GB616031A - Compresed air blast electric switch with delay break connector - Google Patents

Abstract

616,031. Gas-blast switches. ETABLISSEMENTS MERLIN & GERIN. Aug. 21, 1946, No. 24924. Convention date, March 8, 1945. [Class 38 (v)] A voltage-limiting impedance 8, which may be a resistance, capacitance, &c., is connected in shunt to the main-contacts 1, 2 of a gasblast circuit-breaker a short time before the main-arc is extinguished, and disconnected again a short time after the extinguishment. This is effected in Fig. 1, when ionized gas conducted from inside the fixed nozzle 1, via a conduit 13, is discharged between auxiliary electrodes 9, 10 through an orifice 12 in an insulating-casing 11. The auxiliary arc between electrodes 9, 10 will be sustained for a short time after extinguishment of the main arc, until the ionized gas trapped in the conduit 13 by the insulating gas passing through the nozzle 1, has all been discharged through the orifice 12. In Fig. 2 (not shown), the casing 11 itself opens into the blast-chamber to provide a stream of insulating gas between the electrodes 9, 10, the ionized gas in conduit 13 being discharged into the centre of the insulating stream. In Fig. 3, the conduit 13 opens into an exhaust-gas collector 20, which may have an inlet-orifice 21 larger than an outlet-orifice 22. The end of the conduit 13 may alternatively be sealed and project into the upper end of an exhaust-gas collector, ionized gas entering the conduit 13 through a number of holes so as to exclude arc-products, (Fig. 4, not shown). In Fig. 5 (not shown), insulating- gas taken from the blast-chamber is ionized by the main arc as it passes through a permeable tube (e.g. quartz) arranged on the exhaust side of the fixed nozzle. In Fig. 6 (not shown), the conduit 13 opens into an axial hole bored into a solid fixed contact, arc-products being trapped in the blind end of the hole.