A gas-insulated electrical apparatus according to the present invention comprises a grounded tank, a conductor placed inside the grounded tank, and an insulation gas filling the grounded tank. The insulation gas is a mixed gas comprising a first gas mainly responsible for insulation performance and having a global warming potential less than 6500, and a second gas having a small molecular weight, a low insulation performance, and a low global warming potential, as compared to the first gas. The insulation performance of the insulation gas is lower than the insulation performance of the first gas at a same pressure.

An electrical energy transmission device for the transmission of electrical energy has a fluid-holding chamber. An electrically insulating fluid is contained in the fluid-holding chamber. The electrically insulating fluid is, at least in part, air-drawn from the surroundings of the electrical energy transmission device. The insulating fluid is used for insulating phase conductors in order to avoid short circuit conditions.

The use of a gas as a medium for electrically isolating and/or extinguishing electric arcs, the gas including 1-chloro-2,3,3,3-tetrafluoropropene. Also, an electrical device including a sealed chamber containing electrical components and a gas for electrically isolating and/or extinguishing electric arcs, in which the gas includes 1-chloro-2,3,3,3-tetrafluoropropene. The gas may be only 1-chloro-2,3,3,3-tetrafluoropropene.

The use of a gas as a medium for electrically isolating and/or extinguishing electric arcs, the gas including 1-chloro-2,3,3,3-tetrafluoropropene. Also, an electrical device including a sealed chamber containing electrical components and a gas for electrically isolating and/or extinguishing electric arcs, in which the gas includes 1-chloro-2,3,3,3-tetrafluoropropene. The gas may be only 1-chloro-2,3,3,3-tetrafluoropropene.

An insulating medium for an electric energy transmission device is a fluid at room temperature and atmospheric pressure and has at least the following components ≥50% by volume to ≤98% by volume of synthetic air, and ≥2% by volume to ≤50% by volume of an organic fluorine compound. An electric arc extinguishing medium and a fluid-insulated electric energy transmission device are also provided.

An insulating medium for an electric energy transmission device is a fluid at room temperature and atmospheric pressure and has at least the following components ≥50% by volume to ≤98% by volume of synthetic air, and ≥2% by volume to ≤50% by volume of an organic fluorine compound. An electric arc extinguishing medium and a fluid-insulated electric energy transmission device are also provided.

An insulating spacer and a gas insulation shutoff apparatus each having a high dielectric strength against adhesion of a metal foreign substance are provided without increasing size or complicating a shape of the insulating spacer. In an insulating spacer of a gas insulation shutoff apparatus including a grounded tank filled with an insulating gas, a high-voltage conductor provided within the grounded tank, and the insulating spacer supporting and fixing the high-voltage conductor within the grounded tank, the insulating spacer includes a conductor to be connected to the high-voltage conductor, an insulating structure supporting and fixing the conductor within the grounded tank, and a nonlinear resistance layer provided on a creepage surface of the insulating structure, and the nonlinear resistance layer is provided in a portion to be a high-field portion of the creepage surface of the insulating structure.

An insulating spacer and a gas insulation shutoff apparatus each having a high dielectric strength against adhesion of a metal foreign substance are provided without increasing size or complicating a shape of the insulating spacer. In an insulating spacer of a gas insulation shutoff apparatus including a grounded tank filled with an insulating gas, a high-voltage conductor provided within the grounded tank, and the insulating spacer supporting and fixing the high-voltage conductor within the grounded tank, the insulating spacer includes a conductor to be connected to the high-voltage conductor, an insulating structure supporting and fixing the conductor within the grounded tank, and a nonlinear resistance layer provided on a creepage surface of the insulating structure, and the nonlinear resistance layer is provided in a portion to be a high-field portion of the creepage surface of the insulating structure.

A gas circuit breaker that can reduce deterioration of insulation performance thereof and current breaking performance thereof by the unnecessary gas generated from the arc-extinguishing gas sprayed to the arc is provided. The gas circuit breaker includes a sealed container (8) which arc-extinguishing gas is filled therein, a first fixed contactor (2) which is fixed to the sealed container (8), a second fixed contactor portion (4) which is fixed to the sealed container (8), and a movable contactor portion (3) which moves between the first contactor portion (2) and the second contactor portion (4), and which conducts and breaks current between the first contactor portion (2) and the second contactor portion (4), in which an arc 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) at a time of current breaking action is extinguished by an arc-extinguishing gas being sprayed thereto, and the gas circuit breaker (1) includes a gas chamber (5) to accumulate an unnecessary gas generated from the arc-extinguishing gas sprayed to the arc.

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.