Grounding Whirlpool Tub Motor and Heater - Bonding Panel to Electric Water Heater

Discussion in 'Electrical Forum discussion & Blog' started by chuck b, Feb 5, 2012.

  1. chuck b

    chuck b sea-bee

    Messages:
    75
    Location:
    levering, michigan
    Hello! Installing the above. Water comes from a well which supplies our small seasonal cottage through a pvc pipe into the cottage which transitions to copper by the expansion tank. I then progress to a sediment filter, water softener and then an electric water heater. The water heater is bonded to the electric panel, which is grounded to two stakes in the ground (not cement rebar). The water heater also has a jumper between the hot and cold pipes.
    Question: I noted that the water heater has a bonding clamp attached to the cold water side copper pipe. Is that the correct side for that. Then it travels to the electrical panel for bonding/grounding.
    Question: When I ground the whirlpool water heater and motor, can I just bond them both ( 2 separate clamps & 2 separate 20-amp circuits GFCI protected) to 2 clamps on the cold water side of the bathtub plumbing (cold is best right), or do I need to go all the way with both copper wires to the grounding rods? Guessing that the cold water lines are grounded via the bonding at the water heater which travels to the panel and subsequently to the grounding rods. Also, do I use the same gauge copper wire as the circuits they ground, i.e. 12 gauge for 20-amp circuit for grounding to pipes or do I use heavier gauge say a #10 copper wire? Thanks.
    Last edited: Feb 5, 2012
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

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    Location:
    North Carolina
    For the tub you are not grounding but you are bonding. This bond will be required to be a #8 and hit anything metal in the area of the tub and nothing is required to go to the rods
  3. chuck b

    chuck b sea-bee

    Messages:
    75
    Location:
    levering, michigan
    Thanks. Even though the copper pipes transition to pvc and not to a cement in floor pipe ground like homes with a city water supply? Guessing that the metal bathroom bond does continue with an effective "bond" since there is a jumper cold to hot at the water heater, and then to the electrical panel. Am I making sense?
  4. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
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    Location:
    North Carolina
    NO
    What you are doing at the tub is making the water in the tub and the metal objects around the tub at the same potential.

    Grounding has nothing to do with it.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
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    Location:
    Cave Creek, Arizona
    quote; [​IMG]

    NO
    What you are doing at the tub is making the water in the tub and the metal objects around the tub at the same potential.


    That is a matter of semantics. You can "bond" the metal all you want, but if it does not have a path back to "ground" it will not protect in case of a malfunction of the electrical system, and it could become "energized" without tripping the circuit breaker.​
  6. BobL43

    BobL43 DIY Senior Member

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    popcorn time again
  7. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    HJ
    The purpose of bonding all metal around things such as whirlpool tubs, hot tubs, swimming pools, fountains, and other bodies of water is not to open the overcurrent device.

    The purpose is to form an equipontentail plane where the water contained inside the unit and any metal or concrete surrounding the equipment is at the same potential.

    This is like the Faraday cage in this link.
    http://www.youtube.com/watch?v=Dd40ASbGte0

    Notice that the man the air craft and the power line are at the same potential and there was nothing connected back to the source in order to open the overcurrent device.

    The equipment grounding conductor installed with the circuit supplying the pump motor is what will open the overcurrent device not the bonding of all metal and the water.
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