I have been living in my house with a 25,000 gallon inground vinyl pool for nearly six years. The pool also has an attached spa.

Yesterday, we noticed that when in the water at the steps in the shallow end and touching the concrete pavers right in front of the steps, we get a buzzing shock where we touch the concrete. Also, a "stinging" or "biting" sensation is felt on the body part where it meets the water surface (e.g. ankles). Also, if someone is sitting on the concrete, completely out of the pool, and someone in the pool touches that person, both people feel the buzz. Interestingly, no shock is felt when we touch the metal handrails on either side of the steps. The shocking by the steps is mild enough that quickly walking in and out of the pool does not cause you to feel it, but if standing stationary on the concrete and dipping your hand into the water and holding that position, it is enough to make you yelp. It's possible my husband noticed a very slight sting when in the pool and dipping his finger into the spa, which disappeared once he grasped the side of the spa with his other hand. He only felt the sting where he had a cut on his finger. This was a couple of months ago. No one else noticed anything significant until yesterday, and we even had a big pool party three days ago.

Today, I turned off the main breaker of the house and went out and tested it, and the shock still happens when I stand on the steps in the water and touch the concrete pavers. The intensity of the shock is rather localized to about a two- to threee-foot area in front of the steps. The farther you place your hands from this epicenter the weaker the buzzing gets. I tested this by the ladder at the deep end and various other random spots, and this is the only place I feel it. I also could not duplicate what my husband was talking about with the spa.

Some more info that might be relevant -- we live across the street from a high-tension-wire tower. Our soil is sandy/pebbly. Last summer, a transformer (I think) across the street exploded out of the blue, on a beautiful sunny day, and caused our power to flicker for a second and our next-door-neighbor's power to go out completely until LIPA (Long Island Power Authority) came to fix it. This explosion was in the front yard on the opposite side of the house from where I feel the shocks. The tower is on the same side of the house, however.

What puzzles me most is that no one seemed to notice this before this year, and I know people have sat on the concrete with their feet in the water many times. What could have changed?

Until this is corrected or diagnosed, is it safe to swim?

Thanks --
Jody

My advice is no, it is not safe to use until the issue is resolved.

More than 5 milliamps across the heart can be fatal.

Here is a previous thread that discusses a similar issue with shocks from pools:

https://www.askmehelpdesk.com/electrical-lighting/mild-electrical-shock-swimming-pool-118962.html

I need to recommend that you have a qualified electrician come out and begin troubleshoot the problem, as this can be caused by so many reasons.

Not saying it's a fix, but it may be worthwhile doing until the real problem is solved. If you place a plastic tarp over the concrete that's giving you a problem, the shocks MAY go away since the tarp is an insulator, but it needs to be fixed.

Someone should get an idea of the magnitude of the voltage. Current kills when it flows through the heart muscle, stopping the heart. Only about 10 mA is necessary to do this and water lowers the resistance of the body.

I believe the soil has something to do with it and/or improper installation of the concrete. This is not what you wanted to hear, I'm sure.

You can read the section of the NEC code online for free that deals with pools by following the sticky in this section when you first posted.

What's supposed to happen is when the pool was installed, the concrete would have a metal grid embedded in it and the grid would be bonded together. This grid, the railing and the pool ground would be connected together so that they are at the same potential. This is usually electrically inspected before the concrete is poured.

Something is probably amis with this bonding structure. Your soil type contributes to the problem.

Do power poles feed you and your neighbors, including neighbors behind you?
If you can feel it, a Meter will show it and will be safer. If you MUST test with your hand, test with the backside, so any shock will pull your hand away instead of latching on.
An Electrician will start with what you did(turn main off) to determine if caused from a load from your house. Shorted pump. Landscape wiring, etc.
If it still shocks with house power off, I wonder if a neighbor has underground service going under your yard, and a rebar was driven into it. If an electrician can convince Electric coming from someonr else's service, they MAY be able to shut power off to nearby houses to determine the source.
I think I would shut power off to the house, and CAREFULLY remove Ground wire from Ground rod at pool equipment, to see if the voltage is present on Bond wire, or Ground rod. Ground rod and or wire may be live and can Kill.
Good Luck, Be Careful.

Okay -- the LIPA guys came. It appears that the problem is the trees, primarily those on the neighboring property, which they say are close enough to the high tension wires to conduct some electricity and send it through the roots of the tree. That would explain the shock as a recent development -- the root grew further onto our property. Plus, all the wet weather we had would make the trees especially saturated with water, making them more conductive. They tested voltage with a meter and when touching one tip to wet pavers and the other in the water, which is what we were experiencing, he got about 4 volts. However, when putting one tip between wet pavers and the other into the soil farther away from the pool and closer to our neighbor's property (and closer to the high tension wires) he got as much as 14 volts.

