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-   -   Mild electrical shock in swimming pool (https://www.askmehelpdesk.com/showthread.php?t=118962)

  • Aug 12, 2007, 04:54 PM
    CBerryhill
    Mild electrical shock in swimming pool
    :eek: Our swimming pool pump is grounded to the ladder in the pool and also to a copper grounding rod in the ground. The problem is when you touch the wet concrete around the pool while touching the water in the pool you get a mild shock. We've checked it with a voltage meter{the blk. Electrode on the wet concrete and the red electrode in the pool water} we get a reading of .47 on one end of the pool and .14 on the other end. Someone told me it was just static electricity but it really scares me. I'm afraid to let the kids swim until we figure out what is wrong. If you have any suggestions they would be greatly appreciated. I'm very worried somebody could be electrocuted. PLEASE HELP! Oh, by the way when I turn off the breaker feeding the pool, it still shocks us and there is no juice supposed to be there at all with the breaker tripped. I'm so confused about this.
  • Aug 12, 2007, 05:17 PM
    tkrussell
    The voltages you measured are to low to offer any shock. But since you feel something, and just in case your not reading the meter properly , this may be best checked by a pro. There are so many possibilities for a reason.
  • Aug 13, 2007, 06:16 AM
    Stratmando
    Something may be shorting or leaking to ground. Turn off breakers one by one, until voltage
    Not present. Any landscape lighting running under pool deck? An amprobe to check current on ground wires in panel may help locate. Grounds should not have current.
  • Aug 20, 2007, 11:49 AM
    dkmason
    We have also been having the same problem with mild shocks in our pool. At first, I thought it was a chemical reaction with the pool chemicals and cuts and abrasions on our feet. However, it doesn't happen all the time and everything on my pool is grounded. We are not touching pool ladders when we get out of the pool. And, it has happened when I put my hand into the water to clean the filter. Our pool guy is stumped. Do you have a fiberglass pool? We have a fiberglass pool and just installed a salt system in May 2007. We are wondering whether there may be a correlation to using a large amount of Les-Iron to treat the metals in our pool. Would love to know if you have resolved this problem? My kids are afraid to get in and out of our pool.
  • Aug 20, 2007, 05:29 PM
    Stratmando
    If everything grounded and at ground potential is good protection, If you can hook up meter and determine what is making things live, When you turn off breaker to Pump you no longer get shocked(read voltage)? Physically you should be able to see ground continuity, ground rod, all need to be intact. Motor usually first culprit, when lights go on?
  • Aug 26, 2007, 06:34 AM
    dkmason
    I had an electrician and 2 pool people here to investigate. Everything is grounded, no voltage registering on meter with pool on and off (equpiment off and unplugged). We are still getting shocked (feels like a bee sting) when pool equipment off and we step out (one foot on wet concrete deck and one foot in pool). It happens when the pool is active with swimmers. Could it be static electricity conducted through salt water? It doesn't happen all the time nor to everyone in pool!!
  • Aug 26, 2007, 06:47 AM
    tkrussell
    Did they use a standard volt meter? Probably should use a millivolt meter to capture the apparent low level of voltage.

    I doubt this is static.

    There have been case of underground wiring beneath the pool causing something similar to this.

    Could be fault currents flowing in the concrete.
  • Aug 26, 2007, 07:02 AM
    Stratmando
    Were you able to turn off ALL breakers? Turn off all, and Main. Then turn on one by one.
    Had a call one time, someone getting shocked in bathtub, it was pinched phone wire.
    Do you have a solar panel? Need to remove any and all potential voltages, breakers, and phone, then apply one by one until it appears.
  • Aug 26, 2007, 12:13 PM
    KISS
    These problems are really tough. Your run of the mill electrician may have a difficult time finding it. It also may require special tools, like insulation testers, ground impedance meters and ground current meters. These may not be in everybodies tool box. An industrial electrician has a better chance of having them.

    The pool is fed by a GFCI breaker isn't it?
  • Aug 26, 2007, 02:44 PM
    biggsie
    Having worked with electricity in a wet environment and think I can explain the

    Problem... You are standing on wet concrete and are grounded, the pool is at a

    Different potential ( I think there is a posible 110 volt potential in the pool which

    Comes from pump ) which explains why you get shocked...

    The way I see it the wires coming from the breaker need to be checked for

    Voltage with the breaker off, there should be no voltage at the pump, hope it

    Is wired properly, it should be fed from a gfi breaker... It is possible that the

    Pump motor is the problem, an internal short to the motor case would make

    The motor case hot (voltage) and the pump transfers it to the pool... A meggar

    Will check for short in the motor wiring to the case... dissconnecting wiring at

    Pump motor should stop the shock at pool... check and see
  • Aug 27, 2007, 01:23 PM
    dkmason
    Thank you all for your assistance. So far, we have been able to troubleshoot one area of concern. The pool does not have a girlfriend breaker! Also wondering if problem may be with ladder and handrail (by steps). Both are grounded and bonded with underground wiring under the concrete deck. The pool is a 6 year old, fiberglass pool (no solar panel) . My husband and I both got this little sting when we put our hands into the filter and had the other hand on wet concrete deck. We felt the quick sting (like a bee sting) on hand that had an abrasion or cut but not on other hand. My kids have also had cuts/abrasions on feet when they felt it. The sting is enough for the person to quickly draw your hand back. (it is significant) So, is this electrical or chemical? As stated before, it doesn't happen all the time and not to all those in the pool. (also realizing that others have higher pain tolerance). And, we converted to a salt system in May.
  • Aug 27, 2007, 02:50 PM
    biggsie
    I have a test for you to do, you can do it with a meter or test indicator

    Fasten your tester on the ladder or railing and clamp one lead to it

    The other lead goes to a wire and in the pool, now to find the problem

    You should have some indication of power at the pool

    Now you have to turn off breakers one at a time

    Until the faulty circuit reveals the source

    This is probably a 2 person job one to turn off breakers

    And 1 at the pool to let you know when you have the right one
  • Aug 27, 2007, 02:59 PM
    tkrussell
    No GFI, do not use the pool with any motors or lights running until a GFI is installed.

    I believe that either the motor has a ground fault, or something in the home and that does, and that I think the grounding grid in the concrete may not be grounded to the motor, and this is causing you to complete the circuit.

    Is there a bare ground wire attached to the outside of the motor on a visible lug? If it is there, perhaps there is a break disconnecting the motor ground lug from the ground grid.

    All metal, ladders dive boards, railings, in concrete, needs to be connected together with a #8 solid copper wire back to the motor ground lug.


    Using a good digital volt meter should show fault voltage between the motor and the ground grid. This apparently not continuous, so it may the something like the frig or some other appliance that is sending out this voltage.

    This is a very possible theory, worth checking.
  • Aug 31, 2007, 03:14 PM
    dkmason
    Hi All, again I want to thank you for your input regarding the mild shocks in my pool. I think we solved the problem. We had PECO's (electric company) Quality Control Specialist out to investigate and there is a leakage from one of their wires in the street and it is finding its way to our pool. He registered 1.2 volts in the pool. They are coming out next week with an engineer to find faulty wire and may install a new transformer for our home. Hopefully this will be the solution! Thanks for your great advice!! P.s. Just a quick question. OUr pool equipment is hooked into a GFi outlet, do I still need a GFi Breaker?
  • Aug 31, 2007, 04:27 PM
    KISS
    No. Breaker or outlet, but a breaker catches ground faults from the breaker to the pool equipment. The GFCI receptacle catches a fault from the GFCI to the pool equpment. A GFCI breaker COULD be safer.
  • Aug 31, 2007, 04:36 PM
    tkrussell
    OK a GFI outlet is fine, I took once you stated "no GFI breaker' as no GFI protection at all. Sorry for the confusion.
  • Dec 8, 2007, 08:19 PM
    AndresMolina
    We had a similar case in a tub, nothing electrical was close to it light switch was more than 3 feet away and all cables inside piping, inside poored concrete.. Guatemala.. other building methods... but there was no apparent way for the bee stings one getting in and out of the tub... finally we found a wire in the light fixture touching the encasing box, still not surtain how electricity travelled through the concrete having lots of other ground sources in the way like rebar in the columns but, once the wire was fixed the problem ended so check your conections ends a little electrical tape might solve the problem
  • Dec 9, 2007, 07:56 AM
    Cobraguy
    biggsie, I believe the only time the pump needs to be protected by GFCI is if it uses a plug. If it's hard wired, it does not require GFCI. I know all the pumps here in Phoenix (240V) for IN GROUND pools are not GFCI protected because they are hard wired.

