Pool Pump Bonding

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nickie

Member
We are having a pool put in and currently wired to a new panel with GFCI breakers at the pump load center. In looking at both the pool pump & the waterfall pump they have a connection inside the housing for the grounding conductor.

Would these lugs be used to bond to the equipotential grid of the pool's inground rebar?

I also assume this would be tied back to the grounding buss on the panel?

Thanks for the infor...Nickie
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
There will be two connections to the pump chassis. One in the wiring compartment for the equipment ground (and probably only large enough for a #12 wire). The other is usually on the outside and will be large enough to hold a #8 solid wire to the equipotential bonding grid.

The equipment ground wire runs with the circuit conductors and is tied to the panel's grounding bar. The equipotential bonding grid wire just goes to any grid wire, it does not have to go back to any panelboard.
 

nickie

Member
jw electric

There is no relation to the link you listed.

suemarkp:

Thanks for the response. I have one other question. When we do a grounding grid in our line of business, all is tied together and referenced back to the system neutral to eliminate/reduce step and touch potential in the station.

Following the above line of reasoning even though they are different applications; if the equipotential grid for a pool is not referenced back to the ground buss would there not be a potential between the equipotential grid and the grounded conductor if a ground fault problem occurred.

It seems if it was tied to the grounding buss that you would get back to a common reference back at the main disconnet.

Appreciate the thoughts....Nickie
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
I don't believe you're prohibited from connecting it to the ground bus, and you're definitely not required to do it. You already have an "incidental" interconnection on the pump chassis (the bonding lug and ground screw both screw into the same metal motor chassis). If you have a pool light, the niche and the equipment ground are connected in the pool light junction box.

So there really is no need to tie the bonding grid back to the panel ground unless maybe you had a pool with no light and a double insulated pool pump. In that particular case, would you care about a motor fault?
 

nickie

Member
Mark:

Thanks for the reply.

We have a niche light and the pool pump is supposed to be double insulated (need to verify that) however the waterfall pump is not suppose to be double insulated.
 

bphgravity

Senior Member
Location
Florida
A pool's equipotential bonding grid is nothing short of a grounding electrode. During a ground fault and even during normal operational current flow, current can and will flow over pool parts and back to the source. The amount will depend on the particulars of the service grounding arrangement.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Nickie,
When we do a grounding grid in our line of business, all is tied together and referenced back to the system neutral to eliminate/reduce step and touch potential in the station.
Unfortunately in this case, the code required interconnection between the electrical grounding system and the equipotential pool grounding system actually, in some cases, causes a step or touch potential. When you connect these two systems you are energizing the pool grounding grid with a voltage equal to that of the voltage drop on the utility’s multigrounded neutral. This can be a few volts and result in a tingle at the edge of the equipotential grounding system.
Many think that the fine print note after 680.26(A) says that there is no requirement to connect the pool bonding grid to the electrical grounding system, but all the note really says is that there is no requirement to extend the #8 bonding conductor to a panel.
FPN: The 8 AWG or larger solid copper bonding conductor shall not be required to be extended or attached to any remote panelboard, service equipment, or any electrode.
If the equipment is not double insulated there will be an equipment grounding conductor connected to the metal parts of the equipment and the bonding grid must also be connected to the metal parts. This results in a code required connection between the two systems. In the case of double insulated 680.26(B)(4) says.
… 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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