Pool bond question. Potential difference

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electricblue

Senior Member
Location
Largo, Florida
Occupation
EC
Looking at a concrete pool that had a spa added. Pool builder says he chipped into existing pool shell to rebar in 4 spots to reach rebar and rebond then ran a ring around the pool and spa. There is a tingling when touching the pool water and spa water. .668 volts from spa to pool water. I say the old pool is not bonded and at a different potential from the new spa and fire bowls that all have continuity back to the pump. I just want to run this by someone here to double check myself before I have him start pulling up deck and looking into the bond.
 
How did you measure the voltage, and could it have been a DC measurement?

Is the voltage present with power off?

Are there different equipment terminals ( eg. pool and spa pumps) where you can take a resistance measurement?
 
winnie said:
How did you measure the voltage, and could it have been a DC measurement?

Is the voltage present with power off?

Are there different equipment terminals ( eg. pool and spa pumps) where you can take a resistance measurement?
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Ac voltage. Yes power is off. I'm assuming this is NEV.
 
I think you should wait for input from the more pool focused members ( @Mystic Pools comes to mind).

But I think you are correct about something not being bonded. It sounds like the contractor that did the spa did quite a bit of bonding, but clearly some bonding isn't present. Maybe the pool shell wasn't connected to the pool deck or some such.

-Jonathan
'
 
I thought the original poster said the builder tied into the rebar at 4 points on the existing pool. Is this not correct?
 
electricblue said:
I say the old pool is not bonded
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may have been some bonding attempt but apparently not done very well or there been some failures. Bonding to four different points should possibly lessened chances of having potential so makes you wonder what didn't get bonded that should have. Or if portions of concrete had been replaced at some point how well things got tied back together.
 
Dennis Alwon said:
I thought the original poster said the builder tied into the rebar at 4 points on the existing pool. Is this not correct?
Click to expand...

My _guess_ from this is that the builder tied to one component (say the pool deck) but that this component wasn't itself bonded to a different bit (say the shell of the pool in the ground). The voltage difference problem was always present, but now a person can contact two different volumes of water at the two different voltages.
 
winnie said:
My _guess_ from this is that the builder tied to one component (say the pool deck) but that this component wasn't itself bonded to a different bit (say the shell of the pool in the ground). The voltage difference problem was always present, but now a person can contact two different volumes of water at the two different voltages.
Click to expand...
Agreed. To put it another way, adding the spa (likely) didn’t create this problem.
 
electricblue said:
Looking at a concrete pool that had a spa added. Pool builder says he chipped into existing pool shell to rebar in 4 spots to reach rebar and rebond then ran a ring around the pool and spa. There is a tingling when touching the pool water and spa water. .668 volts from spa to pool water. I say the old pool is not bonded and at a different potential from the new spa and fire bowls that all have continuity back to the pump. I just want to run this by someone here to double check myself before I have him start pulling up deck and looking into the bond.
Click to expand...
Am I to assume the deck was torn up and then replaced after the PB found the 4 points and ran the perimeter bond?
Is the new spa concrete? If so, was that rebar included with the new pool bond and perimeter bond? Any rail or ladder sockets? Are they bonded?
Wet niche pool light bonded? Wet niche spa light bonded?

Was a water bond added? Fire bowls bonded? What about the gas pipe at the fire bowl? (If it's black pipe)
I put in fire bowls on a recent project and bonded the SS tray and the black pipe stub. The FB's were within 5' of the water.
 
Could you be measuring phantom voltage? Or it doesn't apply at this case?
 
Little Bill said:
Do you mean fire pit?
We have those here and that's what we call them. Usually just bricks, or rocks, laid in a circle, with either gas, or natural fire.
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No. Fire bowl. It has a SS tray that is filled with colored crushed glass. The tray has a burner when ignited makes a flame that goes through the glass. Different shapes, round, square, rectangle...
Actually, this job also had a fire pit that was gas fired and you would use regular firewood. It was pre-cast kit

1765018726476.png
 
Mystic Pools said:
No. Fire bowl. It has a SS tray that is filled with colored crushed glass. The tray has a burner when ignited makes a flame that goes through the glass. Different shapes, round, square, rectangle...
Actually, this job also had a fire pit that was gas fired and you would use regular firewood. It was pre-cast kit

View attachment 2580947
Click to expand...
Neat!
 
Mystic Pools said:
Am I to assume the deck was torn up and then replaced after the PB found the 4 points and ran the perimeter bond?
Is the new spa concrete? If so, was that rebar included with the new pool bond and perimeter bond? Any rail or ladder sockets? Are they bonded?
Wet niche pool light bonded? Wet niche spa light bonded?

Was a water bond added? Fire bowls bonded? What about the gas pipe at the fire bowl? (If it's black pipe)
I put in fire bowls on a recent project and bonded the SS tray and the black pipe stub. The FB's were within 5' of the water.
Click to expand...
The deck was tore up. There was no obvious bond, so they chipped into the old pool shell to get to rebar and installed 4 stingers. Installed a bond loop and tied it all together. Wet niche lights are a thing of the past and new lights are not bonded anymore. Water bonds are the rebar in concrete pools.
 
electricblue said:
Water bonds are the rebar in concrete pools.
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That's not correct. Anything bonding the water has to be in direct contact with the water.

(C) Pool Water. Where none of the bonded parts is in direct
connection with the pool water, the pool water shall be in
direct contact with an approved corrosion-resistant conductive
surface that exposes not less than 5800 mm2 (9 in.2) of surface
area to the pool water at all times. The conductive surface shall
be located where it is not exposed to physical damage or
dislodgement during usual pool activities, and it shall be
bonded in accordance with 680.26(B).
 
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