Hydraulic drive for low oil-content HV circuit breaker - has control element moved by pressure of open stop valve into required position

摘要

The double-acting drive cylinder is connected to high voltage, and its piston is directly connected to the switching rod (2). A high voltage control element provides supply of the pressure liquid to one or the other side of the piston. A stop valve for the hydraulic liquid, flowing in the same direction as in the cylinder, is connected to earth. The insulating hydraulic liquid is used as extinguishant, and the switching chamber forms a low pressure vessel for the hydraulic system. The control element (20) is forced into a position for the desired switching direction by the pressure generated by opening of the stop valve (36). Preferably the control element has a mid position determined by a spring (32, 33).