TM 1-1680-320-13&P
0003 00
WINCH ASSEMBLY
The winch assembly consists of a winch mechanism, limit switch drive assembly, electric motor, brake cooling
pump, automatic brake assembly, inertia dump assembly, and the cable hook assembly.
The limit switch drive assembly contains four positive action limit switches that control extension and retraction
rates of the rescue cable. One limit switch prevents extension (unreeling) of the cable beyond established limits. A
second switch operates when the cable reaches 3 to 5 safety wraps from full reel off (down limits at 250 (76.2 m)
foot maximum extension). A third switch operates the 10/240 foot caution indicator, decelerating the hoist to 50%
speed when the cable hook is within 10 feet (3.048 m) of full stowed position and 10 feet from maximum
extension. The fourth limit switch operates the hoist when cable hook reaches 18 inches from full stow
(decelerating to 12 feet (3.658 m) per minute).
The automatic brake assembly actuates to prevent reeling or extension of the cable when electric motor is not
operating. Two thermal temperature sensing switches monitor winch and motor operation, actuating when system
components exceed safe temperature limits. The brake cooling pump acts to regulate brake operating
temperature.
