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Thread: Grounding water heaters.

  1. #1
    Join Date
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    Grounding water heaters.

    Got a call water faucets are shocking the tenant. Water heater is gas. Any advice before I go? I was told that a ground bridge at the water meter may be necessary.

  2. #2
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    Just keep in mind that there is a (small) possibility that it is the drain piping that is at an elevated potential, not the supply piping.

    Whether or not the cold water supply is used as a ground electrode any interior piping that is "likely to become energized" needs to be bonded to the EGC.
    That includes the water heater and its piping.

    If the hot and cold water do not come into a common faucet/spout body, the problem could be only the hot water piping. There is often a dielectric union (insulator) on the cold water feed at the heater.

  3. #3
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    Makes total sense. Thank you my friend!

  4. #4
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    Ask if there has been any recent construction, renovation, or repairs; you may find the problem faster that way. Find out what else they are touching when the shock occurs.

    A lost service neutral (either there or a neighbor's house) can cause current to flow on the water pipes. There is a graphic/picture that shows how this can happen tho I cannot find it at the moment.
    Electricians do it until it Hertz!

  5. #5
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    If this is happening in a bathtub with metal drain piping - the drain piping likely is not bonded, is at true earth potential and the water pipe is at whatever level of voltage drop is on the grounded service conductor, or even the voltage drop on the POCO MGN conductor. Bond the drain pipe and all are at the same potential and no more shocking.

  6. #6
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    Ground bridge at the water meter is very necessary so be careful.

  7. #7
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    Quote Originally Posted by alicecolin View Post
    Ground bridge at the water meter is very necessary so be careful.
    Mostly to protect water utility tech if they are removing the meter, otherwise while metallic body meter is installed doesn't really have a useful purpose.

  8. #8
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    GASCO might also use a dielectric coupling on one side of the meter, and in that case would object to your jumper.

    Sent from my XT1585 using Tapatalk

  9. #9
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    Remember that simply installing a bonding jumber can mask a problem that should be corrected.

    My BIL was being shocked in his tub with the difference being between faucets and drain. Bonding the two stopped the shock but did not cure the problem of a high resistance fault to the water line.
    Tom
    TBLO

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