Bonding metal parts of swimming pool cover

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Mystic Pools

Senior Member
Location
Park Ridge, NJ
Occupation
Swimming Pool Contractor
There is a bond lug on the motor that drives the reel, which is connected with a short whip to the aluminum bar attached to the cover itself.

I'm not sure of the cover brand- we use Cover Pool-but it's worth looking on line at the product your working on or calling tech support to see where this whip is.

There have been some issues with the whip, a short bare wire about 2", corroding from the pool chemicals.

The cover track, which is aluminum, should be part of the bond grid.

Cover Pool and Coverstar are 2 I'm familiar with.
 
Location
Athol, MA
This is coverstar, a new install. I called them and couldn’t get threw to anyone. I bonded the lug for motor and frame. I don’t see how it can make a connection without a retractable wire in the cover. There’s no continuity right now between the cover rail and the grid.
 

Mystic Pools

Senior Member
Location
Park Ridge, NJ
Occupation
Swimming Pool Contractor
is it common for people to be in the pool while the cover is out?


Are you asking if people swim while the cover is in the cover mode or if it's partially covered? I cannot say I have witnessed this but it is not advisable and unsafe to swim in the pool unless the cover is completely retracted.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
is it common for people to be in the pool while the cover is out?

Are you asking if people swim while the cover is in the cover mode or if it's partially covered? I cannot say I have witnessed this but it is not advisable and unsafe to swim in the pool unless the cover is completely retracted.

I think he may have been asking what the danger would be if the cover wasn't bonded, when (usually) no one would be in the pool with the cover on.
 

kwired

Electron manager
Location
NE Nebraska
I think he may have been asking what the danger would be if the cover wasn't bonded, when (usually) no one would be in the pool with the cover on.
I think that is what is being asked. If close enough to the pool when uncovered, I would think NEC would still want it bonded. If far enough from the pool when uncovered, maybe have a chance of not needing to bond, most inspectors likely will still want to see it bonded I would guess though.
 

Wire-Smith

Senior Member
Location
United States
the other thought is, it could become energized from the supply circuit, which the motor is grounded and bonded and the frame that connects the motor to the actual cover is grounded and bonded, all bonded to the pool water and everything else. so whats the hazard? i know the code reads it should be bonded, just asking if there is actually a hazard/potential hazard.
i do see a possible hazard when the cover is out, someone set a radio or something on it and it somehow get energized. but not sure that's something to worry about in this circumstance. i'm kind of thinking if the cover will only fully cover pool or completely store itself then there isn't a probable hazard, if it will cover the pool partially i agree i would want it bonded or a different cover. i'm surprised it's not bonded through it's construction already (through bearings or whatever). does this roll up or fold up? if it folds some small short braids could be installed with the cover fully open and at the frame side and just let it fold up on them. if it rolls there are some rotating electrical connection devices which i cannot think of the name for but i will look up, these could be put on the shaft and connected to the grid
 
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kwired

Electron manager
Location
NE Nebraska
the other thought is, it could become energized from the supply circuit, which the motor is grounded and bonded and the frame that connects the motor to the actual cover is grounded and bonded, all bonded to the pool water and everything else. so whats the hazard? i know the code reads it should be bonded, just asking if there is actually a hazard/potential hazard.
i do see a possible hazard when the cover is out, someone set a radio or something on it and it somehow get energized. but not sure that's something to worry about in this circumstance. i'm kind of thinking if the cover will only fully cover pool or completely store itself then there isn't a probable hazard, if it will cover the pool partially i agree i would want it bonded or a different cover. i'm surprised it's not bonded through it's construction already (through bearings or whatever). does this roll up or fold up? if it folds some small short braids could be installed with the cover fully open and at the frame side and just let it fold up on them. if it rolls there are some rotating electrical connection devices which i cannot think of the name for but i will look up, these could be put on the shaft and connected to the grid
I think it would depend on how far from the pool it is before you can say it doesn't need bonded. You have two situations to be concerned about. 1 - typical rise in voltage that happens when there is fault from an ungrounded conductor. 2- smaller rise in voltage on EGC over true ground, which is main reason for EP bonding - you don't want to introduce "true ground" to a point within the area that requires equipotential bonding, that can leave potential voltage gradients that can be lethal to pool users. With EP bonding we don't care what true ground is, we want everything pool users can touch at same time to be at same potential regardless what voltage to true ground is.

