A method monitors gases produced in an insulating medium circuit. The insulating medium circuit is in contact with a transition resistor of an on-load tap-changer. The method includes: ascertaining a time profile of a resistor temperature of the transition resistor during a loading time period; and determining at least one characteristic value for characterizing the gases produced based upon the time profile of the resistor temperature.

A method monitors gases produced in an insulating medium circuit. The insulating medium circuit is in contact with a transition resistor of an on-load tap-changer. The method includes: ascertaining a time profile of a resistor temperature of the transition resistor during a loading time period; and determining at least one characteristic value for characterizing the gases produced based upon the time profile of the resistor temperature.

A vacuum circuit breaker includes: a vacuum valve that is insulated and supported inside a grounded tank; a movable-side frame connecting a lower end of a movable-side external conductor to a movable conductor; a stationary-side frame connecting a lower end of a stationary-side external conductor to a stationary conductor; a movable-side insulating support tube that supports the movable-side frame and insulates thereof from the grounded tank; a stationary-side insulating support tube that supports the stationary-side frame and insulates thereof from the grounded tank; a movable-side flange covering a movable-side end of the grounded tank; and a rubber piece on an inner peripheral surface of the movable-side flange. The movable-side insulating support tube is supported, at an end opposite from an end connected to the movable-side frame, by the movable-side flange via the rubber piece and is movable along an axis and a radius of an arc-extinguishing chamber.

A gas circuit breaker to reduce deterioration of insulation and current-breaking performance thereof includes a sealed container (8) filled with arc-extinguishing gas. A first fixed contactor portion (2) and a second fixed contactor portion (4) are fixed to the sealed container (8). A movable contactor portion (3) moves between the first fixed contactor portion (2) and the second fixed contactor portion (4) and conducts and breaks current between the first fixed contactor portion (2) and the second fixed contactor portion (4). An arc is generated between a fixed arc contactor (21) provided to the first fixed contactor portion (2) and a movable arc contactor (31) provided to the movable contactor portion (3) when current breaking action is extinguished by an arc-extinguishing gas being sprayed thereto. Unnecessary gas generated from the arc-extinguishing gas sprayed to the arc is accumulated in a gas chamber (5).

A gas circuit breaker to reduce deterioration of insulation and current-breaking performance thereof includes a sealed container (8) filled with arc-extinguishing gas. A first fixed contactor portion (2) and a second fixed contactor portion (4) are fixed to the sealed container (8). A movable contactor portion (3) moves between the first fixed contactor portion (2) and the second fixed contactor portion (4) and conducts and breaks current between the first fixed contactor portion (2) and the second fixed contactor portion (4). An arc is generated between a fixed arc contactor (21) provided to the first fixed contactor portion (2) and a movable arc contactor (31) provided to the movable contactor portion (3) when current breaking action is extinguished by an arc-extinguishing gas being sprayed thereto. Unnecessary gas generated from the arc-extinguishing gas sprayed to the arc is accumulated in a gas chamber (5).

A switch-fuse module and a ring main unit. The switch-fuse module includes: a housing having therein a first enclosure including a first insulating gas and a second enclosure including a second insulating gas; at least one switch disconnector arranged within the first enclosure; and at least one fuse at least partially surrounded by the second enclosure; wherein each of the first insulating gas and the second insulating gas has a global warming potential less than a global warming potential of SF6, and the first enclosure is different and separate from the second enclosure.

A switch-fuse module and a ring main unit. The switch-fuse module includes: a housing having therein a first enclosure including a first insulating gas and a second enclosure including a second insulating gas; at least one switch disconnector arranged within the first enclosure; and at least one fuse at least partially surrounded by the second enclosure; wherein each of the first insulating gas and the second insulating gas has a global warming potential less than a global warming potential of SF6, and the first enclosure is different and separate from the second enclosure.

A breaking device for interrupting current includes an electrically conducting outer member, an electrically conducting inner member arranged radially inside the outer member with respect to a breaking axis and an electrically insulating or semiconducting breaking member arranged radially between the outer member and the inner member with respect to the breaking axis, where the breaking member is arranged to move along the breaking axis from a starting position to a protruding position in which the breaking member protrudes from a space within the outer member for interrupting a current between the outer member and the inner member and the breaking member includes an inner tubular element and an outer tubular element, where the outer tubular element is joined to an outer surface of the inner tubular element thereby defining a recess between the outer tubular element and the inner tubular element.

A breaking device for interrupting current includes an electrically conducting outer member, an electrically conducting inner member arranged radially inside the outer member with respect to a breaking axis and an electrically insulating or semiconducting breaking member arranged radially between the outer member and the inner member with respect to the breaking axis, where the breaking member is arranged to move along the breaking axis from a starting position to a protruding position in which the breaking member protrudes from a space within the outer member for interrupting a current between the outer member and the inner member and the breaking member includes an inner tubular element and an outer tubular element, where the outer tubular element is joined to an outer surface of the inner tubular element thereby defining a recess between the outer tubular element and the inner tubular element.

An electrical apparatus have a grounded tank with a conductor at an inside thereof, in which: the inside of the grounded tank is filled with insulating arc-extinguishing gas; the insulating arc-extinguishing gas is confined in the grounded tank by a sealing member; the insulating arc-extinguishing gas includes at least one selected from the group consisting of a hydrofluoroolefin having 3 or 4 carbon atoms and a hydrochlorofluoroolefin having 3 or 4 carbon atoms; and the sealing member includes at least one selected from the group consisting of an ethylene propylene rubber, an isobutylene-isoprene rubber, a chloroprene rubber, a natural rubber, a nitrile rubber, a hydrogenated nitrile rubber, an urethane rubber, a chlorosulfonated polyethylene rubber, a vinylidene fluoride based fluororubber, a tetrafluoroethylene-perfluorovinylether based rubber and a polytetrafluoroethylene.