*Shallow end, being shocked when grabbing railing*

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gamerfan2004 said:
WAIT, WHAT!? You lived in Delaware!!! 🍻👏👍 Most people only drive through it or visit the beach 🤣 You're right about the news, it's only Philly and no one watches that anymore. Btw, you have an awesome backyard and pool.

I'm working on the voltage mapping now. I hope to post it before I go to bed.
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I did live in Dover from 1999-2005; stationed at DAFB. I enjoyed my time there but wasn't a huge fan of summer traffic with SO MANY PEOPLE going south from Jersey, DC and Philly...or NASCAR traffic weekends, oye. I still have lots of friends up there that are still stationed (or retired) in the area.

Thanks for the compliments on the pool/yard. It is an oasis that we enjoy thoroughly!
 
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Rocket J Squirrel said:
If you're getting shocked between the deck and the water without touching the rail, that's a different story.
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It only happens when you are in the water and touch the railing.
mas985 said:
Did you do a voltage measurement from the water hot spot to a screw driver in the ground (as far from the deck as you can)? If my theory is correct, that voltage should be lower than the voltage from the hot spot to the railing.

Those steps appear to be on top of the vinyl. How are they anchored?
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Yes, I actually did that test with a screwdriver in the ground.

123mV AC | Railing to water
0V AC | Railing to deck
120mV AC | Water to deck

The vinyl liner stops right next to the steps by a rubber/vinyl gasket insert. It stops on both sides and runs down around the bottom of the steps. I honestly don't know how the steps are anchored in.
 
HeyEng said:
I did live in Dover from 1999-2005; stationed at DAFB. I enjoyed my time there but wasn't a huge fan of summer traffic with SO MANY PEOPLE going south from Jersey, DC and Philly...or NASCAR traffic weekends, oye. I still have lots of friends up there that are still stationed (or retired) in the area.

Thanks for the compliments on the pool/yard. It is an oasis that we enjoy thoroughly!
Click to expand...
Oh, you were there when the C5 Galaxies were around. Those planes were monsters! Yeah, all of the people coming from out of state to visit our beaches is 👎.
 
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Mike1162 said:
Hopefully it won't come to that.

Here's a couple thoughts for discussion. Use a circular saw with proper abrasive blade and cut a shallow groove in the concrete next to the railing anchors. Drill & tap a hole in the top of the anchors to connect a new bonding wire to each of the anchors. Connect the other end of the bonding wire to the pump motor along with the original bonding wire. Fill the groove with mortar or caulk. If the groove is close enough to the anchors then the anchor caps will hide where the wire comes up from the groove to the anchors. If this isn't a terrible idea then try running a temporary wire between the anchors & pump to see if cures the problem. No sense in cutting into the deck before knowing if it works.
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This is a great idea...after seeing the decking around the step area, would be pretty easy to get a bonding wire to a point where you could bury it to pump pad.
 
gamerfan2004 said:
Yes, I actually did that test with a screwdriver in the ground.

123mV AC | Railing to water
0V AC | Railing to deck
120mV AC | Water to deck

The vinyl liner stops right next to the steps by a rubber/vinyl gasket insert. It stops on both sides and runs down around the bottom of the steps. I honestly don't know how the steps are anchored in.
Click to expand...
I am not sure I understand what you did. To me, when you say "railing to water", that is one probe on the railing and the other in the water and previously that was a higher voltage. How was the screwdriver involved in any of those tests?

What I am interested in is with the bonding wire attached to the pump and pump grounded, testing the voltage between the water and a screwdriver in the ground far from the deck.
 
mas985 said:
I am not sure I understand what you did. To me, when you say "railing to water", that is one probe on the railing and the other in the water and previously that was a higher voltage. How was the screwdriver involved in any of those tests?

What I am interested in is with the bonding wire attached to the pump and pump grounded, testing the voltage between the water and a screwdriver in the ground far from the deck.
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I had a screwdriver driven into the dirt, I took a #8 copper wire and attached it to my common lead. I took the common lead and put it on the railing anchor. The positive lead went into the water. Those results are using that method to measure the voltage.
 
gamerfan2004 said:
I had a screwdriver driven into the dirt, I took a #8 copper wire and attached it to my common lead. I took the common lead and put it on the railing anchor. The positive lead went into the water. Those results are using that method to measure the voltage.
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That wasn't what I was looking for. Here again:

Original configuration before all this testing started: The bonding wire connected to the pump housing, pump green wire connected to the house ground.

