METHOD FOR EARTHING AND ENTERING MULTI-POSITION SWITCHES AND CIRCUIT BREAKERS IN MEDIUM VOLTAGE SWITCHGEAR AND DEVICE FOR CARRYING OUT THE SAME

摘要

The earthing involves insertion of a double key (DB) and rotation of the key in the clockwise direction, for releasing a closure cover for the earthing shaft (EW), to allow insertion of a switch key (SL), for operation of the earthing. After initial rotation of the switch key in the clockwise direction through an angle of about 20 degrees, the switching in of the load switch drive is blocked, with further rotation through an angle of between 40 and 140 degrees for switching the multi-position switch from a neutral position to an earthing position, at which the switching in of the load switch is released. Further rotation causes the switching out of the load switch to be blocked.