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.

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.

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.

The invention relates to a circuit breaker that can be switched between an ON position and an OFF position, such that in the OFF position an interruption path comprising an arcing space is formed. The circuit breaker comprises a storage volume for a quenching gas, which is in gaseous communication with the arcing space and has an inlet port for the quenching gas. The inlet port also has a valve comprising an obturator, and the obturator has a heat-insulating coating.

A circuit breaker having first and second electrical contacts configured to generate an electrical arc upon being separated, an arc chamber surrounding at least a portion of a space between the first and second electric contacts, at least one expansion chamber positioned proximate to the arc chamber, and an arc pressure control valve assembly configured to allow threshold-based flow into and out of the at least one expansion chamber. An arc pressure control valve assembly and method of operating a circuit breaker are described, as are other aspects.

Disclosed is a gas insulated circuit breaker having enhanced insulation properties. A gas insulated circuit breaker comprises: a fixed cylinder unit of which a movable contact point has an internal space; a movable piston unit which is slidably inserted into the inner space of the fixed cylinder unit; a fixing unit provided in a rear of the fixed cylinder unit in the internal space of the fixed cylinder unit; a puffer chamber which is formed by having the movable piston unit, fixed cylinder unit and fixing unit, surrounding the puffer chamber; and a gas inlet unit which forms a path, between the puffer chamber and the outer part of the fixed cylinder unit, through which a gas flows.

A circuit breaker having first and second electrical contacts configured to generate an electrical arc upon being separated, an arc chamber surrounding at least a portion of a space between the first and second electric contacts, at least one expansion chamber positioned proximate to the arc chamber, and an arc pressure control valve assembly configured to allow threshold-based flow into and out of the at least one expansion chamber. An arc pressure control valve assembly and method of operating a circuit breaker are described, as are other aspects.

The invention relates to an electrical switching device including a nominal contact arrangement, an arcing contact arrangement defining an arcing volume in which an arc-quenching medium is present, an exhaust system including a first exhaust opening connected fluidly to a tank volume, an exhaust channel for dissipating hot medium from the arcing volume into the tank volume, the exhaust system further including a piston arranged in a compression guide and defining on its side opposed to the arcing volume together with the compression guide a compression chamber. An inlet channel is fluidly connected to the compression chamber and extends to an inlet opening fluidly connected to the tank volume, wherein the inlet channel and the exhaust channel are fluidly separated from each other.