Equipotential Bonding Pool Pump

[flengineer]

Per 680.26 (B) (6), electrical equipment including pump motors needs to be bonded. My "pool" is actually an aquarium that will be used by divers. The pumping equipment is located remotely (several floors away from the tank).

1. Do I need to provide a bonding conductor from the pumps to the tank bonding grid? 680.26 (B) says that "a...bonding conductor provided to reduce voltage gradients in the pool area shall not be required to be extended or attached to remote panelboards, service equipment, or electrodes." Does this count as remote equipment or is that just referring to unrelated electrical equipment?

2. If a bonding conductor is required, since the reinforcing steel throughout the building is tied together and the building grounding system is tied to the steel, can I bond the pump to the EGC and leave it at that?

 

[Dennis Alwon]

You do need to tie the equipotential bonding back to the pump equipment but it needs go no further than that. If the pump is double insulated then you must tie the equipment grounding conductor to the equipotential bonding. The idea is to keep all pool related equipment and the area around the pool at the same potential.

 

[flengineer]

I assume I can run one bonding conductor from the tank back to each pump room and then bond from pump to pump.

 

[Dennis Alwon]

I assume I can run one bonding conductor from the tank back to each pump room and then bond from pump to pump.

Yes, I usually try and keep it unbroken but you don't have to. You can do it many ways. Here is one example but it is mot showing the equipotential bonding grid.

 

[GoldDigger]

Since the pump equipment is several floors away from the tank and its surroundings, it is not clear that there is any chance of touch or step potentials involving the pump.
Or else that bonding (for equipotential, not fault clearing), should be extended to the metal around the pump too, even though it is not a wet area.
I can see the pump equipotential being significant to the potential of the circulating water. But not at that distance if metal piping is used.
To the OP: will this be fresh or salt water?

Tapatalk!

 

[George Stolz]

Code says bond it, so wondering if a ground fault in the pump would make it back to the pool is academic at best.

 

[GoldDigger]

I was actually thinking more of a need to bond other equipment near the pump motor. On the theory that the pump location extends the equipotential area.

Tapatalk!

 

[flengineer]

Tank will be salt water. Piping is FRP/HDPE or PVC.

The tank has a fiberglass liner placed on top of the hydrophobic concrete structure so bonding of the reinforcing steel is not required. (Steel is epoxy-coated so it would have required a copper grid.)

The deck still needs to be bonded, but there is an expansion joint between the outside edge of the concrete pool structure and the continuation of the deck. This rebar is epoxy-coated as well so I need to install a bonding wire around the perimeter of the tank 18-24" away from the inside edge. This puts me outside the expansion joint. Does this have any impact on the bonding?

 

[ritelec]

You do need to tie the equipotential bonding back to the pump equipment but it needs go no further than that. If the pump is double insulated then you must tie the equipment grounding conductor to the equipotential bonding. The idea is to keep all pool related equipment and the area around the pool at the same potential.

Hi Dennis, Thanks..

A pool question came up an has me thinking.. Please confirm that I have this right in my head...


1) ALL the metal... equipment,ladders,grid, niche (if lighting), all the things in the cartoon, get bonded together.. and that is it.(that number 8 does Not go back to any panel ground).

2) If there's lighting and using a deck box( the deck box has me confused, inside)... please confirm..
if 120v a number 8 would go from inside box to inside of niche... and that is it on the 8 right? (no need to go from panel to box with 8)
Deck box would get equipment ground from panel #12(no splices) right.
So deck box would have circuit ground in, circuit ground and number 8 out to light.

3) low voltage lighting..deck box gets transformer. #12 circuit ground to deck box, lighting cable ground out to fixture. (or would there be any #8 from panel or equipotential bond to that deck box? I had hooked a transformer up in the past and it showed an 8 from the panel in directions???)

Please confirm that I have this correct. thank you.

Now the
3) double insulated pump. how would it tie into the epg..? equipment ground (say 12) and bond ground splice in motor (how)? bond ground goes to panel ground then that "12" to motor is considered bond ground? bond ground goes to panel ground then that 12 "and" a number 8 go to motor ?

 

[GoldDigger]

Hi Dennis, Thanks..

A pool question came up an has me thinking.. Please confirm that I have this right in my head...


1) ALL the metal... equipment,ladders,grid, niche (if lighting), all the things in the cartoon, get bonded together.. and that is it.(that number 8 does Not go back to any panel ground).

In some ways an academic point. All of the parts of the equipotential system are required to be bonded to each other only.
But if any of those parts are also required to be bonded to the GES via an EGC, the result will be that the EP system is grounded.
But there is no need to run individual wires from any particular part directly to the GES unless that is specified in some other part of the code.

 

[George Stolz]

But there is no need to run individual wires from any particular part directly to the GES unless that is specified in some other part of the code.

I am trying to think of an example of "some other part of the code." What are you talking about?

 

[hurk27]

I am trying to think of an example of "some other part of the code." What are you talking about?

Ya me too, 680 is a stand alone code that only when it directs you to another part of the code must it be followed, anything in other parts of the code does not apply unless 680 directs you to it.

 

[hurk27]

Tank will be salt water. Piping is FRP/HDPE or PVC.

The tank has a fiberglass liner placed on top of the hydrophobic concrete structure so bonding of the reinforcing steel is not required. (Steel is epoxy-coated so it would have required a copper grid.)

The deck still needs to be bonded, but there is an expansion joint between the outside edge of the concrete pool structure and the continuation of the deck. This rebar is epoxy-coated as well so I need to install a bonding wire around the perimeter of the tank 18-24" away from the inside edge. This puts me outside the expansion joint. Does this have any impact on the bonding?

if the rebar has a non-conductive coating then you must install a 20' conductive wire within the concrete to bond it, just like a concrete encased electrode, but don't confuse this as a CEE as this is not for the purpose of creating a connection to earth, all you are trying to do is to make sure there is no possible differences of potential by bonding anything around the pool or that is in contact with the circulating water.

 

[david]

I am trying to think of an example of "some other part of the code." What are you talking about?

640.10 Audio Systems Near Bodies of Water.
Audio systems near bodies of water, either natural or artificial, shall be subject to the restrictions specified in 640.10(A) and (B).
Exception: This section does not include audio systems intended for use on boats, yachts, or other forms of land or water transportation used near bodies of water, whether or not supplied by branch-circuit power.
FPN: See 680.27(A) for installation of underwater audio equipment.

(A) Equipment Supplied by Branch-Circuit Power. Audio system equipment supplied by branch-circuit power shall not be placed laterally within 1.5 m (5 ft) of the inside wall of a pool, spa, hot tub, or fountain, or within 1.5 m (5 ft) of the prevailing or tidal high water mark. The equipment shall be provided with branch-circuit power protected by a ground-fault circuit interrupter where required by other articles.

I think he just did not want to assume that something involving swimming pools might show up in some other article not directly referenced in article 680. kind of a cover all statement.

off subject I could give a reasonable explanation to the requirement for receptacles to be placed with 10ft of clearance from the pool water. I have no good explanation as to why that was reduced to a 6 ft. clearance when most appliance cords are limited to a 6ft length. But lets not get off topic the rule is what it is .

 

[ritelec]

if the rebar has a non-conductive coating then you must install a 20' conductive wire within the concrete to bond it, just like a concrete encased electrode, but don't confuse this as a CEE as this is not for the purpose of creating a connection to earth, all you are trying to do is to make sure there is no possible differences of potential by bonding anything around the pool or that is in contact with the circulating water.

Thoughts about this bond grid?

People (including myself) bring epg back to the system ground in many cases (pool panel), though it says you don't have to, many do (at least I haven't seen anywhere that you "can't").....

So where does that play into your grounding electrode system...

Could you actually be creating a better electrode than at the service entrance location ??



(I actually put a grid around an existing pool that was down for repair, and grabbed some exposed rebar where I could. The bond to the motors and grid went to the pool panel ground.. The service...the water ground was not hooked up (looked like a plumber disconnected it) and there was no rod. ).
(I did hook the ground back to the water pipe, but did not install a rod. The ho didn't want to pay... and I'm tired of doing free work..)

