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Wire size reduction for branch circuits

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    #16
    Originally posted by don_resqcapt19 View Post
    The wording in 240.5(B)(2) says those sizes are fixture wire. When you buy a pre-made whip with conductors smaller than 14, they are always made up using fixture wire.

    The types of conductors that are fixture wire are listed in Table 402.3.
    It does not say tap conductors must be fixture wire, it along with the table tell us what size/length fixture wire is acceptable on certain branch circuits.

    Other sections I mentioned have situations where tap conductors can be used and no mention of fixture wire - 410.117 even mentions MC or AC cable which won't have fixture wire in them.
    I live for today, I'm just a day behind.

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      #17
      Originally posted by electrofelon View Post
      So I could take any light fixture and use up to 50 feet of 18 AWG fixture wire in a chapter three raceway to connect it to the branch circuit? OR does it have to come from the factory as part of the fixture to use 240.5(B)(2)?
      Yes, you are permitted to do that, as long as it feeds a single fixture.
      Don, Illinois
      (All code citations are 2017 unless otherwise noted)

      Comment


        #18
        Originally posted by kwired View Post
        It does not say tap conductors must be fixture wire, it along with the table tell us what size/length fixture wire is acceptable on certain branch circuits.

        Other sections I mentioned have situations where tap conductors can be used and no mention of fixture wire - 410.117 even mentions MC or AC cable which won't have fixture wire in them.
        I stand by my statement that if you are using conductors smaller than 14 AWG and protected in accordance with the ampacities shown in 240.5(B)(2), you are required to use fixture wire. 410.117 says nothing about the required overcurrent protection of the "tap conductor".
        Don, Illinois
        (All code citations are 2017 unless otherwise noted)

        Comment


          #19
          Originally posted by D_Norris View Post
          My company installed LED lights in a school. The branch circuit is a 20 amp breaker with 12-2 wire. We installed 40 watt LED panels and a ceiling sensor with 14-3 MC from the switch leg box. The inspector failed us do to the fact the breaker is 20 amp therefore all wire must be 12 gauge. The ceiling sensor only draws 3 amps and has 18 wire hooked up internally. I referenced 240.5 (B)(2) witch states 14 can be used as fixture wire on a 20 amp breaker, but also went to table 402.3 and THWN is no listed. Is there any other code I should reference?
          Thanks all
          #14 in a school? I don't think so!

          Check their specs. I assure you, no #14. The code doesnt matter when you enter the ivory towers of school work...

          Comment


            #20
            Originally posted by don_resqcapt19 View Post
            I stand by my statement that if you are using conductors smaller than 14 AWG and protected in accordance with the ampacities shown in 240.5(B)(2), you are required to use fixture wire. 410.117 says nothing about the required overcurrent protection of the "tap conductor".
            If you are using smaller than 14 AWG I agree, it must be fixture wire, my point all along here has been that use of tap conductors is not limited to fixture wire only.
            I live for today, I'm just a day behind.

            Comment


              #21
              Originally posted by kwired View Post
              If you are using smaller than 14 AWG I agree, it must be fixture wire, my point all along here has been that use of tap conductors is not limited to fixture wire only.
              After taking another look the rules in 240.5(B)(2) included conductors 14 and larger. I think the code language in 240.5(B)(2) needs fixing. As I re-read it, you must use fixture wire anytime you are protecting the conductors at the ampacities listed in that section. Some types of fixture wire is available in 12 and 14 AWG, but I think the code needs fixing here. Not sure there is any reason to have the OCPD rating based on the type of insulation on the conductors. The insulation type is the only real difference between other conductors of the same size and fixture wire.
              Don, Illinois
              (All code citations are 2017 unless otherwise noted)

              Comment


                #22
                Originally posted by don_resqcapt19 View Post
                After taking another look the rules in 240.5(B)(2) included conductors 14 and larger. I think the code language in 240.5(B)(2) needs fixing. As I re-read it, you must use fixture wire anytime you are protecting the conductors at the ampacities listed in that section. Some types of fixture wire is available in 12 and 14 AWG, but I think the code needs fixing here. Not sure there is any reason to have the OCPD rating based on the type of insulation on the conductors. The insulation type is the only real difference between other conductors of the same size and fixture wire.
                Why? 240.5(B)(2) is titled "Protection of Flexible Cords, Flexible Cables, and Fixture Wires." If there is such a rule on other "tap conductors" to a luminaire they it can certainly be in some other section, this one is or fixture wire. I didn't find any specific general rule for tap conductors that are other than fixture wire or cord, but did find the couple specific applications I mentioned code sections for.
                I live for today, I'm just a day behind.

