A Pneumatic Mechanism for Outdoor Oil Circuit Breakers

This compressed-air mechanism has been developed to answer the requirements of a simple and reliable stored-energy mechanism. By arranging this mechanism to be pneumatically trip-free, it has been possible to get the high-speed operations required of modern oil circuit breakers. The mechanism has been tested under severe operating conditions to insure trouble-free performance. Timetravel curves show satisfactory characteristics for closing, tripping, trip-free, and instantaneous reclosing operations. The absence of synchronized mechanical motions and critical mechanical adjustments contributes to a reduction in maintenance and will add to reliable operation.