LIPA will send trimmers to cut back the trees. In the meantime, I am going out to Wal-Mart this afternoon to buy some sort of rubber mat to put on the ground in front of the steps. That way, no one will be touching the concrete and the water at the same time.

Does all this sound plausible to you guys? Oh, and how do volts translate to milliamps? (I'm pretty sure the readings he was giving me were in volts.)

The voltage read will be after being dropped by resistance and conductivity. Then the amount of current in amps/milliamps will be determined by the remaining voltage and your connection to ground.
Have him verify the voltage is gone when he is done.

Not an electrician but I think it is foolish to try to continue using the pool until all is fixed. I have never heard of trees carrying voltage but maybe TK, Strat or KISS can tell us what they know.

Entirely possible:

Electrical energy applied over a distance is electrical field strength. Using an example of 20000 volts/6' (~2 m) is about 10,000 V/m.

Those lines could be 400 kV. Pointy things attract high voltage too. Not sure what the distance between the tree and the line is.

Entirely possible:

Electrical energy applied over a distance is electrical field strength. Using an example of 20000 volts/6' (~2 m) is about 10,000 V/m.

Those lines could be 400 kV. Pointy things attract high voltage too. Not sure what the distance between the tree and the line is.

There are a number of trees in pretty proximity with the line along the length of my property, but directly in front of where the shocks are felt there is an arborvitae (pointy) that looks about 4-5 feet from the wire.

The tree cutters are coming first thing in the morning. They actually showed up this afternoon, but it started to rain before they could begin. I want to have the voltage tested again after they trim to see if it made any difference.

Also, I was reading the other thread about this, and saw something about making sure that ground rods are below the water table to help reduce ground rod resistance when the earth's surface itself is creating the problem. Would this apply to trees, too -- that the farther the roots are from the water table, the more resistance they have? Where I live, the water table is about 50 feet down. Could this be contributing to the problem? A very deep water table, wet weather, pointy tree 4-5 feet from high tension wire?

Could this be contributing to the problem? A very deep water table, wet weather, pointy tree 4-5 feet from high tension wire?

One at a time:

The water table or close to it is likely the reference for the high tension lines. It may not be the reference for your
House.

Wet weather will make the tree more conductive. Have a lower resistance.

pointy tree 4-5 feet from high tension wire That's way to close.

Ask the guys what the voltage is of the high tension line is?

Lots of resistance (from HT line through tree and sandy soil to water table makes a large voltage drop. If you tie the concrete (via an embedded metal grid) to the railing and also tie it to the water (skimmer plate, for instance), then the water, railing and cement are at the same potential.

Following the NEC guidelines for pool installations should make this a non-issue. I'll still be that the concrete isn't bonded. 4-5 feet is way to close to the tree, but knowing the voltage on the lines would help.

This is probably clear as mud: Bonding of Pool Water [Archive] - Mike Holt's Forum (http://forums.mikeholt.com/archive/index.php/t-82655.html)

Bonding of the pool water: bonding of pool water [Archive] - Mike Holt's Forum (http://forums.mikeholt.com/archive/index.php/t-97031.html)

The guys didn't seem to know off the top of their heads what the voltage of the line is. I think he said something like, "It could be 40,000 volts, it could be 400,000." I doubt the tree trimmers will know either, but I'll ask anyway. When the power company guy retests the voltage of my yard, I'll ask for a definite number.

Just trying to be sure of something -- we have concrete pavers (i.e. bricks) for the pool surround, not poured concrete. Does that matter? Would there still have been an equipotential grid beneath them? I assume the only way to know for sure is to rip up the pavers, right? Or is there some kind of instrumentation to determine the presence of such a grid?

I don't know, but I suspect not. A simple metal detector that utilities use would determine the presence of something metallic.


FWIW: There is sophisticated instumentation called ground penetrating radar that's used, for example to locate artifacts, graves, plumbing and leaks under a slab or anything that changes the density of the soil. See Ground-penetrating radar - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Ground_penetrating_radar)

Welcome to Virginia/Maryland Ground Penetrating Radar Systems (http://groundpenetratingradarvirginiamarylandgpr.com/?gclid=CNH6-qyYxpsCFWBB5godJmRDBA)

As I said in my first post, hire a qualified electrician to troubleshoot this issue.

If you have any questions about grounding have the electrician determine this.

