Question about equipotential bonding & grounding

I’m learning about equipotential bonding of the pool area. My question is, how is the equipotential bonding system at the pool area tied into the main grounding system?

I understand that all metal objects near the pool need to be bonded so that if a metal component becomes energized the voltage is dissipated over the equipotential plane. What I don’t understand is how that energy makes its way back to the house’s grounding system and back to the ground rod. Are they connected somewhere (maybe at a ground at the pool electrical shut off switch?) Or does the pool’s rebar act as an independent ground?

It could be , but I would not trust it with out a proper earth ground in place. Now! That is just me.
Why earth ground in the first place? In the simplest terms, It bring the highest point down to the earth ground. And it depends where you are at.
From my experience the water table has a lot to do with it.
Image a tall pine tree with shorter pine trees around it. And we go to the top and put a earth ground ( lighting rod) at it tallest point. What we have done to that tall pine tree is to bring it highest point to earth ground. Will that help it not to get struct? NO! Howevever, We have gave it a lot better chance as to the other pine trees around it.
A continuous earth ground. From point A to Z and all point in between.
It doesn’t necessarily have to be in the equipotential plane, but if it is that would be ideal. It could be stand alone if the situation was correct for it.
I had to look it up to understand the OP. LOL!
"An equipotential plane is an area where wire mesh or other conductive elements are embedded in or placed under concrete, bonded to all metal structures and fixed nonelectrical equipment that may become energized, and connected to the electrical grounding system "

“A continuous earth ground. From point A to Z and all point in between.”

So how is the bonding wire that connects the casing of the pool pump and the pool cage tied into the grounding system? Where is the metallic continuous connection to the ground?

I don’t know!OK? Even to find the efficient earth ground take several rod in the ground and special equpt to read it.
We have a standard here in my part of Florida of proper earth grounding.However, It is insufficient for any home I have build. The more rods the better if they are properly placed.
It all depend on the proper installation.
If it was my pool here in Florida and I wasn’t there to watch what the did to achieve the earth ground, I would drive me a few rod in the ground in all the appropriate places.

I don’t think it is required to be bonded to the house EGC and GEC, but probably already is at the pump through the casing egc. The equipotential bonding of all metal parts is bonded to the pool shell steel grid or perimeter loop around the shell. It’s really just stray voltage or lightning protection.

I think they are (or should be) all connected, all metal components (handrails, screen enclosures, pool equipment etc.) near a pool or permanent spa should be bonded. Current standard in this area is a concrete encased grounding or UFER ground
Which basically utilizes the rebar/wire system used in the reinforcement of the poured concrete in the slab/foundation to provide a maximum ‘ground’ connection. The bonding to exterior systems or components is typically accomplished via a bare 8GA copper conductor.
Having said that one of our well respected electrical experts well be along soon and set everyone straight. :lol:

Jeff? Paul? :lol: Robert? :mrgreen:

All metal parts within 5’ of the pool, the pool pump, the pool water and all metal piping and components associated with the water circulation system are bonded together with a solid copper #8 conductor. The deck area surrounding the pool is also bonded either through the use of the rebar or a buried #8 conductor grid around the perimeter. All of these components are connected together by the #8 solid conductor and that is called equipotential bonding.

The only connecting to the building electrical system is typically the EGC in the branch circuit feeding the pump. Ground rods, CEE’s, or other electrodes are not require nor is it required the #8 run back to the panel.

Thanks Robert!
But everything is connected indirectly?

The bond grid is to create the bird on a wire effect so that is is no difference in potential to create a shock hazard. The grid could be at 13k volts and still not be a shock hazard as anything would all be the same voltage.

A ground rod at the pool is not needed or required.

Every metal part is directly connected to the EGC of the circuit feeding the pool equipment via the bond to the pool pump motor.

For the equipment can the termination point including the pool heater
be attached to the metal screen frame enclosure?

2pool motor-pump electrical bond connection.jpg

3pool motor-pump electrical bond connection.jpg

The metal enclosure needs to be bonded if within 5’.

From my understanding all metal withing 5’ of the pool horizontally (pool cages, window frames, sliding glass door frames, pool ladders) AND all electrical equipment that processes water (pump, heater…) need to be bonded together.

Thanks Jim.
In this case it about 15 ft away.

Okay, I think I am understanding. The breakers for the pool light, pump and heater serve as the overcurrent devices. Faulty or failing wiring will trip the breakers.

The equipotential grid is designed so that there are no voltage differences between metal objects and the pool water so the human has “bird on a wire” protection from stray voltages.

Yes, all the metallic parts are bonded together along with the pool water and will be at the same potential so a difference in potential between two parts (something that can cause a shock or worse) won’t be possible if the system is installed correctly.

So do you recommend GFCI protection for all circuits associated with pools?

The bonding has nothing to do with the grounding (earthing) of the electrical system of the structure. A “continuous connection to the ground” is not necessary for the bonding of pool & spa components to be effective.

Here is the correct way the pool and equipment is required to be grounded hence bonded. All items, pool structure, pumps, lights, heaters and enclosures are #8 copper wire connected to a ground rod that has to be separate and away from the house ground rods. All items are tied together to create a grid or bonding system. Many times it is difficult to find the ground rod for the pool grid system as it gets buried by landscape. All that can be inspected is the ground wiring and correct connections.