Announcement

Collapse
No announcement yet.

Motor load without neutral

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

    Motor load without neutral

    Can i supply 3 core cable without neutral to a 3 phase Y motor load? this is a client request,

    I think no as Per 250.24(C), am i correct?
    "Sleem"

    #2
    All motors that I've encountered do not require a neutral connection to function. The motor might be internally connected in 'wye' but is supplied with only the three phase conductors, no neutral conductor.

    If the _load_ requires a neutral for whatever reason, then you must provide that neutral conductor. But I would be very surprised if a 'motor load' actually requires the neutral.

    Article 250 is about grounding, and 250.24 is about bonding the grounded conductor; relevant for the service but not for supplying an individual load. In addition to the 3 phase conductors, your motor load will require and EGC.

    -Jon
    Last edited by winnie; 08-14-19, 09:55 AM.

    Comment


      #3
      Originally posted by m sleem View Post
      Can i supply 3 core cable without neutral to a 3 phase Y motor load? this is a client request,

      I think no as Per 250.24(C), am i correct?
      The answer is yes. That is the only way to do it. A wye or star motor just describes the way the motor is wired internally or configured in the make up box, it has nothing to do with the circuit powering it.
      If Billy Idol is on your playlist go reevaluate your life.

      Comment


        #4
        250.24(C) refers to bringing the neutral to the service. There is no requirement to bring neutrals to individual pieces of utilization equipment such as motors unless required by the equipment.
        At my age, I'm accustomed to restaurants asking me to pay in advance, but now my bank has started sending me their calendar one month at a time.

        Comment


          #5
          Although they are not very common, I have worked on Fan Powered Boxes that have 277V Single phase PSC motors.
          Microwave Radiation Dangers should be openly discussed

          Comment


            #6
            The only single phase 480V motor I have ever seen was on a piece of refrideratire equipment
            If Billy Idol is on your playlist go reevaluate your life.

            Comment


              #7
              Assuming that voltage surges are not balanced, don't we need a neutral?
              "Sleem"

              Comment


                #8
                No.
                Tom
                TBLO

                Comment


                  #9
                  Originally posted by winnie View Post
                  All motors that I've encountered do not require a neutral connection to function. The motor might be internally connected in 'wye' but is supplied with only the three phase conductors, no neutral conductor.

                  If the _load_ requires a neutral for whatever reason, then you must provide that neutral conductor. But I would be very surprised if a 'motor load' actually requires the neutral.

                  Article 250 is about grounding, and 250.24 is about bonding the grounded conductor; relevant for the service but not for supplying an individual load. In addition to the 3 phase conductors, your motor load will require and EGC.

                  -Jon
                  I have noted that ground and neutral are sometimes confused with each other.

                  Comment


                    #10
                    Originally posted by Besoeker3 View Post

                    I have noted that ground and neutral are sometimes confused with each other.
                    Unfortunately.
                    Tom
                    TBLO

                    Comment

                    Working...
                    X