Patent ID: 7754991

Claim:
Medium-voltage or high-voltage electrical switchgear, the electrical switchgear being a circuit-breaker or a disconnector, comprising an interrupting chamber enclosing an interrupting gas substantially devoid of sulfur hexafluoride (SF 6 ) and of carbon tetrafluoride (CF 4 ), the interrupting chamber containing a first contact member and a second contact member, which contact members are provided respectively with a first arcing contact and with a second arcing contact, the two arcing contacts being suitable, when in service, for taking up a first position in which they are in contact with each other, and a second position in which they are separated from each other, the two arcing contacts moving between the first position and the second position causing an electric arc to strike, while at least one irradiation wall suitable for being reached by the electric arc is provided in the vicinity of said arcing contacts; at least two component materials including at least one element selected from the interrupting gas, the first arcing contact and the second arcing contact, and said at least one irradiation wall, being suitable for decomposing under the effect of the electric arc to form decomposed species suitable for combining in the interrupting chamber to form at least one new gaseous species, at least while the electric arc is being extinguished, the dielectric properties of said at least one new gaseous species being superior to the dielectric properties of said interrupting gas; at least one element selected from the interrupting gas, the first arcing contact and the second arcing contact, and the at least one irradiation wall includes an oxide suitable for decomposing under the effect of the electric arc, so as to form at least one auxiliary decomposed species suitable for combining with the decomposed species, so as to prevent pure carbon from forming, said oxide being associated with at least one solid fluoride, in the same solid element, said electrical switchgear being characterized in that the solid fluoride is a fluorine-containing polymer, the proportion by weight of the fluorine-containing polymer being in the range 50% to 80%, and preferably in the range 60% to 70%, of the total formed by the fluorine-containing polymer and by said oxide.