KYN28A-12 (GZS1) metal armored withdrawable switchgear is an indoor complete set of distribution equipment for three-phase AC 50Hz, rated voltage 3.6-12KV single busbar and single busbar segmented system. Suitable for indoor power supply systems such as power plants, substations, airports, docks, factories, mines, enterprises, hotels, financial high-rise buildings, and civil buildings, used for receiving, distributing electrical energy and monitoring and protecting the power grid. The switchgear has the functions of preventing misoperation of circuit breakers, preventing the pushing and pulling of carts under load, preventing the live closing of grounding switches, preventing the grounding switch from transmitting power when in the grounding position, and preventing accidental entry into live intervals (referred to as the five protections). It is a high-performance power distribution device. The main components inside the switchgear are domestic VS1 vacuum circuit breakers, as well as general Siemens 3AE, ABB VD4, and Schneider HVX12.