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Single 15A receptacle on a 20A breaker

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    Single 15A receptacle on a 20A breaker

    I was recently asked a question by an electrical work planner as to whether you could install a single 15A receptacle on a 20A breaker. From my understanding you can not from Article 210.21(B)1, however you are allowed to install two or more 15A receptacles, and a duplex receptacle counts as two, on a 20A breaker per Articles 210.21(B)3 and 210.24. Just was curious if there is something I might have missed such as some exception I don't know about. Thanks for the responses.

    #2
    Noting missed you are correct. A single receptacle on an individual branch circuit must be greater or equal to the size of the OCPD. You could put a 20 amp single on a 15 amp circuit.
    Rob

    Moderator

    All responses based on the 2017 NEC unless otherwise noted

    Comment


      #3
      Originally posted by infinity View Post
      Noting missed you are correct. A single receptacle on an individual branch circuit must be greater or equal to the size of the OCPD. You could put a 20 amp single on a 15 amp circuit.
      You sure?

      210.21 Outlet Devices

      B) Receptacles

      (1) Single Receptacle on an Individual Branch Circuit. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.
      -Hal

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        #4
        Originally posted by hbiss View Post

        You sure?



        -Hal
        Doesn't the section you quoted confirm what Rob said?

        Comment


          #5
          Originally posted by david luchini View Post

          Doesn't the section you quoted confirm what Rob said?
          I think so.
          Rob

          Moderator

          All responses based on the 2017 NEC unless otherwise noted

          Comment


            #6
            Yeah, I guess it does. My mind goes blank when confronted with something that doesn't make sense.

            -Hal

            Comment


              #7
              Originally posted by hbiss View Post
              Yeah, I guess it does. My mind goes blank when confronted with something that doesn't make sense.

              -Hal
              What is it that doesn't make sense? Plug a 50A load into a circuit protected by a 15A breaker and the breaker trips.
              If Billy Idol is on your playlist go reevaluate your life.

              Comment


                #8
                Originally posted by ActionDave View Post

                What is it that doesn't make sense? Plug a 50A load into a circuit protected by a 15A breaker and the breaker trips.
                Exactly that! Why does the Code encourage a situation that will insure an overload condition and breaker trip?

                You install a 20A dedicated circuit with a 20A single receptacle to supply some piece of equipment that requires 20A. Why on earth would anybody run a 15A circuit to that receptacle?

                -Hal

                Comment


                  #9
                  Originally posted by hbiss View Post

                  Exactly that! Why does the Code encourage a situation that will insure an overload condition and breaker trip?

                  You install a 20A dedicated circuit with a 20A single receptacle to supply some piece of equipment that requires 20A. Why on earth would anybody run a 15A circuit to that receptacle?

                  -Hal
                  For example that code sections specifically addresses a 40 amp circuit with a single receptacle, there are no standard 40 amp receptacles so for a 40 amp range circuit you would use a 50 amp receptacle and a 50 amp cord and plug on the appliance.
                  Rob

                  Moderator

                  All responses based on the 2017 NEC unless otherwise noted

                  Comment


                    #10
                    Originally posted by hbiss View Post
                    ......You install a 20A dedicated circuit with a 20A single receptacle to supply some piece of equipment that requires 20A. Why on earth would anybody run a 15A circuit to that receptacle?

                    -Hal
                    That's a design issue. 210.21 is one of the few places left where the code stays true to its stated purpose of not being a design manual or installation guideline.
                    If Billy Idol is on your playlist go reevaluate your life.

                    Comment


                      #11
                      Originally posted by hbiss View Post

                      Exactly that! Why does the Code encourage a situation that will insure an overload condition and breaker trip?

                      You install a 20A dedicated circuit with a 20A single receptacle to supply some piece of equipment that requires 20A. Why on earth would anybody run a 15A circuit to that receptacle?

                      -Hal
                      I'll point out the obvious...You wouldn't run a 15A circuit to that receptacle. That would be a violation of 210.19 and/or 210.20.

                      Comment


                        #12
                        So why the contradiction that leads to confusion?


                        -Hal

                        Comment


                          #13
                          Elsewhere, in the real world, it is extremely common to put a NEMA 6-50R on a 30A ckt for welding equipment. It's considered the standard plug design even on a machine that draws 18 amps.

                          Comment


                            #14
                            The manufacturer is free to put any plug they choose on their equipment. But if we install a 6-50R it should be on a 40 or 50A breaker. And if an equipment manufacturer puts a 6-50P on their equipment, they need to take the fact into consideration that the receptacle will be on a 40 or 50A circuit.

                            Point is that we have all kinds of receptacle and plug configurations that reflect the current rating, voltage and number of phases. One purpose of having different configurations is to prevent the connection of equipment to a circuit that it's not intended to operate from. Another is to allow you to see what the voltage/current/number of phases available at that receptacle is by observation. Bad enough this practice isn't always followed but there is no excuse for the code to suggest that you don't need to. Might as well throw the whole system out the window.

                            -Hal

                            Comment


                              #15
                              Originally posted by david luchini View Post
                              I'll point out the obvious...You wouldn't run a 15A circuit to that receptacle. That would be a violation of 210.19 and/or 210.20.
                              I'm missing something. How is this "obvious?" The outlet device is not "the load" so how is this a violation of the actual code?

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