Transformer is 75kva 3 phase 120-208. The panel does not have a main breaker just (4) 100 amp breakers. I'm trying to figure out if setting a 200 amp single phase subpanel is going to be to much for the transformer to handle. I am calling the local power company to see what the usage in Kwh's. What is the best way to determine if the transfomer can handle the additional load? How do I turn Kwh's into useful information? Thanks!