Quote:

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Originally Posted by tkrussell

Yes, I mentioned it here:



Plus I bet I can find a problem with your grounding system.

So far you spoke to a tree guy, a pool guy, and a couple of utility guys, notice how they seem to be not forthcoming sometimes?

Who came up with the idea of driving a ground rod? The utility? Nevermind the legalities of them on your property doing electrical work, they are not trained electricians and do not know building grounding. Esp pools.

Be sure the rod gets disconnected and abandoned.

Any plans for an electrician coming by soon?

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Even if there is a problem with our grounding system, if they shut off our power at the meter and the problem persists, wouldn't that mean that there is current coming from somewhere else? And there shouldn't be, right? Also, how would we determine if there is a problem with our system?

My next door neighbor, who works for systems operations at the utility, does not think the downed wire has anything to do with it. He's convinced it's something underground (counterpoints or something), and agrees that it's definitely not us. He's going to try to make some calls on our behalf.

The ground rod was the utility servicemen's idea. Once it made no difference, and even seemed to worsen the problem, I decided to ask them to remove it when they return tomorrow.

I want to pursue the utility until at least I can get an engineer out here. At that point, we will consider getting a private electrician. Or a lawyer. Or both.

One thing that can be done is to place a clamp-on relatively sensitive ammeter on your neighbor's and your water pipe where it enters the houses. It can offer some clues.

That ground rod might be useful until the problem is solved. They should remove the bond though.

Has utility verified it is not coming in on the Neutral?

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Originally Posted by Stratmando

Has utility verified it is not coming in on the Neutral?

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I know they put the meter around the neutral in the meter box, and everything there was fine. Is that what you mean?

Was it an Ampmeter? And wondering if they removed Neutral from Top of Meter Can for test, as well.

Quote:

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Originally Posted by Stratmando

Was it an Ampmeter? And wondering if they removed Neutral from Top of Meter Can for test, as well.

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The meter was handheld, with one red and one black wire coming from it, each with a probe at the end. Also, there was a "pincer" looking thing at the top of it which they used to surround various pipes and wires to test for current. It had a digital readout, and a dial on the front that looked like it may have switched the display from volts to amps or whatever, but the purpose of the dial I'm not sure about. I do know that when they clicked it around, numbers on the display changed.

Don't know if they actually removed the neutral from the top of the can. I'll ask next time someone comes.

Quote "Don't know if they actually removed the neutral from the top of the can. I'll ask next time someone comes".
Good deal.
They likely measured Current and Voltage.
Hope so. Good Luck

PROBLEM SOLVED!!

So, after doing more tree removal a block over where the line went down, and then repairing the line, THE SHOCKS ARE GONE!

While I was out, they did remove the bond from the ground rod, although they left the rod as is. I think my husband will ask that they remove it, too.

My husband says that the guy was getting some sort of reading around our box (perhaps the neutral?), so that's why they are still supposedly going to replace our service. This was unrelated to the pool problem.

I am pleasantly surprised. After my utility-employee-neighbor expressed doubts that the fallen line had anything to do with our problem, I was pessimistic. But lo and behold! And it only took a week and a day. ;-)

Thank you all for your input. Your suggestions gave us lots to work with and go to the "powers" that be (excuse the pun) with.

I am glad to hear the stray voltage is gone.

Last time I will insist that there is something that needs repair with your system and pool grounding.

I promise.

Hmm, the utility is going to replace your service?

I been doing this too long to buy what they are telling you.

I think that this one is good enough to make it a sticky all it's own. Who would have expected something a block away causing the problem.

Was going to edited my other best, best to add here I think.

Let me a bit clearer, I do believe the stray is coming from the overhead utility system.

One of their grounds probably failed and sent neutral currents, faults, etc out looking for a ground. This often is sent to services connected nearby. Properly grounded systems in buildings keep all voltages to zero or earth potentials on all intentionally grounded surfaces.

No one ever notices.