                Comment


                  #23
                  Originally posted by kwired View Post
                  Why? 240.5(B)(2) is titled "Protection of Flexible Cords, Flexible Cables, and Fixture Wires." If there is such a rule on other "tap conductors" to a luminaire they it can certainly be in some other section, this one is or fixture wire. I didn't find any specific general rule for tap conductors that are other than fixture wire or cord, but did find the couple specific applications I mentioned code sections for.
                  (B)(2) is specific to fixture wire. (B)(1), (B)(3) and (B)(4) apply to flexible cords. (A) covers the requirements for flexible cable.
                  I see nothing in the other sections that you cited that act to change the requirements of 240.5.
                  Don, Illinois
                  (All code citations are 2017 unless otherwise noted)

                  Comment


                    #24
                    Originally posted by kwired View Post
                    Why? 240.5(B)(2) is titled "Protection of Flexible Cords, Flexible Cables, and Fixture Wires." If there is such a rule on other "tap conductors" to a luminaire they it can certainly be in some other section, this one is or fixture wire. I didn't find any specific general rule for tap conductors that are other than fixture wire or cord, but did find the couple specific applications I mentioned code sections for.
                    Originally posted by don_resqcapt19 View Post
                    (B)(2) is specific to fixture wire. (B)(1), (B)(3) and (B)(4) apply to flexible cords. (A) covers the requirements for flexible cable.
                    I see nothing in the other sections that you cited that act to change the requirements of 240.5.
                    Correction, 240.5 is titled "Protection of Flexible Cords, Flexible Cables, and Fixture Wires."

                    If your tap conductor is not fixture wire flexible cord or flexible cable, nothing in 240.5 applies to it, is what I have been trying to say all along.

                    Does AC or MC cable count as flexible cable? If so then I take back some of what I said. How about THHN in flexible metal conduit? Supposed to be a raceway not a cable?
                    I live for today, I'm just a day behind.

                    Comment


                      #25
                      Originally posted by kwired View Post
                      Correction, 240.5 is titled "Protection of Flexible Cords, Flexible Cables, and Fixture Wires."

                      If your tap conductor is not fixture wire flexible cord or flexible cable, nothing in 240.5 applies to it, is what I have been trying to say all along.

                      Does AC or MC cable count as flexible cable? If so then I take back some of what I said. How about THHN in flexible metal conduit? Supposed to be a raceway not a cable?
                      Correct, if it is not one of those, nothing in the section applies. However that means other than the very very limited branch circuit taps permitted in Article 210, those other conductors have to be protected at their ampacity.

                      AC and MC are not flexible cables, and neither is THHN. Flexible cables are those found in Table 400.4.
                      Don, Illinois
                      (All code citations are 2017 unless otherwise noted)

                      Comment


                        #26
                        Originally posted by don_resqcapt19 View Post
                        Correct, if it is not one of those, nothing in the section applies. However that means other than the very very limited branch circuit taps permitted in Article 210, those other conductors have to be protected at their ampacity.

                        AC and MC are not flexible cables, and neither is THHN. Flexible cables are those found in Table 400.4.
                        So is it acceptable to use a fixture tap that is THHN in flex or AC/MC cable or must you run same size as branch circuit when using those methods?

                        I think 410.117 is one place that specifically says you can, though that is a specific situation and not a general thing there.
                        I live for today, I'm just a day behind.

                        Comment


                          #27
                          Originally posted by kwired View Post
                          So is it acceptable to use a fixture tap that is THHN in flex or AC/MC cable or must you run same size as branch circuit when using those methods?

                          I think 410.117 is one place that specifically says you can, though that is a specific situation and not a general thing there.
                          In my opinion if you want to protected the fixture tap wires at the ampacities specified in 240.5(B)(2) the conductors must be fixture wire and not THHN.
                          Don, Illinois
                          (All code citations are 2017 unless otherwise noted)

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                            #28
                            Good piece of information posted here.

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