Abstract: A gas insulated switchgear is provided which uses an SF6 substitute gas as an insulating gas and thus causes reduced environmental load while achieving high dielectric strength and excellent interrupting performance. The gas insulated switchgear includes a switchgear housed in a container filled with an insulating gas.

Abstract: A disconnector for a gas insulated switchgear in which the disconnector includes, in a metallic container filled with an insulated gas, a stationary electrode having a contact, a stationary electrode shield electrically connected to the stationary electrode to surround the contact, the stationary electrode shield made of an electrically resistant material and having a free end portion and inner and outer surfaces, and a movable electrode arranged to face the contact and being movable into and out of electrical contact with the contact, and in which the stationary electrode shield is arranged to flow discharging current therethrough due to an interelectrode voltage applied between the stationary electrode and the movable electrode. The disconnector includes an annular metallic electrode coaxially mounted on the free end portion of the stationary electrode shield so as to allow the movable electrode to pass therethrough.

Abstract: A superconducting current limiting apparatus includes a first container, a superconducting current limiting element accommodated in the first container, a refrigerant filling the first container for cooling the superconducting current limiting element accommodated in the first container, a second container for accommodating the first container in such a manner that the first container is heat insulated, and a conductor for connecting the superconducting current limiting element to an external power supply system. Such a superconducting current limiting apparatus can be used to limit a short-circuit current. It can be incorporated in a short circuit controlling superconducting system.

Abstract: A CO.sub.2 gas laser device comprises a plurality of divided cathode electrodes disposed in a linear row extending transversely across a high-speed flow of a gas containing CO.sub.2, and parts of the cathode electrodes producing negative glow are disposed at the same height as anodes at a downstream position. Additionally, a device for controlling the distribution of gas flow velocity, which functions doubly as means for creating turbulent flow, and a preliminary discharge electrode are disposed on the upstream side of the cathode electrodes, the former being set at a height position corresponding substantially to that of the middle portions of the cathode electrodes.

Abstract: A compressed gas dielectric circuit breaker comprising fixed main contacts (11), fixed arcing contacts (8A), a moving assembly comprising main contacts (21) and arcing contacts (22A), a blast device comprising a semi-moving cylinder (16) divided into first and second chambers (15, 35) by a fixed piston (3B), with the first chamber (15) communicating with a blast nozzle (12), and a thermal volume (9) opening out into the zone where the fixed arcing contacts (8A) separate from the arcing contacts (22A) of the moving assembly, communication (26) being established between the thermal volume (9) and said second chamber (35) in order to enable gas heated by the arc in the thermal volume to increase in pressure and to assist in the displacement of the cylinder (16) and thus in the compression of the gas in the first chamber (15).

Abstract: A compressed dielectric gas high-tension circuit breaker comprising: a fixed assembly comprising main contacts and arcing contacts; a moving assembly comprising main contacts and arcing contacts; a blast chamber comprising a piston which moves on separation of the contacts to urge compressed blast gas towards a blast nozzle situated in the zone where an arc is struck; and a thermal volume; wherein the thermal volume is in communication with the downstream portion of the blast nozzle via channels and passages extending the path between the thermal volume and said nozzle, said communication being closed by a calibrated non-return valve which opens only when the pressure in said channels and in said passage reaches a threshold value, said non-return valve closing the passage between the blast chamber and the nozzle when said communication is opened.

Abstract: A circuit breaker actuator device of the type comprising an operating wheel (R) whose rotation drives the moving circuit-breaking members, said wheel being connected to a first spring (S'1) by a first chain (C1) passing over a first pulley (P1) and fixed to a first point (A1) close to the periphery of the wheel. The wheel is held fixed when the spring (S1) is under tension/compression by means of a retaining member (K1) which can be retracted to allow the wheel to rotate. The device further includes a second spring (S2) connected by a second chain (C2) passing over a second pulley (P2) and fixed to a second point (A2) on said wheel. The center of the wheel is situated, when both springs are under tension/compression, between the length of the first chain connecting the first point to the first pulley and the length of the second chain connecting the second point to the second pulley, with the second spring applying a force which is less than the force applied by the first spring.

Abstract: A vacuum switch having two main electrodes encased in a vacuum vessel to be operable in opening and closing the main electrodes, is provided with a contact piece made of a copper-chromium alloy secured or formed on at least one of the main electrodes. The operational property of the main electrodes is substantially improved by flowing and interrupting an electric current of a predetermined current density for a number of times through the two main electrodes for improving surface condition of the contact piece by forming a recrystallized layer over the outer surface of the contact piece.

Abstract: An electrode structure disposed in a vacuum switch generally comprises a pair of relatively separable electrodes and a pair of contacts provided on the opposing surfaces of the electrodes and surface areas of the contacts are selected to be smaller than the surface areas of the electrodes. The vapor pressure P.sub.0 and specific resistance .rho..sub.0 of the electrode material and the vapor pressure P.sub.1 and specific resistance .rho..sub.1 of the contact material are held in a relation ##EQU1## and values representing specific heat, heat of fusion and heat of evaporation of the contact material are 100.+-.20% of those of the electrode material except a portion on which the contact material is provided.