Since a loose or broken connection or wire out on the utility can happen, so can happen, often, in buildings. For any metal , esp around a pool, to get energized to noticeable levels, is a dead giveaway to a loose or broken connection, with the pool grounding.

Thinking about making a Best Of Sticky thread, Kiss.

Quote:

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Originally Posted by tkrussell

Since a loose or broken connection or wire out on the utility can happen, so can happen, often, in buildings. For any metal , esp around a pool, to get energized to noticeable levels, is a dead giveaway to a loose or broken connection, with the pool grounding.

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Since I had to read it twice, I'll try an alternate version of the above.

Had an equipotential grid been installed, you would have not gotten shocked. The equipotential grid would have protected you against the "utility" fault. "Utility" can mean anywhere along the system including your own home or your neighbor's.

Quote:

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Originally Posted by tkrussell

I am glad to hear the stray voltage is gone.

Last time I will insist that there is something that needs repair with your system and pool grounding.

I promise.

Hmm, the utility is going to replace your service?

I been doing this too long to buy what they are telling you.

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So, you're saying that if our pool grounding system was what it should be, then even if there was stray voltage from another source, we still shouldn't feel it?

Could you elaborate on what makes you suspicious about them replacing the service?

A little postscript -- the problem actually is not completely resolved. After I posted yesterday, we got a message from a guy explaining that although the voltage was greatly reduced, there is still voltage (he measured 2.8 in one spot where it was formerly around 14 volts). I can no longer feel it with my hand, but my husband can still feel a slight tingle on a cut he has. The are coming back today to do further investigation -- hopefully this time with an engineer.

Quote:

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Originally Posted by KeepItSimpleStupid

Had an equipotential grid been installed, you would have not gotten shocked. The equipotential grid would have protected you against the "utility" fault. "Utility" can mean anywhere along the system including your own home or your neighbor's.

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I see what you're saying (sorry -- didn't see your post when I posted my previous message). Well, at this point, since the problem doesn't seem to be with the grounding wires that connect directly to the two pump motors (one for the filter, one for the spa), then it would have to be underground. Finding out/repairing that would involve destroying and then reinstalling our patio, which is an expense well beyond our means right now. So, at the very least, we will continue to push to remove any stray voltage that shouldn't be there in the first place.

However, one of the higher-up guys who was here said he firmly believes there is nothing wrong with our pool grounding. Any ideas on how he could be so sure of this?

Before the problem was fixed, he measured voltage and current on your ground, when tree and wiring were corrected and the voltage gone, He felt everything is back where it should be?

You would only have to redo 5 feet minimum around the pool.

Quote:

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Originally Posted by Stratmando

Before the problem was fixed, he measured voltage and current on your ground, when tree and wiring were corrected and the voltage gone, He felt everything is back where it should be?

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No, actually, he feels the voltage should be 1 volt or less, and with one probe in the water and the other in the grass it was over 2.

At any rate, there was a group here this morning, and they did in fact replace our service. Then, when that had no effect, they went across the street to the utility tower (the one holding up the 69K volt transmission wires) and re-grounded it. Presto! Even by the pool pump ground wire, which had the highest readings originally of 14V, we're getting .2 or less.

It was explained to me that the grounding job they did is a "temporary" fix; that while it could last for years, there is an underlying problem with the counterpoise (sp?). They will be returning to do more permanent corrections to that.

So, based on these fixes, do you guys still feel we have issues with our own pool graounding system?

Your Pool could be OK, I think the problem was with their wire/tree problem, putting voltage on your neutral/ground.
I think We're all shocked they changed your Service.
I like to find the cause, they almost sound like Parts changers, if that doesn't work, change a different part?
Good this is done. Take Care

If you had a the equpotential grid within 5' of the pool, bonded properly faults elsewhere would not be a problem.

When you got out of the pool the deck, rail and the 5' landing strip would be at the same potential. The gradient, if there was one would diminish as you got further from the edge of the grid.

Quote:

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Originally Posted by KeepItSimpleStupid

you would only have to redo 5 feet minimum around the pool.

