GB1340802A - Selectively mountable starter unit with reversibly positionable circuit breaker operating mechanism - Google Patents

Abstract

1340802 Switchgear structures; switch cases SQUARE D CO 19 April 1972 [28 April 1971 (2)] 18239/72 Heading H1N A motor starter unit is provided for use in association with a circuit-breaker and a panelboard having a stack of flat, elongate, bus-bars on either side of which the circuit breaker may be selectively mounted with terminals at one end plugged on to the bus-bars, the said starter unit comprising a box having mounted therein a circuit-breaker operating mechanism which is connectible to the circuit-breaker operating member when the box is mounted on the panelboard, the operating mechanism including an external handle and being mountable in the box selectively in either of two angularly displaced positions in accordance with the selected side of the stack of bus-bars on which the box and breaker are mounted such that similar movements of the external handle produce the same sense of movement of the circuit-breaker operating member with respect to the stack of busbars, whichever side of the bus-bar stack the box and breaker are mounted. As shown, a box 21 has feet 26a by which it can be secured to a panelboard (such as that disclosed in Specification 1,161,030) on the left or right of a stack of bus-bars thereon. The box 21 has a relatively deep compartment 21f containing a motor control unit (not described) with buttons 38, 40, 42 and pilot lights 39, 41, and a relatively shallow "overhanging" compartment 21g accommodating an operating mechanism 24 with a handle 44 for operative connection to a moulded-case circuit breaker (not shown) which may be mounted on the panelboard beneath the compartment 21g and in connection with the bus-bars. According to the position of the box (and circuit breaker) with respect to the bus-bars the mechanism 24 is secured in the box 21 by engagement of keyhole slots in the mechanism support frame with four of the eight screws 84 in the compartment 21g such that the mechanism 24 is to the left (as shown) or, alternatively, it may be rotated 180 degrees and fitted to the right (Fig. 4, not shown) using the other four screws 84. A hinged cover 22 closes both compartments and has a slot 22b for handle 44 in either mounting position of mechanism 24, the latter carrying an inner pivoted cover member 76a which extends to act as a filler plate for the unused portion of slot 22b. The mechanism 24 includes an actuating member 60 with portions extending laterally which co-operate with an interlock bracket 62 on cover 22 when the mechanism is in the ON condition to prevent opening of the cover 22. The bracket 62 is pivoted on cover 22 by a rivet 82 with a screwdriver slot whereby the bracket may be turned against action of a spring 83 to defeat the interlock. A further interlock member (80, Figs. 6, 7, and 8, not shown) pivoted on mechanism 24 is loaded by a spring (81) to move into interference with member 60 when the cover 22 is opened and then prevents the handle 44 being moved to the ON position.