Abstract: A circuit breaker according to the present invention includes a terminal switching unit mounted in an enclosure thereof, and the terminal switching unit accommodates, in a base as an outer casing thereof, a fixed contactor and a movable contactor contactable with and separated from each other, a sliding unit rotatably supporting the movable contactor, and a detection mechanism to detect a fault current. Radiators are provided at side portions of at least one of a contact portion where the movable contactor comes in contact with the fixed contactor, the sliding unit and the detection mechanism, each radiator radiating heat to the outside of the base. This may prevent an increase in temperature of the circuit breaker within a limited space without an increase in costs.

Abstract: Disclosed is a gap adjusting method which easily adjusts a gap between a bimetal and a crossbar by using a gap adjusting block and an adjusting screw in a trip mechanism of a molded case circuit breaker without a separate additional device. The gap adjusting method in the trip mechanism of the molded case circuit breaker includes setting a reference gap between a crossbar and a bimetal, measuring a total resistance of the trip mechanism and a trip stroke of a switching mechanism to set a compensation gap, placing a gap adjusting block on a position separated from a crossbar by a gap based on the sum of the reference gap and the compensation gap, rotating an adjusting screw assembled with the bimetal to contact the adjusting screw with the gap adjusting block, and adhering the adjusting screw to the bimetal.

Abstract: A circuit breaker according to the present invention includes a terminal switching unit mounted in an enclosure thereof, and the terminal switching unit accommodates, in a base as an outer casing thereof, a fixed contactor and a movable contactor contactable with and separated from each other, a sliding unit rotatably supporting the movable contactor, and a detection mechanism to detect a fault current. Radiators are provided at side portions of at least one of a contact portion where the movable contactor comes in contact with the fixed contactor, the sliding unit and the detection mechanism, each radiator radiating heat to the outside of the base. This may prevent an increase in temperature of the circuit breaker within a limited space without an increase in costs.

Abstract: Disclosed is a gap adjusting method which easily adjusts a gap between a bimetal and a crossbar by using a gap adjusting block and an adjusting screw in a trip mechanism of a molded case circuit breaker without a separate additional device. The gap adjusting method in the trip mechanism of the molded case circuit breaker includes setting a reference gap between a crossbar and a bimetal, measuring a total resistance of the trip mechanism and a trip stroke of a switching mechanism to set a compensation gap, placing a gap adjusting block on a position separated from a crossbar by a gap based on the sum of the reference gap and the compensation gap, rotating an adjusting screw assembled with the bimetal to contact the adjusting screw with the gap adjusting block, and adhering the adjusting screw to the bimetal.

Abstract: Disclosed is a method for controlling a gap in a circuit breaker, the circuit breaker configured to interrupt a circuit by separating a movable contactor from a fixed contactor as a cross bar is pressed to be rotated by a pressing member due to bending of a bimetal, the method including: a gap forming step of bending the bimetal by apply of a set current, in a state where the pressing member is coupled to a coupling hole so as to be freely-movable, the coupling hole formed at an upper part of the bimetal; and a gap fixing step of interrupting the set current when a prescribed time has lapsed, and of welding the pressing member to the bimetal.

Abstract: A circuit breaker includes: a bimetal bent by heat generated from a conductive current; a pressing member coupled to an upper part of the bimetal; a cross bar spaced from the pressing member by a prescribed gap, and configured to contact the pressing member and to rotate by being pressed when the bimetal is bent; and a switching mechanism operated by rotation of the cross bar, and configured to separate a movable contactor from a fixed contactor, wherein a coupling hole for coupling the pressing member is provided at an upper part of the bimetal, and wherein the pressing member is bonded to the coupling hole after a prescribed gap between the pressing member and the cross bar has been determined by apply of a current when the pressing member is in a state of being freely movable in the coupling hole.

Abstract: Disclosed is a method for controlling a gap in a circuit breaker, the circuit breaker configured to interrupt a circuit by separating a movable contactor from a fixed contactor as a cross bar is pressed to be rotated by a pressing member due to bending of a bimetal, the method including: a gap forming step of bending the bimetal by apply of a set current, in a state where the pressing member is coupled to a coupling hole so as to be freely-movable, the coupling hole formed at an upper part of the bimetal; and a gap fixing step of interrupting the set current when a prescribed time has lapsed, and of welding the pressing member to the bimetal.