Abstract: A circuit breaker with overload and short-circuit protection functions for a motor, on which is mounted a thermally actuated overload tripping device including an adjustment dial to set a value corresponding to a rated current value of the motor on a scale. The dial has a standard setting pointer mark and a correction setting pointer mark side-by-side along a perimeter. The standard setting pointer mark applies to using the circuit breaker as a single item. The correction setting pointer mark applies to using a number of circuit breakers arranged in a line in close contact with each other. By setting a mark selected according to the arrangement of the circuit breaker at the rated current value, the steady state current value of the tripping device can be adequately set to correspond to the rated current value of the motor.

Abstract: A circuit breaker with overload and short-circuit protection functions for a motor, on which is mounted a thermally actuated overload tripping device including an adjustment dial to set a value corresponding to a rated current value of the motor on a scale. The dial has a standard setting pointer mark and a correction setting pointer mark side-by-side along a perimeter. The standard setting pointer mark applies to using the circuit breaker as a single item. The correction setting pointer mark applies to using a number of circuit breakers arranged in a line in close contact with each other. By setting a mark selected according to the arrangement of the circuit breaker at the rated current value, the steady state current value of the tripping device can be adequately set to correspond to the rated current value of the motor.

Abstract: A circuit breaker includes terminals with screws on a power supply side and a load side disposed at a front end section and a rear end section of a main body case containing a current interrupting unit and a switching mechanism. A terminal cover is detachably attached onto the main body case at a position corresponding to the terminals on at least one of the power supply side and the load side. A terminal cover attaching surface is formed on an upper surface on the power supply side and/or the load side of the main body case. The terminal cover is inserted while sliding on the attaching surface from a front end, so that the terminal cover is attached to the main body case with a snap-fit coupling unit at an assembling position.

Abstract: A circuit breaker includes terminals with screws on a power supply side and a load side disposed at a front end section and a rear end section of a main body case containing a current interrupting unit and a switching mechanism. A terminal cover is detachably attached onto the main body case at a position corresponding to the terminals on at least one of the power supply side and the load side. A terminal cover attaching surface is formed on an upper surface on the power supply side and/or the load side of the main body case. The terminal cover is inserted while sliding on the attaching surface from a front end, so that the terminal cover is attached to the main body case with a snap-fit coupling unit at an assembling position.

Abstract: In a terminal device of a switching device, a terminal screw with a washer is screwed in a terminal strip having a screw hole therein for connecting an external wire. The terminal strips are placed on terminal boards of power supply side and load side formed at both ends of a switching device case. A case cover covers the terminal screw, and a screwdriver is inserted through an insertion hole formed in an upper surface of the case cover to tighten the terminal screw. The terminal device includes a terminal lifter connected to the terminal screw for manually lifting the terminal screw upwardly from the upper surface of the case cover, so that the terminal screw is temporally attached to the case cover at a lifted position after the terminal screw is loosened and detached from the terminal strip with the screwdriver.

Abstract: A circuit breaker includes a rectangular box-shaped intermediate housing and lower housing; a power supply side fixed contact and a load side fixed contact disposed in the intermediate housing and facing each other; and a movable contact housed in the lower housing for bridging the power supply side fixed contact and the load side fixed contact. The lower housing has arc gas emission holes formed in front and rear walls thereof, and is connected to a lower part of the intermediate housing via an engagement part such that the lower housing covers the lower part of the intermediate housing. A thin wall portion is formed in each of the front and rear walls to eject arc gas by bending.

Abstract: A circuit breaker includes a rectangular box-shaped intermediate housing and lower housing; a power supply side fixed contact and a load side fixed contact disposed in the intermediate housing and facing each other; and a movable contact housed in the lower housing for bridging the power supply side fixed contact and the load side fixed contact. The lower housing has arc gas emission holes formed in front and rear walls thereof, and is connected to a lower part of the intermediate housing via an engagement part such that the lower housing covers the lower part of the intermediate housing. A thin wall portion is formed in each of the front and rear walls to eject arc gas by bending.

