Which parameter is commonly used to indicate the capacity of a transformer?

The capacity of a transformer is commonly indicated by its power rating, typically expressed in volt-amperes (VA) or kilovolt-amperes (kVA). This rating reflects the maximum amount of electrical power the transformer can effectively handle while operating safely. It combines both voltage and current ratings into a single parameter that signifies the capacity for which the transformer was designed.

When analyzing transformers, understanding their power rating is crucial because it determines how much load can be safely connected to the transformer without risking overheating or damaging the device. The power rating helps ensure that the transformer can supply the required energy for the connected equipment and systems without exceeding its limitations.

While voltage rating and current rating are also important specifications, they represent the maximum voltage and current the transformer can handle individually rather than its overall capacity to supply power. Frequency rating pertains to the AC signal frequency the transformer is designed for, which does not directly indicate its power capacity. Thus, the power rating is the most comprehensive measure of a transformer’s capacity.