"Slip ring" the word you are trying to think of?

Center pivot irrigation sometimes they call them "collector"
 
Location
Athol, MA
I think it would depend on how far from the pool it is before you can say it doesn't need bonded. You have two situations to be concerned about. 1 - typical rise in voltage that happens when there is fault from an ungrounded conductor. 2- smaller rise in voltage on EGC over true ground, which is main reason for EP bonding - you don't want to introduce "true ground" to a point within the area that requires equipotential bonding, that can leave potential voltage gradients that can be lethal to pool users. With EP bonding we don't care what true ground is, we want everything pool users can touch at same time to be at same potential regardless what voltage to true ground is.

"Slip ring" the word you are trying to think of?

Center pivot irrigation sometimes they call them "collector"



You understand this well! It is 6” from the pool edge so well within the 5 ft required by code. It needs to be bonded by code and would be of best interest to bond it for the “what if’s”. A lot of people need to understand the difference of the right and wrong installation. They both work until something goes wrong
 

Wire-Smith

Senior Member
Location
United States
You understand this well! It is 6” from the pool edge so well within the 5 ft required by code. It needs to be bonded by code and would be of best interest to bond it for the “what if’s”. A lot of people need to understand the difference of the right and wrong installation. They both work until something goes wrong

have any theories of what the what if in this situation would be?
 

kwired

Electron manager
Location
NE Nebraska
You understand this well! It is 6” from the pool edge so well within the 5 ft required by code. It needs to be bonded by code and would be of best interest to bond it for the “what if’s”. A lot of people need to understand the difference of the right and wrong installation. They both work until something goes wrong

have any theories of what the what if in this situation would be?
What if's sort of don't matter, 680.26(B)(6) would require it to be bonded if it is electrically operated pool cover even if it is more than 5' from the pool.

If not electrically operated then (B)(7) would require it to be bonded if within 5 feet of the pool.

The what if's are same as they are for other objects - you want equipotential bonding between conductive objects in/near the pool to eliminate any possible voltage gradient between those objects. We don't care what voltage to ground is that much around a pool we care about what voltage between objects in the vicinity of pool users is, that is what causes shock/electrocution hazards.
 

Wire-Smith

Senior Member
Location
United States
What if's sort of don't matter, 680.26(B)(6) would require it to be bonded if it is electrically operated pool cover even if it is more than 5' from the pool.

If not electrically operated then (B)(7) would require it to be bonded if within 5 feet of the pool.

The what if's are same as they are for other objects - you want equipotential bonding between conductive objects in/near the pool to eliminate any possible voltage gradient between those objects. We don't care what voltage to ground is that much around a pool we care about what voltage between objects in the vicinity of pool users is, that is what causes shock/electrocution hazards.

i agree its required by code, just wondering how it would become a hazard
 

kwired

Electron manager
Location
NE Nebraska
i agree its required by code, just wondering how it would become a hazard
Same way other objects in the same areas become a hazard. Bonding assures all bonded objects are at same potential. If you have a rise of 2-5 volts on your service neutral because of voltage drop, all your EGC's that are bonded to the neutral via the main bonding jumper also rise 2-5 volts. Bring that EGC to an item in pool vicinity and you have that same 2-5 volts to earth - pool user probably at very least feels something with this voltage, especially if they are immersed in the water when touching something with that potential. Now bond that item to everything else that is in or close to the pool and you raise the entire pool and everything around it that 2-5 volts, but to the user there is no potential between objects and that is what matters most. Entire pool and everything else bonded to it could be at 1000 volts to earth and users are still not subject to any voltage differences in what they can contact while in the pool - same reason nothing happens to birds sitting on a bare high voltage distribution line, you need to contact points of different potential to get shocked.
 