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So, do you mean 5 square feet?

Apparently, there are likely to be broken counterpoises throughout the system, which would take hundreds of thousands of dollars to fix permanently. I'm thinking of offering the utility this option: either we push to have those repaired, or they spend a few thousand dollars to install an equipotential grid under our patio (which they would have to rip up and then replace). Think they would go for that?

No, five linear feet. i.e. take a ruler and measure 5' from the edge of the pool. That's the area you have to cover. It's kind of difficult for a person to span that distance with a body part in the water.

It looks as if the inspector missed the grid when the pool was installed. The 69kv transmission line nearby wasn't factored into the entire equation. Most residential primaries are only a few thousand volts.

I do agree, that replacing the service was goofy, If they replaced the ground rod or grounding system for the service then I wouldn't think it was goofy. You could either have aground rod or your power system would be grounded via copper water pipes.

You never mentioned what kind of piping you have for water and how the service is connected to "ground".

"Ground" is a reference, but thing can change what ground is over distance, Thunderstorms have the ability to create a gradient across the ground.

I know if a computing center whose data lines were damaged that went from wnd to end of the building over a maybe 200'. They replaced that section with fiber rather than copper to eliminate the problem.

Quote:

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Originally Posted by tkrussell

Was going to edited my other best, best to add here I think.

Since a loose or broken connection or wire out on the utility can happen, so can happen, often, in buildings. For any metal , esp around a pool, to get energized to noticeable levels, is a dead giveaway to a loose or broken connection, with the pool grounding.

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Just to clarify -- while there was voltage being picked up on the handrails by a meter (around 2.5 volts), it could not be felt by humans unless touched directly on an open wound while in the pool. The only noticeable current to unbroken skin was not on metal at all, but on the wet pavers by the pool steps, if you were also touching the pool water at the same time. You did not even have to be in the pool -- you could touch wet pavers with one hand, and dip the other in the water (even while wearing shoes) and you would feel it. Does this make a difference in your assessment?

Not one bit. Resistance between body parts varies because of the type of tissue, open wounds, water which isn't pure because of the chemicals added.

A potential difference between the wet pavers existed between the pavers and the pool, so it depends on the value of the resistance, how much current flows between two points i.e. two hands. It doesn't matter if the feet have shoes on or not. An open wound, just makes the resistance less and the current larger.

We also don't know if the water is "bonded" to ground.

See:
Effects of current passing through the human body

Okay, now we're making an appointment with an agency that specializes in testing grounding around pools. Apparently they have some sort of instrumentation that measures potential or something, and if it beeps when contacting two surfaces, it's good; if it doesn't beep, uh-oh.

Just making sure I understand about the equipotential grid, KISS. You're saying that this grid would need to be placed 5 feet away from the water's edge, all around the pool? We have concrete pavers surrounding the entire pool, but much of it is narrower than 5 feet. However, the true patio area, where the spa and furniture are, is about 15 x 20 feet. Right in front of the steps, where we had felt the strongest shocks, is about 4'10", and the grass in front of that, between the pavers' edge and the fence between my property and the neighbor's, is about 3.5 feet. The steps, spa, and large patio area are the closest parts of the pool to the transmission wires, FWIW. Picture a piece of loose leaf paper. The margin line down the left side is the transmission wires. Our pool forms a backwards L near that line, with the bottom line of the L forming the shallow end leading to the steps, and the spa is a circle in the right angle formed by the L, with the patio "above" the spa. So, if you include the patio area in our pool's footprint, the whole thing forms a big rectangle. If I hazard a guess, I would say that the edge of the water by the steps is no more than 15-20 feet from being directly underneath the transmission wires.

Now that the problem is fixed, we are taking your concerns about our pool's grounding seriously, since it is so close to these high voltage sources, and who knows if something like this could happen again -- but worse.

No, the copper grid would go from near the edge of the pool, call it 0" to 5' away from the pool. 0 is impossible and 5' is impossible in places. The grid is about 1' x 1' square.

