KYN28A-12 is a 12 kV metal-clad, withdrawable AC switchgear using a center-mounted vacuum circuit breaker (VS1/ZN63A, VD4, HVX, EV12s). Rated for 50 Hz three-phase networks up to 12 kV, it handles power receiving, distribution, control, and protection in utilities, industry, transport, and municipal systems. Features an aluminum-zinc coated steel enclosure with separated compartments and complete five-prevention interlocks. Type-tested for internal arc (IAC) and conforms to GB 3906, GB/T 11022, DL/T 404, IEC 62271-1/200.