Page 1 of 5 123 ... LastLast
Results 1 to 10 of 48

Thread: Grouping of disconnects for feeders to separate buildings

  1. #1
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    22,835

    Grouping of disconnects for feeders to separate buildings

    Me again. I have a customer who is adding a large out-building. He has a 200a service on the house, meter outside, main-breaker panel inside, which supplies two electric-heat HVAC systems, meaning there's little headroom, amperage-capacity speaking.

    Instead of adding a 100-amp breaker to the already-full panel by using tandems, if we upgrade the service, and place a disconnect for the new underground feeder next to the meter, must we also add a disconnect for the existing panel for the purpose of grouping, or is labeling adequate?
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  2. #2
    Join Date
    Dec 2006
    Location
    Chapel Hill, NC
    Posts
    33,165
    IMO, you don't need a disconnect for the 100 amp panel. Use double lugs and feed the detached structured directly from the meter. Since it is outside and underground there is no issue with not having a disconnect.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  3. #3
    Join Date
    Jun 2004
    Location
    Cherry Valley NY, Seattle, WA
    Posts
    4,315
    Quote Originally Posted by Dennis Alwon View Post
    IMO, you don't need a disconnect for the 100 amp panel. Use double lugs and feed the detached structured directly from the meter. Since it is outside and underground there is no issue with not having a disconnect.
    Thats what I would do. 230.40 exception #3. Luv it....
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  4. #4
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    22,835
    So, you're saying that we wouldn't even need ONE disconnect at the meter, much less two, correct?

    Plus, with no disconnect for the outbuilding, the feeder need be only three conductors, not four, right?
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  5. #5
    Join Date
    Jul 2005
    Location
    Tennessee
    Posts
    15,973
    0 disconnects
    3 wire

    not much different from your feeding UG straight from the pole except the meter is in the line
    At my age, I'm accustomed to restaurants asking me to pay in advance, but now my bank has started sending me their calendar one month at a time.

  6. #6
    Join Date
    Sep 2011
    Location
    woodbridge, ct. USA
    Posts
    1,093
    Quote Originally Posted by augie47 View Post
    0 disconnects
    3 wire

    not much different from your feeding UG straight from the pole except the meter is in the line
    So to finish this job what does the grounding look like at the outbuilding? Two rods, water if available, ground and neutral bonded?

  7. #7
    Join Date
    Jun 2004
    Location
    Cherry Valley NY, Seattle, WA
    Posts
    4,315
    Quote Originally Posted by GerryB View Post
    So to finish this job what does the grounding look like at the outbuilding? Two rods, water if available, ground and neutral bonded?
    YES
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  8. #8
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    22,835
    Doesn't 250.32(B)(1) mean I must run a separate EGC?

    Next question: What size must the feeder conductors be for a 100a panel in the new building? In other words, can #3-cu or #4-cu or #2-al be used, or do I need #2-cu or #1-al?
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  9. #9
    Join Date
    Jul 2005
    Location
    Tennessee
    Posts
    15,973
    Quote Originally Posted by LarryFine View Post
    Doesn't 250.32(B)(1) mean I must run a separate EGC?

    Next question: What size must the feeder conductors be for a 100a panel in the new building? In other words, can #3-cu or #4-cu or #2-al be used, or do I need #2-cu or #1-al?
    If you come straight from the meter (no disconnect),,250.32 does not apply as you are installing new service conductors, not feeders.
    It is not a dwelling unit so #3 Cu or #1 AL if you are terminating in a 100a panel.
    At my age, I'm accustomed to restaurants asking me to pay in advance, but now my bank has started sending me their calendar one month at a time.

  10. #10
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    22,835
    Quote Originally Posted by augie47 View Post
    If you come straight from the meter (no disconnect),,250.32 does not apply as you are installing new service conductors, not feeders.
    Oh, that makes sense.

    It is not a dwelling unit so #3 Cu or #1 AL if you are terminating in a 100a panel.
    So does that. Thanx!
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

Posting Permissions

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