The invention relates to a medium-, high-, or very high-voltage circuit breaker, comprising at least one arc-control chamber and an outer casing in which the arc-control chamber is arranged. The circuit breaker includes a discharge cap (40) forming a portion of the outer wall external of the arc-control chamber (12), the discharge cap being situated inside the outer casing and internally defining a gas-flow chamber (31). In the invention, the discharge cap (40) includes at least one portion (40) that is movable under the effect of the gas pressure in the gas-flow chamber (31), in such a manner that its volume is extensible.

A fast earthing switch for a GIS, including a movable contact rod, having an end; a cylinder, fixed to the contact rod and forming a gas chamber around at least part of the contact rod, the gas chamber including an outlet around the contact rod so that gas can flow along the contact rod and its end when it moves from a closed to an open position; and means for actuating the contact rod between a closed and an open position.

A high-voltage circuit breaker filled with gas, including two arcing contacts, a support in which a thermal volume, a compression volume, and an exhaust gas chamber are formed. A first radial wall separating the thermal volume and the compression volume, which is movable within the support. A second radial wall separating the compression volume and the exhaust gas chamber. A buffer volume is formed in the support and is separated from the compression volume and the exhaust gas chamber by associated walls, that are designed to be connected to the compression volume only to allow gas stored in the buffer volume to be discharged towards the compression volume.

A circuit breaker including a stationary frame, at least a pair of arc contacts, an actuation rod, a compression chamber in which a portion of the dielectric gas is compressed; a cylinder and a piston connected with the rod, which are movable within the stationary frame along main axis, for compressing the portion of the dielectric gas in the compression chamber; a link mechanism connecting the piston to the rod, wherein the stationary frame includes a cylindrical portion with which each of the piston and of the cylinder are radially in gastight contact and which bounds the compression chamber together with the piston and the cylinder.

To provide a gas circuit breaker designed to achieve further improvement in interruption performance for a small to medium current. The gas circuit breaker according to the present invention includes: an operation mechanism 1; a heat puffer chamber 19; a machine puffer chamber 32; a release valve 34; a movable main contact 5 and movable arc contact 11; a stationary main contact 6 and stationary arc contact 12; a movable-side leading conductor 14; and a stationary-side leading conductor 15, and features: a separation cylinder 21 for radially partitioning the heat puffer chamber 19; an inner circumferential flow path 24 formed on an inner circumferential side of the separation cylinder 21; and a check valve 22 for opening or closing a communication hole 23.

The gas-circuit-breaker includes a container, opposing part, movable-part, and nozzle. An arc-extinguishing gas fills the container. The opposing-part is housed in the container and includes an opposing-arc-contact and an exhaust stack. The movable-part is housed in the container and includes a movable-arc-contact coming in contact with the opposing-arc-contact in a connected-state and separating from the opposing-arc-contact in an open-state; and a pressure-accumulation-part where an arc-extinguishing gas pressure increases. The nozzle is housed in the container and includes a space where arc-discharge occurs between the movable-arc-contact and the opposing-arc-contact. The nozzle includes a middle-part where the opposing-arc-contact is inserted and one or more jet-holes that eject, toward the space, partial arc-extinguishing gas flowing in from a flow-passage between the pressure-accumulation-part and the middle-part. The arc-extinguishing gas whose pressure increases in the pressure-accumulation-part flows into the space via the flow-passage and the jet-holes to extinguish the arc-discharge.

A medium-, high-, or very high-voltage circuit breaker (10), comprising at least one arc-control chamber (12) and an outer casing (14) in which the arc-control chamber (12) is arranged. In the invention, the circuit breaker includes sealing ring (52) for sealing an opening (50) in a discharge cap (40) of the arc-control chamber (12), the ring (52) being movable between a sealing position and a retracted position in which they allow the gas to pass, the circuit breaker being configured in such a manner that in the closed position, the sealing ring (52) are in their retracted position, and in such a manner that passage from the retracted position to the sealing position takes place during an operation of opening the circuit breaker.

A pair of fixed arc electrodes are arranged facing each other within a sealed container that is filled with arc-extinguishing gas 1. There are provided: a compression puffer chamber for accumulating pressurized gas that is obtained by elevating the pressure of the arc-extinguishing gas; and an insulated nozzle that directs the pressurized gas towards the arc discharge from the compression puffer chamber. A buffer chamber is provided, in which hot exhaust gas generated by the heat of the arc discharge is temporarily accumulated. A pressurized gas through-flow space is provided, communicating with the compression puffer chamber. In the pressurized gas through-flow space, an opening/closing section prevents inflow of hot exhaust gas by assuming a closed condition during the earlier half of the current interruption period, and in the latter half of the current interruption period the opening/closing section 41 is opened to allow flow of pressurized gas.

The invention relates to an electric arc-blast nozzle for a circuit breaker comprising a middle portion forming a throat defining internally an axial passage for interrupting an electric arc, and two end portions extending on either side of the middle portion and being designed to receive respective arcing contacts and that are movable axially relative to each other.

The middle portion and the two end portions are made of a same dielectric material obtained from a composition consisting of a fluorocarbon polymer matrix and of at least one oxide, the oxide(s) being present in a proportion by weight lying in the range 11% to 50%, relative to the total weight of the composition.

The invention also relates to a circuit breaker including such a nozzle.

The gas circuit breaker includes a sealed container filled with an arc-extinguishing gas, a pair of fixed arc electrodes arranged in the sealed container to be opposite to each other, a trigger electrode movably arranged between the fixed arc electrodes and generating an arc discharge according to movement, a pressurization chamber pressuring and increasing a pressure of the arc-extinguishing gas with pressurization means, and a pressure accumulation chamber in communication with the pressurization chamber and accumulating the pressurized arc-extinguishing gas. The trigger electrode switches the pressure accumulation chamber into a closed state or an open state. The pressure accumulation chamber is switched to the closed state in a first half of breaking of the electric current, and the pressure accumulation chamber is switched to the open state in a latter half of breaking of the electric current. The arc-extinguishing gas in the pressure accumulation chamber is guided to the arc discharge.