The present device was conceived in order to resolve the aforementioned problem, and the objective thereof is to provide an arc chamber of a circuit breaker that enhances assemblability and ensures the consistency of the product. An arc chamber of the circuit breaker according to one embodiment of the present device comprises: a plurality of grids arranged at predetermined intervals outside a motion locus of a movable contactor and having a body portion and a leg portion extending from one side of the body portion; and a fixing cap having a receiving portion that is inserted into the leg portion in a press-fitting manner, wherein the fixing cap has a coupling portion extending to a side of the body portion at one side thereof.

A power distribution unit includes a circuit protection device having output terminals and a current transformer board connected to the output terminals of the circuit protection device. The power distribution unit further includes a signal board connected to the current transformer board and a measurement board connected to the signal board.

A power distribution unit includes a circuit protection device having output terminals and a current transformer board connected to the output terminals of the circuit protection device. The power distribution unit further includes a signal board connected to the current transformer board and a measurement board connected to the signal board.

An apparatus includes a cell pan that supports a circuit breaker within a switchgear cell, and a lift pan that carries a circuit breaker outside of the switchgear cell. The lift pan has a track for a roller on the circuit breaker. The apparatus further includes an extension rail that interconnects the lift pan with the cell pan in an aligned position. With the lift pan in aligned position, the track on the lift pan can receive the roller upon horizontal draw-out movement of the circuit breaker from the cell pan. A latch on the extension rail has a blocking position in which it blocks the roller from rolling outward off the cell pan, and has a non-blocking position in which it does not block the roller from rolling outward off the cell pan. The latch automatically moves from the blocking position to the non-blocking position under the influence of the lift pan upon movement of the lift pan into the aligned position.

An apparatus includes a cell pan that supports a circuit breaker within a switchgear cell, and a lift pan that carries a circuit breaker outside of the switchgear cell. The lift pan has a track for a roller on the circuit breaker. The apparatus further includes an extension rail that interconnects the lift pan with the cell pan in an aligned position. With the lift pan in aligned position, the track on the lift pan can receive the roller upon horizontal draw-out movement of the circuit breaker from the cell pan. A latch on the extension rail has a blocking position in which it blocks the roller from rolling outward off the cell pan, and has a non-blocking position in which it does not block the roller from rolling outward off the cell pan. The latch automatically moves from the blocking position to the non-blocking position under the influence of the lift pan upon movement of the lift pan into the aligned position.

A power distribution unit includes a circuit protection device having output terminals and a current transformer board connected to the output terminals of the circuit protection device. The power distribution unit further includes a signal board connected to the current transformer board and a measurement board connected to the signal board.

A power distribution unit includes a circuit protection device having output terminals and a current transformer board connected to the output terminals of the circuit protection device. The power distribution unit further includes a signal board connected to the current transformer board and a measurement board connected to the signal board.

A modular auxiliary switch includes a housing including a first housing part and a separate second housing part secured to the first housing part. A printed circuit board is housed in one of the first and second housing parts, and has a first side facing the first housing part and a second opposite side facing the second housing part. An actuator mechanism is housed in the first housing part and is coupled to the printed circuit board. A separate first electrical contactor is selectively mounted to the printed circuit board so that a first electrical contact surface of the first electrical contactor overlaps and is in direct contact with one of the first side and the second side to define a first electrical contact pad on the printed circuit board.

A modular auxiliary switch includes a housing including a first housing part and a separate second housing part secured to the first housing part. A printed circuit board is housed in one of the first and second housing parts, and has a first side facing the first housing part and a second opposite side facing the second housing part. An actuator mechanism is housed in the first housing part and is coupled to the printed circuit board. A separate first electrical contactor is selectively mounted to the printed circuit board so that a first electrical contact surface of the first electrical contactor overlaps and is in direct contact with one of the first side and the second side to define a first electrical contact pad on the printed circuit board.

Circuit breakers are configured with line terminal geometry that drives the current from a terminal input in a direction that can reduce electromagnetic forces and that can also or alternatively include an arc chute assembly that can reduce repulsive electromagnetic forces to improve the operating level of withstand current (Icw).