Manitowoc 999 Service And Maintenance Manual

Reference Only
INTRODUCTION 999 SERVICE/MAINTENANCE MANUAL
1-32
Published 05-16-17, Control # 233-03
Free Fall Hoisting
See Figures 1-21, 1-22, and 1-23
The following description is for the front drum while operating
in free fall. Operation of rear drum is the same, except for
different drum, brake, pawl and brake/clutch. Front drum
hoisting in free fall operates the same as full power hoisting.
Apply front drum brake/clutch pedal as front drum handle is
moved to neutral position. After control handle neutral switch
opens the PC sends an output signal to disable brake
release solenoid HS-16 to spring-apply drum brake, before
front drum pump de-strokes.
WARNING
Falling Load Hazard!
When operating in free fall, load will lower uncontrolled if
front drum brake/clutch pedal is not applied.
Be ready to apply front drum brake/clutch pedal so
lowering speed can be controlled and load can be
stopped immediately, when necessary.
FIGURE 1-21
FULL POWER OPERATION
FREE FALL OPERATION
FRICTION DISCS ROTATE
DRUM BRAKE
ENGAGED
FREE FALL BRAKE/CLUTCH
DISENGAGED
ROTATING COMPONENTS
STATIONARY COMPONENTS
FREE FALL BRAKE/CLUTCH
ENGAGED
SUN GEAR
FRICTION DISCS AND
OUTER PLATES STATIONARY
FREE FALL
CLUTCH STAFT
DRUM BRAKE
RELEASED
PLANETARY
CARRIER
999CSM1-120
999CSM1-121

Manitowoc 999 Specifications

General

Brand	Manitowoc
Model	999
Category	Construction Equipment
Language	English