The ZN85-40.5 handcart indoor high-voltage vacuum circuit breaker is a high reliability switchgear designed specifically for 40.5kV power systems. It adopts vacuum arc extinguishing technology and has excellent short-circuit current breaking capacity (up to 40kA). The modular design of the handcart supports quick plugging and greatly reduces maintenance and power outage time. It is compatible with metal armored cabinets (KYN series) and is suitable for high-voltage protection in substations, industrial and mining power distribution, and data centers. Compliant with GB/T 1984 and IEC 62271-100 standards, with a mechanical lifespan of over 10000 cycles, flexible operating mechanism (electric/manual optional), protection level of IP4X, ensuring stable operation in humid and dusty environments.