thanks again for your help all. i have used the typical %Z and x/r values from the SKM program. i have also seen the IEEE 399 standard graph for these values. i was just curious to know whether actual values could be calculated from the nameplate data to provide a more accurate short circuit...
i am trying to figure out how the x/r ratio is determined for power transformers, given only nameplate %Z information. i use SKM software currently, and based on some backward calculations using their default x and r values, have determined that the impedance angle used is approximately 80...