Wire-Smith

Senior Member
Location
United States
Same way other objects in the same areas become a hazard. Bonding assures all bonded objects are at same potential. If you have a rise of 2-5 volts on your service neutral because of voltage drop, all your EGC's that are bonded to the neutral via the main bonding jumper also rise 2-5 volts. Bring that EGC to an item in pool vicinity and you have that same 2-5 volts to earth - pool user probably at very least feels something with this voltage, especially if they are immersed in the water when touching something with that potential. Now bond that item to everything else that is in or close to the pool and you raise the entire pool and everything around it that 2-5 volts, but to the user there is no potential between objects and that is what matters most. Entire pool and everything else bonded to it could be at 1000 volts to earth and users are still not subject to any voltage differences in what they can contact while in the pool - same reason nothing happens to birds sitting on a bare high voltage distribution line, you need to contact points of different potential to get shocked.

in your scenario wouldn't that egc rise be taken care of at the cover motor which is bonded to the equipotential bonding system.

the hazards i always thought of that were being prevented were; the one you cited and also say for instance something that is in contact with earth and the pool which would be a conduit for transient current. but with this cover i'm not seeing a potential hazard, what could likely energize it (the cover motor or egc) is bonded to the pool water and everything else, the stationary parts of the cover are also bonded.

again i'm not arguing that its not required by code, just trying to think of the potential hazard.

thanks
 

kwired

Electron manager
Location
NE Nebraska
in your scenario wouldn't that egc rise be taken care of at the cover motor which is bonded to the equipotential bonding system.

the hazards i always thought of that were being prevented were; the one you cited and also say for instance something that is in contact with earth and the pool which would be a conduit for transient current. but with this cover i'm not seeing a potential hazard, what could likely energize it (the cover motor or egc) is bonded to the pool water and everything else, the stationary parts of the cover are also bonded.

again i'm not arguing that its not required by code, just trying to think of the potential hazard.

thanks
The EBS isn't intended to get rid of the EGC rise it is intended to equalize potential between all bonded objects. If you have a large metallic object that isn't bonded - how do you know it it will take on said EGC rise or take on earth potential? If the entire pool is sitting there at a few volts above "earth" and that object happens to take on earth potential the risk of shock increases.

Bonding it assures it will be at the EBS potential.
 

Wire-Smith

Senior Member
Location
United States
The EBS isn't intended to get rid of the EGC rise it is intended to equalize potential between all bonded objects. If you have a large metallic object that isn't bonded - how do you know it it will take on said EGC rise or take on earth potential? If the entire pool is sitting there at a few volts above "earth" and that object happens to take on earth potential the risk of shock increases.

Bonding it assures it will be at the EBS potential.

i agree, what i am asking and trying to think of is how that cover would get to a different potential than the pool with its stationary frame and driving equipment being bonded to the EBS. i agree there is an ability for it to happen, i am really just asking if anyone can think of a circumstance that that would happen. the only thing i can come up with is someone setting something on the cover that's connected to something outside of the pool.

https://www.est-aegis.com/shaft-grounding-ring/SGR-Standard.php

by the way, here is a shaft grounding ring
 

kwired

Electron manager
Location
NE Nebraska
i agree, what i am asking and trying to think of is how that cover would get to a different potential than the pool with its stationary frame and driving equipment being bonded to the EBS. i agree there is an ability for it to happen, i am really just asking if anyone can think of a circumstance that that would happen. the only thing i can come up with is someone setting something on the cover that's connected to something outside of the pool.

https://www.est-aegis.com/shaft-grounding-ring/SGR-Standard.php

by the way, here is a shaft grounding ring
I will admit not being familiar with equipment that may be used here, and if it is on a stationary frame and attached to the driving equipment - it may already be bonded, and that bonding of moving components could be already taken care of as well with specific equipment for such a purpose. Listing of equipment may come into play as well.
 
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