Mid mounted PT Handcart indoor vacuum circuit breaker is a high-voltage switchgear with a mid mounted integrated voltage transformer (PT), designed specifically for 40.5kV indoor distribution systems. Adopting vacuum arc extinguishing technology, the short-circuit current breaking capacity reaches 40kA, the mid mounted handcart structure saves 50% of installation space, and supports the integration of PT voltage monitoring and protection functions. Compliant with GB/T 1984 and IEC 62271-100 standards, with a mechanical lifespan of over 10000 cycles and a protection level of IP4X, it is compatible with KYN series switchgear and suitable for scenarios such as data centers, industrial and mining power distribution, and rail transit, achieving intelligent power protection with "high-density, zero SF6 emissions".