The vacuum circuit-breakers of type VD4 on withdrawable parts for 10 KV or 40.5 KV rated voltage are intended for indoor installation in air-insulated switchgear system. Their switching capacity is sufficient to handle any conditions arising from switching of equipment and system components under normal operating and fault conditions. particularly short-circuits, within the parameters of their technical data.

Vacuum circuit-breakers have particular adswitching frequency in the working current range and/or where a certain number of short-circuit breaking operations are expected. Type VD4 vacuum circuit-breakers are suitable for autoreclosing, and have exceptionally high operating reliability and long life.