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

Transformer equivalent circuit open and closed circuit test

  1. Oct 16, 2013 #1
    I see the open and closed circuit test on the transformer section

    I dont understand why we doing that(open and closed circuit test)

    can anyone explain and give some example?
  2. jcsd
  3. Oct 16, 2013 #2


    User Avatar

    Staff: Mentor

    Could you be more specific please? What kind of transformers? Where have you seen this? Can you post a link? Do you have any ideas yet for why it is done?
  4. Oct 18, 2013 #3
    Transformer equivalent circuit open and closed circuit tests are some of required Power Transformer Tests [IEC 60076-1Standard]
    1)Measurement of voltage ratio and check of phase displacement :eek:pen secondary winding test. Since primary EMF in this case is approximately equal to supply voltage and secondary EMF is secondary output voltage the ratio of primary to secondary voltage
    it is EMF ratio then directly proportional with number of turns of the windings.
    2) Measurement of short-circuit impedance and load loss :short-circuited secondary winding. The primary voltage will rise until the primary current shall not be less than 50 % of rated. The transformer short-circuit impedance will be then Voltage/Current. The resistance has to be
    measured separately. As the supply voltage is reduced the no-load losses-magnetic losses-will be negligible. So the active power
    measured in short-circuit test will be proportional will the load-loss.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook