GAS CIRCUIT BREAKER

摘要

Provided is a gas circuit breaker which can smoothly evacuate a gas. This gas circuit breaker is provided with: an air-tight container filled with an arc-extinguishing gas; a fixed arc contact (11) and a movable arc contact (21) which are arranged opposite of each other inside of the air-tight container and which come into contact or separate from each other when the breaker is shut off or turned on; an operation rod (25) comprising a hollow portion (50) to which the fixed arc contact (11) or the movable arc contact (21) is attached, which communicates with the space between the two arc contacts (11, 21), and which becomes the evacuation flow path of the gas; a narrowed portion (53) which adjusts the flow path cross sectional area of the hollow portion (50); and an evacuation hole (51) for evacuating the gas in the hollow portion (50). Further, the evacuation hole (51) is provided downstream of the narrowed portion (53), and the narrowed portion (53) comprises a shrinking portion (53a), in which the flow path cross sectional area gradually shrinks in the downstream direction, a smallest portion (53b), in which the flow path cross sectional area is smallest, and an expanding portion (53c), in which flow path cross sectional area gradually expands in the downstream direction.