GB1362828A - Enclosed switchgear - Google Patents

Abstract

1362828 Snap-action switches WESTINGHOUSE ELECTRIC CORP 30 Sept 1971 [10 Nov 1970] 45567/71 Heading H1N In an enclosed switch-fuse, each fuse 89 is supported in fuse clips 65, 71, and the fuse clip 71 is mounted on a conductive terminal block 73 adjacent an opening 81 in the end wall 19 of the casing, and connector 85, to secure external conductor 87 in block 73, is located between fuse clips 65, 71 so that access to connector 85 through the openable front of the casing is blocked by fuse 89 when this fuse is in position in the fuse clips. As shown, there are two independently operable switch fuses in the casing, both being three pole and both being identical and each having its own door 13 and operating handle 93. For each switch fuse, pivoting handle 93 rotates on inner operator 99, Fig. 5, which pivots operating lever 37 to pivot bar 35, through an overcentre spring mechanism (not shown) to pivot movable contact blades 33 into clip type fixed contacts 31. Blades 33 are connected by flexible conductors 69 and conductors 67 to fuse clips 65. Opposite clip contacts 31 on the two switches are joined by straps 49 which serve as the terminals for external line conductors. Each door 13 is hinged at 21 and interlocked with the casing so that the door cannot be opened when the switch is on. Each interlock comprises a latch 105, Fig. 5, urged by a torsion spring 107, when handle 93 is in the on position shown, so that a hook on latch 105 engages a projection 109 on the side wall of the casing. Movement of handle 93 to the off position causes part 113 of inner operator 99 to engage a part 115 of latch 105 to pivot latch 105 to remove the hook from projection 109 and allow door 13 to open. When the door 13 is latched closed, the interlock can be defeated by a bolt 117, Fig. 6 (not shown), which when rotated frees latch 105 from projection 109 so that door 13 can be opened. If latch 105 is in the latched position and the cover is open then moved to the closed position, a cam surface 119, Fig. 6, engages projection 109 to cam latch 105 clockwise until it has cleared pin 109, when spring 107 urges latch 105 to its latching position. The depth 123, Fig. 6, of latch 105 is such that if handle 93 is in the off position and the door 13 is not fully closed, surface 123 engages projection 109 to prevent latching of latch 105, and part 113 on internal operator 99 engages surface 127 on latch 105 to prevent handle 93 being moved from off to on.