Yb - 12 series of box type substation, will pressure room, transformer room, low-pressure chamber three parts to assembly, welding combination as a whole box, with complete and strong, covers an area of small, appearance installation period is short, safe and reliable operation and other advantages. Has a widely use, versatility and interchangeability, is a new equipment of city power network reconstruction for oilfield, mining, ports, high-rise buildings, urban street, residential quarters, factories, enterprises and institutions, power plant and power supply system of internal self powered, in line with the SD32089 the box type substation technical conditions "and ZB4000189 the combined substation," standard.