Abstract: A puffer type gas insulated circuit breaker has releasably engaging stationary and movable arc contacts contained in a vessel filled with an arc extinguishing gas. An operation rod serving as a supporting member of the movable arc contacts has openings and helps define a puffer chamber. In the breaker, gas is pressurized by an arc generated between said stationary arc contacts and said movable arc contacts in an initial breaking phase, this gas being taken into the puffer chamber. The holes are used as a heat exhaust passage.

Abstract: A gas-insulated switching apparatus comprises gas-insulated interrupters, gas-insulated buses and gas-insulated disconnecting switches, whereby the movable electrode side terminals of all the disconnecting switches accommodated in the apparatus are so arranged as to be connected to gas-insulated interrupters to be disconnected from a power source, i.e., to a load line side to be interrupted by the disconnectors.

Abstract: A DC circuit breaker of the type using a blown arc-extinguishing gas is disclosed which allows for reliable fast interruption of DC currents through the provision of arc extension current paths. The extension current paths are relatively long and are bent after the incidence of the arc-extinguishing gas on the arc. The arc is formed to extend for a long distance in a loop configuration. An auxiliary electrode short-circuits the extended arc with one auxiliary electrode being provided for each extension current path.

Abstract: In a method of and apparatus for synthetic testing of a multi-break circuit breaker having a metallic tank and a series connection of interrupter units, and a non-grounded and a grounded lead conductors connected to the first and the second ends of the series connection, a short-circuit current is made to flow through the series connection, the circuit breaker is then operated, and upon completion of the interruption of the current, a first transient recovery voltage is supplied to the non-grounded lead conductor and is applied, in effect, across a first one of the interrupter units at the second end or across a train of interrupter units including said first one of the interrupter unit, and, simultaneously, a second transient recovery voltage is supplied to the tank, the first and the second transient recovery voltages having the same polarity and the second transient recovery voltage having substantially the same magnitude as the whole transient recovery voltage to be applied across all the interrupter unit

Abstract: A DC circuit breaker apparatus comprises a first interrupter and a second interrupter connected in series. A first capacitor and a discharge gap are respectively connected in parallel with the first and second interrupters. An impedance element is connected between a first junction between the first capacitor and the discharge gap and a second function between the first and second interrupter, and a second capacitor is connected in parallel with the second interrupter.

Abstract: A current interruption apparatus comprises a series-connected combination of at least one vacuum interrupter and at least one gas-blast interrupter. Each vacuum interrupter is coupled in parallel with a non-linear resistor, while each gas-blast interrupter is coupled in parallel with a capacitor. During the initial period of the recovery voltage developed upon current interruption, most of the recovery voltage is applied to the vacuum interrupter. After the instant at which the non-linear resistor represents its constant voltage characteristics, the SF.sub.6 gas-blast interrupter will take the largest portion of the entire voltage increased thereafter.

Abstract: An arrester having at least two stacks of non-linear resistors connected in series, an arcing gap device connected to shunt one stack of resistors when the gap means sparks over, and a hermetically sealed housing enclosing the resistor stacks and arcing gap device and filled with sulfur hexafluoride gas having a gauge pressure not less than 2 kg/cm.sup.2. The impedance of the one resistor stack is from about 15% to about 35% of the total impedance of the two resistor stacks when the arcing gap means sparks over, and the rated voltage of the arrester is not less than about 50 KV.

Abstract: In a vacuum circuit breaker of the type comprising coil electrodes for producing longitudinal magnetic flux and contacts made of an Ag-WC sintered alloy, the intensity of the magnetic field is made to be higher than 50 gausses/I.sub.B.

Abstract: Disclosed is a process and apparatus for treating noxious gases and/or substances which are produced by virtue of an electric arc in the event of a switching operation or due to corona discharge. A gas insulated electrical apparatus is connected to a container for a cleaning solution including a volatile solvent. A conduit connects the container for the cleaning solution to the gas insulated electrical apparatus, and another conduit, including a filter apparatus, connects the gas insulated electrical apparatus to the container for the cleaning solution, for returning the cleaning solution, which has been used to wash the gas insulated electrical apparatus, to the container for the cleaning solution. Vacuum or pressure producing apparatuses may be provided for aiding in the transfer of the cleaning solution.

Abstract: A series circuit of a gap section and a valve block is connected between a transmission line and the ground. The valve block consists of a plurality of nonlinear resistor elements connected in series. A first impedance circuit consisting of a resistor and a capacitor connected in series is connected in parallel to the gap section. Also, a second impedance circuit consisting of another resistor and another capacitor connected in parallel is connected in parallel to the valve block. The ratio of the voltage applied across the gap section to that applied across the valve block is determined by the ratio of the impedance of the first impedance circuit to that of the second impedance circuit. A pair of discharge electrodes included in the gap section, which are a prescribed distance apart from each other, comprise a narrower gap region at which spark is started.

Abstract: A circuit breaker apparatus of high voltage direct currents is connected in series with an external circuit comprising an AC-DC converting device connected to an AC power supply and a DC reactor connected to the AC-DC converting device, and comprises a circuit breaker connected in series with the external circuit, a disconnecting switch connected to the circuit breaker, and a series circuit connected in parallel with the circuit breaker and constituted of a blocking capacitor and a primary winding in a transformer. A charge storage capacitor is connected to a secondary winding of the transformer through a starting switch and polarity changeover switch, and an AC power supply for charging is connected through a diode to the charge storage capacitor.