The kilovolt ampere (kVA) is the measure of power and is 1 kV amps. kVA is equivalent to the current in a circuit produced by the voltage of that line, usually measured in a transformer, that is, it is a unit of current. And kilowatt refers to the power of an electrical appliance, that is, the unit of power. The rated capacity represents the guaranteed value of the output power of the transformer under rated operating conditions and is the apparent power of the transformer.