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.

The invention concerns a double-motion circuit breaker comprising primary and secondary movable contacts slidingly mounted within primary and secondary holders, wherein the primary movable contact comprises a tulip and a contact cylinder attached thereto, and the secondary movable contact comprises a pin for engaging the tulip but no counter-contact for engaging the contact cylinder. The circuit breaker also has a non-linear linkage mechanism with a pin and slot mechanism, and a fixed dielectric shield provided on the secondary holder. During disconnection, the linkage mechanism is preferably arranged to move the pin more than the tulip, proportionally to their maximum stroke, so as to quickly bring the pin tip within the fixed dielectric shield, whereafter the tulip moves more than the pin. This circuit breaker is cheaper, lighter and can be disconnected more quickly.

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.

The present disclosure relates to an arc extinguishing assembly, including side members which are spaced apart by a certain distance and disposed to face each other; an exhaust which is installed at an upper part of the side member; a plurality of grids which are installed between the side members and having both ends fixed to each of the side members; and an arc guide whose one side is coupled to the side member and which is installed at a lower part of the plurality of grids, wherein the arc guide is made of a material having heat resistance, and a circuit breaker including the same.