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    stray voltage

    I am trying to solve stray voltage at a pool. You can remove the bond wire to the pool pump and the voltage never shows up. I have had as much as 3 volts from the pool water to the handrail leading out of the pool. I have checked all grounds. ANy ideas?

    #2
    Re: stray voltage

    IMO grounding is not your problem, bonding is your problem. You need a #8 Cu. from everything metallic to the rebar or equipotential plane that encircles the pool. That equipotential plane would then need to be bonded to the circuit conductor that feeds the pool. This is my understanding of pool bonding.
    Charlie Eldridge, Indianapolis, Utility Power Guy[COLOR=red][/COLOR]

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      #3
      Re: stray voltage

      Charlie, don't get mad, but if grounding and bonding conductors are not direct electrical connections (physically connected circuit conductors) as some experts want us to believe, how would bonding have an effect on equipotential ground immpedence levels or currents/voltages that may be circulating or present?

      I know, I'll shut up

      Roger
      Moderator

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      • #4
        Re: stray voltage

        Maybe both sides of the handrail are not bonded. In some handrail designs even though they appear connected the two sides can be electrically isolated (insulated). If the two sides are isolated then there needs to be two bonding connections-- one for each handrail. It's a long shot.

        As for the direct connection here is my interpretation. The handrail is connected to the grid. The diving board is connected to the grid. The wet-niche is connected to the grid. Etc. The handrail does not need a direct connection to the diving board. The handrail is bonded to the diving board through the grid. The language is confusing. Feel free to shred my interpretation.

        The bonding of these parts does not mean they are required to be connected to each other; rather, it means they are required to be connected to a common bonding grid with an insulated, covered, or bare solid copper conductor not smaller than 8 AWG.

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          #5
          Re: stray voltage

          Soon as the grounding grid is connected to the motor frame, the grid attains the voltage above ground according to the neutral ground potential.

          This voltage is usually low, but can be felt as a tingle when a person is wet with chlorinated water.

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            #6
            Re: stray voltage

            the grid attains the voltage above ground according to the neutral ground potential.
            Right, so Delton, is the panel that supplies the pool pump a sub-panel?. If so, check to see if the panel enclosure is bonded (illegally) to the neutral wire.

            If the load on that panel is unbalanced, the feeder neutral could be carrying considerable current.
            The more current it is carrying, the higher it's voltage drop will be, and the more voltage difference there will be between the load (panel) end of it, and the earth.

            If an illegal neutral/ground bond exists, that voltage would be applied to the pool grid, as Bennie stated, whenever the pool pump bond wire is connected.

            Ed

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              #7
              Re: stray voltage

              If the pool grid is installed properly and ALL metallic parts are connected to the grid, and metallic parts (like the ladder) extend into the water, there will be no tingle even though the grid was not connected to anything else. Consider the pool as a HV wire and you are the bird. If you step on the wire and are insulated from everything else, it does not matter if the voltage is in the 8.66 kV class. The same applies to the pool and the bond to the circuit grounding conductor brings the wire down to earth potential. :cool:
              Charlie Eldridge, Indianapolis, Utility Power Guy[COLOR=red][/COLOR]

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                #8
                Re: stray voltage

                If everything appears to be bonded property, try the following.

                OH YEAH, Check all bonding where possible.

                Check the sub panel for the pool for proper installation as noted.

                Also check for net currents on the pool sub panel feeder and all branch circuits (with loads on). Utilize an amp clamp and read all phases and neutral of the feeder, for the branch circuits read all the circuit conductors (not the EGC) reading should be zero if not investigate.

                Check for ground currents.

                Isolate the motor and branch circuit wiring for the pool megger all conductors phase to phase, phase to neutral, neutral to ground,(check the pool pump separately), investigate any low resistance readings.
                Brian John
                Leesburg, VA

                Comment


                  #9
                  Re: stray voltage

                  This could be coming from outside the premises. a loss neutral at another house or a loss MGN at the pole transformer. try shutting the main to the sub-panel off if it doesn't go away then try the main if it is still there then it has to be coming in from the outside try to lift the water pipe bond with the main to the house off if it goes away then its a lost neutral at another house if it is still there then it has to be the MGN at the pole. just don't lift the EC as if the primary MGN is lost at the pole transformer you could get high voltage into the house grounding. call the POCO immediately. P.S. When you lift the water pipe bond the voltage on the service grounding might go up so be very careful as these voltages can be high. use a remote ground rod driven in earth about 20' out from the service to get your voltage readings from.
                  Wayne A. From: N.W.Indiana
                  Be Fair, Be Safe
                  Just don't be fairly safe

                  Comment


                    #10
                    Re: stray voltage

                    I believe that the #8 AWG copper bonding wire must also be bonded to the pumps with unbroken conductor. The grounding conductor does not carry current-it only establishes an equipotential plane. Bonding all metal components, including handrails, to the #8 conductor prevents potential gradients.

                    My idea for what it is worth.

                    Chuck

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                      #11
                      Re: stray voltage

                      Just an update, I was finally able to prove the bonding was not attached to all points of the pool. Thanks for all your help

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                        #12
                        Re: stray voltage

                        Thank You for the Update........
                        Brian John
                        Leesburg, VA

                        Comment


                          #13
                          Re: stray voltage

                          Take a blank piece of paper. Draw a pool in the center of the paper, then draw the parts, such as a ladder, diving board, fence, etc... Now draw a line between all of the parts (the line represents the bond wire), this will connect all of the parts and make them of equal potential.

                          Stray voltage can come from a neighbor's property, the utility, maybe a lightning storm miles away. As the stray voltage passes through your pool area, it may raise the voltage level of the area. As long as the equipotential plane is properly installed, the raised potential will not affect people in the pool area, as like the bird on a line there will be no potential difference in the pool area that can cause problems.

                          Pierre

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