A switching device for an encapsulated electric power distribution switchgear and an electric power distribution switchgear with at least one such switching device are disclosed. The switching device has a first electrically conducting housing which encloses an actuator mechanism for a first contact assembly and a second electrically conducting housing which encloses a second contact assembly. The first electrically conducting housing is arranged at a distance from the second electrically conducting housing. The switching device further has a third housing which is electrically insulating and arranged between the first electrically conducting housing and the second electrically conducting housing. The switching device is a puffer type switch.

The present invention relates to a dielectric-insulation or arc-extinction fluid for an apparatus for the generation, the transmission, the distribution and/or the usage of electrical energy, the fluid being a mixture comprising a fluoroolefin and oxygen. According the fluoroolefin is a monohydrofluoroolefin containing from 4 to 5 carbon atoms, the hydrogen atom being bound to a carbon atom of the double bond or directly adjacent to the double bond.

The present invention relates to a dielectric-insulation or arc-extinction fluid for an apparatus for the generation, the transmission, the distribution and/or the usage of electrical energy, the fluid being a mixture comprising a fluoroolefin and oxygen. According the fluoroolefin is a monohydrofluoroolefin containing from 4 to 5 carbon atoms, the hydrogen atom being bound to a carbon atom of the double bond or directly adjacent to the double bond.

A method of distributing an electrically insulating liquefied gas mixture to high-voltage electrical equipment from a storage means containing an insulating gas mixture, including: heating the insulating gas mixture to a temperature such that the contents of the storage means are a homogeneous fluid; and withdrawing the insulating mixture resulting from step a) to fill high-voltage electrical equipment by raising the temperature of the mixture resulting from step a), wherein, during step b), a set value for regulation is applied at variable pressure, calculated in real time based on weighing the storage means, when the change in the set value of pressure is less than 0.2 bar per 1 kg/m.sup.3 of change in density, and then a set value for regulation is applied at constant temperature until the storage means is emptied of its content.

The present disclosure relates to switchgear. Various embodiments may include medium- or high-voltage switchgear with a gas-tight insulating space. For example, a switchgear may include: a gas-tight insulating space where an insulating gas is kept above atmospheric pressure and two switching contacts in the space. At least one of the contacts may movable with respect to a nozzle. The insulating gas may include a mixture of at least 90% by mass of nitrogen and oxygen or nitrogen and carbon dioxide. The nozzle may include a plastic with at least 65% by mass in total of the elements carbon, nitrogen, and oxygen.

The present disclosure relates to switchgear. Various embodiments may include medium- or high-voltage switchgear with a gas-tight insulating space. For example, a switchgear may include: a gas-tight insulating space where an insulating gas is kept above atmospheric pressure and two switching contacts in the space. At least one of the contacts may movable with respect to a nozzle. The insulating gas may include a mixture of at least 90% by mass of nitrogen and oxygen or nitrogen and carbon dioxide. The nozzle may include a plastic with at least 65% by mass in total of the elements carbon, nitrogen, and oxygen.

The present invention relates to an insulating gas used for electrical insulation or arc extinguishing of an electrical device, and an electrical device for insulating electricity using the same. The insulating gas of the present invention, which may replace SF.sub.6 gas, consists of a mixed gas of trifluoromethyl trifluorovinyl ether (CF.sub.3OCFCF.sub.2) and a carrier gas. The insulating gas of the present invention has the characteristics of a low boiling point, high dielectric strength, low toxicity, and a low global warming potential (GWP=1 or less), and thus may replace SF.sub.6, and the low global warming potential with no loss of high insulating capacity and arc extinguishing capability may reduce greenhouse gases.

A medium-voltage or high-voltage electrical device comprising a sealed enclosure in which are located electrical components covered with a solid dielectric layer and a gaseous medium ensuring electrical insulation and/or extinguishing electrical arcs, the gaseous medium comprising heptafluoroisobutyronitrile and a dilution gas, the thickness of the solid dielectric layer being less than 1 mm and being produced from a material comprising a polyepoxide or polyurethane resin optionally containing a filler or aluminum oxide.

A medium-voltage or high-voltage electrical device comprising a sealed enclosure in which are located electrical components covered with a solid dielectric layer and a gaseous medium ensuring electrical insulation and/or extinguishing electrical arcs, the gaseous medium comprising heptafluoroisobutyronitrile and a dilution gas, the thickness of the solid dielectric layer being less than 1 mm and being produced from a material comprising a polyepoxide or polyurethane resin optionally containing a filler or aluminum oxide.

The invention relates to an electric arc-blast nozzle for a circuit breaker comprising a middle portion forming a throat defining internally an axial passage for interrupting an electric arc, and two end portions extending on either side of the middle portion and being designed to receive respective arcing contacts and that are movable axially relative to each other. The middle portion and the two end portions are made of a same dielectric material obtained from a composition consisting of a fluorocarbon polymer matrix and of at least one oxide, the oxide(s) being present in a proportion by weight lying in the range 11% to 50%, relative to the total weight of the composition. The invention also relates to a circuit breaker including such a nozzle.