    There are so many different ways your pool could be wired we can't begin to tell you where to look. Does your pool use a control panel that serves as a sub? Is it directly wired from the main panel with separate circuits? Is the pool light on a separate circuit and GFCI protected? Is ALL the metal equipment around the pool (panels, pumps, ladders, etc.) bonded together? NOT grounded... but BONDED. There is a big difference. Swimming pools require both. I have to tell you... I'm pretty darn familiar with swimming pool wiring and it scares me to death due to the dangers of making a mistake. You need to call a pool dealer in your area and have them send out the electrician they use for installing their pools. He should know what's going on. Until then, I wouldn't even think of getting near that pool. Maybe I'm being way too paranoid here, but you're playing with lives here.
  • Dec 9, 2007, 08:03 AM
    tkrussell
    Cobra, correct, 240 volt pump motors do not need GFI protection, but a hard wired 120 motor does. The condition is 120 volts, not if hardwired.
  • May 22, 2008, 04:20 PM
    JEHaynes4
    Has there been a solution to any of the mild shocks listed above that anyone can share? I too am experiencing a difference of potential between the pool water and wet concrete even with the main circuit breaker to the house turned off. I had the local utility out to investigate with no solution thus far. One of the latest visits did show something interesting. The utility turned off the main circuit breaker, still voltage. They removed my electric meter from the meter base, still voltage. I asked them to disconnect the system neutral from my meter base and the voltage in the pool went away! Of course the neutral had to be replaced so I can have electric, but the voltage returned. Does anyone have any ideas? I'm stumped.
  • May 22, 2008, 04:25 PM
    stanfortyman
    Here is some very good reading on this, with some good links as well.

    Stray Voltage in North Carolina Part 2 of 3
  • May 22, 2008, 04:29 PM
    stanfortyman
    And more...

    The Utility is not Always at Fault
  • Jun 8, 2008, 06:11 AM
    NCPat
    Good morning... I did a search and found this thread. We noticed yesterday (although I think it may have been happening for a few weeks) some electrical voltage in our pool. It is not in all places. It is most noticeable on the metal handrail at the steps leading out of the pool. It is also noticeable completely on the other side of the pool on the "rim" of the pool. This is noticeable whether you touch it while in the pool or out of the pool. (Our pool is a vinyl liner pool... 40,000 gallons). It is also noticeable when reaching your hand/arm into the skimmer to remove leaves, etc... feels like your hand is "going to sleep." It is NOT noticeable on the metal legs of the diving board or on the metal ladder in the deep end of the pool. I thought I was CRAZY over the past few weeks but it became more noticeable yetesday when we had several people in the pool. The pool is 15 years old and we have never had this issue before. However, last summer we did install a new pump and filter. (Pentair Intellifo and Titon II filter). It is a chlorine pool... not saltwater.

    We have turned off ALL breakers to the pool... no power to the pump or pool light whatsoever and it STILL does the same thing.

