Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: Electrical Shock In Swimming Pool

  1. Back To Top    #1

    Electrical Shock In Swimming Pool

    We have an inground vinyl liner swimming pool with a salt generator on it.
    Last August 2007, we added the generator, right after we added it, we started to notice a slight sting once in awhile.
    I checked the water with a volt meter, and found out we were showing 1.5 volts in the water.
    We just started noticing the voltage again a couple of days ago.
    Here is what we know.
    1. Pool is properly bonded and grounded.
    2. Pool has a small leak, which we cannot find.
    3. We have shut off power supply individually from the breaker box, and that makes no difference.
    4. Only time we noticed voltage went away, is when we had a power outage.
    5. Power company came out, and suspects it could be stray voltage.
    6. Tested water for high concentration of metals, to see if that was a problem, but that came back negative.
    7. Stray voltage, is more noticeable when ground is very dry, as the electricity is searching for a ground.

    Curious if the salt is making the water more conductive, if so maybe the problem was always there, but the salt brought it to light. Concerned it is a safety issue.

    Any suggestions?

  2. Back To Top    #2
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,089
    If the pool were properly bonded, you wouldn't be able to feel the stray voltage. When you added the SWCG, did you add a connection to the bond wire for it? When do you feel the shock? The most common time is when touching the water and the concrete deck around the pool, and the reason is failure to bond the rebar in the deck.

    It is extremely common for pool bonding to be done incorrectly. Very few electricians really understand it.

    Shutting off the power at the breaker only disconnects the hot, not the neutral and ground, both of which can cause what you are experiencing.

    If in fact your pool is grounded as you say, that could be the cause of the shock.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  3. Back To Top    #3
    welcome to TFP!

    8200 gallon 20' x 48" round vinyl frame pool, manually chlorinated with 10% liquid, salt added to ~2000, 12" sand filter, 1600gph pump, TF100 test kit
    Handy Links: PoolMath, TF-100 Test Kit, Pool School, Chlorine/CYA Chart
    "Shock" is a process, not a product!

  4. Back To Top    #4
    CRG_80cc's Avatar
    Join Date
    Jul 2007
    Location
    Nor-Cal
    Posts
    81
    Maybe the small leak could be finding it's way to a stray voltage source. Since you have a salt generator, the salt ions are helping conduct the voltage back to your pool.
    30K gal. IG Free form
    Cartridge Filter, Solar and Gas Heater
    Using BBB

  5. Back To Top    #5

    Join Date
    Jun 2007
    Location
    SF Bay Area
    Posts
    441
    MJ1,

    I don't have much to add except to say that JohnT is spot on with his comments.

    3. We have shut off power supply individually from the breaker box, and that makes no difference.
    In order to determine whether the stray voltage is coming from you or others (neighbors or utility), you would have to remove the meter base. This should disconnect both the hot and neutral from the utility. I don't think this would disconnect the utility ground, though.

    5. Power company came out, and suspects it could be stray voltage.
    Wow, you have half the battle already won if the utiliity is already saying this. My experience is that a utility will hem and haw and stonewall and deny that stray voltage is the problem. Typically the utility will try and blame the homeowner and a improperly bonded pool. Alhough JohnT is correct - a properly bonded pool will mask the effects of stray voltage, which is exactly what its purpose is.

    Can you go into more detail of 1) what the utility did, 2) what the utility said, and 3) what the utiltiy is proposing to do to correct the problem?

    Also, when and under what specific conditions are you feeling the shock?

    If in fact your pool is grounded as you say, that could be the cause of the shock.
    JohnT, I'm confused by this statement. Can you elaborate on what you mean?

    Last August 2007, we added the generator, right after we added it, we started to notice a slight sting once in awhile.
    Can you go into more detail about this since this seems to correlate with the onset of shocking? Who installed the SWG? Was an electrician involved?

    Titanium
    24,000 gallon inground freeform pool/spa circa 1983 (113 ft perimeter, 625 sq ft) with 350 gallon attached spill-over spa
    2007 2 HP, three-phase Hayward TriStar pump which is powered by an Ikeric VS-200 variable speed drive system
    1983 Laars XE Pool/Spa Heater Type ES 400,000 BTU, 1998 Hayward Super Star-Clear C-4000 cartridge filter (400 sq ft, 4 separate cartridges)
    1998 Polaris 380 pressure-side cleaner w/ 3/4 HP booster pump
    One skimmer :( and one PoolSkim :), One Supervision Galaxy LED pool lamp, Second story solar panels
    Hayward/GoldLine AquaLogic PS4 (replaced 1983 vintage dual circuit Intermatic timer)

  6. Back To Top    #6
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,089
    Quote Originally Posted by Titanium
    If in fact your pool is grounded as you say, that could be the cause of the shock.
    JohnT, I'm confused by this statement. Can you elaborate on what you mean?

    Titanium
    If the pool bond wire is tied to a grounding electrode, which is required by code in Canada but not the US, this point COULD BE at a much different voltage than the pool structure or the service entrance grounding electrode. This COULD cause a current to flow resulting in a voltage gradiant. Even connecting the bond wire to the service entrance grounding electrode could still induce a flow for equipment that might have a neutral connection.

    The grounding could be the cause of the voltage or it could be the means that the stray voltage is being introduced into the pool.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  7. Back To Top    #7

    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    12,082

    Re: Electrical Shock In Swimming Pool

    Quote Originally Posted by MJ1
    Curious if the salt is making the water more conductive, if so maybe the problem was always there, but the salt brought it to light.
    In addition to what others have said, what you say above is also true. Conductivity is roughly proportional to TDS so you probably increased conductivity from 2-6 times (depending on your initial TDS) when you added the salt. So any stray voltage that was there before would result in 2-6 times as much current at the higher salt level (all else equal).

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •