Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations pierreick on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by Luiseng

  1. Luiseng

    Impedance Voltage

    Hi All, we are adquiring two power transformers and the value of impedance voltage was specified as 12.25% +-10 but the value after the tests is 14.1%. the question is what are the implications, advantages or disavantages of having a value higher than specified. thanks best regards...
  2. Luiseng

    Power losses calculations

    Hi all, I was given the formula sheet that the manufacturer of one of my power transformer as used to do all the calculations for the power losses. I ma trying to understand them but some formulas do no tie up. the one I am stuck at the moment is this one: Ur% = (Pk/Pn)*100 where Ur% is Ohms...
  3. Luiseng

    Power transformer calculations

    Hi Chris8410, I have also tried what you sugested, and it does not tie in with the values given by the manufacturer. the resistance I gave is the average resistance value on one winding. I probably done something wrong... thanks best regards Luis
  4. Luiseng

    Power transformer calculations

    Hi Edison123, You are a Star, this seems to be it. I have used the formula in the 60076 standard for temperature compensation for oil-immersed transformers with reference temperature of 75ºC R75 = Rr*(310/(235+tr)), where Rr is the calculated resistance from the measured resistances and tr is...
  5. Luiseng

    Power transformer calculations

    I Edison123, It still does not tie in... rated currents are 43.3A/2327A, primary resistance is 1.164Ohms and secondary is 0.0005497Ohms and the claimed I^2R losses are 9348W. I'm lost... thanks for the help. best regards Luis
  6. Luiseng

    Power transformer calculations

    Hi all, I have a 3ph 2700KVA continuous rating or 12677KVA pulsed at 36KV/670V transformer, I received the test results sheet from the manufacturer and I am trying to go trough the calculations to check it out. They also kindly supplied the formulas that they use for their calculations. The...

Part and Inventory Search