GAS INSULATION VACUUM CIRCUIT BREAKER

摘要

PROBLEM TO BE SOLVED: To downsize a gas insulation vacuum circuit breaker by enhancing withstand voltage without enlarging the radius of curvature of an electric field relaxation electrode. SOLUTION: In a gas insulation vacuum circuit breaker in which insulation gas is filled and which is provided with a vacuum valve equipped with an insulation vessel and electric field relieving electrodes the end portions of which are arranged at both ends of the insulation vessel apart by gas gap G, a quasi- uniform electric field is set to have 0.35 or more of utilization factor U which is obtained by the equation U=R/ 0.9(R+G)} based on the radius of curvature R of an electric field relieving electrode 16a outer peripheral face and the gas gap G, and a coating 23a made of insulation material is formed on one half or more of the outer peripheral face except a part opposite to the insulation vessel 13 on the electric field relaxation electrode 16a.