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Thread: Listed compression connectors for Cu wire to steel rebar acting as CCE

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    Listed compression connectors for Cu wire to steel rebar acting as CCE

    Hi, can someone provide a product make/model/number for a listen compression connector that would prevent galvanic corrosion when taking credit for 20'+ of steel rebar per 250.52(A)(3)(1) as a CCE? The idea is to prevent having a separate 20' of Cu conductor run if we can just go down far enough with Cu to connect to the highest layer of rebar, then bring that up through a PVC sleeve and compression clamp to the structural steel (we don't allow exothermic welding due to byproducts). I believe such a product exists but don't have the construction experience to find it.

    Thanks.

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    So you're looking for a compression connector to go from the copper GEC to the rebar?
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

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    Correct. I think I may have answered my own question, "KPL-1-DB - Bronze Ground Clamp" is one solution.

    I had also wanted to verify that this is a typical solution. I've also found some verbiage from:
    http://www.ecmweb.com/design/cathodi...ystems-and-nec

    Wherein they state:
    When bonding the copper ground ring to the concrete-encased rebar, several approaches can be used; however, an effective path must be provided. One may choose to use exothermic welding on the rebar (Photo) or listed compression connectors — and attach a copper wire “pigtail” to the rebar. (It's important to note that all grounding must be done with either exothermic welding or listed materials per the NEC.) This wire can then be run just outside the foundation forms and extended at a later time to the ground ring
    So thanks anyways I believe I resolved this.

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    What is interesting is that IEEE 142 (Green Book) states:
    By using a different metal than copper for grounding, the copper-steel galvanic couple can
    be eliminated. If this metal were closer to iron in the electromotive series, there would be
    a smaller potential, therefore the galvanic couple would be less. The metal should have
    good electrical conductivity because a ground must offer low impedance to fault current
    and lightning. It should be noted that steel rebar, when encased in concrete, has
    approximately the same potential as copper and thus will not corrode.

    Whereas the previously linked article states:
    If the resistance to earth of “concrete-encased electrodes” is sufficiently low to make bonding
    to them an improvement to the facility grounding, the reader can be assured that ionic current
    will flow from the steel anode to the copper cathode, and the rebar will deteriorate (Fig. 5).

    Even more interesting is that it goes on to state:
    Galvanized steel rods would not be used in actual grounding because the zinc will corrode
    away and expose bare steel, which would rust. Instead, we would use a zinc anode, which
    consists of a small steel core embedded in zinc.

    Despite NEC 250.52(A)(3)(1) allowing use of "bare" or "zinc galvanized" or "other electrically coated steel reinforcing bars or rods".

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    No comments? Bueller?

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    Are you asking about these connections for systems of petroleum and chemical facilities as mentioned in the article in your link or is it for something else like a single family dwelling?
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

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    Petrochemical.

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