Do not attempt to investigate what your grounding system is now, as there is much you do not know about grounding.

Do not attempt to begin to understand grounding, and what may need to be done to correct any deficiencies.

Also, as you are aware now, do not ask tree cutters about the utility electrical system.

Only deal with the Power company representative.

Be sure to put the power company on notice that you need this resolved, and must know exactly what caused this and what the solution is.

They may try to ignore you, or give you limited information.

Keep in mind, they know that they are liable for any damages or possible injury that may be caused by their negligence.

Okay -- some more info. The high tension wires are running at 69,000 volts.

I now have a cut on my finger from slicing bread yesterday, and I feel slight shocks on the cut all around the pool if I touch wet pavers with one hand and stick the cut finger into the pool. I do not feel anything if I put a non-cut body part into the water except by the pool steps. I also feel the shock on just my cut when I put one hand into the water and the other into the spa. This is what my husband experienced a couple of months ago when standing in the pool, and he said the sting stopped when he grasped the plastic edge of the spa with his other hand. This makes me wonder: Is it possible that the water of the pool is somehow receiving current from the nearby tension wires through the air?

Spoke to the pool company. The pool was installed several years before we bought the house, but the owner is pretty sure that there is no equipotential grid under the paver patio. He said their procedure is as follows: It's a steel pool with grounding wire run around it and an electrical inspection done on the whole system before the patio is put in.

Typically you'll find distribution voltages of 15 or 4 KV in a residential neighborhood. This is a BIG difference from 69 KV.

See Electricity distribution - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Electricity_distribution)

The setup that you have, I think would be more susceptable to shock because of the higher voltages. Somebody missed the detail here. I don't think it was intentional and I don't thnk there are any guidelines for installing pools near 69 KV type of voltages.

How close if your nearest neighbor? Specifically the nearest neighbor's water line. Is it in the path of the pool from your electrical service?

Why I said to get someone to check this. 69KV is a big deal, this is extremely strong lethal energy. If the trees were just touching, the tree will be vaporized or caught on fire. If contact was good the high voltage protection would kick in, or off as it were.

I was a half bock away from a 69KV line falling and hitting the ground, I saw the flash. The sound was deafening, and the ground was in bad shape.

This is killer stuff.

If contact was just right, and neither happened, then something would be steaming, or some indication other than the tingle.

Good question, can it go through air. There is an event called corona, this is where the sharp points come in, the air becomes ionized between a live surface and a pointed grounded object. This usually occurs at sharp points on insulators.

This is not typical of trees and HV lines. Believe me, there are plenty of trees in Maine that are extremely close to HV lines. Everyone has a generator here.

You mention a transformer blowing, is this ground mounted, or are there any underground lines. These are susceptible to all kinds of weird things, and go undetected.

Hate to sound like a broken record, but by hiring someone with good test equipment. BTW, we use ultrasound detectors to find corona, not your typical electrician will have this.

But a good service electrician will be able to check all local wiring including the grounding of the entire system. Be sure to ask for that specialty.

Bad system grounds at services have been known to leak or connect power from the grid into homes. Shutting off the Main was a good start, but does not end there.

Once a licensed electrician disqualifies your system from any fault, then he can push the utility to look into this further. If they are, or any reason for that matter, the cause, it will not get better or or go away on its own.

Could be any hand rail or metal piece of the pool was not grounded properly, or the connection has failed. An electrician should know that temp grounding a surface to a know ground will help determine this.

Pavers do not use reinforcing steel, as in poured concrete. The steel mesh is intentionally grounded. All metal within five feet of the pool is bonded to this grid.
The grid is then connected to equipment ground by a #8 wire, this is true for your system also, to a lug on the exterior of the pump motor. The equipment ground of the feed to the pump motor then gets grounded back at the breaker panel..

As you can see there is a great deal to check.

You can try chasing the utility, but I just don't think you will get far, unless they can see something fairly obvious. I do suspect any underground utilities nearby, and grounding problems.

The 69,000 volt wires are transmission lines running directly to the power station. They are live wires that cause the tops of trees near them to turn brown. A bit further away on the neighbor's property are distribution lines with the thicker, black-coated wires. Those are 14,000 volt lines.

How would I determine where the neighbor's water line is?

The tree cutting foreman suggested that I call LIPA again and have someone a step up from a regular service person come and diagnose to rule out (or confirm) "voltage tracking." P.S. -- after them trimming trees all day, there are still shocks in the pool. No trees are in contact with any of the transmission lines anywhere now.