Thank you

 

[david]

Thoughts about this bond grid?
Could you actually be creating a better electrode than at the service entrance location ??


Thank you

you may and IMO I would never take the # 8 copper to the pool panel. Keep in mind the equipment ground from the pool panel is bonded through the pool pump or perhaps the light fixture

 

[Little Bill]

Hi Dennis, Thanks..

A pool question came up an has me thinking.. Please confirm that I have this right in my head...


1) ALL the metal... equipment,ladders,grid, niche (if lighting), all the things in the cartoon, get bonded together.. and that is it.(that number 8 does Not go back to any panel ground).

2) If there's lighting and using a deck box( the deck box has me confused, inside)... please confirm..
if 120v a number 8 would go from inside box to inside of niche... and that is it on the 8 right? (no need to go from panel to box with 8)
Deck box would get equipment ground from panel #12(no splices) right.
So deck box would have circuit ground in, circuit ground and number 8 out to light.

3) low voltage lighting..deck box gets transformer. #12 circuit ground to deck box, lighting cable ground out to fixture. (or would there be any #8 from panel or equipotential bond to that deck box? I had hooked a transformer up in the past and it showed an 8 from the panel in directions???)

Please confirm that I have this correct. thank you.

Now the
3) double insulated pump. how would it tie into the epg..? equipment ground (say 12) and bond ground splice in motor (how)? bond ground goes to panel ground then that "12" to motor is considered bond ground? bond ground goes to panel ground then that 12 "and" a number 8 go to motor ?

This may help make things clearer for you. These pics are from a pool that was re-gunited (re-poured). I installed the new lights and redone the bonding. To be clear, you need a EGC to the light from the deck junction box. It is part of the 3-wire cable that comes with the light.
Then you need a separate insulated #8 run from the JB to the inside of the niche. Both of these are installed on a common ground bar in the junction box. Also, the insulated EGC from the panel goes on the bar.

Then, you need a bare #8 run from the outside of the niche to the equipotential bond around the pool. This is as far as the bare #8 needs to run. I don't and wouldn't run this back to the panel.


Niche with the insulated #8 installed and attached to the lug in the niche.



With the #8 and the cable from the light



With the potting compound applied



Showing the niche and the ample amount of cable from the light to allow relamping on the deck.



Next 2 are the bare #8 that attaches to the lug on the outside of niche, and the bare #8 to the rebar.






Finally, the complete light installed

 

[ritelec]

Thank you Little Bill...
That's what I needed to know.

"NO" 8 bare or insulated back to panel. "YES" 8 insulated to fixture.

"NO" 8 bare or insulated line into xformer mounted to deck box or load out to fixture.

Got it !

 

[hurk27]

Thank you Little Bill...
That's what I needed to know.

"NO" 8 bare or insulated back to panel. "YES" 8 insulated to fixture.

"NO" 8 bare or insulated line into xformer mounted to deck box or load out to fixture.

Got it !

I noticed that you used EPG but I would suggest to use EPB because it is a bonding system and has nothing to do with grounding, this may help you understand the different purpose of the EPB system verses the EGC's and other types of grounding that are intended to be connected to earth, actually even though EGC's do eventually connect to earth they too are a bonding conductor design to cause a breaker to open in the event of a fault, an EPB system is not design for this purpose, and has nothing to do with any circuits ran to electrical equipment for a pool, all it does is make everything become one conductor so there is no difference of potential, this is why there is no reason to run it back to any panel, that is what EGC's are for.

 

[ritelec]

I noticed that you used EPG but I would suggest to use EPB because it is a bonding system and has nothing to do with grounding, this may help you understand the different purpose of the EPB system verses the EGC's and other types of grounding that are intended to be connected to earth, actually even though EGC's do eventually connect to earth they too are a bonding conductor design to cause a breaker to open in the event of a fault, an EPB system is not design for this purpose, and has nothing to do with any circuits ran to electrical equipment for a pool, all it does is make everything become one conductor so there is no difference of potential, this is why there is no reason to run it back to any panel, that is what EGC's are for.

Nice.. Thank you.