User Tag List

Results 1 to 7 of 7

Thread: T250.102

  1. #1
    Join Date
    Mar 2003
    Location
    Wisconsin
    Posts
    992
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    T250.102

    480/277 volt service
    parallel 3 * 750mcm AL XHHW-2
    per table 3*750= 2250mcm * 12.5% = 281.xx mcm

    Main Bonding jumper needs to be 300mcm

    POCO inspector said 4/0

    What am I missing here?

    Thanks for all the help.

    tim

  2. #2
    Join Date
    Dec 2011
    Location
    Wisconsin
    Posts
    609
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have never heard of a POCO inspector around here. I don't think you are missing anything. You need a 300 kcmil for your main bonding jumper.

  3. #3
    Join Date
    Dec 2006
    Location
    Chapel Hill, NC
    Posts
    34,364
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    I wonder if the power company guy is using the grounding electrode conductor table which is 250.66. T 250.102 was added more recently and the only change is at the bottom of the table 250.102 otherwise the two tables are identical.
    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



  4. #4
    Join Date
    Jul 2003
    Location
    New Jersey
    Posts
    27,001
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Maybe he saying #4/0 copper. I didn't do the calculation so I'm guessing.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

  5. #5
    Join Date
    Dec 2006
    Location
    Chapel Hill, NC
    Posts
    34,364
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Dennis Alwon View Post
    I wonder if the power company guy is using the grounding electrode conductor table which is 250.66. T 250.102 was added more recently and the only change is at the bottom of the table 250.102 otherwise the two tables are identical.

    Forget this-- this table only goes to 3/0-- I misread the question.... Anyway I believe you are correct but what difference does it make. You will more than satisfy the power company with 300 kcm anyway.

    Trevor does have a point about copper vs aluminum
    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



  6. #6
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    40,197
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by tshea View Post
    480/277 volt service
    parallel 3 * 750mcm AL XHHW-2
    per table 3*750= 2250mcm * 12.5% = 281.xx mcm

    Main Bonding jumper needs to be 300mcm

    POCO inspector said 4/0

    What am I missing here?

    Thanks for all the help.

    tim
    If 4/0 is all that is needed and you ran 300 - I don't see a problem, run 750 if you want.
    I live for today, I'm just a day behind.

  7. #7
    Join Date
    Mar 2003
    Location
    Wisconsin
    Posts
    992
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Thanks!

    I have some scrap 4/0 and 300mcm. Think I'll take both pieces with and whichever fits the lugs...

    I'll use the 300mcm. Don't want to have the guy call me again.

    Thanks again!

Posting Permissions

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