Short-Circuit Voltage

The short-circuit voltage refers to the necessary voltage that must be applied to a transformer’s input winding to achieve the rated input current when the output winding is short-circuited, and the windings are at ambient temperature. It is usually expressed as a percentage of the rated input voltage and represented by the symbol uk​.

A low short-circuit voltage indicates that the transformer is designed to have low copper losses at the rated current. However, in some applications, such as with certain converters in drive technology, a higher short-circuit voltage is necessary. In these cases, it might be beneficial to connect a line choke upstream of the transformer.