    We live in Wilmington, NC. Could you tell me, please, the best way to go about tracing this and getting it fixed? I'm afraid to let others swim in the pool because of potential liability. So I call the pool equipment store? An electrical? Who?

    Thanks so much for your help!
    Pat
  • Jun 8, 2008, 09:28 PM
    KISS
    If the stray voltage is there, then presumably you can measure it.

    This flow chart should be followed from one of the links.

    http://www.mikeholt.com/documents/st...ForUtility.pdf

    If you can turn off the main breaker and the shock still happens, get the utility involved. If you can measure it, that may hel get someone out.

    It would be nice if you could say, "I have a stray voltage problem with my pool, I have turned off the main breaker to the house and I measure 5 volts AC between a wet me in the pool and the metal part of the strainer and various other places.
  • Jun 9, 2008, 03:02 AM
    NCPat
    Thanks very much. I do have a voltage meter... just don't know how to use it for A/C power. I used to use it for 12v on a large sailboat. But I will download the directions and figure it out. Our pool is 220, not 110, by the way. I assume that doesn't make a difference?

    Thanks again.
    Pat
  • Jun 9, 2008, 03:24 AM
    stanfortyman
    You mean you pump is 240v, maybe some other equipment. The POOL cannot be 240v.

    Even if you turn your main off and still get voltage, it may not be the POCO. See the link above.

    You will NOT feel 5v. You may measure 5v from the water to a metal object, but measuring the water itself like that is almost useless. The water is not the good of a conductor.
    If you get 5v from the water to an object chances are there is more there than that.
  • Jun 9, 2008, 04:13 AM
    NCPat
    Yes... sorry... the pool pump is 240V as is the Hot Tub pump next to it (completely separate) But they are connected to the same breaker box (separate breakers) outside on the side of the house... plus there are additional breakers in the main breaker box in the house. When ALL are off, we still get the voltage feeling in certain areas in the pool... and not necessarily just around metal (although our pool is vinyl liner so I assume it is surrounded by a metal mesh).

    I will read the link in the previous answer and see if I understand. I am not the least bit knowledgeable about this type of thing... only minor experience with 12v systems on a liveaboard sailboat.

    Thanks for your response.
    Pat
  • Jun 10, 2008, 07:53 AM
    MJ1
    We have the same problem since we put on a salt system. Problem may have always been there, and the salt water (more conductive), made it more noticeable.
    I have shut off all our breakers, and we still notice 1.5 Volts. I can only conclude we are getting stray voltage from the power company line. We have a small leak in the pool (can't find), so I am concluding that in this extremely dry weather, the electricity is looking for a ground, and possibly it is seeking out our leak. I am assuming the short in the motor issue, could not hold true, if we still get voltage, even if the breakers are all shut down. Frustrated, we are waiting for an engineer from the power company to come out to shut power off at the transformer. Any suggestions out there? Pool has been checked, and bonding is OK.
  • Jun 10, 2008, 12:49 PM
    stanfortyman
    1.5volts you would NEVER feel. It is obviously more, but there is no accurate way to test it.
    Sticking the probe in the water and into the earth (or touching concrete is NOT an equivalent test to a touch test.
  • Jun 11, 2008, 04:14 AM
    MJ1
    Is there a way to accurately test for it? The power company came out yesterday, and saw our reading, and felt it. They did not read anything when they probed the water, and touched the ladder bolt that is grounded.
  • Jun 11, 2008, 05:06 AM
    MJ1
    One other thing the power company did shut off power from the transformer to our house, and the neighbors, and there was still voltage. Today they plan on coming back to check the neutral? They would have done it yesterday , but they needed 2 guys to do it.
  • Jun 11, 2008, 06:09 AM
    Stratmando
    Do you have any Solar Panels?
    I ran into a problem with customer getting shocked in bath tub, turned out to be Phone Line pinched behind tub? Maybe disconnect Cable, and phone in addition to Electric to see if problem persist.
  • Jun 11, 2008, 10:00 AM
    MJ1
    No solar panels. Just spoke with phone company, and they are coming out this afternoon to verify their line is not the problem. Power company said "stray voltage" could be coming from anywhere.
  • Jun 11, 2008, 10:40 AM
    Mikeysal
    NCpat, I also live in Wilmington, NC and just bought a house that has the same problem as you. I was just wondering if you were able to solve the problem.
  • Jun 12, 2008, 06:13 PM
    jenniferousley
    I live in Eastern Kentucky. We recently installed an inground pool and are experiencing the same problem. Pool installation company, certified electricians, and an engineer from the power company have all been involved in solving this problem, but still no solutions yet. The current is noticeable to touch and reads between 2 and 3 volts on the meter. It seems to get worse after we have been in the pool and is worse in certain areas of the pool. The engineer believes the problem is the build up of static electricity due to the vinyl liner. The current can only be felt when standing on wet concrete and reaching into the pool. What do I do?
  • Jun 12, 2008, 07:04 PM
    stanfortyman
    Seems lot of folks have the same problem. I suggest you read this whole thread and see the links posted.

