What does it indicate if a higher HV rated number is listed first on a transformer nameplate, such as 13200/7620?

When a higher HV rated number is listed first on a transformer nameplate, it signifies that the transformer is designed to handle that higher voltage effectively. In the example given, 13200/7620, the first number, 13200, represents the higher voltage rating. This typically indicates that the transformer is equipped with a single high-voltage bushing designed to connect to an external higher voltage line.

Transformers commonly have both high voltage (HV) and low voltage (LV) sides, and the relationship between these sides is critical in the overall functionality of the transformer. A single bushing is sufficient for connection to the higher voltage side when that side is designated as the primary connection.

Other interpretations, like multiple bushings, would imply a different design to accommodate additional connections and voltages, while performance is more about the transformer’s application and not strictly indicated by the voltage rating effectively. Thus, understanding that the first number highlights the single high voltage capability clarifies its practical application in transformer use.