Analysis and improvement of linkage transfer position for the operating mechanism of MCCB

Linkage transfer phenomenon, which exists in the opening process of the operating mechanism of the molded case circuit breaker MCCB, is introduced. The influence of the linkage transfer position on the behavior of the mechanism is analyzed. According to the analysis result, the linkage transfer position of an actual operating mechanism is improved with virtual prototype technology software ADAMS. Simulation and experiment results show that after improvement, the opening time of the mechanism is shortened by about 1 ms. Short-circuit tests demonstrate that the operating mechanism with its linkage transfer position improved is helpful for enhancing the interruption performance of MCCB while breaking the low-current faults.