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Thread: 250.118 - using emt conduit as a ground

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    250.118 - using emt conduit as a ground

    Looks like it's okay in 250.118 to use emt as a ground. Is it also code to run subpanel feeder circuit without a equipment grounding conductor as long as the wires are within emt pipe the whole way?

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    Yes; why would think it wouldn't be?

    Roger
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    To add to Roger's response, many studies have shown that a metallic raceway performs better at clearing a fault than a wire type equipment grounding conductor.

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    We use EMT as an EGC all of the time unless someone is paying for a wire type EGC in the raceway.
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

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    Quote Originally Posted by infinity View Post
    We use EMT as an EGC all of the time unless someone is paying for a wire type EGC in the raceway.


    I don't get the obsession with wire EGC's. I always encounter EMT installations done from the 1960's to the 1980's and it never had a separate ground wire. Now it does.

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    emt as ground

    just seems weird, but ok. thanks

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    emt as ground

    I have probably spent too many years as a romex jockey.

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    Quote Originally Posted by difowler1 View Post
    just seems weird, but ok. thanks
    Not weird at all. The size of EMT large enough for a given set of conductors has a lower impedance than the associated EGC size would.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

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    Quote Originally Posted by difowler1 View Post
    just seems weird, but ok. thanks
    It did to me, too, because all my apprenticeship years were for places that spec'd the wire EGC, so it was normal for me. Now, people pay me to just make it work, and I'm the one buying and pulling the wire, so....

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    Quote Originally Posted by peter d View Post


    I don't get the obsession with wire EGC's. I always encounter EMT installations done from the 1960's to the 1980's and it never had a separate ground wire. Now it does.
    Seen many from the time period you mentioned with poorly supported raceway contributing to broken fittings resulting in loss of EGC, also seen loose set screws or compression nuts, but that is all workmanship issues more than anything IMO. Have seen poorly made up EGC's in cable wiring methods as well - open continuity is still open continuity.

    I do a lot of grain storage bins and handling equipment. Generally all steel structures and equipment. I do run EGC's in flexible conduits or in any non metallic raceways (which is usually just underground raceways in these applications) but see running any wire EGC in most of said systems as pointless, the equipment/structures are very effective fault return path, and usually more effective than my raceways, so if a fitting didn't get tightened it doesn't really matter much from equipment grounding perspective.
    I live for today, I'm just a day behind.

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