The invention relates to a medium-, high-, or very high-voltage circuit breaker, comprising at least one arc-control chamber and an outer casing in which the arc-control chamber is arranged. The circuit breaker includes a discharge cap (40) forming a portion of the outer wall external of the arc-control chamber (12), the discharge cap being situated inside the outer casing and internally defining a gas-flow chamber (31). In the invention, the discharge cap (40) includes at least one portion (40′) that is movable under the effect of the gas pressure in the gas-flow chamber (31), in such a manner that its volume is extensible.

A gas circuit breaker includes a trigger electrode which is arranged to be movable between a first arc contactor and a second arc contactor, a compression chamber for pressurizing arc-extinguishing gas, the compression chamber being formed by a cylinder which has an outer wall and an inner wall, each being formed in a cylindrical shape, and which is provided to the second arc contactor, and a piston that slides between the outer wall and the inner wall in conjunction with the trigger electrode, and an insulation nozzle that guides the arc-extinguishing gas pressurized in the compression chamber to an arc ignited between the first arc contactor and the second arc contactor. The insulation nozzle is supported by the inner wall of the cylinder.

A gas-insulated high or medium voltage circuit breaker comprising: a first arcing contact and a second arcing contact, wherein at least one of the two arcing contact is axially movable along a switching axis, wherein during a breaking operation, an arc between the first arcing contact and the second arcing contact is formed in a arcing region; a buffer housing defining a pressurizing volume; a nozzle arranged at a nozzle side of the pressurizing volume, the nozzle defining a channel connected to the pressurizing volume and directed to the arcing region, for blowing an arc extinguishing gas towards the arcing region during the breaking operation, the nozzle comprising a nozzle front face facing towards the interior of the pressurizing volume.

Provided herein is an electric arc-blast nozzle for a circuit breaker comprising a median part internally defining an axial electric arc cut-off passage and formed with a first dielectric material, first and second end parts formed with the first dielectric material and extending on either side of the median part and being intended to receive first and second arc contacts being axially moveable in relation to each other. The nozzle further comprises a sheath that is disposed on the external surface of the first end part and on a portion of the external surface of the neck-forming median part, said portion having the same radial external section than the first end part, is formed with a second dielectric material different from the first dielectric material and is obtained from a second composition comprising a thermoplastic polymer chosen from either a polysulfone or a polyetherimide, but not comprising fibrous reinforcements.

There is provided a gas circuit breaker that can appropriately ensure a pressure and a density of arc-extinguishing gas to be sprayed to an arc, and can more surely maintain electric insulation performance. A gas circuit breaker 1 includes a first arc contactor 21 electrically connected to a first lead-out conductor 7a, a cylindrical guide portion 41 provided on a second lead-out conductor 7b side, a trigger electrode 31 which is arranged to be movable between the first arc contactor 21 and the guide portion 41, and which ignites an arc generated between the first arc contactor 21 and the trigger electrode along with a movement in a first half of a current breaking action, a compression chamber 36 for pressurizing arc-extinguishing gas, the compression chamber being formed by a cylinder 42 which has an outer wall 51 and an inner wall 52 both formed in a cylindrical shape, and which is provided on the guide portion 41 side, and a piston 33 that slides between the outer wall 51 and the inner wall 52 in conjunction with the trigger electrode 31, and an insulation nozzle 23 which guides the arc-extinguishing gas pressurized in the compression chamber 36 to an arc ignited at the first arc contactor 21. The insulation nozzle 23 is formed integrally with the inner wall 52 of the cylinder 42.

A gas-insulated switch has a first contact and a second contact. A contact unit is connected to the first contact as a movement contact unit having a drive unit and is movably mounted along a switch axis. The gas-insulated switch further has a multi-part insulation nozzle system with a primary nozzle and an auxiliary nozzle. A heating channel is formed between the primary nozzle and the auxiliary nozzle. The heating channel originates from an electric arc chamber and opens in a gas reservoir, wherein the gas reservoir is delimited by a ram. The gas reservoir is radially delimited by a wall, in respect of the switch axis, which is not a component of the movement contact unit, and the ram is part of the movement contact unit and is movably mounted such that the ram moves along the switch axis away from the second contact to enlarge the gas reservoir.

A switching arrangement has a first contact set and a second contact set which can be moved with respect to the first contact set, and an insulating nozzle arrangement. The insulating nozzle arrangement is supported on the first contact set which includes a first arcing contact piece. The first arcing contact piece can be moved with respect to the insulating nozzle arrangement.

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 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 fluid flow and cooling system and method are provided. The system has a substantially cylindrical tube shape and is configured to be installed in a circuit breaker for allowing the flow of fluids while dissipating heat from said fluids. The system comprises a plurality of openings on each of front and back surfaces, the openings of the front surface being connected to the openings of the back surface by a plurality of side passages. By having a plurality of side passages for the flow of fluids, heat dissipation may be improved compared to previous circuit breakers tubes for dispensing arc quenching fluid. The method cools a fluid flowing in a cooling device having side passages.