I saw this problem somewhere and I wanted to give it a try, but the numbers I've got seem to be pretty outlying.
We have a 25kV / 4160V transformer which is out of circuit for now. To protect it from humidity in a freezing cold conditions, we need to keep it warm by short-circuiting its primary coil and connecting the secondary coil to a 208V, 3ph line. How much heat will be generated in this way? The transformer specifications are as follows.
My try:
Since the primary coil is short-circuited, all the loss occurs at the core. And since it is operating at 5% of its nominal voltage, the coil loss will be 5% of its nominal value, i.e. about 650 watt. Though I suspected that since the loss is proportional to V^2
then it would be even lower, but nonetheless, the numbers are way too lower than what I've been told (which was 57% of the full-load loss).
So I would appreciate if anyone guide me on how to approach such problems.