    Jennifer, if you recently had this pool installed there is no reason you should feel anything. The bonding should have been done to the latest standards.
  • Jun 12, 2008, 07:08 PM
    MJ1
    Do you have a salt pool? We only started noticing it after we put the salt system on our pool. Prior to that we just used chlorine. Water by itself is not a great conductor, but salt water is a better conductor. We are thinking it could be stray voltage, but we can't find out from where. We've had our power shut off from the pole, and had the phone line shut off, but there is still a small voltage reading. Power company says you will notice stray voltage more, when conditions are very dry, as the electricity is looking for a ground. I did hear of one owner who had stray voltage in the neutral wire, had to get a code variance from the county to remove the grounding from the neutral wire from their house to the sub panel at the pool. We are still trying to figure out what is going on.
  • Jun 12, 2008, 09:43 PM
    KISS
    Where is the utilities transformer, relative to your main fuse box, relative to the swimming pool. Take the closest straight line distance.

    e.g. transformer to main is 100'
    Pool located at about 50' along that 100' and 20' perpendicular to that line.

    Describe your soil. Clay, rock, dry, wet, sand etc.
  • Jun 13, 2008, 04:04 AM
    MJ1
    Transformer is about 100' away from fuse box.
    Edge of pool is 20' from power line for about 25' of the 100'.
    Clay
  • Jun 13, 2008, 08:50 AM
    KISS
    If you take a look at this link:

    Household Electric Circuits

    What's probably happening because of the distance, there is a gradient of voltage because of the ground resistance over such a large distance. I'll bet that the magnitude of the potential increases with the neutral current.

    Normally 240 volt loads put no net neutral current. The neutral carries the difference in the 120 V loads on the two hot legs. This usually translates to the loads on every other breaker space.

    Note that there is a code variation discussed that may, in fact, fix your problem. What would be required is the separation of the ground and neutral busses at the breaker box.

    This would truly give one ground point.

    Moving the utility transformer closer to the service might also help.

    So could removing the neutral bond at the transformer.

    The CATV utility could be the utility most affected by removing the ground bond at the main panel.

    If these were done, I would make surge supression a SEPARATE electrode. Surge supression would then be provided for telephone and the main panel.

    Again, cable TV creates a glitch because of the grounded shield. Something like Jensen Transformers VRD 1FF 1 Ch Digital CATV Isolator | Full Compass might have to be used on the CATV signal.

    The problem is basically that there are multiple grounds and CATV is a single-ended utility.

    Going through this analysis, it seems like there are two options:
    1) Remove ground to neutral bond at the transformer
    2) Move transformer closer to the main panel.

    IF the ground-neutral bond is removed, then whole house surge supression should be provided through a separate ground rod.

    My $0.02

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