An overcurrent tripping device includes a tripping conductor connected to the main circuit; a fixed core inside which the tripping conductor penetrates and which is excited by current flowing through the tripping conductor; a movable core which is arranged to be opposed to the fixed core with a magnetic gap therebetween, and which forms a magnetic circuit in cooperation with the fixed core, and moves by being attracted by the fixed core when overcurrent flows through the tripping conductor; and a shaft fixed to the movable core to guide the movement of the movable core, and linked to the tripping mechanism of the circuit breaker, wherein the fixed core has a narrow gap formed in such a direction as to cross the magnetic circuit, so that magnetic saturation is suppressed by the narrow gap.

The invention relates to a switching device including a housing having a front housing and a rear housing. The rear housing includes a rear housing face, and a first sidewall, first end a second sidewall, and a second end wall projecting from the rear housing face to form at least one interior chamber. The sidewalls of the rear housing include a rear housing tab that projects away from the rear housing face. The switching device further includes a splitter plate support, comprising first and second support panels, located within the interior chamber. The first support panel further includes a support hook that extends from the outer panel face. The support hook has an aperture that engages the rear housing tab, in which the rear housing tab extends through the aperture of the support hook, forming a double-walled panel and reinforcing the housing.

The present disclosure relates to an arc extinguishing assembly which, when an arc is generated, has a structure that can push the generated arc in a direction farther away from a stationary contact point by forming a transient pressure difference between arc guides.

The present disclosure relates to an arc extinguishing assembly including a sealing member and a circuit breaker including same. The sealing member is pressed and elastically deformed between coupling surfaces of the arc extinguishing assembly and the circuit breaker, and accordingly, a gap between the coupling surfaces of the arc extinguishing assembly and the circuit breaker is sealed. Accordingly, when an arc is generated, a temporary pressure increase in the circuit breaker increases and the arc can be smoothly extended.

The present disclosure relates to an arc extinguishing assembly, including side members which are spaced apart by a certain distance and disposed to face each other; an exhaust which is installed at an upper part of the side member; a plurality of grids which are installed between the side members and having both ends fixed to each of the side members; and an arc guide whose one side is coupled to the side member and which is installed at a lower part of the plurality of grids, wherein the arc guide is made of a material having heat resistance, and a circuit breaker including the same.

A modular breaking unit with a holder-guiding assembly, wherein: the modular breaking unit includes a casing unit; a holder for holding a movable contact of the modular breaking unit is accommodated in the casing unit; the movable contact of the modular breaking unit is mounted on the movable contact holder; the holder-guiding assembly is installed in the casing unit and arranged to support and guide the movable contact holder to move between an open position and a closed position; the holder-guiding assembly is made of thermoplastic material; the movable contact holder is made of thermosetting plastic material. A contactor including at least one said modular breaking units.

Provided is a molded case circuit breaker including a front space, a rear space divided from the front space, a fixed contact unit provided on one side of the front space and in electric contact with one of a power supply and a load, a movable contact unit installed in the front space to be movable and in contact with the fixed contact unit, a switching device installed in the rear space and operating to allow the movable contact unit to be in selective contact with the fixed contact unit, an operation device installed in the front space and the rear space and transferring the movable contact unit according to operation of the switching device, an arc extinguishment chamber installed on the one side of the front space and extinguishing an arc induced while the fixed contact unit is being separated from the movable contact unit, and a barrier preventing backward movement of the arc from at least one position of a moving way of the movable contact unit, the position separate from the fixed contact unit.

In present disclosure, a movable bar guide portion is formed to protrude toward a movable bar in a shaft having a movable bar, and when a fault current is applied and the movable bar is rotated due to electromagnetic repulsion force, the movable bar and the movable bar guide portion contact each other, and thus, when the movable bar is rotated through the movable guide portion, movement of a rotation center of the movable bar is minimized.

The present disclosure provides a conductive member for a circuit breaker high voltage portion conductor assembly, the conductive member including a body with a transfer portion and a coupling portion. The body transfer portion has an electro-thermally efficient contour. That is, the body transfer portion has an electrically efficient contour and a thermally efficient contour. The body transfer portion includes a number of slots defining fins. In this configuration, the body transfer portion distributes current generally evenly across a cross-sectional area of the conductive member body. Further, the fins provide heat dissipation via convection.

A modular breaking unit with a holder-guiding assembly, wherein: the modular breaking unit includes a casing unit; a holder for holding a movable contact of the modular breaking unit is accommodated in the casing unit; the movable contact of the modular breaking unit is mounted on the movable contact holder; the holder-guiding assembly is installed in the casing unit and arranged to support and guide the movable contact holder to move between an open position and a closed position; the holder-guiding assembly is made of thermoplastic material; the movable contact holder is made of thermosetting plastic material. A contactor including at least one said modular breaking units.