star connection

Discussion in 'Homework Help' started by segecious, Nov 7, 2014.

  1. segecious

    Thread Starter New Member

    Nov 6, 2014
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    I have a problem solving the following assignment question.
    A star-connected balanced three phase load 30 ohms resistance per phase is supplied by 415 v, three-phase generator of efficiency 90%. calculate the power input to the generator.
     
  2. segecious

    Thread Starter New Member

    Nov 6, 2014
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    i need solution to that question.
    please help me out!
     
  3. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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  4. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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  5. WBahn

    Moderator

    Mar 31, 2012
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    What have YOU done to try to answer YOUR homework problem?

    What power is delivered to a balanced, start-connected load if each phase has a load resistance of R and the three-phase power is 415 V? What assumptions do you need to make, or what additional information do you need, in order to answer that part of the question?
     
  6. segecious

    Thread Starter New Member

    Nov 6, 2014
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    Vph=415/√3=239.6

    V=IR

    Iph=v/R = 239.6/30=7.99

    VL =√3Vph

    Vph=239.6/√3=138.3

    IL=138.3/30=4.6A

    p=3*I2R

    =3*4.62*30=1917w



    this is what i got please assist me
     
  7. WBahn

    Moderator

    Mar 31, 2012
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    Why are you dividing the voltage by sqrt(3) twice?
     
  8. segecious

    Thread Starter New Member

    Nov 6, 2014
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    thanks
     
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