Everyone I talk to seems mystified that we still feel the shock even when the main circuit breaker for our entire property (including pool pump and lights) is turned off. This leads me to think it HAS to do with the LIPA lines. What do you think?

Here is an interesting article concerning pavers and pools:

http://www.rctlma.org/building/content/docs/284_11_equipotential_bonding_grid_for_swimming_poo ls_and_decks_and_spas.pdf

Sorry, TK, I was just answering KISS when I saw your post.

The transformer that blew was mounted on a wood telephone pole. I don't think there are any underground lines here -- it's an older neighborhood (most houses built in the late '60s, before they buried telephone and electric lines around here).

I agree with your sense that I won't get much farther with the utility (LIPA). But I'll keep pushing. So, you're saying that the fact that I still felt it with the Main off does indicate some problem with the utility on some level?

No problem, I saw the time stamp.

To answer your last question, Not necessarily, I was referring to if there were underground lines, but there have been instances where house wiring had problems because of grounding problems in your home and/or outside, even on utility poles. Look at utility poles, and any wire you see running down to the ground from above that is broken or damaged is an obvious reason.

Other homes or utilities connection problems can be sending you stray voltages on your grounding system. Defects in your system exasperate this condition.

Utility systems, esp 69 KV levels, usually are well installed and maintained. Not to discount them, but utilities usually know the consequences of high voltage.

Home wiring and overhead utility systems are more prone to bad installations (homes), and wear and tear, both homes and utilities.

Here is an interesting article concerning pavers and pools:

http://www.rctlma.org/building/content/docs/284_11_equipotential_bonding_grid_for_swimming_poo ls_and_decks_and_spas.pdf


Nice white paper, bet there is no concrete under those pavers? That is what I imagined.

That's what I suspected too. What I didn't expect was a 69 kV power line and a very close tree and poor soil conditions. All nasty ingredients for disaster. It's all in the details. Most people look at you funny.

I didn't know what a paver was until today.

Tk:

Think about the possibility of merging this with the other older thread and possibly making a sticky when this thread fizzles out?

I was thinking of making the other a sticky on it's own just before this one arrived,


Think about the possibility of merging this with the other older thread and possibly making a sticky when this thread fizzles out?

Then this one popped up so I delayed waiting for this to come to a conclusion.

Great minds think alike.

Oh pee-eww.

I am not so sure it is the HV. The symptoms are too localized. High Voltage is not easily held captive, it goes where it wants when it wants.

In any event, I think the "safety net" (equipotential grid) is broken.

This discussion has been really interesting. Lots of twists and turns. Not sure where it's going to end up.

There is the return path through the plumbing, if a neighbor has a bad ground bond to consider.

How about surround the pool with a series of ground rods?

No problem, I saw the time stamp.

To answer your last question, Not necessarily, I was referring to if there were underground lines, but there have been instances where house wiring had problems because of grounding problems in your home and/or outside, even on utility poles. Look at utility poles, and any wire you see running down to the ground from above that is broken or damaged is an obvious reason.



Interesting. On one of the black lines at the front of the house running from a telephone pole, the trimmer showed me how the tree against it had given it a "chewed" appearance.

About the grounding problems in the home (the tree foreman suggested there might be loose grounding wires under the circuit board, and that turning off the main wouldn't necessarily stop current in that case. But even so, when the utility serviceman went around the house with his meter, saying everything seemed "beautifully balanced," would that be if there were loose grounding wires?

In the meantime, the tree foreman (who is being very helpful) told me he is contacting a fellow at the utility who has dealt with this issue before -- to the extent where his nickname is "the pool shock guy." Hopefully he'll contact me today. Also, I left a message for the electrician at the pool company who said he had a friend with a similar problem, and that the utility came and corrected it. My message asked him to find out exactly what they did.

What can happen, is that you can have the balanced connection, but a neighbor might not.

Let's say his ground is not connected to earth by via a ground rod. His system finds a path to your ground rod, via buried water pipes.

That current, if it runs through the pool will set up a gradient of voltage. Current measured through the water pipe with a clamp on meter is a dead giveaway.

Here's the latest -- another utility serviceman came by this evening and went around our property again with his meter. Even cutting off our service at the meter, still gets 4 volts when touching pool and wet pavers; when touching wet pavers and soil farther from the pool gets 10 volts, and so on. He also went to our neighbor's property and got no voltage there. He swears it's nothing to do with anything on our property, that it's the utility's problem. He theorizes that our pool has a "better ground" than the utility does (being more recently installed, perhaps?) and that the electricity is finding its way to us because of that. He says that they will get engineers out here to investigate further, as well as "replacing the service," which he says is really not the problem, but they will do anyway as part of a process-of-elimination tactic.

