Not only that but any phase angle imbalances or faults on the utility side will cause the transformer to act as a grounding transformer. It can either trip the OCPDs or burn up the unit.By the way, I hope you did NOT connect the X0 terminal on the 208Y side of that transformer... If you did, remove it immediately.
If your transformer is too small, you could be causing it to saturate with the starting current of the motor, which will cause a voltage drop, which reduces the starting torque of the motor and it can stall. But again, without DETAILS, as in NUMBERS on this equipment, we can only take stupid guesses.
The utility furnished the 550V from their system or the utility installed the step up transformer?Yes set up worked on original power from utility