Abstract: A protective switch includes a switch housing, a switching mechanism for closing and opening a movable contact, a tripping mechanism instantaneously pulling a plunger upon detection of an instant current, a tripping control device, an alarm switch, and a trip member. The trip member is divided into an upper trip member away from a bottom of the housing, and a lower trip member close to the bottom of the housing urged by a back spring. The upper trip member includes a plunger operating section opposed to an operating member of the plunger and a switch operating section opposed to an actuator of the alarm switch. The lower trip member includes a locking member operating section opposed to a locking member of a switching mechanism and a tripping section opposed to an operating member of a tripping control device.

Abstract: A circuit breaker includes a molded case comprised of a case and a cover. Terminal parts to be connected to a power supply and a load are provided respectively at front and rear ends of the molded case. A control mechanism for switching a movable contact is disposed between the front and rear terminal parts. The cover is divided into three parts for covering the control mechanism and the terminal parts disposed at front and rear of the control mechanism, respectively. The front and rear parts of the cover covering the terminal parts are detachably mounted on the molded case as terminal covers.

Abstract: A mounting structure for mounting a switch device includes a main body case for the switch device having slots formed in lower portions of the front and rear surfaces, and mounting plates to be inserted into the slots. Each mounting plate has a screw hole at one end and an insertion portion at the other end The insertion portions are inserted into the slots to allow the main body case to be fixed by the mounting plates. The switch can be mounted using screws inserted into the screw holes in the mounting plates.

Abstract: A protective switch includes a switch housing, a switching mechanism for closing and opening a movable contact, a tripping mechanism instantaneously pulling a plunger upon detection of an instant current, a tripping control device, an alarm switch, and a trip member. The trip member is divided into an upper trip member away from a bottom of the housing, and a lower trip member close to the bottom of the housing urged by a back spring. The upper trip member includes a plunger operating section opposed to an operating member of the plunger and a switch operating section opposed to an actuator of the alarm switch. The lower trip member includes a locking member operating section opposed to a locking member of a switching mechanism and a tripping section opposed to an operating member of a tripping control device.

Abstract: A mounting structure for mounting a switch device includes a main body case for the switch device having slots formed in lower portions of the front and rear surfaces, and mounting plates to be inserted into the slots. Each mounting plate has a screw hole at one end and an insertion portion at the other end thereof. The insertion portions are inserted into the slots to thereby allow the main body case to be fixed by the mounting plates. The switch can be mounted using screws inserted into the screw holes in the mounting plates.

Abstract: A terminal unit having connection conductors to be connected to corresponding terminals of a switch is installed in a terminal section of the switch, and an external electric wire is connected to each terminal section of the connection conductors. Thus, the insulation distance between phases for the terminal sections and the insulation distance between the terminal section and a panel cut surface are increased according to the requirement of the switch. The shape and size of the terminal unit can be set regardless of the switch, so that a required insulation distance is obtained without increasing the size of the switch main body.

Abstract: In a terminal structure of a switch which is arranged in a manner that a terminal conductor 14 with a terminal screw drawn from the inner portion of the casing is disposed at every phase in the terminal portion of a casing formed by the three-divided structure of an upper cover 2, an intermediate cover 3 and a lower cover, and wires inserted into the terminal portion from the outside are respectively fastened by the screws to be coupled to the terminal conductors, the terminal conductors of the respective phases are pressed into the terminal fixing grooves 3b formed at the intermediate cover and fixed to the casing in a manner that the left and right side edges of each of the terminal conductors are pressed into the grooves.

Abstract: In a make-and-break mechanism for use in a circuit breaker, an alarm output plate 56, which is disposed so as to be slidable in the vertical direction along the frame (cover plate) 27 of the make-and-break mechanism, is secured to the engaging projection 27d of the cover plate 27 through a pair of right and left guide holes 57 formed therein. At the same time, one end of a handle spring 59, which, in the trip operation, is used to rotate an operation handle 26 to a trip display position, is caught on the alarm output plate 56.