Device for making and/or breaking a current including a pair of permanent contacts (3, 4), at least one of the contacts (3, 4) being movable. At least one permanent contact (3, 4) including a main portion (3.1, 4.1) having a free end and an end protection portion (3.2, 4.2) secured to the free end of the main portion (3.1, 4.1), designed to be in mechanical and electrical contact with the other permanent contact (4, 3) only during an operation for opening or closing the pair. The end protection portion (3.2, 4.2) is made of a single transition metal having a melting temperature that is strictly higher than that of the main portion (3.1, 4.1) to which it is secured, or of an oxide or carbide of such a metal, or even of zinc oxide. For application in particular to high- or medium-voltage circuit breakers.

A switch includes an insulating base having an upper surface and an assembly having a mounting surface. The assembly configured to be arranged on the insulating base, the assembly having a lower surface, the assembly being configured to be arranged on the upper surface of the insulating base with an open space between the lower surface of the assembly and the upper surface of the insulating base. The switch further includes a plurality of fixed contact units mounted in an aligned arrangement on the mounting surface of the assembly and a movable contactor mounted to move within the bore of the insulating body and the electrical contacts of the plurality of fixed contact units.

A fast earthing switch for a GIS, including a movable contact rod, having an end; a cylinder, fixed to the contact rod and forming a gas chamber around at least part of the contact rod, the gas chamber including an outlet around the contact rod so that gas can flow along the contact rod and its end when it moves from a closed to an open position; and means for actuating the contact rod between a closed and an open position.

A high- or medium-voltage circuit breaker, in which a movable contact (1) is moved in sliding in order to separate stationary contacts (11, 12) from its sliding surface (2). In accordance with the invention, the stationary contacts (11, 12) have switching portions (9) that separate from the movable contact more or less simultaneously as a result of a setback (19) in the movable contact (1), thereby causing two simultaneous switching arcs to appear (14, 15), which arcs are extinguished much more quickly than a single arc, before the current is transferred to the conventional arcing contacts (5). This disposition enables the stationary contacts (11, 12) and their environment to be less exposed to damage.

An internal tulip sleeve for the female arcing contact of a high voltage circuit breaker. According to the invention, this sleeve comprises a body of non-magnetic steel or of copper-tungsten alloy, this body comprising an internal face covered with copper.

The invention relates to a circuit breaker comprising a first and a second contact assembly, wherein one of the contact assemblies comprises contact fingers arranged in a finger cage configuration and the other contact assembly comprises a tube or rod contact. The contact fingers comprise an impact point where the tube or rod impacts the contact fingers for the first time during electrical connection establishment, and a contact zone which contacts the tube or rod when the electrical connection is established. The contact zone comprises two contact points separated from one another and arranged on a line which is perpendicular to the longitudinal axis.

A switching arrangement includes an interrupter unit with a first and a second switching contact piece. A switching path can be formed between the two switching contact pieces under a relative movement of the same. At least one of the switching contact pieces is arranged within a hollow body. The switching contact piece is supported by a transversal crosspiece that crosses the hollow body. The transversal crosspiece is braced at opposite sections of the hollow body.

A contact pin for a high-voltage and/or medium-voltage switch includes a contact tip of arc-erosion resistant material, a tubular support sleeve connected to the contact tip and a support core in the sleeve. The contact tip is in a forward region of the contact pin where arcs arise during use. The sleeve is in a rearward region of the contact pin, adjoining the forward region, where no arcs arise during use. A pipe contact includes an arc-erosion resistant annular contact and a support pipe connected to the annular contact. The annular contact is in a forward region of the pipe contact where arcs arise during use, and the support pipe is in a rearward region of the pipe contact, adjoining the forward region, where no arcs arise during use. Methods for producing a contact pin and a pipe contact are also provided.

A front-accessible bus-connection mounting frame assembly in a draw out switchgear cabinet is fastened to the back wall of the breaker cabinet. The frame assembly provides for insertion and bayonet mounting of a primary bus connector's cylindrical conductor onto the mounting frame. The primary bus connector is bayonet mounted on the internal ribs of a central cylinder of the mounting frame assembly. The primary bus connector is then fixed in position by bolts front mounted down the central cylinder and out through a bus riser fitted at the back of the mounting frame assembly to establish electrical continuity. The central cylinder further provides a current transformer bushing tube around the primary bus connector and necessary flanges to mount the mounting frame assembly to the back wall and secure the current transformers around the bushing.

Gas-insulated high voltage puffer breaker comprising a puffer unit with a movable piston running in a puffer cylinder and delimiting a puffer volume. A piston and a first contact member are attached to a piston stem. A piston and a first contact member are attached to a piston stem. An electric arc is extinguishable in an arcing zone when the first contact member moves from a first position to a second position. The puffer volume is fluidly connected to a gas nozzle by a gas channel such that the puffer volume comprises the gas channel as well as a portion of the puffer cylinder. The gas channel is provided radially outside of the puffer cylinder between a puffer cylinder wall delimiting the puffer cylinder and a wall structure of the puffer unit.