I'll keep you posted!

Oh -- and he says that all the rain we've had (it rained something like 25 out of 30 days in June here on Long Island, NY, plus another few inches so far in July) could have raised the water table (normally around 50 feet down) and be contributing to our recent discovery of the problem.

It all sounds odd, replacing the Service is really ODD. You should not have to pay any money for this, if they do.

May not be related, but I ran into someone getting shocked in their Bath tub, Turned out Tub was set on top of a phone wire, when it rang, they felt it?

Do you have any low voltage landscaping lights?

Oh, I'm certainly not paying for it!

But everything is starting to make sense to me. Our pool guy told us there's grounding wire from the handrails and running all around the pool. Realizing that the strongest shocks in the pavers seem to be directly in between the two handrails by the steps, I was suddenly able to envision the grounding wires running from each handrail like a V and then to the grounding wire that runs the perimeter of the pool. This would explain why I do feel very slight (only with my cut finger) shocks all around the pool, and finally gives me an explanation of why I would get a shock in my spa when I have one hand in there and the other in the pool! It's because the handrail to the spa also has a grounding wire connected to everything -- but the difference between the handrail of the spa and the handrails by the steps is that the spa handrail GOES INTO THE WATER! The step handrails go only into the patio! Being that the spa is a plastic circle, it contains the current from the handrail even though the water circulates throughout the whole system! Therefore, by touching the charged water in the spa and then touching the pool water without touching the plastic side of the spa completes the circuit and creates a shock! So I can totally see what the serviceman is saying when he says current from the poorer utility ground is seeking out our pool's grounding system.

Do you have any low voltage landscaping lights?

No, I do not. The only ones we had were solar, and are no longer in use.

Worth a shot

Oops -- made a mistake. The spa handrail does NOT go into the water.

Well! A new development. Another service crew was here today doing what everyone else has already done, such as shutting off our service and still getting voltage. They, however, found stronger voltage near our pool pump system. So, they decided to drive a copper grounding rod into the ground near there, by the fence, and ran an insulated grounding wire from there to the grounding wire on the pump motor. Their theory was that there was something wrong with our pool grounding system, and that the rod would dissipate it. However, while it did reduce the voltage at the pump motor ground wire (from about 15v to 9v), the voltage at the pool steps and patio was unchanged -- if anything, a little higher (4v to 4.5v). Their theory didn't hold water to me (albeit I'm a novice), since if the pool ground's purpose is to ground OUR electrical system, and it still happens with the main power off, that electricity is coming from somewhere else, and there shouldn't be any. Period.

While one guy was driving the copper rod, a fourth guy showed up. "I need one of you guys to come with me for a minute," he said in a somewhat mysterious way. "We need to go around the corner." So one of the guys went off with him. When he returned, it was just as we were discovering the grounding rod had had no real effect on the pool voltage, and he said, "We gotta go." It turns out this guy that showed up had discovered that the next transmission tower over had been hit by lightning, likely right around the time we started noticing the shock. There was a pretty heavy storm on July 3 that dropped nearly an inch of rain on my zip code. I was told then that a line service crew would be coming out there today and probably be working on it all day, and that these guys would be back tomorrow to test and see if that repair fixes our problem.

The key here, I think, is what the tree foreman told us -- "Don't let anyone try to tell you this is your fault. This has absolutely nothing to do with your property." Hopefully this lightning-struck tower is the answer.

Correction -- it's not the transmission wire, but the primary distribution (and I think he said also a neutral wire) that is down on the ground one block over. Do you guys think this is the explanation for our pool shocks?

We'll find out, I still think it may be a Neighbors house.
Don't know if you answered, but, Undrground services around your house?

Yes, I mentioned it here:



Home wiring and overhead utility systems are more prone to bad installations (homes), and wear and tear, both homes and utilities.

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? Never mind 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?

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?

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?

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

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.

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

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.

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.

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.

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.

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.

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.

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.

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?

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.

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

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.

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.



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 (http://www.epanorama.net/documents/wiring/voltage_effect.html)

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/electrical-lighting/reading-nfpa-70-etc-national-electric-code-online-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.

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?

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 (http://www.inspectionnews.net/home_inspection/electrical-systems-home-inspection-commercial-inspection/12365-bonding-pool-water.html)

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 (http://corrosion-doctors.org/Corrosion-Kinetics/Ohmic-drop-soil.htm)

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.

Yes for your first question.

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

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.