GB940511A - Improvements in or relating to air-break, magnetic blow-out electric circuit interrupters - Google Patents

Abstract

940,511. Arc-rupturing in switches. I-T-E CIRCUIT BREAKER CO. Nov. 11, 1960 [March 18, 1960], No. 38750/60. Heading H2B. An air-break, magnetic blowout circuitbreaker has an arc chute divided into two sections and two blowout coils connected and arranged so that the fluxes generated by both coils in at least the first section are in aiding relationship. The circuit-breaker comprises movable main and arcing contacts 46, 50 cooperating with fixed contacts 48, 52 and an arc chute 58 having rear, mid and front runners 60, 61, 62, one blowout coil 70 being connected between the runner 60 and the fixed contact structure 40, and the other coil 84 being connected between the structure 40 and the runner 61 through a resistor 22. The magnetic structure 68 and the coils 70, 84 are constructed and arranged, Fig. 3 (not shown), in a manner similar to that of Specification 859,802, the coils being of the face-wound type. Upon opening an arc is formed between contacts 50, 52 and one end transfers to runner 60 so energizing the coil 70. The arc subsequently divides between runners 60, 61 and the runner 61 and movable arm 42, this division energizing the coil 84 and resistor 22 to enable the arc between runners 60, 61 to be extinguished by current transfer. Further movement of the arm 42 causes an arc to form between runners 61, 62, the resistor 22 limiting its current and the coil 84 causing its extinction. The coil 70 may be arranged as two series-connected coils 70a, 70b (Fig. 5) encompassing the chute area 80a, and the coil 84 as two series-connected coils 84a, 84b encompassing the whole chute area 80. In a modification, Fig. 6 (not shown), the coils 70a, 70b also encompass the whole chute area. The coil 84 may be made of high resistance wire to replace the resistor 22, in which case the coil turns are embedded in heat resistant insulation, Figs. 7 and 8 (not shown).