Applicable to three-phase AC power systems with a rated voltage of 7.2-12kV and a frequency of 50Hz, the matched metal-clad removable withdrawable switchgear has a cabinet width of only 550mm. Widely used in real estate, hospitals, administrative, commercial, substations, and other places with dense personnel and buildings, serving for the protection and control of electrical facilities. It is especially suitable for locations requiring frequent operation at rated current or multiple interruptions of short-circuit current. The product complies with GB1984 "AC High-Voltage Circuit Breakers," DL/T403 "Technical Conditions for Ordering 12~40.5kV Indoor AC High-Voltage Circuit Breakers," as well as IEC60694, IEC62271-100, and other relevant standards. The VKY-12 series 550mm cabinet solid-sealed high-voltage vacuum circuit breaker adopts advanced APG technology, sealing the vacuum interrupter and main conductive circuit directly within the epoxy resin pole to form a solid-sealed insulation method, representing the world's highest level in the design and manufacturing of high-voltage vacuum circuit breakers.