A load-break switch has a housing holding insulation gas at ambient pressure; a first main contact and a second main contact being movable relative to each other in an axial direction of the switch; a first arcing contact and a second arcing contact being movable relative to each other in the axial direction and defining an arcing region where an arc is formed during a current breaking operation, wherein the arcing region is located radially inward from the first main contact; a pressurizing system pressurizing a quenching gas during the current breaking operation; and a nozzle system arranged to blow the pressurized quenching gas onto the arc. The first main contact includes at least one pressure release opening to allow gas flow in a radial outward direction. A total area of the pressure release opening suppresses a reduction of gas flow out of the pressure release opening.

A load-break switch has a housing holding insulation gas at ambient pressure; a first main contact and a second main contact being movable relative to each other in an axial direction of the switch; a first arcing contact and a second arcing contact being movable relative to each other in the axial direction and defining an arcing region where an arc is formed during a current breaking operation, wherein the arcing region is located radially inward from the first main contact; a pressurizing system pressurizing a quenching gas during the current breaking operation; and a nozzle system arranged to blow the pressurized quenching gas onto the arc. The first main contact includes at least one pressure release opening to allow gas flow in a radial outward direction. A total area of the pressure release opening suppresses a reduction of gas flow out of the pressure release opening.

Embodiments of the disclosure relate to an electric switching unit provided with an arc-blasting unit. In one embodiment, an electric switch can be provided. This electric switch can include an arc-blasting unit with a compression cylinder enclosing a compression chamber mobile together with the mobile contacts, and a stationary piston at an end of the compression chamber, provided with a support rod made up as a blowpipe which channels the gas compressed in the chamber when the contacts separate to a nozzle that directs the flow to a separation place of the contacts so as to efficiently blast electric arcs. The arrangement can be relatively lightweight and can occupy relatively little space.

Embodiments of the disclosure relate to an electric switching unit provided with an arc-blasting unit. In one embodiment, an electric switch can be provided. This electric switch can include an arc-blasting unit with a compression cylinder enclosing a compression chamber mobile together with the mobile contacts, and a stationary piston at an end of the compression chamber, provided with a support rod made up as a blowpipe which channels the gas compressed in the chamber when the contacts separate to a nozzle that directs the flow to a separation place of the contacts so as to efficiently blast electric arcs. The arrangement can be relatively lightweight and can occupy relatively little space.

A gas-insulated low- or medium-voltage load break switch includes: a housing defining a housing volume for holding an insulation gas at an ambient pressure; a first arcing contact and a second arcing contact arranged within the housing volume, the first and second arcing contacts being movable in relation to each other along an axis of the load break switch and defining a quenching region in which an arc is formed during a current breaking operation; a pressurizing system having a pressurizing chamber arranged within the housing volume for pressurizing a quenching gas from an ambient pressure p.sub.0 to a quenching pressure p.sub.quench during the current breaking operation; and a nozzle system arranged within the housing volume for blowing the pressurized quenching gas in a subsonic flow pattern from the pressurization chamber onto the arc formed in the quenching region during the current breaking operation. The nozzle system includes at least one nozzle arranged for blowing the quenching gas from an off-axis position predominantly radially inwardly onto the quenching region.

A gas-insulated low- or medium-voltage load break switch includes: a housing defining a housing volume for holding an insulation gas at an ambient pressure; a first arcing contact and a second arcing contact arranged within the housing volume, the first and second arcing contacts being movable in relation to each other along an axis of the load break switch and defining a quenching region in which an arc is formed during a current breaking operation; a pressurizing system having a pressurizing chamber arranged within the housing volume for pressurizing a quenching gas from an ambient pressure p.sub.0 to a quenching pressure p.sub.quench during the current breaking operation; and a nozzle system arranged within the housing volume for blowing the pressurized quenching gas in a subsonic flow pattern from the pressurization chamber onto the arc formed in the quenching region during the current breaking operation. The nozzle system includes at least one nozzle arranged for blowing the quenching gas from an off-axis position predominantly radially inwardly onto the quenching region.

A switchgear includes a movable part capable of reciprocating movement, a movable contact coupled to the movable part, a member that biases the movable contact, a latch capable of switching between a first state in which movement of the movable contact is restricted and a second state in which movement is permitted, a part that accommodates the movable part and the movable contact therein, a fixed contact provided outside of the accommodating part, and a moving part that moves with the movable contact. The latch is switched to the second state when the movable contact has moved against the biasing force. The accommodating part contains a first region and a second region, which is on a side of the fixed contact with respect to the first region within a range of movement of the moving part. The first region has an inner diameter smaller than that of the second region.

A switchgear includes a movable part capable of reciprocating movement, a movable contact coupled to the movable part, a member that biases the movable contact, a latch capable of switching between a first state in which movement of the movable contact is restricted and a second state in which movement is permitted, a part that accommodates the movable part and the movable contact therein, a fixed contact provided outside of the accommodating part, and a moving part that moves with the movable contact. The latch is switched to the second state when the movable contact has moved against the biasing force. The accommodating part contains a first region and a second region, which is on a side of the fixed contact with respect to the first region within a range of movement of the moving part. The first region has an inner diameter smaller than that of the second region.

A gas circuit breaker includes a gas suppresser composed of a protruded portion which is formed on a horizontal surface facing an exhaust cylinder of a shaft guide and which forms a gap between itself and the exhaust cylinder and an enlarged portion which is adjacent to the protruded portion and where a gap to the exhaust cylinder is enlarged so that the shaft guide, which operates along an inner circumferential surface of the exhaust cylinder, which is provided to an inner circumferential portion of a movable side main conductor and is provided to outer circumferences of an exhaust shaft and an operation rod, and couples the operation rod with the exhaust shaft, is axially adjacent to a sliding member that slides along the exhaust cylinder with no space to the exhaust cylinder and suppresses discharge of heated and pressurized insulating gas.

A gas circuit breaker includes a gas suppresser composed of a protruded portion which is formed on a horizontal surface facing an exhaust cylinder of a shaft guide and which forms a gap between itself and the exhaust cylinder and an enlarged portion which is adjacent to the protruded portion and where a gap to the exhaust cylinder is enlarged so that the shaft guide, which operates along an inner circumferential surface of the exhaust cylinder, which is provided to an inner circumferential portion of a movable side main conductor and is provided to outer circumferences of an exhaust shaft and an operation rod, and couples the operation rod with the exhaust shaft, is axially adjacent to a sliding member that slides along the exhaust cylinder with no space to the exhaust cylinder and suppresses discharge of heated and pressurized insulating gas.