This limit switch has a rotary screw driven by a gear reduction that is coupled to the end of the drum shaft. Adjustment discs operate the contacts of separate switches, one for the hoisting circuit and one for the lowering circuit. The switch assembly must be wired in accordance with the appropriate wiring diagram, which is shipped with the hoist. Instructions for adjusting limit switch are inside cover and are repeated below (see Figure 7-2).

SWITCH LOCKING ADJUSTMENT SWITCH

PLATE DISC

Figure 7-2. Screw-Type Limit Switch Adjustment (Wires Not Shown For Clarity.)

WARNING

Be certain that electrical power supply is OFF and locked in the open position before removing limit switch cover.

a)Remove four screws and lift off switch cover.

b)Loosen locking plate screws. Slide locking plate away from adjustment disc.

c)Turn proper adjustment disc (right for up, left for down) toward switch to reduce hook travel or away from switch to increase hook travel.

d)Slide locking plate back into position ensuring slots on adjustment discs are fully engaged, tighten locking plate screws to 4 in-lbs.

e)Replace cover.

f)Carefully check limit switch operation without load before placing hoist in service. If misadjusted, repeat steps above. Allow 3” for hook drift in both directions. Never allow less than two (2) complete wraps of rope on drum with hook in lowest position.

WARNING

Check limit switch operation carefully, without load, before placing hoist in service. If misadjusted, SEVERE DAMAGE AND/OR A DROPPED LOAD COULD RESULT. Allow 3” for hook drift in both directions. Never allow less than two (2) complete wraps of rope on drum with hook in lowest position.

Provide a light film of MPG grease (Paragraph 4-7) on gear of both limit switches.

7-4.SHORTENING OF PUSHBUTTON CABLE.

WARNING

Be certain that electrical power supply is OFF and locked in the open position before attempting shortening of push button cable.

a)Loosen screws at cable connectors and clamps at top of cable.

b)Adjust steel support cable to proper length and tighten screws.

c)Loosen upper cable grip and pull excess cable into connection box at hoist.

d)Tighten cable grip and cut off excess cable.

e)Strip cable sheath and connect wires with the same type of terminals previously furnished (care must be taken to match previous wire color coding with wire markers in accordance with wiring diagram furnished with hoist.)

SECTION VIII – WIRING DIAGRAMS

8-1.GENERAL. Comprehensive wiring diagrams for Yale electric hoists have been omitted from this book because of the many possible variations. This is due to different currents and types of electrical components used in their construction. Figures 8-1 and 8-2 are examples of typical two-speed hoist and trolley wiring diagrams respectively. However, please consult the exact wiring diagrams for your hoist. A print of the correct wiring diagram for each hoist is furnished as a separate insert and shipped with the hoist. We suggest you carefully file the wiring diagram with this book for future reference.

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Yale 11353395D manual Section Viii Wiring Diagrams, Shortening of Pushbutton Cable