how to size a 3 phase transformer?

To size a three-phase transformer, first determine the total load in kilowatts (kW) that the transformer will supply. Convert this load to kilovolt-amperes (kVA) by dividing by the power factor (typically between 0.8 and 1). Use the formula: kVA = kW / Power Factor. Consider future load growth and any applicable local codes. Finally, select a transformer with a kVA rating that meets or exceeds this calculated value to ensure reliable operation.