Abstract: A circuit breaker for overcurrent protection and earth leakage protection includes a main housing, a circuit board, a zero-phase current transformer, an earth leakage detection circuit, a trip coil, a sensitivity current-switch, an action time switch, and an earth leakage test switch. The earth leakage detection circuit, the sensitivity current-switch, the action time switch, and the earth leakage test switch are mounted on the circuit board and installed in the main housing.

Abstract: An earth leakage breaker includes a main body housing having, in a single structure, a casing and a case cover, and an auxiliary cover for covering the case cover. The case cover has a recess for mounting an internal accessory device. Components including a main circuit contact, a contact switching mechanism, an operation handle, an overcurrent tripping device, an earth leakage detection circuit combined with a zero-phase current transformer, and an earth leakage tripping device, are retained in the main body housing. An earth leakage operation output switch is detachably mounted in the recess formed in the case cover of the main body housing. The earth leakage operation output switch is an internal accessory device that indicates earth leakage trip operation electrically and linking mechanically with the earth leakage trip device to operate the earth leakage operation output switch in the earth leakage trip operation.

Abstract: A circuit breaker for overcurrent protection and earth leakage protection includes a main housing, a circuit board, a zero-phase current transformer, an earth leakage detection circuit, a trip coil, a sensitivity current-switch, an action time switch, and an earth leakage test switch. The earth leakage detection circuit, the sensitivity current-switch, the action time switch, and the earth leakage test switch are mounted on the circuit board and installed in the main housing.

Abstract: An earth leakage breaker includes a main body housing having, in a single structure, a casing and a case cover, and an auxiliary cover for covering the case cover. The case cover has a recess for mounting an internal accessory device. Components including a main circuit contact, a contact switching mechanism, an operation handle, an overcurrent tripping device, an earth leakage detection circuit combined with a zero-phase current transformer, and an earth leakage tripping device, are retained in the main body housing. An earth leakage operation output switch is detachably mounted in the recess formed in the case cover of the main body housing. The earth leakage operation output switch is an internal accessory device that indicates earth leakage trip operation electrically and linking mechanically with the earth leakage trip device to operate the earth leakage operation output switch in the earth leakage trip operation.

Abstract: An earth leakage breaker includes a main contact, a switch mechanism, an operating handle, a leakage tripping device and an over-current tripping device having an earth-leakage-detection circuit disposed in a main-body case. A power-supply line connects the earth-leakage-detection circuit to the main circuit for supplying voltage between phases of the main circuit as a power source of the earth-leakage-detection circuit. Further, a test switch is provided for turning on and off a power-supply circuit of the power-supply line connected to the earth-leakage-detection circuit, and an operation of the test switch is linked to an ON/OFF operation of the switch mechanism.

Abstract: A circuit breaker has a molded case with a main case, a middle cover and a top cover being dividable from one another. The main case contains contactor sections, each including a stationary contactor and a movable contactor for a pole corresponding to each phase in a polyphase circuit, an arc-extinguishing device, an overcurrent tripping device actuating a tripping mechanism by detecting an overcurrent, and a zero-phase current transformer detecting a leak current. The middle cover has a partitioned recess for containing a switching mechanism and the tripping mechanism. Interpole partitions, surrounding the contactor section and the arc-extinguishing device, and a screen-like intermediate partition, isolating the contactor sections from the overcurrent tripping device, are formed with the middle cover laid on the main case. A wall with gas outlets for an arc gas is provided on the back of the arc-extinguishing devices.

Abstract: A circuit breaker has a molded case with a main case, a middle cover and a top cover being dividable from one another. The main case contains contactor sections, each including a stationary contactor and a movable contactor for a pole corresponding to each phase in a polyphase circuit, an arc-extinguishing device, an overcurrent tripping device actuating a tripping mechanism by detecting an overcurrent, and a zero-phase current transformer detecting a leak current. The middle cover has a partitioned recess for containing a switching mechanism and the tripping mechanism. Interpole partitions, surrounding the contactor section and the arc-extinguishing device, and a screen-like intermediate partition, isolating the contactor sections from the overcurrent tripping device, are formed with the middle cover laid on the main case. A wall with gas outlets for an arc gas is provided on the back of the arc-extinguishing devices.

Abstract: A circuit breaker includes a fixed contact; a movable contact disposed in a rotary-type contact holder; a switching device; an operation handle; and an over-current tripping device. The operation handle is operated to open and close main-circuit contact points through the switching device. The switching device includes a handle lever connected to the operation handle; a toggle linkage having an upper toggle link and a lower toggle link; a switching spring placed between the handle lever and an arm connecting point of the toggle linkage; and a side plate for holding the components. The circuit breaker further includes a device for preventing the operation handle from moving to an off position when the contact points are stuck together. The device includes first stoppers formed on a cross bar of the contact holder and the handle lever facing the cross bar, and a second stopper formed on the side plate.

Abstract: An earth leakage breaker includes a main contact, a switch mechanism, an operating handle, a leakage tripping device and an over-current tripping device having an earth-leakage-detection circuit disposed in a main-body case. A power-supply line connects the earth-leakage-detection circuit to the main circuit for supplying voltage between phases of the main circuit as a power source of the earth-leakage-detection circuit. Further, a test switch is provided for turning on and off a power-supply circuit of the power-supply line connected to the earth-leakage-detection circuit, and an operation of the test switch is linked to an ON/OFF operation of the switch mechanism.

Abstract: A circuit breaker includes a fixed contact; a movable contact disposed in a rotary-type contact holder; a switching device; an operation handle; and an over-current tripping device. The operation handle is operated to open and close main-circuit contact points through the switching device. The switching device includes a handle lever connected to the operation handle; a toggle linkage having an upper toggle link and a lower toggle link; a switching spring placed between the handle lever and an arm connecting point of the toggle linkage; and a side plate for holding the components. The circuit breaker further includes a device for preventing the operation handle from moving to an off position when the contact points are stuck together. The device includes first stoppers formed on a cross bar of the contact holder and the handle lever facing the cross bar, and a second stopper formed on the side plate.