CIRCUIT BREAKER

摘要

A circuit breaker in which inter-phase blocks are not required between breaker units, and the cases constituting the breaker units are hardly broken by blast of the arc gas generated between the contacts when a large current such as a short circuit current flows. The circuit breaker has a contact mechanism consisting of a movable contact (18) and a fixed contact (17), an opening/closing mechanism (30) for opening/closing the contact mechanism, an arc extinguishing device (59) for guiding an arc generated when the contact mechanism separates in a prescribed direction, a case (10) housing the mechanisms and devices. In such a circuit breaker, the contact mechanism and the arc extinguishing device are housed in the cases (51 and 52) made of an insulation material to constitute single-pole breaker units (50, 53, 56), and a plurality of single-pole breaker units are arranged closely side by side to constitute a multi-pole circuit breaker.