Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Transformers connected in wye-delta

  1. May 31, 2010 #1
    1. The problem statement, all variables and given/known data
    Three single phase transformers rated 100kVA, 13.2kV/2.4KV are connected in wye-delta on a 3-phase, 18kV line.

    I need to find the maximum load that can be connected to the transformer bank and the outgoing line voltage.


    2. Relevant equations



    3. The attempt at a solution
    I am completely stuck, so far I've got:
    Voltage across primary is 2.4kV therefore voltage across secondary is 13.2kV
    Es=13.2[tex]\sqrt{3}[/tex]=22.86kV?

    Any help would be greatly appreciated.

    Adam
     
  2. jcsd
  3. May 31, 2010 #2
    This can't be right can it? Do you have a 2.4KV transformer connected to an 18KV line?
     
  4. May 31, 2010 #3
    I'm not 100% sure if that's what the question is implying as I'm completely stuck on it.
    Thanks for the quick reply though.
     
  5. May 31, 2010 #4
    Well, I don't know how 3 phase transformers are voltage rated, as I haven't studied them. However, if the voltage of a Delta is measured from phase to phase and voltage of a Wye is measured neutral to any phase, then you don't use the factor of sqrt(3).
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook