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Thread: Myers hubs

  1. #1
    Join Date
    Dec 2008
    Posts
    3

    Myers hubs

    Using Myers hubs with grc nipple between a ct can and disconnect in a No Ring Knock out. Inspectors says i have to put a lug on hub and bond it with a bonding jumper, i say the way the hubs bite into the cans and nipple threads in to them all wrench tight that the race way is bonded. These dont have your normal lock nuts on them. Am i right on this? He is also trying to tell me i have to bond the myers hub i have in the disconnect that the grc feeder is screwed into has to be the same way. Now i know he is wrong on that.

    Any advise would be great.

  2. #2
    Join Date
    Dec 2006
    Location
    Chapel Hill, NC
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    25,862
    I believe the hub must be listed for service equipment and be listed for bonding. This is from the UL book

    Grounding and Bonding Hubs — Grounding and bonding hubs are Listed hubs (see DWTT) provided with a Listed grounding or bonding locknut. They serve in a manner similar to grounding and bonding bushings except they are only for use with threaded rigid metal and intermediate metal conduit. Grounding hubs provide the electrical continuity required by NEC 250.92 at service equipment and the electrical continuity required by NEC 250.97 for circuits rated over 250 V.

  3. #3
    Join Date
    Mar 2006
    Location
    SW Florida
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    2,376
    What does a Myers hub do that a sealing locknut will not do?
    Unlimited Electric Contractor/Standard Electric Inspector/Traffic Signal Inspector/Highway Lighting and Level One Traffic Signal Installer.

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  4. #4
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    Dec 2006
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    Quote Originally Posted by Cavie View Post
    What does a Myers hub do that a sealing locknut will not do?
    I don't believe you need a bonding bushing with a myers hub but you do with a sealing locknut.

  5. #5
    Join Date
    Feb 2003
    Location
    Massachusetts
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    48,433
    Quote Originally Posted by Dennis Alwon View Post
    I don't believe you need a bonding bushing with a myers hub but you do with a sealing locknut.
    I don't think the rules are any different for either.

  6. #6
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    Dec 2006
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    Chapel Hill, NC
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    Quote Originally Posted by iwire View Post
    I don't think the rules are any different for either.
    So the quote above does not pertain to myers hubs where it says it serves as a bonding bushing?

  7. #7
    Join Date
    Dec 2006
    Location
    Eastern Oregon
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    We don't have any trouble using regular myers hubs and grc nipples.

  8. #8
    Join Date
    Feb 2003
    Location
    Portage, Indiana NEC: 2008
    Posts
    9,747
    Myers hubs are already listed for sealing so a sealing locknut will be of little use, but the bonding requirment is required, and Myers does offer hubs with a bonding lug on them for this purpose, there is a thread on here about this, I dont under stand why it can be just bonded at the other end?
    Wayne A. From: N.W.Indiana
    Be Fair, Be Safe
    Just don't be fairly safe

  9. #9
    Join Date
    Apr 2003
    Location
    Fort Collins, Colorado
    Posts
    1,359
    I believe 250.92(B)(2) allows a Meyers hub, assuming a meyers hub is the same as a threaded boss.
    May your electrons flow forever, and mine, one day longer! Ron

  10. #10
    Join Date
    Dec 2008
    Posts
    3

    crouse-hinds responce

    This is the responce i got back from the manufacturer.


    Re. Myers Hubs

    To Whom It May Concern:

    This letter is to certify that Crouse-Hinds Myers Scru-TiteĀ® hubs meet the UL requirements for ground continuity. The ST series hubs are listed to UL standard 514B and have been tested to this standard to insure the ground integrity of the conduit system. The UL requirements include a resistance test that measures the millivolt drop between the conduit and the outside of the enclosure. The UL test requires the voltage drop to be less than 10 millivolts. The Scru-Tite hubs meet this requirement and provide superior ground continuity.

    The STG series hub with ground terminal are required when running conduit into a non-metallic enclosure.

    If you have any further questions, please give us a call.


    Yours truly,



    Brad Delans
    Product Line Manager
    Fittings

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