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 gas-insulated switch gear composed of a combination of a plurality of gas-insulated equipment, including a plurality of vertically mounted disconnecting switches having outlet sections located at respective upper and lower sides of the switches, main buses and an output bus connected across the lower output sections of the disconnecting switches, and a circuit breaker horizontally mounted beneath the main buses and coupled to the upper output sections of the disconnecting switches.

Abstract: A circuit breaker fitted with a parallel resistor and provided with main contacts and resistor contacts arranged electrically in parallel with the main contacts wherein the resistor is formed of a material selected from the group consisting of Cr, CrN, Cr.sub.3 C.sub.2, CrB, NiO and Mgo. The resistor element generally is made of a material in which the product of the specific heat expressed in Cal/g.degree.C. with the density expressed in g/cm.sup.3 is at least 0.7.

Abstract: A circuit breaker device is disclosed which includes a main contact coupled in parallel with a series combination of a resistor and a resistor contact. The wipe length of the resistor contact is longer than that of the main contact. Means are provided for moving both contacts simultaneously at the same rate in the closing direction such that the main contact closes prior to the closing of the resistor contact. Means are provided for moving the contacts in the opening direction such that the resistor contact moves at a slower rate than the main contact whereby the main contact is opened prior to the resistor contact.

Abstract: A gas insulated bus is provided with a tubular conductor inside a grounded metal sheath filled with an insulating gas. The tubular conductor includes gas inlet holes, positioned a predetermined distance apart from each other, and a gas outlet which is formed in the tubular conductor at an intermediate point between the gas inlet holes. A cooling case is attached to the sheath at a position corresponding to the gas outlet, and the gas outlet communicates with the cooling case by means of a tubular passage device, whereby the heated insulating gas within the tubular conductor is circulated by natural convection from the gas outlet to the gas inlet holes through the cooling case to cool the gas.

Abstract: In a gas circuit breaker of the type in which compressed gas is blasted about an arc generated by the separation of at least a pair of relatively movable contacts, there are provided an arc extinguishing chamber, a stationary contact mounted on the inside wall of the chamber, an operating rod located in the chamber, a movable contact disposed to oppose the stationary contact and moved by the operating rod, a device for creating a blast of compressed gas when the contacts are separated, and a plurality of partition plates separated from each other in the direction of the movement of the movable contact. The partition plates are provided with gas passing passages and function to channel the compressed gas and blast it about the arc at a plurality of spaced apart interrupting points.

Abstract: In a method for detecting foreign matters present in gas sealed electrical apparatus including a tank at the ground potential and containing an insulating gas and a high voltage live part disposed in the tank, a voltage is applied to the high voltage live part causing generation of ultrasonic waves and the ultrasonic waves propagated through the tank is sensed by a sensing element mounted on the tank.