ZW7-40.5 Outdoor high-voltage vacuum circuit breaker is for alternating current of rated voltage of 40.5kV for outdoor installation, and for service frequency of 50Hz. Spring operation mechanism can be remote controlled or manual controlled for opening/closing. The design is in accordance with GB1984-89 High Voltage Circuit Breaker and IEC-56 High Voltage Circuit Breaker. ZW7-40.5 vacuum circuit breaker is mainly used for control and protection of outdoor power transmission systems of rated voltage of 35kV, as well as used for normal operation and short-circuit protection for users like distribution networks for city, country, and enterprises. The whole structure of this product is divided by two parts, the up porcelain is fitted with vacuum interrupter, and the down unit is supporting porcelain. This product is suitable for frequent operations, having the advantages of good air tightness, resistance to high temperature and pressure, no hazard of explosion and selfignition, easy installation and maintenance.