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problem with this calculation see if i am right. or they posted it wrong

    #1
  1. Join Date
    May 2016
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    problem with this calculation see if i am right. or they posted it wrong

    Using the given information, determine the approximate short circuit current available at the transformer secondary: 13,800-277Y/480V, 2500 kVA, 5% Impedance

    60,000 A
    54,500 A
    42,000 A
    37,500 A
    25,000 A


    first should be 480Y/277 not 277y/480.

    basically this would be the calculation. I= (2500*1000)/(480*1.732)= 3007.08
    z= (100/5)= 20
    short circuit = 3007.08*20= 60189

    so i would just go with the closest answer correct? and also they should fix the error on 277Y.
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  2. #2
  3. Join Date
    Jan 2015
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    Agreed

    I work it out to the same answer. Seems you did it right and I would go for the closest answer.



    Quote Originally Posted by rasilva View Post
    Using the given information, determine the approximate short circuit current available at the transformer secondary: 13,800-277Y/480V, 2500 kVA, 5% Impedance

    60,000 A
    54,500 A
    42,000 A
    37,500 A
    25,000 A


    first should be 480Y/277 not 277y/480.

    basically this would be the calculation. I= (2500*1000)/(480*1.732)= 3007.08
    z= (100/5)= 20
    short circuit = 3007.08*20= 60189

    so i would just go with the closest answer correct? and also they should fix the error on 277Y.
    Reply • 

  4. #3
  5. Join Date
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    The questions clearly states "determine the approximate short circuit current". Go with the closest answer.
    Reply • 

  6. #4
  7. Join Date
    May 2016
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    Quote Originally Posted by madMAX View Post
    The questions clearly states "determine the approximate short circuit current". Go with the closest answer.

    yes sir but its wrong wording that what confused 277y/480 doesn't exist, 480y/277 exist
    Reply • 

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