A BLOCK OF BUSHINGS OF A THREE-PHASE ROTARY SWITCH-DISCONNECTOR

摘要

The invention disclosed is a block of bushings of a three-phase rotary switch-disconnector with a double isolating clearance between the electric contacts, intended for multiple switching of currents in electric circuits that are in a working status, and also for emergency switching-on of electric circuits that are in a fault condition. The block of bushings of a three-phase rotary switch-disconnector is a resin casting in the form of a rotary shaft (2) with three bushings (3a, 3b) fitted with circumferential petticoats (7a, 7b). The bushings (3a, 3b) are arranged along the axis of the rotary shaft and perpendicularly to the axis of the shaft, and the shaft axis divides the body of each of the bushings into two symmetrical parts in which a common conducting rod (4) is located, whose ends protrude outside the bushing body and make a movable element of the current path of the switch-disconnector. The bodies of the bushings (3a, 3b) in a cross- section have the contour in the shape of an ellipse or an ellipse with the vertexes truncated on both sides.