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    Standard breaker size

    I installed 4.5kw, 277V, single phase water heater with branch circuit breaker size of 30A.

    Inspector flagged it and says should be 25A.

    I cannot find 25A circuit breakers. All sizes found are 20 or 30A. Does anyone know of any? Are they hard to find? Does nec 2014 article 240.6 standard overcurrent sizes apply to fuses and certain type of breakers?

    #2
    25A breakers are a standard size, even if not nearly as common. A REAL electrical warehouse will have them, or even especially Amazon, like this one: https://smile.amazon.com/MP225-25-Am...ircuit+breaker

    You are asking about how to find a circuit breaker, and don't even tell us what brand and type so we can help.

    Comment


      #3
      Originally posted by MAC702 View Post
      25A breakers are a standard size, even if not nearly as common. A REAL electrical warehouse will have them, or even especially Amazon, like this one: https://smile.amazon.com/MP225-25-Am...ircuit+breaker

      You are asking about how to find a circuit breaker, and don't even tell us what brand and type so we can help.
      Breaker you posted is rated for 240V. I have 277V single phase.

      Sent from my SM-G935U using Tapatalk

      Comment


        #4
        Originally posted by hhsting View Post
        Breaker you posted is rated for 240V. I have 277V single phase.
        Was just a quick example to show 25 as a standard size.

        https://smile.amazon.com/SCHNEIDER-E...ircuit+breaker

        There's another one. Can't help further because we still don't know what brand you need. But the point is they are standard and available, even if not common.

        Comment


          #5
          Originally posted by hhsting View Post
          I installed 4.5kw, 277V, single phase water heater with branch circuit breaker size of 30A.

          Inspector flagged it and says should be 25A.

          I cannot find 25A circuit breakers. All sizes found are 20 or 30A. Does anyone know of any? Are they hard to find? Does nec 2014 article 240.6 standard overcurrent sizes apply to fuses and certain type of breakers?
          Look at 420.11(E) for over current protection. If you have a over current protection marked on the water heater use that as your OCPD if not you have to multiply your amps x 1.5 if your amps are more than 13.3A and no over current marking on the device.If it doesnt correspond to standard OCPD you can select the next size up. In your case 4500/277=16.25x1.5=24.36 and next standard size is 25A.

          Comment


            #6
            Originally posted by shortcircuit1 View Post
            Look at 420.11(E) for over current protection. If you have a over current protection marked on the water heater use that as your OCPD if not you have to multiply your amps x 1.5 if your amps are more than 13.3A and no over current marking on the device.If it doesnt correspond to standard OCPD you can select the next size up. In your case 4500/277=16.25x1.5=24.36 and next standard size is 25A.
            420.11(E) applies to appliance like toaster etc not to water heater.

            Sent from my SM-G935U using Tapatalk

            Comment


              #7
              Originally posted by hhsting View Post
              I cannot find 25A circuit breakers. All sizes found are 20 or 30A. Does anyone know of any?
              What kind of panel, what style of breaker?

              Comment


                #8
                "listed" breaker is for specific panel. Just get a "classified" breaker if not sure.

                Comment


                  #9
                  Originally posted by shortcircuit1 View Post
                  Look at 420.11(E) for over current protection. If you have a over current protection marked on the water heater use that as your OCPD if not you have to multiply your amps x 1.5 if your amps are more than 13.3A and no over current marking on the device.If it doesnt correspond to standard OCPD you can select the next size up. In your case 4500/277=16.25x1.5=24.36 and next standard size is 25A.
                  My experience has been a water heater this size would meet the 422.13 requirement and only be permitted to be sized at 125%. Nonetheless, it still calculates to the 25A OCPD, but you can see how it might change depending on what number you plug in.

                  Comment


                    #10
                    Fact: While 25 amps is a standard breaker size, it is not available in all breaker configurations, for example a Square D QOB 10KAIC is available, but a 22KAIC one is not. They are not available in an GFCI configuration in many panels. When you run in to that, it stinks. You basically have to install a fused disconnect in lieu of a breaker. I have usually had success in passing the cost for this on with the proper argument.


                    I know what I don't know, and I know where to go to find it!

                    Comment


                      #11
                      Originally posted by hhsting View Post
                      420.11(E) applies to appliance like toaster etc not to water heater.

                      Sent from my SM-G935U using Tapatalk
                      There is nothing that says an appliance is a typical kitchen appliance. A water heater is an appliance and is covered by 422.11(E).
                      Don, Illinois
                      (All code citations are 2017 unless otherwise noted)

                      Comment


                        #12
                        Originally posted by don_resqcapt19 View Post
                        There is nothing that says an appliance is a typical kitchen appliance. A water heater is an appliance and is covered by 422.11(E).
                        Oh yea well how come water heater manufacturer list minimum circuit breaker size per NEC 2014 Article 422.13 but never maximum circuit breaker size manufacturer instruction?

                        If NEC 2014 Article 422.11(E) apply to water heater then manufacturer should also list maximum size per 422.11(E) but they never do and so thats a hint 422.11(E) does not apply to water heaters.
                        If it did it would be on manufacturer instruction.

                        Comment


                          #13
                          Originally posted by hhsting View Post

                          If NEC 2014 Article 422.11(E) apply to water heater then manufacturer should also list maximum size per 422.11(E) but they never do and so thats a hint 422.11(E) does not apply to water heaters.
                          If it did it would be on manufacturer instruction.
                          422.11 doesn't say anything about manufacturers' markings, so lack of a marking of maximum breaker size would not be evidence that a water heater isn't an appliance with regards to Art. 422.

                          More pertinent would be that "water heater" is specifically mentioned in 422.11(F)(3) and 422.13. A water heater is an appliance, and is subject to the Art 422 requirements.

                          Comment


                            #14
                            Originally posted by david luchini View Post
                            422.11 doesn't say anything about manufacturers' markings, so lack of a marking of maximum breaker size would not be evidence that a water heater isn't an appliance with regards to Art. 422.

                            More pertinent would be that "water heater" is specifically mentioned in 422.11(F)(3) and 422.13. A water heater is an appliance, and is subject to the Art 422 requirements.
                            Ok is it subject to nec 2014 article 422.11(E)(3)? Where is manufacturer marking stated on article 422.13 but thats still provided?

                            Sent from my SM-G935U using Tapatalk

                            Comment


                              #15
                              Originally posted by hhsting View Post
                              Ok is it subject to nec 2014 article 422.11(E)(3)? Where is manufacturer marking stated on article 422.13 but thats still provided?
                              )
                              Sent from my SM-G935U using Tapatalk


                              Yes, it is subject to 422.11(E)(3)

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