Vacuum circuit-breakers are used for making and breaking load and fault currents during operation of transformers, capacitors and other consumers in medium-voltage grids. The SION 3AE2 is a special vacuum circuit-breaker designed for generator switching. Accordingly, it is type-tested according to IEC/IEEE 62271-37-013. It is conceived not only for fixed mounting, but also for any kind of withdrawable solutions.