Abstract: The present invention relates to an arc-extinguishing insulation material molded product provided in the vicinity of a contact point between contactors in a gas circuit breaker. The arc-extinguishing insulation material molded product includes a polymer which contains a carbon-oxygen bond in the main chain, and in which a part of or all of terminal atoms are non-hydrogen atoms.

Abstract: An arc extinguishing device of a gas circuit breaker includes: an arc chamber in which an arc generated between a movable electrode and a fixed electrode is formed; a heat puffer chamber disposed so as to surround the arc chamber; a blow port in which the arc chamber communicates with the heat puffer chamber in the circumferential direction of the arc chamber; hydrogen absorbents which are disposed on an inner wall of a pressure chamber; an exhaust port which passes to the outside of an arc extinguishing chamber; and a hydrogen absorbent disposed at a position surrounding the movable electrode. Deterioration of insulation due to a product formed by decomposition of arc extinguishing gas by the arc during a contact opening operation can be suppressed.

Abstract: A bus is placed at the center of a housing. Breakers and cables forming branch circuits branching from the bus are placed at the upper and lower stages in the housing, being displaced in the right-left direction. Spaces formed between the side wall of the housing and the side walls of an upper-stage breaker compartment and an upper-stage cable compartment containing the upper-stage apparatuses are used as paths leading to the housing ceiling for a bus compartment, and a lower-stage breaker compartment and a lower-stage cable compartment containing the lower-stage apparatuses. The bus compartment and all the apparatus compartments each directly lead to a ceiling portion of the housing and have an opening portion. Pressure discharge plates are provided on the opening portions.

Abstract: A switchgear includes a fixed contactor provided in a tank filled with insulating gas, and a movable contactor provided in the tank, the movable contactor being connected to and disconnected from the fixed contactor so as to move forward and backward. The switchgear includes an arc extinction member including a surrounding portion which is slidably connected to the outer circumferential surface of the movable contactor halfway in a movement range from a close contact state to an open contact state and is formed so as to surround an arc space portion in a sealed manner, the surrounding portion being formed with a through hole through which the arc space communicates with the outside of the arc space.

Abstract: A switchgear includes a fixed contactor provided in a tank filled with insulating gas, and a movable contactor provided in the tank, the movable contactor being connected to and disconnected from the fixed contactor so as to move forward and backward. The switchgear includes an arc extinction member including a surrounding portion which is slidably connected to the outer circumferential surface of the movable contactor halfway in a movement range from a close contact state to an open contact state and is formed so as to surround an arc space portion in a sealed manner, the surrounding portion being formed with a through hole through which the arc space communicates with the outside of the arc space.

Abstract: A gas circuit breaker includes: a sealed tank filled with insulation gas; a pair of arc contacts that are arranged to face each other in the sealed tank and connectable and disconnectable with each other; a thermal puffer chamber that is provided on an outer circumferential portion of the pair of arc contacts; a mechanical puffer chamber that is provided on an outer circumference of the thermal puffer chamber and constituted by a cylinder formed in a toric shape centering around an axial line of the arc contacts; and a piston that is formed in a toric shape centering around the axial line and accommodated in the cylinder, and configured to move according to connection and disconnection of the arc contacts.

Abstract: A gas circuit breaker is provided, avoiding change in the position of a cover member and without weakening of the blow of gas to the arc in an arc discharge cavity even when a surface of the cover member in contact with the arc discharge cavity is damaged. The gas circuit breaker includes a contact ring, a holder attached to the contact ring, and extending to a path of arc-extinguishing gas that extinguishes an arc, and an electrically insulative cover member attached to the holder.

Abstract: There are provided a switching-device remaining lifetime diagnosis method and a switching-device remaining lifetime diagnosis apparatus, wherein as status amount history data, there are accumulated status amounts related to a deterioration status of a switching device, estimated based on measurement data obtained through measurement of performance characteristics of the switching device; based on the accumulated status amount history data, there are created a plurality of system data pieces in which the status amounts are arranged with the respective abscissas of an elapsed time during an operation period of the switching device, the number of operations of the switching device, an inoperative time of the switching device, and an accumulated operation time of the switching device; based on the created system data pieces, the remaining lifetime of the switching device is estimated.

Abstract: A gas circuit breaker includes: a pair of electrodes provided so as to be able to come in contact with and separate from each other; and an insulating material that is placed so as to generate a decomposition gas in response to a direct or indirect action from an arc occurring between the pair of electrodes when a current is broken, wherein the decomposition gas generated from the insulating material when the current is broken is configured to be utilized for extinguishing the arc, and wherein an ablative material that does not include hydrogen atoms but has a carbon-oxygen bond in a main chain or ring part is used as the insulating material.

