A switching apparatus including one or more electric poles. For each electric pole, the switching apparatus includes a first pole terminal, a second pole terminal, a ground terminal, and a plurality of fixed contacts spaced apart one from another. For each electric pole, the switching apparatus further includes a movable contact and a vacuum interrupter. The vacuum interrupter includes a fixed arc contact and a movable arc contact reversibly movable along a corresponding translation axis between a coupled position with the fixed arc contact and an uncoupled position from the fixed arc contact. For each electric pole, the switching apparatus further includes a motion transmission mechanism operatively coupled to a contact shaft coupled to the movable arc contact. The motion transmission mechanism is actuatable by the movable contact to cause a movement of said movable arc contact along said translation axis, when said movable contact moves about said rotation axis.

A method for assembling a switching apparatus for medium voltage electric systems is provided. The method includes, for each electric pole of the switching apparatus, providing a mounting assembly. The mounting assembly includes a support structure, a vacuum interrupter, a motion transmission mechanism, and an auxiliary contact. The method further includes providing a first semi-finished structure of the switching apparatus, where the first semi-finished structure includes, for each electric pole of the switching apparatus, a first pole terminal and a first fixed contact electrically connected to the first pole terminal. The method further includes, for each electric pole of the switching apparatus, installing the mounting assembly on the first semi-finished structure.

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 high voltage electric switch includes contacts with graphite carbon electrode forming the arc gap. In addition, the carbon contacts are located in a chamber containing at least 60% carbon dioxide (CO2) as a dielectric gas to achieve improved arc interrupting performance. In conventional switches, the metallic contacts introduce metallic vapors into the arc plasma that inhibits the ability of the dielectric gas to interrupt high voltage, high current arcs. As the element carbon is inherently present in CO2 gas, the addition of vapors from the carbon electrodes into the dielectric gas does not significantly interfere with the dielectric arc-interrupting performance of the CO2 dielectric gas.

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.

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 switch-fuse module and a ring main unit. The switch-fuse module includes: at least one fuse; and at least one fuse canister having the fuse inside; the security device including: at least one slider configured to linearly move between an open slider position and a closed slider position; at least one earthing switch that i) is galvanically connected to an end of the fuse, ii) is operable between an open and a closed state, iii) is designed to earth the end of the fuse in the closed state, and iv) is coupled to the slider in such a manner that the open slider position effects the open state of the earthing switch and the closed slider position effects the closed state of the earthing switch; an energy-storing propulsion element configured to move the earthing switch from the open to the closed state when discharging; and a locking mechanism adapted for blocking access to the fuse in a locked state and for releasing access to the fuse in an unlocked state, wherein the slider is coupled to the locking mechanism in such a manner that the slider is in the closed slider position while the locking mechanism is in the unlocked state, so that the fuse may only be accessed if it is ensured that the fuse is earthed.

A fuse adapter kit for a fuse of a switch-fuse module and a switch-fuse module. The fuse adapter kit includes: a fuse canister having an axially elongated fuse receiving portion adapted to receive the fuse; and at least one terminal having i) an axial fuse receiving opening for receiving an axial end portion of the fuse, ii) a lateral protrusion forming a mechanical male connector, and iii) an electrical terminal connector laterally arranged within the mechanical male connector for electrically connecting the fuse to an electrical canister connector; wherein the fuse canister has a fuse mounting wall portion extending axially along a back side of the fuse receiving portion, the fuse mounting wall portion having at least three fuse mounting openings at different axial positions along the fuse mounting wall portion, each of the fuse mounting openings forming a mechanical female connector matching the mechanical male connector of the terminal to form a mechanical plug connection, and wherein the fuse canister further includes the electrical canister connector arranged at at least one of the fuse mounting openings for electrically connecting to the electrical terminal connector.

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.

A high voltage electric switch includes contacts with graphite carbon electrode forming the arc gap. In addition, the carbon contacts are located in a chamber containing at least 60% carbon dioxide (CO2) as a dielectric gas to achieve improved arc interrupting performance. In conventional switches, the metallic contacts introduce metallic vapors into the arc plasma that inhibits the ability of the dielectric gas to interrupt high voltage, high current arcs. As the element carbon is inherently present in CO2 gas, the addition of vapors from the carbon electrodes into the dielectric gas does not significantly interfere with the dielectric arc-interrupting performance of the CO2 dielectric gas.