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Sizing based on largest ungrounded condcutor

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    Sizing based on largest ungrounded condcutor

    What would you think if the NEC changed 250.122 to:

    "Table 250.122 Minimum Size Equipment Grounding
    Conductors for Grounding Raceway and Equipment"



    "Size of largest ungrounded copper conductor" "Copper"

    #14 #14
    #12 #12
    #10 #10
    #8 #10
    #6 #8
    #4 #8
    #3 #6
    #2 #4
    #1 #4
    #1/0 #4
    #2/0 #4
    #3/0 #3
    #4/0 #3
    #250 #3
    #350 #2

    ect


    #2
    Why would you change this.. What is your substantiation.
    You don't just make up numbers because you think it is better so Where did those numbers come from?

    BTW, I hate the idea. LOL
    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

    Comment


      #3
      Originally posted by Dennis Alwon View Post
      Why would you change this.. What is your substantiation.
      You don't just make up numbers because you think it is better so Where did those numbers come from?

      BTW, I hate the idea. LOL


      Easier to understand and clears up confusion such as upsizing circuits for voltage drop.

      I did increase the EGC size for a few cases, I think the impedance is to high at time- like a 200amp OCPD being opened with #6- but that is open for debate.

      Comment


        #4
        Submit a proposal with that substantiation.

        Roger
        Moderator

        Comment


          #5
          Originally posted by roger View Post
          Submit a proposal with that substantiation.

          Roger
          LOL...............
          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

          Comment


            #6
            IMO it's a great idea just replace that dumb Table 250.122 and get rid of 250.122(B). I believe that Don has been saying this for years.
            Rob

            Moderator

            All responses based on the 2017 NEC unless otherwise noted

            Comment


              #7
              Originally posted by roger View Post
              Submit a proposal with that substantiation.

              Roger
              Why this substation? It doesn't have the numbers or an in depth explanation.

              Comment


                #8
                Originally posted by infinity View Post
                IMO it's a great idea just replace that dumb Table 250.122 and get rid of 250.122(B). I believe that Don has been saying this for years.
                What was Don's idea? I remember bits and pieces of it and it was good.

                Comment


                  #9
                  Originally posted by mbrooke View Post

                  Why this substation? It doesn't have the numbers or an in depth explanation.
                  Well that's the substantiation you used when you answered Dennis.

                  Roger
                  Moderator

                  Comment


                    #10
                    Originally posted by mbrooke View Post

                    What was Don's idea? I remember bits and pieces of it and it was good.
                    Base the EGC on the size of the ungrounded conductor similar to T250.66 for GEC's.
                    Rob

                    Moderator

                    All responses based on the 2017 NEC unless otherwise noted

                    Comment


                      #11
                      Originally posted by infinity View Post

                      Base the EGC on the size of the ungrounded conductor similar to T250.66 for GEC's.
                      Yeah that was what Don said but what was the substantiation.. I think he wrote a proposal but obviously it was not accepted.
                      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

                      Comment


                        #12
                        Originally posted by infinity View Post

                        Base the EGC on the size of the ungrounded conductor similar to T250.66 for GEC's.
                        Yes! I like that idea

                        Comment


                          #13
                          Originally posted by roger View Post

                          Well that's the substantiation you used when you answered Dennis.

                          Roger
                          Going into reactance, resistance and suseptance, average circuit runs and typical breaker pickup curves would take more effort to type out and make the thread more confusing. I know Dennis is smart, but, I want to save everyone the long list of numbers.

                          Comment


                            #14
                            Originally posted by mbrooke View Post

                            Going into reactance, resistance and suseptance, average circuit runs and typical breaker pickup curves would take more effort to type out and make the thread more confusing. I know Dennis is smart, but, I want to save everyone the long list of numbers.
                            So make the proposal and use that for your substantiation.

                            Roger
                            Moderator

                            Comment


                              #15
                              Originally posted by Dennis Alwon View Post

                              Yeah that was what Don said but what was the substantiation.. I think he wrote a proposal but obviously it was not accepted.
                              I did a quick scan of a few old ROP's but couldn't find a proposal. Maybe he will chime in.
                              Rob

                              Moderator

                              All responses based on the 2017 NEC unless otherwise noted

                              Comment

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