Auto-pneumatic HV circuit breaker - has several series switching positions, switching cylinders and moving contacts driven by central insulating rod

摘要

Each switching position consists of a pressurised gas pump with a piston/cylinder unit, and insulating nozzle, a power contact and a rated current contact. The cylinder (5) and the moving contact (3, 4) are driven by a central insulating rod (7), passing through the entire system. The insulating nozzle (8) is mounted at the cylinder edge. The stationary part (2) of the rated current contact is of strip shape and consists of two opposite circular segments. The insulating parts, coming into contact with the light arc gases, may be protected by a coating of heat resistant plastics. The switching positions may be surrounded by insulating tubes (9) forming simultaneously paralle capacitors, as known.