| 摘要 |
A molded case circuit breaker includes separable contacts, a conventional operating mechanism, and means for magnetically stretching the arc upon contact separation to provide current limiting action. In a first embodiment, the arc stretcher comprises three separate stacks of spaced parallel U-shaped magnetic plates each oriented to provide a slot parallel to the plane of the loop formed by an expanding arc. In a second embodiment, the U-shaped plates each comprise a plurality of coplanar interleaved magnetic plates electrically insulated therebetween and having extending members to form pins lining the sides of the slot formed by the stack of plates. Additional independent pins inserted into the slots of an arc chute are also provided. A third embodiment includes fixed and movable contact arms and conductive means attached thereto to provide current flow in opposite directions through the contact arms. The contact arms and conductive means are positioned and sized so as to provide positive arc positioning.
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