Look at it this way:

Water*GRID*GRID*GRID*NO GRID*NO GRID
**a**********b****************c*******

I'll call those areas a, b and c. If a human laid down on b and put his hand in a and his foot in c, he could conceiveably touch the GRID and NO GRID.

This isn't the same as what you have now because the NO GRID area won't be an instantaneous change in ground resistance.

When you would sit at he edge of the pool, you would be in the equipotential area and thus no shock.

When you walked out of the pool, you would be in aneqipotential area and hence no shock.

GRID to NO GRID should not give you a shock either.

I think you should be able to work on just the exposed areas to your property line. If you can go 5 feet, then do.

So the grid doesn't start at 5', but rather as close to the pool as practical and extends to 5'. In your case, it can't.

Also remember to ground the water in the pool.

I don't think the SPA poses a problem.

Make sense?

If you go here:

https://www.askmehelpdesk.com/electr...ne-270277.html

And jump through some hoops and register (free) with the NFPA, you can read the NEC handbook online. Can't search, can't print, can't copy. Just read.

Section 680 deals with pools an Hot Tubs.

Quote:

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Originally Posted by KeepItSimpleStupid

No, the copper grid would go from near the edge of the pool, call it 0" to 5' away from the pool. 0 is impossible and 5' is impossible in places. The grid is about 1' x 1' square.

I think you should be able to work on just the exposed areas to your property line. If you can go 5 feet, then do.


Also remember to ground the water in the pool.


Make sense?

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Okay, so you're saying I could put one of these 1-square-foot grids only in the spot where we felt noticeable shocks (the "exposed areas"); i.e. in front of the pool steps. Perhaps, to be safe, we could also put one by the ladder at the deep end. There was actually voltage read all around the pool when the wire was down, but it could only be felt if you had a cut.

How do you ground the pool water?

I don't feel your problem was a broken ground system, I feel your ground was energised.

There are a few products mentioned in this thread:

Bonding pool water - InspectionNews - Home Inspection

The square inch requirement could be met by a bonded lighting fixture, a ladder etc.

Sporatically protecting the areas isn't going to do much good. You can sit on the edge of the pool with your feet in the water, so perimeter protection is necessary.


Voltage across some resistance is defined by ohms law as V = I * R where I is current and R is resistance.

Suppose we use a nice round number like 1 Amp (very lethal o the human body).

If R was 1 ohm, you would have 1 volt across it. If R was 1000 ohms you would have 1000 V across it, if R was 10,000 ohms you would have 10,000 V across it. What this is saying is that the lower the resistance the lower the drop. The grid lowers the resistance.

There is another formula that defined R=pl/A where p is a material property and is usually in ohm-cm, l is the length that the current is passing and A is the cross sectional area.

Thus, if you plug in the resistivity of copper, the length and the area of the circular diameter, you can compute R.

For bulk samples such as soil, it gets more complicated.

Here is some info relating to that.

Soil resistivity measurement

I was looking at the link you posted, KISS. What I'm getting (and please correct me if I'm wrong) is that since I have a metal pool ladder going into the water at the deep end, plus two underwater lights in metal housings, most likely the pool water is already grounded since the metal in contact with the water is grounded.

And, in regards to the grid, you're saying it WOULD need to run around the perimeter of the pool to protect any bathers who might sit on any part of the pavers with their feet in the water. In my case, this would involve ripping up the whole patio all around in order to install it. Correct?

Yes for your first question.

The second is just the pavers within 5' of the pool, not the entire patio.

Quote:

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Originally Posted by KeepItSimpleStupid

Yes for your first question.

The second is just the pavers within 5' of the pool, not the entire patio.

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Well, since I have pavers that abut the pool's edge all the way around, that would involve ripping up the whole perimeter. I realize that the pavers on the main part of the patio that are located beyond 5' of the edge could be left alone, but that's a relatively small area in comparison to the whole.

Yes for your first question.

The second is just the pavers within 5' of the pool, not the entire patio.