Announcement

Collapse
No announcement yet.

2 Pole Breaker for 1 Pole Circuit

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    2 Pole Breaker for 1 Pole Circuit

    Hello,

    I cannot find the code that supports the allowable usage of a 1P 20A circuit on a 2P 20A Breaker.

    Situation: Customer has existing 220V 20A 2P equipment. Customer's equipment installer removes one leg from the existing 2P 20A breaker and re-tapes, re-labels one wire as a neutral and lands on the neutral bar. The equipment is hardwired. Customer's equipment installer re-labels the same wire as a identified neutral (same as in the panel) and lands it on the neutral connection in the equipment. The existing 2 Pole breaker now has one leg being used as a hot and nothing on the second leg. The Customer's equipment installer tells the customer that he has it wired to work but it isn't to code because it is being fed by a 2P breaker and it should be switched to a 1P 20A Breaker.

    Customer calls me, I go look and see what has happened and I explain to the customer that it is legal per code (I'm fairly certain) but it is simply wasting a potential space in your panel. I told them I'd cite the code but I cannot find anything 100% like it.

    NEC - 240.15 Ungrounded Conductors
    (B) Circuit Breaker as Overcurrent Device: Circuit Breakers shall open all ungrounded conductors of the circuit both manually and automatically unless otherwise permitted in 240.15(B)(1), (B)(2), (B)(3), (B)(4).

    I'm not violating this, is that what I can cite to be in compliance?

    #2
    There's is nothing in the NEC that says that you cannot use a two pole CB with a conductor connected to only one pole.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

    Comment


      #3
      The answer is there is nothing in the NEC that says you can not use one leg or phase of a multi pole breaker, so it is fine but here is a minor problem, if the conductors are not part of a cable assembly they can not be re-identified as a neutral below a #4. Would I worry about that, heck no.

      Roger
      Moderator

      Comment


        #4
        Originally posted by roger View Post
        The answer is there is nothing in the NEC that says you can not use one leg or phase of a multi pole breaker, so it is fine but here is a minor problem, if the conductors are not part of a cable assembly they can not be re-identified as a neutral below a #4. Would I worry about that, heck no.

        Roger
        Not to be a worry wort but I would be concerned about re-identifying a wire in small size like here. Someone is bound to screw it up in the future.

        I've seen it happen. Dead short , found someone had landed the black wire on a ground once.

        Comment


          #5
          Originally posted by Sierrasparky View Post
          Not to be a worry wort but I would be concerned about re-identifying a wire in small size like here. Someone is bound to screw it up in the future.

          I've seen it happen. Dead short , found someone had landed the black wire on a ground once.
          This is where due diligence and "qualified" need to come together. If I see a small conductor has been re-identified I will need to find out why before I start landing it on different places.

          Roger
          Moderator

          Comment


            #6
            Originally posted by Sierrasparky View Post
            Not to be a worry wort but I would be concerned about re-identifying a wire in small size like here. Someone is bound to screw it up in the future.

            I've seen it happen. Dead short , found someone had landed the black wire on a ground once.
            The world will end in the future, I'm not worried about it today.
            Tom
            TBLO

            Comment


              #7
              I think the only thing in the NEC that might apply would be if the manufacturer of the breaker said you can't do it in the instructions. As noted, there is nothing electrically wrong with it (assuming a normal breaker.)

              Comment


                #8
                Originally posted by MAC702 View Post
                I think the only thing in the NEC that might apply would be if the manufacturer of the breaker said you can't do it in the instructions. As noted, there is nothing electrically wrong with it (assuming a normal breaker.)
                You could run a MWBC with no load connected to one of the poles - still sort of have same thing as far as the breaker is concerned.
                I live for today, I'm just a day behind.

                Comment


                  #9
                  Originally posted by Sierrasparky View Post
                  Not to be a worry wort but I would be concerned about re-identifying a wire in small size like here. Someone is bound to screw it up in the future.

                  I've seen it happen. Dead short , found someone had landed the black wire on a ground once.
                  If Bozo the Electrician looks at a black wire wrapped in white tape and wonders why it's landed on the neutral bar, then Bozo should do something else for a living.

                  Comment


                    #10
                    Originally posted by MAC702 View Post
                    I think the only thing in the NEC that might apply would be if the manufacturer of the breaker said you can't do it in the instructions. As noted, there is nothing electrically wrong with it (assuming a normal breaker.)
                    As I remember, all UL 489 Listed multi-pole breakers have been tested with fewer than all poles being loaded (i.e. 2-pole as 1-pole, and 3-pole as both 2-pole and 1-pole).
                    Just because you can, doesn't mean you should.

                    Comment


                      #11
                      This is so obvious to me. If there is a short between one hot wire and a neutral or ground the cb will trip regardless if there are 2 poles connected. It would not be any different for overcurrent.
                      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


                      sigpic

                      Comment


                        #12
                        Thanks guys!

                        Comment


                          #13
                          Originally posted by jim dungar View Post
                          As I remember, all UL 489 Listed multi-pole breakers have been tested with fewer than all poles being loaded (i.e. 2-pole as 1-pole, and 3-pole as both 2-pole and 1-pole).
                          If not we wouldn't be able to use them for feeders or MWBC's where the load isn't guaranteed to be balanced between poles at all times.
                          I live for today, I'm just a day behind.

                          Comment

                          Working...
                          X