Arrangement for arc transfer in high amperage molded case circuit breaker

摘要

Arc control in a high amperage molded case circuit breaker is provided by a steel horn for each of a plurality of contact blades for each phase. The horn has a portion extending into a U-shaped recess in a steel arc runner plate. As the contacts separate, the portion travels close to one wall of the recess and then close to the other wall to transfer the arc from the contacts first to the one wall and then to the other wall which is located adjacent the arc suppressor assembly. A respective adjustment member extending through each horn controls the spacing between the blades and a contact carrier to in turn control the opening sequence of the contacts for minimizing arcing across certain contacts. Arc suppressor plates of alternating length are arranged in an arc corresponding to blade travel and define passageways having their larger exits aligned with respective vents defined by a molded insulator engaged in the wall of the base.