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#10 conductor on a 50amp breaker 220/240VAC

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    #16
    Look at article 440.22. You may go 175% to 225% of the motor compressor rated current or the branch cir. selection current- whichever is greater.

    Not sure how this all plays out but my understanding would be that in some cases the OCPD can be greater than the nameplate.
    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

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      #17
      Originally posted by knightstar View Post
      If I read this correct, the breaker is not there to protect the conductor from over heating? What is suppose to protect the conductor?
      I think you editted this post after you posted, :0... Ok, I was to say something else but anyways; 9/10th of the time one is only protecting the circuit. It's when you get into a specific disconnect that your protecting that application, forward from this point. Your equipment is cutoff via the breaker/disconnect making it the protection to this device. The circuit to this service is still protected itself by some kind of breaker.

      Also keep in mind the math and ratio balancing that within electrical equations, generally if the voltage goes up the amps usuage goes down. In industrial it's not unusall to see tons of 20 AMP /480 motors, most only draw 5-7 continually (mostly less) well below when used to apply any required summary equation. MCA is the way to go if present and a good reminder.

      The NEC tells us to address the requirements of each type of circuit service, with-in are the specific's as presented
      with exceptions, use them.
      Last edited by cadpoint; 02-26-12, 09:55 AM.
      If you are even thirsty, you are two quarts low.

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        #18
        The only time I've ever seen something like this in the field has been #14 on a 30amp 3 phase breaker, the overloads of the motor starter rated at 7amp

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          #19
          http://ecmweb.com/ar/keep_your_cool/


          Click image for larger version

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          Last edited by stickboy1375; 02-26-12, 10:33 AM.
          "Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."

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            #20
            Stick has provided a good graphic. I will note one thing about this one it's based on the 2008 and earlier version of the NEC. This would no longer be applicable under the 2011.

            Rob

            Moderator

            All responses based on the 2017 NEC unless otherwise noted

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              #21
              Originally posted by infinity View Post
              Stick has provided a good graphic. I will note one thing about this one it's based on the 2008 and earlier version of the NEC. This would no longer be applicable under the 2011.

              Rob, what changed after 2008? Were still on 2005.
              "Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."

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                #22
                Originally posted by stickboy1375 View Post
                Rob, what changed after 2008? Were still on 2005.
                Rob

                Moderator

                All responses based on the 2017 NEC unless otherwise noted

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                  #23
                  So the change was 310.16... so 14,12, and 10AWG changed respectively?

                  Not that I'm worried, I don't think Connecticut will ever advance in NEC code changes...
                  "Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."

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                    #24
                    Originally posted by stickboy1375 View Post
                    So the change was 310.16... so 14,12, and 10AWG changed respectively?

                    Not that I'm worried, I don't think Connecticut will ever advance in NEC code changes...
                    Rob

                    Moderator

                    All responses based on the 2017 NEC unless otherwise noted

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                      #25
                      Why didn't the Canadian code change theirs instead?

                      Thank you for the input, btw...
                      "Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."

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                        #26
                        Originally posted by stickboy1375 View Post
                        Why didn't the Canadian code change theirs instead?

                        Thank you for the input, btw...
                        I find the entire concept to be absurd, following Canadian code, as well as the changes to a table that has been around for decades.
                        Rob

                        Moderator

                        All responses based on the 2017 NEC unless otherwise noted

                        Comment


                          #27
                          Originally posted by infinity View Post
                          I find the entire concept to be absurd, following Canadian code, as well as the changes to a table that has been around for decades.
                          Especially since it wasn't a problem to begin with...
                          "Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."

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                            #28
                            Still trying to get my head around this.

                            Kind of getting the conductor/oc on ac together.

                            But also trying to locate in 430 how the air handler branch circuit and relative OC is determined as ac.


                            Just to clarify again...........just when I think I suk at this........I'm always proved right........

                            working on it.
                            " I'm at a crucial part of my painting "...........Monika Danneman

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                              #29
                              Originally posted by ritelec View Post
                              Still trying to get my head around this.

                              Kind of getting the conductor/oc on ac together.

                              But also trying to locate in 430 how the air handler branch circuit and relative OC is determined as ac.


                              Just to clarify again...........just when I think I suk at this........I'm always proved right........

                              working on it.
                              The air handler will have a nameplate, just go by it. Its already been sized by the manufacture.
                              "Electricity is actually made up of extremely tiny particles called electrons, that you cannot see with the naked eye unless you have been drinking."

                              Comment


                                #30
                                Originally posted by stickboy1375 View Post
                                The air handler will have a nameplate, just go by it. Its already been sized by the manufacture.
                                An air handler may not have a nameplate like a compressor unit does and you may have to do your own calculations.
                                Don, Illinois
                                (All code citations are 2017 unless otherwise noted)

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