Page 2 of 2 FirstFirst 12
Results 11 to 13 of 13

Thread: Bonding Jumper Required?

  1. #11
    Join Date
    Dec 2015
    Location
    Texas
    Posts
    158
    Quote Originally Posted by jumper View Post
    The drawing does not match the info in the OP. Length is way different.
    Correct, I was thinking of this being an issue on a much larger scale from the second post in an attempt to see at what point would a bonding strap mitigate any potential hazard; apologize for confusion:

    They are; I could see this being an issue on a much larger scale (hundreds/thousands of feet on either side of this LFNMC conduit), as if you had a fault on the EMT side of the LFNMC furthest away from the Panel side, you could introduce a step potential hazard, as the fault would go back to the enclosure, and then via EGC back to panel. It's a stretch, but was the line of thinking that had me worried.


  2. #12
    Join Date
    Dec 2015
    Location
    Texas
    Posts
    158
    Quote Originally Posted by petersonra View Post
    If you have an effective GF path, there will be no potential across the LFNMC because the OCPD at the source will trip.

    If you don't have an effective GF path, it's possible the OCPD won't trip and then you have a real problem. I think you would need to calculate the impedance from the origination point to the LFNMC and make sure it is adequate to trip the OCPD reliably. BTW, this is a required part of the installation. Usually it is not an issue because distances are usually short enough that it does not matter any. But you are not releived from the requirement to provide an effective ground fault path just by using the EMT as the EGC or providing an EGC that is of the typical size for the OCPD rating supplied.
    This answered the second question regarding the increased distances. Thank you for your in depth response.

  3. #13
    Join Date
    Jan 2009
    Location
    3 Hr 2 Min from Winged Horses
    Posts
    15,030
    Quote Originally Posted by tw1156 View Post
    Correct, I was thinking of this being an issue on a much larger scale from the second post in an attempt to see at what point would a bonding strap mitigate any potential hazard; apologize for confusion:

    They are; I could see this being an issue on a much larger scale (hundreds/thousands of feet on either side of this LFNMC conduit), as if you had a fault on the EMT side of the LFNMC furthest away from the Panel side, you could introduce a step potential hazard, as the fault would go back to the enclosure, and then via EGC back to panel. It's a stretch, but was the line of thinking that had me worried.

    No problem.

    Um, Bob....he changed scenarios, so I retract my answer.
    "Electricity is really just organized lightning." George Carlin


    Derek

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •