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Thread: fence post ground tabs

  1. #1
    Join Date
    May 2018
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    Rust Belt, USA
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    199

    fence post ground tabs

    has anyone used, found or ran across fence posts with ground tabs?

  2. #2
    Join Date
    Jul 2003
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    New Jersey
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    Not me. I was a fence installer years ago and I never saw one. Is this for a pool?
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

  3. #3
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    Quote Originally Posted by infinity View Post
    Not me. I was a fence installer years ago and I never saw one. Is this for a pool?

    substations

  4. #4
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    Jul 2013
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    Resting under the Major Oak UK
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    Not really much use as I’m on the wrong side of the pond.

    We would run earth bonds to the perimeter fence of substations. The fence would be of all bolted construction and so electrically continuous. All well and good until someone decided they had a better use for the copper tape and stole it from all our remote substations.
    The reports of my death are greatly exaggerated.

  5. #5
    Join Date
    Apr 2007
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    Huntington Beach, CA (19 Hrs. 22 Min. from Winged Horses)
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    Quote Originally Posted by Wire-Smith View Post
    substations
    figured as much. done a lot of them. cadweld 2/0 tails onto
    them, and T weld the tails to a 4/0 buried 18" down in the dirt.

    if anyone had such a thing, LADWP would'a figured it out by now.
    they spend a lot of time cadwelding poles.
    ~New signature under construction.~
    ~~~~Please excuse the mess.~~~~

  6. #6
    Join Date
    Jan 2016
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    Earth
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    Quote Originally Posted by Wire-Smith View Post
    substations
    yes, common
    required by the nesc and ieee stds
    the mat should extend 3' beyond the fence also

  7. #7
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    Aug 2004
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    Northern illinois
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    why would one need to "ground" a fence post that is already in the ground?
    Bob

  8. #8
    Join Date
    Apr 2006
    Location
    Springfield, MA, USA
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    You don't need to ground the fence post.

    You need to bond them with all of the other 'grounded' components, eg. equi-potential bonding grid, ground rings, etc.

    At a substation during a fault, step potential can be a serious issue, so lots of 'grounded' components are subject to pretty serious bonding connections.

    -Jon

  9. #9
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    Jan 2016
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    Quote Originally Posted by petersonra View Post
    why would one need to "ground" a fence post that is already in the ground?
    as noted step and touch potential
    assume a fault of 20 ka with station bed connected to xo
    station ground mat 2 Ohm
    fence 10 Ohm (not bonded)
    total thru fence to xo = fence + mat = 12
    station i 17.15 ka + 2.85 from fence = 20 ka
    fence i alone 2.85 ka

    v station ~ 2 x 20 = 40 kv
    v fence ~ 10 x 2.35 = 23.5 kv

    touch potential fence to station mat = 40 - 23.5 = 17.5 kv, 17.5 A thru avg person
    if you bond fence to station > 0

  10. #10
    Join Date
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    Quote Originally Posted by winnie View Post
    You don't need to ground the fence post.

    You need to bond them with all of the other 'grounded' components, eg. equi-potential bonding grid, ground rings, etc.

    At a substation during a fault, step potential can be a serious issue, so lots of 'grounded' components are subject to pretty serious bonding connections.

    -Jon
    That makes sense.
    Bob

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