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 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 disclosure relates to a circuit-breaker for high-voltage applications including at least one making and breaking unit having a first contact and a second contact for forming an electrically conductive connection in a connection region, wherein the first contact has an outlet arranged distant to the connection region for insulating gas passing the connection region and through the first contact and wherein the first contact is movable along an axially extending switching axis of the circuit-breaker over a moving distance between a closed position where the electrically conductive connection is formed and an open position where the electrically conductive connection is separated; a gas compression cylinder that is motion-coupled to the first contact and which defines a cylinder volume for the insulating gas, wherein the cylinder volume is variable by means of a piston sliding in the gas compression cylinder when moving the first contact.