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    Simple Ampacity Calculation Question

    Student studying for electrical calculations final and need help with the following question:

    Given 2 Electric ranges sized at 5500W, 2 ovens sized at 6500W and 2 broilers sized at 3500W, all to be installed in a single family residential dwelling, calculate the ampacity of this circuit.

    I can calculate the demand load for these, but am super at how to figure the ampacity. Thanks in advance.

    #2
    Originally posted by TrayLo1201 View Post
    Student studying for electrical calculations final and need help with the following question:

    Given 2 Electric ranges sized at 5500W, 2 ovens sized at 6500W and 2 broilers sized at 3500W, all to be installed in a single family residential dwelling, calculate the ampacity of this circuit.

    I can calculate the demand load for these, but am super at how to figure the ampacity. Thanks in advance.
    Do you know what the voltage is? You need that for the calculation.
    Si hoc legere scis nimium eruditionis habes.

    Comment


      #3
      Originally posted by Besoeker View Post
      Do you know what the voltage is? You need that for the calculation.
      The OP's question involves using a table (220.55) All the ratings are in kW. It's true he needs to know the voltage but first he must determine the kW.

      OP, look at the Table 220.55 and see which part applies to the question. If you need help, post back with your questions.
      [COLOR=navy]If you aim at nothing, you will hit it every time![/COLOR]

      Comment


        #4
        Originally posted by Little Bill View Post
        ...OP, look at the Table 220.55 and see which part applies to the question. ...
        And make sure to read the Notes. I believe at least one assumption is in order.
        [COLOR=RoyalBlue]I will have achieved my life's goal if I die with a smile on my face.[/COLOR]

        Comment


          #5
          Originally posted by TrayLo1201 View Post
          Student studying for electrical calculations final and need help with the following question:

          Given 2 Electric ranges sized at 5500W, 2 ovens sized at 6500W and 2 broilers sized at 3500W, all to be installed in a single family residential dwelling, calculate the ampacity of this circuit.

          I can calculate the demand load for these, but am super at how to figure the ampacity. Thanks in advance.
          I am curious as to what a broiler is--Isn't that an oven? Also if you did calculate the demand then just divide by 240V as that is the usual voltage for a residence
          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

          Comment


            #6
            "calculate the ampacity of this circuit."

            Huh?

            I could see calculating demand for those appliances but not a circuit ampacity as they would be on different circuits (plural).
            Electricians do it until it Hertz!

            Comment


              #7
              I assume they mean a feeder.
              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

              Comment


                #8
                Originally posted by Dennis Alwon View Post
                I am curious as to what a broiler is--Isn't that an oven?
                It's what we in UK would call a grill. It's an oven that heats from the top - the heating element is above the food. My dear wife, an American, has just confirmed that.
                Maybe you don't do the cooking in your house...................

                With the possible caveat for fan assisted ovens the loads are resistive which keeps the calculation simple. And I take your point about the 240V being the norm but unless it is given in the question I'd be inclined to suggest that the student adds a note to say that's what he used for the calculation. Just me crossing the Is and dotting the Ts............
                Si hoc legere scis nimium eruditionis habes.

                Comment


                  #9
                  Simplest answer?

                  We are supposed to be trying to answer more simply correct? Wouldn't we merely instruct the OP that the demand load IS the ampacity? He already indicated he knows how to figure it out. What am I missing?


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

                  Comment


                    #10
                    Originally posted by Besoeker View Post
                    It's what we in UK would call a grill. It's an oven that heats from the top - the heating element is above the food. My dear wife, an American, has just confirmed that.
                    Maybe you don't do the cooking in your house...................

                    With the possible caveat for fan assisted ovens the loads are resistive which keeps the calculation simple. And I take your point about the 240V being the norm but unless it is given in the question I'd be inclined to suggest that the student adds a note to say that's what he used for the calculation. Just me crossing the Is and dotting the Ts............
                    Since you are not an NEC user we will cut you some slack this time.

                    The demand table is in kW, demand load being asked for would still be in kW.

                    You will need to know voltage/number of phases if you are going to convert this to how many amps will the circuit draw.
                    I live for today, I'm just a day behind.

                    Comment


                      #11
                      Originally posted by Strathead View Post
                      We are supposed to be trying to answer more simply correct? Wouldn't we merely instruct the OP that the demand load IS the ampacity? He already indicated he knows how to figure it out. What am I missing?
                      You are not missing anything...
                      [COLOR=RoyalBlue]I will have achieved my life's goal if I die with a smile on my face.[/COLOR]

                      Comment


                        #12
                        Originally posted by Besoeker View Post
                        It's what we in UK would call a grill. It's an oven that heats from the top - the heating element is above the food. My dear wife, an American, has just confirmed that.
                        Maybe you don't do the cooking in your house...................

                        With the possible caveat for fan assisted ovens the loads are resistive which keeps the calculation simple. And I take your point about the 240V being the norm but unless it is given in the question I'd be inclined to suggest that the student adds a note to say that's what he used for the calculation. Just me crossing the Is and dotting the Ts............
                        Yes but every oven I have seen has a broiler... I have never seen a unit that was just a broiler
                        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

                        Comment


                          #13
                          Originally posted by Smart $ View Post
                          You are not missing anything...
                          Phew!


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

                          Comment


                            #14
                            Originally posted by Dennis Alwon View Post
                            I am curious as to what a broiler is--Isn't that an oven? Also if you did calculate the demand then just divide by 240V as that is the usual voltage for a residence
                            Kinda a toaster and portable oven. Cord and plug

                            (eta: removed busted link)

                            I'd call it a toaster tho I think most people think the pop-up kind now. or maybe I'm wrong again.
                            Electricians do it until it Hertz!

                            Comment


                              #15
                              Originally posted by JFletcher View Post
                              Kinda a toaster and portable oven. Cord and plug

                              (eta: removed busted link)

                              I'd call it a toaster tho I think most people think the pop-up kind now. or maybe I'm wrong again.
                              There is a common appliance like that, called a toaster oven. Is that what it is, or something more substantial?

                              Comment

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