The ZW20-12 type outdoor boundary high-voltage vacuum circuit breaker (hereinafter referred to as the circuit breaker) is an outdoor power distribution equipment with a rated voltage of 12kV and a three-phase AC 50Hz. It uses vacuum arc extinguishing and SF6 gas as the insulating medium. The box adopts the gas sealing, explosion-proof, and insulation structure technology of Toshiba's VSP5 introduced from Japan. The inlet and outlet conduits have also been improved in sealing performance, resulting in excellent overall sealing performance. The internally filled SF6 gas does not leak and is unaffected by external environmental conditions. Its spring operating mechanism has been miniaturized and optimized for reliability and stability, employing direct chain transmission and a multi-level trip system, significantly improving operational reliability and stability compared to traditional domestic mechanisms. The contact between the shaft and sleeve of the main circuit adopts an inwardly retracting and outwardly expanding chain structure, resulting in low contact resistance and low temperature rise. Therefore, the ZW20-12 type outdoor boundary high-voltage vacuum circuit breaker is a maintenance-free product and an excellent choice among pole-mounted circuit breakers.
The ZW20-12 type outdoor boundary high-voltage vacuum circuit breaker complies with the national standard GB1984 ("High-Voltage AC Circuit Breakers") and GB/T11022 ("Common Technical Requirements for High-Voltage Switchgear and Control Equipment Standards") as well as relevant IEC standards. It features overcurrent protection, ground protection, and reclosing functions. Through an aviation connector connected to the controller, it possesses automated functions such as automatic removal of single-phase ground faults, automatic disconnection of phase-to-phase short-circuit faults, rapid fault location, and event recording. Excellent electrical and mechanical performance makes the ZW20-12 type outdoor boundary high-voltage vacuum circuit breaker widely applicable. It is primarily used for breaking and closing load currents and short-circuit currents in 10kV power systems, suitable for protection and control in substations and industrial and mining enterprise power distribution systems, and particularly suited for frequently operated grid scenarios. This product, paired with a controller, serves as a boundary circuit breaker for the first circuit breaker at the boundary between power companies and users, offering comprehensive protection performance, excellent recloser functionality, and meeting the requirements of distribution automation systems.