holt have written that this isn't suppose to happen. The green 8 AWG wire in Fig. 680-20 that is attached to the light can as part of the equipotential bond clearly goes to the pool junction box and on to other boxes where it is tied to the ground (bonding) of those boxes. In addition the rigid conduit coming from the light can goes directly to the metal deck. The 8 AWG green wire and the rigid conduit are part of the eqipotential bonding and go directly to the metal deck box (metal required in 680). This also ties the ground (bonding) and the eqiupotental bond together. Why?

Mike
 
I think what you are asking about is the two green conductors from the light to the junction box.
One is the equipment grounding conductor that carries fault current back to the service and the other is the equipotential bonding conductor that is used to bond all metal parts of the pool together.
Both are doing their job. One to clear faults the other to keep every at the same potential.
 
jwelectric said:
I think what you are asking about is the two green conductors from the light to the junction box.
One is the equipment grounding conductor that carries fault current back to the service and the other is the equipotential bonding conductor that is used to bond all metal parts of the pool together.
Both are doing their job. One to clear faults the other to keep every at the same potential.
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Yes, and the #8 EGC is required to be either solid or stranded and insulated....therefore the green color.
 
It is a misconception that the grounding and bonding at a pool are not to be interconnected. This misconception is driven by the FPN in 680.26(A). All this note says is that you are not required to extend the bonding conductor back to a panel. It says nothing about connecting the bonding conductor to the grounding conductor. 680.26(B)(4) and (B)(6) requires the interconnection by requiring the electrical equipment to be connected to the bonding conductor. Other code rules require that the electrical equipment have an EGC and this results in an interconnection.
The last part of 680.26(B)(6)(a) makes it clear that the bonding system is required to be connected to the grounding system.
... Where a double-insulated water-pump motor is installed under the provisions of this rule, a solid 8 AWG copper conductor that is of sufficient length to make a bonding connection to a replacement motor shall be extended from the bonding grid to an accessible point in the motor vicinity. Where there is no connection between the swimming pool bonding grid and the equipment grounding system for the premises, this bonding conductor shall be connected to the equipment grounding conductor of the motor circuit.
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I am not sure why we want to energize the pool bonding grid but that is exactly what the current code rules require. This is because the electrical grounding system is energized with a voltage that is equal to the voltage drop on the utility primary grounded conductor. I believe it would be better to prohibit any electrical equipment in or within 5' of a pool and require the use of double insulated, GFCI protected pool pumps and prohibit any connection between the grounding and bonding system. If you want a pool light you would be required to use a remote head, fiber optic light.
 
Thank you Don!

Thank you Don!

Don... Thank you for pointing directly to 680.26 (B) (4)....wow it really does say it.


1. Why not have all equipotential hardware tied together in one common box and never go close to any electrical panal?

and....

2. Why not have all of the electrical and associated grounding (bonding) run in conduits completly separate from the equipotental bonding?

Cheers,

Mike
 
Mike,
If you bring electrical equipment to the pool you have to connect the bonding and grounding systems together to prevent a potential difference between the two. One of the issues here is that a few volts between the water and something that can be touched by a person in the water can incapacitate the person enough that he/she cannot get out of the water.
 
Understanding the necessity of the equipotential bonding grid, under 2005 NEC, should the electrical contractor and inspector ensure that the concrete company has the individual squares of reinforcing steel tied with tie wires at all corners, or is the common practice of skipping around to every third or fourth square acceptable to maintain the integrity of the equipotential plane?
In another post with the question of " are chairs required to bring the steel a minimum of 2" above the earth" such as with a CEE, an engineer stated that as long as the concrete is touching the steel the integrity of the bond is not lost.
 
Don....

You stated on 3/16.......

I am not sure why we want to energize the pool bonding grid but that is exactly what the current code rules require. This is because the electrical grounding system is energized with a voltage that is equal to the voltage drop on the utility primary grounded conductor. I believe it would be better to prohibit any electrical equipment in or within 5' of a pool and require the use of double insulated, GFCI protected pool pumps and prohibit any connection between the grounding and bonding system. If you want a pool light you would be required to use a remote head, fiber optic light.
Click to expand...

I stated on 3/18

1. Why not have all equipotential hardware tied together in one common box and never go close to any electrical panal?

and....

2. Why not have all of the electrical and associated grounding (bonding) run in conduits completly separate from the equipotental bonding?
Click to expand...

You stated on 3/19

If you bring electrical equipment to the pool you have to connect the bonding and grounding systems together to prevent a potential difference between the two. One of the issues here is that a few volts between the water and something that can be touched by a person in the water can incapacitate the person enough that he/she cannot get out of the water.
Click to expand...

It am getting mixed signals (no pun intended). Which is the safest way to go? Is this a place where the code needs some change?

Cheers,

Mike
 
If you have any electrical equipment at the pool, I don't think there is any question that the bonding and grounding systems need to be connected together. There is too much chance of a difference in potential between the two systems if you they are both within the pool and not connected together.

In my opinion the safest installation would be to prohibit any electrical equipment in or within 6' of the pool, require all electrical pool pumps and other equipment to be double insulated and GFCI protected and not make a connection between the grounding and bonding systems.
 
Don....

You stated on 3/16.......


Quote:
I am not sure why we want to energize the pool bonding grid but that is exactly what the current code rules require. This is because the electrical grounding system is energized with a voltage that is equal to the voltage drop on the utility primary grounded conductor. I believe it would be better to prohibit any electrical equipment in or within 5' of a pool and require the use of double insulated, GFCI protected pool pumps and prohibit any connection between the grounding and bonding system. If you want a pool light you would be required to use a remote head, fiber optic light.

I stated on 3/18


Quote:
1. Why not have all equipotential hardware tied together in one common box and never go close to any electrical panal?

and....

2. Why not have all of the electrical and associated grounding (bonding) run in conduits completly separate from the equipotental bonding?

You stated on 3/19


Quote:
If you bring electrical equipment to the pool you have to connect the bonding and grounding systems together to prevent a potential difference between the two. One of the issues here is that a few volts between the water and something that can be touched by a person in the water can incapacitate the person enough that he/she cannot get out of the water.

It am getting mixed signals (no pun intended). Which is the best "safest" way to go? Why is there so much in the literature about keeping the equipotential bonding completly separate from the grounding bonding if in fact they are to be tied togetherer?

I really need an answer to this question. I can't believe how ambigueous the answers to this basic question have been so far.

Thank you,

Cheers,

Mike

Cheers,

Mike
 
At this point you don't have a choice the code requires the grounding and bonding systems to be interconnected. This is the safest and only way, if there is any electrical equipment associated with the pool. The only time you can get around connecting the grounding and bonding systems would be if a pool has no electrical equipment and that would include a pool pump.
 
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