JPS6414841A - Circuit breaker - Google Patents

Abstract

PURPOSE:To enlarge rating, ensure the easy setting of a tripping operation level and prevent the delay of shortcircuit current detection by applying the constitution wherein a tripping device is actuated on secondary current output from a secondary current output means and thereby tripping operation is made. CONSTITUTION:A main circuit 30 is provided with a converter 32 and when shortcircuit current runs, a tripping device 33 is actuated with secondary current output from the converter 32, thereby causing a tripping process. As compared with the case of a primary conductor as coiled, a device can be made compact and the rating thereof can be made large. For the adjustment of a tripping operation level, it is required simply to adjust pertinently the secondary current output from the converter 32. Consequently, it is unnecessary to adjust the spring force of the tripping device 33, thereby enabling the easy setting and adjustment thereof. Furthermore, as constitution is so made that the tripping device 33 is actuated with the secondary current output, the rate of current change is detected and the delay of shortcircuit current detection can be made short. Furthermore, the signal processing of the secondary current output is not made when the tripping device 33 is actuated with the secondary current output, thereby enabling the simplification of electrical constitution.