Not too much "electronics" here, more "electrics" ... ;)
We need to make a test fixture for 3-phase motors that will be run no load. So the current draw will be a few amps per phase.
Input power is the standard industrial for our area: 460VAC (nominal), 60Hz, 3-phase.
The motors to be tested will be (all 60Hz 3-phase) 460V, 208V, and occasionally 575V for our friends in Canada.
None of us here are electrical "power" engineers. So when I start looking generically for 3-phase transformers for this, I really don't find any with step-up+step-down taps.
I saw some references about running step-down (from e.g. 575V) "backwards" with appropriate derating. Is that the way to go, as the current draws are modest?
As it is a one-off test rig, we'd rather be spending hundreds vs. thousands of dollars.
Any ideas? TIA