Abstract: A bus is placed at the center of a housing. Breakers and cables forming branch circuits branching from the bus are placed at the upper and lower stages in the housing, being displaced in the right-left direction. Spaces formed between the side wall of the housing and the side walls of an upper-stage breaker compartment and an upper-stage cable compartment containing the upper-stage apparatuses are used as paths leading to the housing ceiling for a bus compartment, and a lower-stage breaker compartment and a lower-stage cable compartment containing the lower-stage apparatuses. The bus compartment and all the apparatus compartments each directly lead to a ceiling portion of the housing and have an opening portion. Pressure discharge plates are provided on the opening portions.

Abstract: A switchgear includes a fixed contactor provided in a tank filled with insulating gas, and a movable contactor provided in the tank, the movable contactor being connected to and disconnected from the fixed contactor so as to move forward and backward. The switchgear includes an arc extinction member including a surrounding portion which is slidably connected to the outer circumferential surface of the movable contactor halfway in a movement range from a close contact state to an open contact state and is formed so as to surround an arc space portion in a sealed manner, the surrounding portion being formed with a through hole through which the arc space communicates with the outside of the arc space.

Abstract: A gas circuit breaker includes: a sealed tank filled with insulation gas; a pair of arc contacts that are arranged to face each other in the sealed tank and connectable and disconnectable with each other; a thermal puffer chamber that is provided on an outer circumferential portion of the pair of arc contacts; a mechanical puffer chamber that is provided on an outer circumference of the thermal puffer chamber and constituted by a cylinder formed in a toric shape centering around an axial line of the arc contacts; and a piston that is formed in a toric shape centering around the axial line and accommodated in the cylinder, and configured to move according to connection and disconnection of the arc contacts.

Abstract: An arc extinguishing device of a gas circuit breaker includes: an arc chamber in which an arc generated between a movable electrode and a fixed electrode is formed; a heat puffer chamber disposed so as to surround the arc chamber; a blow port in which the arc chamber communicates with the heat puffer chamber in the circumferential direction of the arc chamber; hydrogen absorbents which are disposed on an inner wall of a pressure chamber; an exhaust port which passes to the outside of an arc extinguishing chamber; and a hydrogen absorbent disposed at a position surrounding the movable electrode. Deterioration of insulation due to a product formed by decomposition of arc extinguishing gas by the arc during a contact opening operation can be suppressed.

Abstract: A gas circuit breaker is provided, avoiding change in the position of a cover member and without weakening of the blow of gas to the arc in an arc discharge cavity even when a surface of the cover member in contact with the arc discharge cavity is damaged. The gas circuit breaker includes a contact ring, a holder attached to the contact ring, and extending to a path of arc-extinguishing gas that extinguishes an arc, and an electrically insulative cover member attached to the holder.

Abstract: There are provided a switching-device remaining lifetime diagnosis method and a switching-device remaining lifetime diagnosis apparatus, wherein as status amount history data, there are accumulated status amounts related to a deterioration status of a switching device, estimated based on measurement data obtained through measurement of performance characteristics of the switching device; based on the accumulated status amount history data, there are created a plurality of system data pieces in which the status amounts are arranged with the respective abscissas of an elapsed time during an operation period of the switching device, the number of operations of the switching device, an inoperative time of the switching device, and an accumulated operation time of the switching device; based on the created system data pieces, the remaining lifetime of the switching device is estimated.

Abstract: A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.

Abstract: A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.

Abstract: An optical submarine communication system has a land cable connected to a terminal apparatus which is installed on land near the seashore for transmitting an optical signal and electric power. The land cable is connected to an optical submarine cable through a beach manhole, and a repeater is connected to the optical submarine cable. The optical submarine communication system has a surge suppressor provided on the land cable, whereby a surge generated from the terminal apparatus side because of a lightning stroke or an insulation failure is suppressed and prevented from reaching and damaging the repeater.

Abstract: An optical submarine communication system has a land cable connected to a terminal apparatus which is installed on land near the seashore for transmitting an optical signal and electric power. The land cable is connected to an optical submarine cable through a beach manhole, and a repeater is connected to the optical submarine cable. The optical submarine communication system has a surge suppressor provided on the land cable, whereby a surge generated from the terminal apparatus side because of a lightning stroke or an insulation failure is suppressed from reaching and damaging the repeater.

Abstract: A switch for use in electric power includes a fixed contact, a moving contact performing a switching operation with respect to the fixed contact, a cylinder working with the moving contact, a piston slidably provided in the cylinder, a buffer chamber which is surrounded by the cylinder and the piston, and is filled with an arc-extinguishing gas, and a second insulating nozzle mounted to an end of the cylinder on the side of the fixed contact, wherein the arc-extinguishing gas in the buffer chamber is sprayed through the nozzle on an arc generating between the fixed contact and the moving contact at an opening time of the moving contact.