Abstract: A gas insulated switchgear device includes a pair of main bus lines arranged in parallel; a pair of auxiliary bus lines arranged in parallel; three sets of circuit breakers each including at both ends thereof respective disconnecting switches, the three sets of circuit breakers being electrically connected in series between the pair of main bus lines via the pair of auxiliary bus lines; and a cable head provided at junction points between the disconnecting switches belonging to the respective adjacent circuit breakers. The pair of main bus lines and the pair of auxiliary bus lines are arranged in parallel with each other over a substantially horizontal plane near their installation plane, and the three sets of circuit breakers are vertical type circuit breakers and are disposed at one side of the pair of main bus lines and of the pair of auxiliary bus lines along their axial direction.

Abstract: An instrument current transformer for a main power cable which is composed of three power cables for three phases disposed in a power cable laying hole and three current transformer coils for the three phases, each of the three current transformer coils surrounding a corresponding one of the three power cables, the instrument current transformer including: a plurality of upper circumferential installation unit members disposed near an end portion of the power cable laying hole along circumference sides of an opening portion of the power cable laying hole, each of the upper circumferential installation members being provided with at least one securing portion extending in a radial direction and the upper circumferential installation unit members being secured to the end portion of the power cable laying hole via respective at least one securing portions; three axial installation members for the three phases, each extending along corresponding ones of the three power cables, first ends of the axial installation

Abstract: The present invention provides a three-phase lumped together gas insulated switchgear, which is small-sized and simply constructed, including main busbar conductors and disconnectors connected to the main busbar conductors. In the gas insulated switchgear, phases of the main busbar conductors are respectively disposed on the vertexes of a triangle. Further, the axes of the disconnectors and disconnector movable side conductors, both of which correspond to three phases, are arranged between one phase of the main busbar conductor and the other two phases of the main busbar conductors so that the axes of the disconnectors for the busbars become parallel with each other. Furthermore, the movable side conductors are connected to the main busbar conductors. Because of the above construction, a circuit breaker and the busbars can be linked within the shortest possible distance to the disconnectors arranged between the circuit breaker and the busbars.

Abstract: A gas-insulated switchgear comprises a sealed enclosure filled with an electrically insulating gas, isolators of three phases for making/breaking a main circuit, and earthing switches of the three phases for grounding the main circuit. The isolators and the earthing switches are disposed in the sealed enclosure, with the isolator of each phase including oppositely disposed stationary and movable side contacts, and a movable contact for turning on or off electrical connection between them. The earthing switch of each phase includes an earth stationary contact connected to one of the movable side conductors and an earth movable contact for connection with or disconnection from the earth stationary contact. The components of the isolators of the three phases and the components of the earthing switches of the three phases are respectively situated on two virtual planes, which are adjacent to each other and disposed substantially along a longitudinal direction of the sealed enclosure.

Abstract: In a gas insulated switchgear equipment device, at least one gas insulated main bus bar is arranged on an attachment surface and a plurality of feeder units each having one end connected to the gas insulated main bus bar and the other end connected to an insulating terminal are arranged along a longitudinal direction of the gas insulated main bus bar, thereby constituting a substation equipment device. A gas insulated bus-section-unit is arranged on a portion of the gas insulated main bus bar and has at least a circuit breaker and disconnecting switches connected to both ends of the circuit breaker, and one end of the bus-section-unit is connected to the corresponding gas insulated main bus bar and the other end of the bus-section-unit is provided with at least one external lead-out device connectable to an external connecting device.

Abstract: A gas-insulated switchgear apparatus has a sealed container including a cylinder body having a substantially circular cross-section and end plates closing the end portions of the cylinder body. The sealed container accommodates breaker portions situated so as to work opening and closing actions in the vertical direction and current transformers. Main bus bars located on the side of the sealed container are connected with the breaker portions located inside of the sealed container through openings formed in the end plates. A line side terminal portion located on the side of the sealed container is connected with the breaker portions locating inside of the sealed container through openings formed in the end plates.

Abstract: An apparatus for operating switches including a driving shaft having an operation lever portion supporting one end of a spring mechanism, with the driving shaft being separated from an operation shaft associated with a switch. A driving lever fixed to the driving shaft is connected to a main lever with a recess fixed to the operation shaft. An angle formed by central axes of these levers is set to an angle slightly exceeding 90.degree. when a switch opening or closing operation is completed. Members for regulating the opening and closing positions of the switch are provided at positions opposed to the driving lever. By setting the angle to the above value, in a side where the angle exceeds 90.degree., an operating force transmitted from the driving lever to the main lever acts in a direction opposite to a direction to which the operating force acts until the angle reaches 90.degree., thus cancelling operating inertia energy and residual energy in the driving lever.

Abstract: A gas-insulated switchgear forming a bus section unit used in substations. In a double bus scheme where non-segregated 3-phase gas-insulated buses are laid on a horizontal installation area, this invention applies to a bus structure in which sectionalized gas-insulated main buses arranged in line on the same axis are connected by the bus section unit. By the side of the sectionalized gas-insulated main buses are installed bus section circuit breakers for three phases. A shifted bus section leading from one of the sectionalized main buses is disposed above the third gas-insulated main bus which is located farther from the circuit breaker. The shifted bus section is used to connect the sectionalized main buses. This structure improves the seismic resistance of the bus section unit without increasing the installation area of the unit.

Abstract: A novel connecting system for a gas-insulated switchgear apparatus is disclosed. An electrical device is installed on a foundation adjacent to gas-insulated devices of respective phases in a predetermined indoor installation space, and bushing are arranged on the other side of the electrical device. The gas-insulated devices are connected to the bushings by gas-insulated bus bars respectively. Pits for gas-insulated bus bars are formed independently through the foundation of the electrical device, and a transport unit is laid in each of the pits. This transport unit is combined with a transfer unit mounted on each of the gas-insulated bus bars to transport the gas-insulated bus bars of respective phases to facilitate the laying thereof. The gas-insulated bus bars are thus laid in a short distance without reducing the strength of the foundation of the electrical device while at the same time facilitating the laying of the gas-insulated bus bars.

Abstract: An earthing switch for gas-insulated switchgear apparatus is disclosed, in which conductor within an enclosure is provided with a stationary contact, and a moving contact is movably provided to connect with and disconnect from the stationary contact by an operating mechanism within an operating mechanism case which is mounted on a branch tube of the enclosure interposing an insulating plate therebetween. For connecting the moving contact to the enclosure electrically, a plurality of earthing bars are employed, and further, directions of electromagnetic forces generated between the moving contact and individual earthing bars are considered in the connection of the earthing bars. By virtue of the connection of the plurality of earthing bars, the influence of the electromagnetic forces acting on the moving contact can be reduced to a great extent.