An arrangement includes a gas-insulated switchgear which is configured for filling with a first electrical insulation fluid. A surge arrester is provided to reduce the protection level of the gas-insulated switchgear such that the switchgear has insulation spacings of at most the same size as those of a switchgear insulated with a second electrical insulation fluid which has a higher dielectric strength than the first electrical insulation fluid.

An arrangement includes a gas-insulated switchgear which is configured for filling with a first electrical insulation fluid. A surge arrester is provided to reduce the protection level of the gas-insulated switchgear such that the switchgear has insulation spacings of at most the same size as those of a switchgear insulated with a second electrical insulation fluid which has a higher dielectric strength than the first electrical insulation fluid.

Methods for dielectrically insulating electrical active parts The invention concerns methods for dielectrically insulating electrical active parts using certain fluorinated cyano-substituted ethers as well as compositions and apparatus comprising such compounds.

Methods for dielectrically insulating electrical active parts The invention concerns methods for dielectrically insulating electrical active parts using certain fluorinated cyano-substituted ethers as well as compositions and apparatus comprising such compounds.

A circuit breaker, comprising an enclosure comprising: at least two arcing contacts that are movable axially relative to each other, between an open position of the circuit breaker in which the arcing contacts are separated from each other and a closed position of the circuit breaker in which the arcing contacts are in contact with each other; and a gas inlet configured to blow an arc-control gas in order to interrupt an electric arc that is likely to form during movement of the arcing contacts from the closed position to the open position of the circuit breaker, wherein the arc-control gas comprises at least 80% of carbon dioxide; wherein the enclosure further comprises a catalytic material, which converts carbon monoxide that forms after ionization of the carbon dioxide during arcing, into carbon dioxide, said catalytic material comprising ceria and a precious metal.

A circuit breaker, comprising an enclosure comprising: at least two arcing contacts that are movable axially relative to each other, between an open position of the circuit breaker in which the arcing contacts are separated from each other and a closed position of the circuit breaker in which the arcing contacts are in contact with each other; and a gas inlet configured to blow an arc-control gas in order to interrupt an electric arc that is likely to form during movement of the arcing contacts from the closed position to the open position of the circuit breaker, wherein the arc-control gas comprises at least 80% of carbon dioxide; wherein the enclosure further comprises an adsorbing material, which adsorbs carbon monoxide that forms after ionization of the carbon dioxide during arcing, said adsorber being a metal-organic framework comprising nickel and/or iron.

The invention relates to medium- or high-voltage, gas-insulated electrical apparatus (10) comprising: a hermetically sealed chamber (12) filled with a dielectric gas, the gas containing at least one of fluoronitrile, carbon dioxide, dinitrogen or dioxygen; at least two electrical contacts (16, 20) arranged coaxially with a main axis (A) of the chamber (12), of which at least one (20) can move axially inside the chamber (12) between a closed position in which the two contacts (16, 20) are in electrical contact with one another and an open position in which the contacts (16, 20) are located at a distance from one another; and a cut-off mechanism (14) for extinguishing the electric arc that forms between the two contacts (16, 20) as the at least one moving contact (20) moves from the closed position into the open position. The cut-off mechanism is of the rotating arc type.

The invention relates to medium- or high-voltage, gas-insulated electrical apparatus (10) comprising: a hermetically sealed chamber (12) filled with a dielectric gas, the gas containing at least one of fluoronitrile, carbon dioxide, dinitrogen or dioxygen; at least two electrical contacts (16, 20) arranged coaxially with a main axis (A) of the chamber (12), of which at least one (20) can move axially inside the chamber (12) between a closed position in which the two contacts (16, 20) are in electrical contact with one another and an open position in which the contacts (16, 20) are located at a distance from one another; and a cut-off mechanism (14) for extinguishing the electric arc that forms between the two contacts (16, 20) as the at least one moving contact (20) moves from the closed position into the open position. The cut-off mechanism is of the rotating arc type.

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.

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.