Abstract: An object of the present invention is to provide a vacuum switch which secures safety of a worker at performing maintenance and inspection and is high in reliability, and to provide a vacuum switchgear using the vacuum switch.

Abstract: A vacuum switch comprises a first vacuum container containing therein a circuit breaker, a second vacuum container containing therein the first vacuum container and grounded, and a third vacuum container connected to the second vacuum container, containing therein a disconnecting switch and an earth device and grounded. The second and third vacuum containers are isolated in vacuum from the first vacuum container, and the second vacuum container is electrically insulated from the first vacuum container. The second vacuum container contains an insulator fixed to a conductor connected to the circuit breaker and a movable rod partially disposed out of the vacuum containers and operating the circuit breaker to open and close. The disconnecting switch, circuit breaker and the insulator are arranged in a line. A vacuum switchgear comprises the above-mentioned vacuum switches of the number corresponding to three phases and necessary components, each being contained in a metal box.

Abstract: A vacuum switch gear provided with a vacuum container grounded within a grounded vacuum container or a gas-insulated ground container, and a pair of buses connected to an external conductor of the switch gear. A portion for connecting the buses and the external conductor is interface insulation in which an elastic body and solid insulation are utilized in combination. The interface insulation performs adhering and tightening work by rotating an adjuster from the outside.

Abstract: There is disclosed a vacuum insulation switch provided with a movable electrode, a stationary electrode and an earthing electrode, which are insulated from each other, in a vacuum container made of a conductive material which is earthed, and a switchgear using the same. Since the vacuum insulation, which is excellent in the insulation ability, is utilized, the switch is drastically miniaturized and the number of constituent parts are reduced, whereby the manufacturing cost of the switch and the switchgear can be decreased.

Abstract: Disclosed is a vacuum circuit breaker including a small-sized electrode structure capable of reducing deformation with age thereby enhancing the reliability and a vacuum bulb and a vacuum bulb electrode used for the breaker. In the vacuum circuit breaker, each of a fixed electrode and a movable side electrode includes an arc electrode made from particles of a refractory metal material, a high conductive metal material and a low melting point metal; an electrode supporting portion, made from the high conductive metal material, for supporting the arc electrode; a back conductor having a diameter smaller than the electrode supporting portion; and an external side connecting portion having a diameter larger than that of the back conductor. The arc electrode is integrated with the electrode supporting portion, back conductor, and external side connecting portion by the high conductive metal material, preferably, by melting of the highly conductive metal material.

Abstract: A vacuum switch 1 includes a grounded vacuum vessel 2. The reliability of monitoring and measuring the vacuum pressure is improved by providing a vacuum pressure measuring terminal 30 at a side plane of the vacuum vessel 2 such that a main circuit 13 and the measuring terminal 30 are electrically separated from each other.

Abstract: A vacuum insulation switch provided with a movable electrode, a stationary electrode and an earthing electrode, which are insulated from each other, in a vacuum container made of a conductive material which is earthed, and a switchgear using the same.

Abstract: A bellows, of which one end portion is fixed to a movable lever passing through a vessel wall and the other end portion of which is fixed to the vessel wall, has a spring constant at a central portion in an expansion direction which is smaller than that at the end portions in the expansion direction. The bellows damps stress concentration at the end portions and improves the life thereof, without enlarging the size of the bellows. The bellows may be used in a vacuum switch.

Abstract: A vacuum switching apparatus for automatically performing a series of breaking and disconnecting operations includes a fixed electrode and a movable electrode mounted in a vacuum vessel. The movable electrode is sequentially movable between a closing position, an opening position and a disconnecting position. After the movable electrode passes through the opening position located between the closing position and the disconnecting position, the between-electrode opening speed of the movable electrode is reduced by a decelerating means. With this configuration, it is possible to move the movable electrode from the closing position to the disconnecting position without lowering the breaking performance, and hence to automatically perform a series of breaking and disconnecting operations.

Abstract: According to the present invention there are provided a highly reliable electrode of high strength which undergoes little change even with the lapse of time, and a method for making the same, as well as a vacuum valve using such electrode and a vacuum circuit breaker using such vacuum valve. The vacuum circuit breaker has a fixed electrode and a movable electrode, each comprising an arc electrode, an arc electrode support member for supporting the arc electrode, and a coil electrode contiguous to the arc electrode support member, the arc electrode, the arc electrode support member and the coil electrode being formed as an integral structure by melting, not by bonding, particularly the arc electrode support member and the coil electrode being constituted by a Cu alloy containing 0.05-2.5% by weight of at least one of Cr, Ag, W, V and Zr.

Abstract: A protection apparatus for a spot network substation has a plurality of receiving lines connected between a network bus and a plurality of power sources. Each receiving line is connected to a primary switching device, a network transformer and a protector CB. A detector for detecting a phase of each receiving line voltage and a judging unit for judging the detected phase are provided on the primary side of each network transformer. A previously stored basic phase is compared with the detected phase of the receiving line voltage. If there is a lag in the detected phase of the receiving line voltage, it is judged to be a power-stop of the corresponding power source and the protector CB is tripped.

Abstract: According to the present invention there are provided a highly reliable electrode of high strength which undergoes little change even with the lapse of time, and a method for making the same, as well as a vacuum valve using such electrode and a vacuum circuit breaker using such vacuum valve. The vacuum circuit breaker has a fixed electrode and a movable electrode, each comprising an arc electrode, an arc electrode support member for supporting the arc electrode, and a coil electrode contiguous to the arc electrode support member, the arc electrode, the arc electrode support member and the coil electrode being formed as an integral structure by melting, not by bonding, particularly the arc electrode support member and the coil electrode being constituted by a Cu alloy containing 0.05-2.5% by weight of at least one of Cr, Ag, W, V and Zr.

Abstract: An electrode for a vacuum circuit breaker provided with a connecting portion made of a material having the same resistivity as the arc running face portions across the corresponding arc guiding channel at the outer circumferential end thereof, wherein when the outer diameter of the connecting portion is D.sub.1 and the inner diameter of the connecting portion is D.sub.2, the width of the connecting portion is designed so that the ratio D.sub.2 /D.sub.1 is in a range of more than 0.9 and less than 1.0. An arc generated between the electrodes is magnetically driven over the arc running face portions via the connecting portion so that the current interrupting capacity of the electrode is increased and the size and weight of the electrode are reduced.

Abstract: According to the present invention there are provided a highly reliable electrode of high strength which undergoes little change even with the lapse of time, and a method for making the same, as well as a vacuum valve using such electrode and a vacuum circuit breaker using such vacuum valve. The vacuum circuit breaker has a fixed electrode and a movable electrode, each comprising an arc electrode, an arc electrode support member for supporting the arc electrode, and a coil electrode contiguous to the arc electrode support member, the arc electrode, the arc electrode support member and the coil electrode being formed as an integral structure by melting, not by bonding, particularly the arc electrode support member and the coil electrode being constituted by a Cu alloy containing 0.05-2.5% by weight of at least one of Cr, Ag, W, V and Zr.

Abstract: A portion of a highly conductive metal member is infiltrated in voids of a porous high melting point metal member, and both the metal members are integrally joined to each other. An arc electrode portion 13 is formed of a high melting point area 11 in which the highly conductive metal is infiltrated in voids of the high melting point metal member. A coil electrode portion 14 is formed by hollowing out the interior of a highly conductive metal area 12 composed only of highly conductive metal and by forming slits 15 to 17 thereon. A rod 18 is hard-brazed on the rear surface of the coil electrode portion 14. With this electrode, it is possible to reduce the number of parts, and to omit the brazing portion between the arc electrode portion 13 and the coil electrode portion 14 for lowering the electric resistance and thereby the calorific value.

Abstract: A low cost and highly reliable vacuum circuit interrupter and a method of manufacturing the same improve production efficiency and vacuum tight sealing property of the vacuum circuit interrupter. In the vacuum circuit interrupter, within a sealed vacuum vessel 100 a pair of separable conductors in center axial direction of the sealed vacuum vessel composed of a stationary conductor 3 and a movable conductor 5 are disposed.

Abstract: According to the present invention there are provided a highly reliable electrode of high strength which undergoes little change even with the lapse of time, and a method for making the same, as well as a vacuum valve using such electrode and a vacuum circuit breaker using such vacuum valve. The vacuum circuit breaker has a fixed electrode and a movable electrode, each comprising an arc electrode, an arc electrode support member for supporting the arc electrode, and a coil electrode contiguous to the arc electrode support member, the arc electrode, the arc electrode support member and the coil electrode being formed as an integral structure by melting, not by bonding, particularly the arc electrode support member and the coil electrode being constituted by a Cu alloy containing 0.05-2.5% by weight of at least one of Cr, Ag, W, V and Zr.

Abstract: In a power board, network transformers are disposed horizontally to reduce their height, network buses are disposed above the network transformers and a protector breaker and take-off breakers are disposed at the front of the power board in electric chambers and connected to the network buses. This arrangement places the two types of breakers and the electric chambers within the range of height accessible by an operator's hand to permit him to manually handle these breakers, thereby improving ease of handling of the power board.

Abstract: In a power receiving system, a network transformer, a protector breaker and a current detector are connected between the load side of each of a plurality of network lines and a network bus, a breaker is connected to the primary side of the network transformer, the current detector being operative to detect an accident current on the secondary side of the network transformer, and relays or an operation controller is provided which is responsive to the detection signal to open the breaker and protector breaker to switch off accident currents on the primary and secondary sides of the network transformer, whereby the protective range is so expanded as to cover a line section between the network transformer and the protector breaker and the scale of the overall power receiving system is reduced.

Abstract: Object of the present invention is to provide a controller for distribution apparatus which prevents extension of power failure.In accordance with the controller for distribution apparatus related to the present invention, when a short circuit accident, for example, occurs in a control circuit for distribution apparatus, a breaker for distribution opens, an auxiliary coil becomes unexcited condition, and power failure is caused, but, an auxiliary contact point of the unexcited auxiliary coil closes in the other control circuit for distribution apparatus so as to excite a closing coil, and consequently, the other control circuit starts its operation immediately. Accordingly, extension of the power failure can be prevented and reliability of power supply can certainly be maintained.