GB1486261A - Protective automatic circuit breaking arrangement - Google Patents

Abstract

1486261 Electromagnetic circuit breakers SIEMENS AG 13 Sept 1974 [27 Sept 1973] 40117/74 Heading H1N An automatic circuit breaker has a moving contact 9 retained by a latching mechanism 8 and an electromagnetic operating system which comprises a single coil 5, a core 1 and two armatures 3, 4, one armature 3 acting on the latching mechanism 8 to release it on actuation, the second armature 4 acting on the moving contact 9, to separate the contacts 9, 10 on actuation, there being a saturable shunt in the air gap L 2 between the second armature 4 and the core 1 that will prevent movement of the second armature 4 until after saturation of the shunt, the arrangement being such that for a first range of currents the unlatching armature 3 unlatches the latching mechanism 8 either before the contact moving armature 4 opens the contacts or instead of the contact moving armature 4 opening the contacts, whereon for a second, higher, range of currents, the contact moving armature 4 opens the contacts before the latching mechanism released by the latching mechanism armature 3, releases the moving contact 9. In a first pair of embodiments, Fig. 1 (and Fig. 2, not shown) the shunt is constituted by a part of the first armature 3, the two armatures 3, 4 being coaxial plungers and in a second pair by an extension of the core 15, Fig. 7 (1b Fig. 8, not shown). For interrupting three phase current, three circuit breakers may be controlled by a single latching mechanism (Fig. 13, not shown).