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Homework Help: Two wattmeter method question

  1. Aug 20, 2011 #1
    1. The problem statement, all variables and given/known data
    Wattmeters are in the lines B and C of a three-wire, 173.2 volt, CBA system which supplies a balanced load. Find the wattmeter readings if line current Ia= 32.7 angle of (-41.9). Answer: 1170, 5370 w


    2. Relevant equations
    Wb= Vba Ib cos ( angle between Vba and Ib)
    Wc= Vca Ic cos (angle between Vca and Ic)
    Wb+Wc = 3 phase power
    Wc-Wb = 3 phase reactive power


    3. The attempt at a solution
    I have solve for Vba , Vca Ic and Ib by phasor method..
    Wb = (173.2 ) (32.7) cos ( 180- 78.1)
    Wb= - 1167.87 w
    Wc= (173.2) (32.7) cos (161.9 - 120)
    Wc= 4215.5 w
    my problem is when i checked my answer on the book my answers are not like in the book..
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
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