The application relates to a method for determining a property of a fluid component of a fluid present in a compartment of an electrical apparatus by means of a measurement device arranged outside the compartment and comprising a chamber for receiving a quantity of the fluid from the compartment. Amongst other steps of the method, an optical path in the chamber is illuminated by a light source and a first intensity of light is measured by a light detector. Then fluid is released from the compartment into the chamber and a second intensity (Ix) of light is measured. Based on these measurements the property of the fluid component is determined.

An electrical switching device is provided for interrupting an electrical connection. The device has a switching chamber and two contact pieces being arranged directly in the switching chamber or in an encapsulated housing arranged in the switching chamber and configured to be gas-tight in relation to the switching chamber. The contact pieces are movable relative to each other to bring about a switching action. A fluid insulation medium is also provided, which is arranged in the switching chamber or in a storage volume which can be connected to the switching chamber. The switching chamber or the storage volume has an outlet for letting out the fluid insulation medium. A filter is provided at or adjacent to the outlet, the filter configured to filter gaseous components of the insulation medium, or the reaction products thereof, conducted through the outlet.

The invention relates to an electric arc-blast nozzle (5) for a circuit breaker comprising a middle portion (7) forming a throat defining internally an axial passage (13) for interrupting an electric arc, and two end portions (9, 11) extending on either side of the middle portion (7) and being designed to receive respective arcing contacts (1) and (3) that are movable axially relative to each other.

The middle portion (7) and the two end portions (9, 11) are made of a same dielectric material obtained from a composition comprising a fluorocarbon polymer matrix, at least one inorganic filler and micro-capsules of liquid heptafluoro-iso-butyronitrile.

The invention also relates to a circuit breaker including such a nozzle (5).

A gas-insulated puffer-type switch device for operating inside a sealed gas tight enclosure of an electric power distribution switchgear, the sealed gas tight enclosure being filled with a dielectric gas having a global warming potential lower than that of SF6. The switch device has at least one of improved compactness, minimised electrical stress, maximised heat dissipation and reduced environmental impact.

A gas insulation apparatus has a sealed container, an insulation gas, a high-voltage portion, and a removal material. The insulation gas has CO.sub.2 and O.sub.2 filling the sealed container as main components. The high-voltage portion is stored in the sealed container. The removal material reduces concentrations of HF, CO, and O.sub.3 in the insulation gas.

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.

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.

A switch-fuse module and a ring main unit. The switch-fuse module includes: a housing having therein a switch enclosure including an insulating gas and a cable compartment that is different and separate from the switch enclosure; at least one switch disconnector arranged within the switch enclosure; and at least one fuse canister with a vertically oriented longitudinal axis; wherein the fuse canister i) is adapted to receive a fuse, and ii) is arranged within the cable compartment, and the insulating gas has a global warming potential less than a global warming potential of SF6.

A high-voltage device has an encapsulation housing and at least one bushing for at least one conductor, through which a current flows, into the encapsulation housing and/or out of the encapsulation housing. At least one electrode at free potential is surrounded by the bushing. The at least one electrode at free potential increases the dielectric strength in the high-voltage device, especially in the region of the bushing.