Gunner Asch wrote:

On Wed, 04 Jan 2012 22:27:16 -0600, Ignoramus8679
wrote:

I understand that there is a bit of fudge factors involved, but I want
to know, approximately what size motors (with a usual load, like a
compressor or a lathe) can I start with a 45 kVA transformer feeding it.

No soft start of course.

Thanks

15hp
Well, 15 Hp is about 11 KW continuous, maybe 15 KVA including the power
factor. But, such a transformer should be able to handle a larger motor.
You should be able to start a 50 Hp motor, although the line voltage might
dip just a bit. Typical transformers are designed to permit starting
motors near the full running KVA of the motor. Not sure how your running
the transformer in reverse and altering the primary turns have affected
this.

Jon