GB412246A - Improvements in electric motor starters - Google Patents

Abstract

412,246. Controllers. COX, F. B., 65, Fleet Street, Liverpool. Nov. 23, 1932, No. 33076. [Class 38 (iii).] A star-delta or auto-transformer starter comprises a three-pole two-way two-armed switch H, and a three-pole oil immersed circuitbreaker J, the insulated moving contact o<1> of one arm of the switch H and o of the circuitbreaker in each phase being connected together and to a terminal P<1> above the oil, and the insulated moving contacts o<2> on the other arm of the change-over switch being connected together. Rotation of a handle b<1> in an anticlockwise direction from the position shown in Fig. 9 causes a link c' at the handle side of the casing to move the switch H from the position shown in Fig. 9 to the start position in which the contacts o<2> engage the fixed contacts P<3>, and a link e<2> at the side of the casing remote from the handle to close the circuit-breaker J and lift an armature E, Fig. 9<a> to its attracted position in relation to a no-volt magnet F. The armature E is retained in this position by a catch K and is, therefore, not controlled by the magnet F until the handle is returned nearly to its initial position in which a cam D releases the catch K. Return of the handle releases a latch L by means of a cam C and the changeover switch H previously held by the latch L and a member h<2> in the start position, is returned by a spring to the " run " position shown in Fig. 9. An overload coil R and the no-volt magnet F release under overload or novolt conditions the armature E which drops and opens the circuit-breaker J with a percussive action due to the slot e<4> in the link e2. Specification 371,856 is referred to.