Quote from: Trends on January 01, 2015, 01:15:49 AM

Each of the 3 distribution panels (208/120 breaker panels) would have a 225 amp main breaker, not one single 225A breaker on the 208V output of the transformer.

Transformers are sized to permit 100% of their rating therefore 278 Amps (100080 watts) of 208V is avaliable for the 3 distruibution panels to share depending on connected load at each panel. In theroy it would be possible to load up the distribution panels (even following the 80% rule) to exceed the 278A output of the transformer but doing so would cause the main transformer breaker to trip on overload.
Best to have a qualified electrician or electrical eng review your plans.

Trends

Always a good idea to get a review by an expert. Some transformers can be overloaded depending on their insulation class and ambient temperature.