On the economics....
A 225 kVA XFMR is huge. Regardless of the true load it will bleed energy to sustain its magnetic circuit.
Correct sizing would mean a XFMR of 75kVA.
So you're bleeding off 225/75 = 3 times as much parasitic losses as would be nominal.
Do run your calculations.
BTW 3 is the lower bound.
Power cost being what it is -- you'd very likely be much better off scrapping/ reselling the gear and downsizing to a new/used transformer.
Talk to Salinger and others in the used electrical equipment market. You'll have your eyes opened.http://www.salingerelectric.com/