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Line Current for 30kW 3 phase motor

  1. Mar 3, 2012 #1
    1. The problem statement, all variables and given/known data
    Calculate the line current required for a 30kW 3 phase motor having a power factor of 0.85 lagging if it is connected to a balanced source with a line voltage of 440V.


    2. Relevant equations
    P=√3Vl*IlCos ∅
    Il=[itex]\frac{P}{√3VlCos ∅}[/itex]


    P=Average Power
    Il=Line Current
    Vl=Line Voltage
    ∅=∅v-∅i=∅Z


    3. The attempt at a solution
    Il=[itex]\frac{30000}{440√3\times0.85}[/itex]=46.31A

    The answer given is 50.94A
     
  2. jcsd
  3. Mar 3, 2012 #2

    NascentOxygen

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    Staff: Mentor

    http://img7.imageshack.us/img7/8738/p0813.gif [Broken]
     
    Last edited by a moderator: May 5, 2017
  4. Mar 4, 2012 #3
    That's what I thought. This book has plenty of errors. Although it hasn't stopped me from learning a lot.
     
    Last edited by a moderator: May 5, 2017
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