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Thread: Definition Of Conductors

  1. #11
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    Quote Originally Posted by iwire View Post
    Bonding Conductor or Jumper. A reliable conductor toensure the required electrical conductivity between metal
    parts required to be electrically connected.
    Quote Originally Posted by tnt8197 View Post
    Why would you consider this a bonding jumper in lieu of a grounding conductor? The conductors are going from the main grounding bus bar to the downstream portion of the unit substations? Wouldn't that be the main grounding conductor for the separately derived system?
    How are we supposed to know what the units are? 'Substation' is not a descript NEC term. Now if you say the units are SDS's, then we have the possibility of one being a GEC, another being an BC/BJ (likely an EBJ), while another being an SSBJ or an EGC. Note that an SSBJ or EGC will only be run with circuit conductors.

    Under the NEC
    • an EGC is required to be run with the primary conductors
    • an SSBJ is required to be run with the secondary conductors
    • a GEC is required for grounding the secondary if it is a grounded system, and it must be run to the same enclosure where the SBJ is located
    • an EBJ could be required but in most cases it is a superfluous and not required in most industrial scenarios
    I'll never get there. No matter where I go, I'm always here.

  2. #12
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    Quote Originally Posted by tnt8197 View Post
    Why would you consider this a bonding jumper in lieu of a grounding conductor?
    In short, but not limited to the fact that if those are intended to be EGCs they are not run as EGCs are required to be. See 300.3(B)

  3. #13
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    Seems common in cell sites, its bonding for lightning IMO
    Moderator-Washington State
    Ancora Imparo

  4. #14
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    Quote Originally Posted by Smart $ View Post
    ... 'Substation' is not a descript NEC term....
    For what it's worth...

    Article 100, Part II...
    Substation. An enclosed assemblage of equipment
    (e.g., switches, interrupting devices, circuit breakers,
    buses, and transformers) through which electric energy
    is passed for the purpose of distribution, switching, or
    modifying its characteristics.
    It was new in the 2014 NEC.

    And also see 250.191 and 250.194
    The term 'bonding jumper' is used.

    I'm inclined to agree with iwire.

  5. #15
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    Quote Originally Posted by jaggedben View Post
    For what it's worth...



    It was new in the 2014 NEC.

    And also see 250.191 and 250.194
    The term 'bonding jumper' is used.

    I'm inclined to agree with iwire.
    Well, I'll be...

    Thanks for pointing that out.




    The answer to the query as posed is IMO as iwire responded: bonding conductor or jumper. As details are revealed, such as being an SDS, more specific acronyms will apply.
    I'll never get there. No matter where I go, I'm always here.

  6. #16
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    My concern is that in the event of a fault, current will flow on all parallel paths. Not only will it not all flow with the energized conductor path as it should, but current will flow through the supplemental bonding (or whatever you desire to call them) conductors. This can cause extreme heating as well as the potential to shock a person who might be in contact with the supplemental grounding system, thereby creating an additional path for current flow. With properly engineered over-current/fault current protection, the time frame in which this could happen is minimal, but the NEC has minimized this potential over the years from my understanding. Thoughts?

  7. #17
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    Quote Originally Posted by Jim1959 View Post
    My concern is that in the event of a fault, current will flow on all parallel paths. Not only will it not all flow with the energized conductor path as it should, but current will flow through the supplemental bonding (or whatever you desire to call them) conductors. This can cause extreme heating as well as the potential to shock a person who might be in contact with the supplemental grounding system, thereby creating an additional path for current flow. With properly engineered over-current/fault current protection, the time frame in which this could happen is minimal, but the NEC has minimized this potential over the years from my understanding. Thoughts?
    Despite my gripes about the NEC it is still a good safety standard. I don't need a silver plated Cadillac to get me to work everyday, my old Honda is perfectly safe.

    As far as over doing it with the earthing scheme, it doesn't really matter how much you connect to the earth you are not really going to send that much more current into it during a fault.

    Check out this old thread, http://forums.mikeholt.com/showthread.php?t=116358
    Once in a while you get shown the light
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  8. #18
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    Quote Originally Posted by Jim1959 View Post
    Thoughts?
    To be frank ... find the bodies, find the emergency room reports, find the property damage reports, find the insurance payouts from this issue before worrying about what could happen.

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