Minor nitpick, transformers are sized in volt-amps, not watts. Apparent power is measured in volt-amps and actual power is measured in watts, the ratio between

Minor nitpick, transformers are sized in volt-amps, not watts. Apparent power is measured in volt-amps and actual power is measured in watts, the ratio between the two is the power factor. Plus, “one mega volt-amp” sounds way cooler than “a million watts” :) It may have been a 1MVA transformer with a 480V three-phase secondary, that’s the properly sized transformer, but the utility may have undersized it at 500kVA based on calculated load. That transformer was already oil-cooled, so adding a couple thousand extra gallons probably didn’t hurt the transformer too much lol.