Abstract: Disclosed is a vacuum circuit breaker (1) including a vacuum interrupter (3) accommodated in a ground tank (2) filled with insulating gas. At least one of a fixed electrode (10) and a movable electrode (11) of the vacuum interrupter (3) uses an electrode material in which particles containing a solid solution of a heat resistant element and Cr are finely and uniformly dispersed and in which Cu textures as a high conductive component are finely and uniformly dispersed. The electrode material contains 20 to 70% by weight of Cu, 1.5 to 64% by weight of Cr and 6 to 76% by weight of the heat resistant element relative to a weight of the electrode material. The particles of the solid solution in the electrode material have an average particle size of 20 ?m or smaller.

Abstract: Disclosed is a vacuum circuit breaker (1) including a vacuum interrupter (3) accommodated in a ground tank (2) filled with insulating gas. At least one of a fixed electrode (10) and a movable electrode (11) of the vacuum interrupter (3) uses an electrode material in which particles containing a solid solution of a heat resistant element and Cr are finely and uniformly dispersed and in which Cu textures as a high conductive component are finely and uniformly dispersed. The electrode material contains 20 to 70% by weight of Cu, 1.5 to 64% by weight of Cr and 6 to 76% by weight of the heat resistant element relative to a weight of the electrode material. The particles of the solid solution in the electrode material have an average particle size of 20 ?m or smaller.

Abstract: A vacuum circuit breaker includes a ground tank, first and second vacuum interrupters, a link mechanism for opening and closing the vacuum interrupters and a link mechanism case housing the link mechanism and supported by an insulating support tube. An insulating operation rod for operating the link mechanism is provided through the insulating support tube and a side portion of the ground tank. An operation room is provided around the portion of the ground tank through which the insulating operation rod is inserted. A conversion mechanism for driving the insulating operation rod is arranged in the operation room. A space communicating with inner sides of bellows of the vacuum interrupters (including the inside of the link mechanism case and the inside of the insulating support tube) is filled with insulating gas of 0.3 MPa or lower. The other space is filled with insulating gas of higher pressure.

Abstract: Vacuum circuit breakers are to gain an extended lifetime by reducing contact face damage of moving and fixed electrodes with improved voltage withstand performance therebetween and enhanced interruption performance. Vacuum circuit breaker of the present invention has bulb 10 having: insulative vacuum tube 11; and fixed electrode 12 on end of current-carrying conductor 13 and moving electrode 15 on end of another current-carrying conductor 16 arranged in insulative vacuum tube 11 with their electrode contact faces opposed each other. Operation system for manipulating current-carrying conductor 16 of moving electrode 15 is equipped with compression-spring 20 and auxiliary compression-spring 21 that increases initial opening speed of moving electrode 15. Auxiliary compression-spring 21 ceases energizing in the middle of a circuit breaking movement of moving electrode 15 and begins storing spring energy in the middle of a circuit closing movement of the same.

Abstract: A vacuum circuit breaker includes a movable-side conductor that is tubular and comprises an inside cavity. A movable side contact case includes a chamber which communicates with a space on a non-vacuum side of a bellows. The chamber is isolated from a space filled with insulating gas in a ground tank by a sealing device. The chamber communicates with an outside atmosphere through the inside cavity of the movable-side conductor.

Abstract: Vacuum circuit breakers are to gain an extended lifetime by reducing contact face damage of moving and fixed electrodes with improved voltage withstand performance therebetween and enhanced interruption performance. Vacuum circuit breaker of the present invention has bulb 10 having: insulative vacuum tube 11; and fixed electrode 12 on end of current-carrying conductor 13 and moving electrode 15 on end of another current-carrying conductor 16 arranged in insulative vacuum tube 11 with their electrode contact faces opposed each other. Operation system for manipulating current-carrying conductor 16 of moving electrode 15 is equipped with compression-spring 20 and auxiliary compression-spring 21 that increases initial opening speed of moving electrode 15. Auxiliary compression-spring 21 ceases energizing in the middle of a circuit breaking movement of moving electrode 15 and begins storing spring energy in the middle of a circuit closing movement of the same.

Abstract: [Task] To prevent damage of a bellows, to reduce the size, and to prevent the global warming. [Means for solution] A dry air of a high pressure is enclosed in a ground tank 2. A movable-side contact case 8 is supported at one end in the ground tank 2, through an insulating support tube 5 and an insulating support member 7, and a fixed-side contact case 9 is supported at the other end in the ground case 2, through a support insulating member 6. A vacuum interrupter 10 is supported between the contact cases 8 and 9. Lower ends of conductors 35 and 15 are connected, respectively, with the contact cases 8 and 9, and upper ends of the conductors 35 and 15 are connected, respectively, with bushing terminals 20 and 21. Conductors 35 and 15 are surrounded, respectively, by bushings 16 and 17. The movable-side conductor 35 is tubular.