CIRCUIT BREAKER

摘要

A molded case (2) is constituted of a case main body (11) and a cover (12) mounted on the upper part of the case main body. The case main body is constituted of a lower part case (13) and a middle case (14) that has a bottom part (14a) that provides a shield between the same and the lower part case and is mounted on the upper part of the lower part case. Contact parts (3, 5) and an arc extinguishing device (9) are integrated into an internal space in the lower part case, and an opening and closing mechanism (7), an overcurrent trip device (8), and an ancillary switch (10), which is an internally installed ancillary device, are integrated into an internal space in the middle case.