Abstract: Rotary disconnect switch assembly, including a metal encapsulation insulated with SF.sub.6 gas, flanges integral with the encapsulation, support insulators disposed on the flanges, a drive shaft passing through the encapsulation and having a portion disposed outside and a portion disposed inside the encapsulation, a drive connected to the outside portion of the drive shaft, a profile formed on the inside portion of the drive shaft, three disconnect blades fastened side by side in axial direction of the inside portion of the drive shaft, intermediate pieces passing through the support insulators being connectible to phase conductors, and an opposite pair of first and second fixed contacts for each individual phase connected along the intermediate pieces in axial direction of the drive shaft, the blades being rotatable between an "on" position in which they connect the first and second contacts to each other and a "disconnect" position.