KYN28-12 Indoor metal-clad Middle-mounted Switchgear (hereafter referred to as Switchgear) is the complete set of switchgear used for three phase AC single busbar of 3-10KV and 50/60Hz and single bus section system. It is mainly used for power plant, medium and small size power plant to distribute electric power, for the industrial and mining business to distribute electric power, for the secondary substation of electric power system to accept and distribute electric power, as well as for the start of large size HV dynamo. The switchgear conforms to IEC 298 and GB 3906 standards. It has such functions as followings: Preventing live load from pushing and pulling the handle of the circuit breaker, preventing from false breaking or closing the circuit breaker, preventing from closing or opening the circuit breaker when the earthing switch is on the closing position, preventing from false getting into the live compartments and preventing from false closing the live interlock of the earthing switch. It can be equipped with VS1, VD4, VB2, 2AH5, and 10VPR vacuum circuit breaker. It is really a power distribution device with good performance.