KYN28A-12 series are the medium voltage switchgears that the Zhongshan Mingyang Electric Co., Ltd. manufactures, which are suitable to indoor AC metal medium voltage switchgear with rated voltage of 7.2~12kV and frequency of 50Hz. It's mainly used as the PTD control device of single bus and single bus section system which receives and distributes the electric energy in switching room of power station, substation and industrial and mining enterprises.