Screw driver in ground away from deck and house on one lead of volt meter and the other lead in the water. No other wires connected to either probe. This is an independent measurement to see if the water in the hot spot is close to the same potential as earth.
 
mas985 said:
Screw driver in ground away from deck and house on one lead of volt meter and the other lead in the water. No other wires connected to either probe. This is an independent measurement to see if the water in the hot spot is close to the same potential as earth.
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Understood.

  • 50mV AC to water
  • 1V AC on deck and increases as you get closer to the railing anchors
  • .5V AC at the closest cover anchor
  • 1.7V AC at the railing anchor
 
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gamerfan2004 said:
(a) It only happens when you are in the water and touch the railing.

123mV AC | Railing to water
(b) 120mV AC | Water to deck
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I am having trouble understanding how statements (a) and (b) can be consistent. Does it mean you can feel 123 mv but not 120 mv?
 

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Rocket J Squirrel said:
I am having trouble understanding how statements (a) and (b) can be consistent. Does it mean you can feel 123 mv but not 120 mv?
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No, this was a different test with my ground/common lead connected to the screwdriver in the ground. However, the placement of this test has been deemed inconclusive based on the location of the screwdriver. The bonding wire coming off of the pump runs under this area, hence having around 120mV AC. The test that I just did has legitimate results since the screwdriver was far away from the pool and pump.
 
gamerfan2004 said:
Understood.

  • 50mV AC to water
  • 1V AC on deck and increases as you get closer to the railing anchors
  • .5V AC at the closest cover anchor
  • 1.7V AC at the railing anchor
Click to expand...
Thanks, that is exactly what I was expecting.

That tells me that the water hot spot is somehow more closely connected to earth potential rather than the bond potential.

Now the hard part is to figure out why.
 
Does the following theory have any merit?
Let's assume the ground has 5 volts and the bonding grid is working perfectly.
The bonding grid should also have 5 volts as well as the the stair railing and deep end ladder.
The 5 volts is entering the pool water through the deep end ladder.
The water has much more resistance than the bonding grid so let's say we're getting voltage drop of 2.5 volts from the ladder to stairs.
You measure voltage from the water at the stairs to railing & show 2.5 volts.
 
Let's assume the ground has 5 volts and the bonding grid is working perfectly.
The bonding grid should also have 5 volts as well as the the stair railing and deep end ladder.
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The first assumption can only happen when something energizes the ground. It doesn't happen in isolation.

But also, the bonding grid would not have 5 volts in your scenario because it is attached to neutral which is not energized in your scenario. The bonding wire will always obtain the same potential as neutral since the resistance of the wire is very low.

The OP voltage/current measurements indicate that the source of the voltage is from the neutral and not the earth.
NEV is fairly common in power distribution systems so I am pretty sure that is what the OP is seeing here.

As for next steps, the stair area is clearly a different potential than the railing so that is the area that I would focus on. There is probably some attachment points that are going through the stairs into the ground. Note that is probably the only area where there is not a metal wall that is bonded.
 
The bonding wire from the pump hits that corner first. If the bonding points on the
Mike1162 said:
I thought we were quite certain that the ground is energized. Isn't that what NEV does? Maybe I should have said earth or soil instead of ground.
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We were trying to identify the source of the stray voltage that has been plaguing my ground/neutral bar. If we remove the ground wire that attaches to the timer and pump, the voltage goes away. The hunt continues for the protagonist and mending the victim (the corner deck area of my pool).
 
NEV is caused by voltage on the neutral, not the earth. Generally the earth only has voltage with a nearby source. Get far enough from the source and the earth is no longer energized.

In power distribution systems, ideally the neutral does not carry any current on 3-phase WYE lines. However, if the 3-phase system is feeding a single phase system via transformers (aka residential power distribution), the 3-phase phases can become imbalanced (one of the branches carries more current than the others). This forces current on the neutral line of the WYE which then has a voltage drop as a function of distance from the sub-station (or where the Delta converted to WYE). The neutrals are connected around the transformers so any voltage developed along the distribution lines is transferred to the residential neutrals. This can be avoided by using delta transformers instead of WYE (isolated neutral) but unfortunately sometimes WYE is used instead where it should not be.

en.wikipedia.org

Stray voltage - Wikipedia

en.wikipedia.org en.wikipedia.org
www.ecmweb.com

Clearing Up Neutral-to-Ground Voltage Confusion

Because effects from N-G voltage can range from nonexistent to significant, you must learn to identify true common-mode events
www.ecmweb.com www.ecmweb.com
 
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Yesterday you measured 1.7 volts between the screwdriver & railing anchor.
If you have time, repeat that test to confirm & check again after disconnecting the bonding wire at the pump.
Also are both of those readings the same whether or not the pump is running?
 

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