OPERATING CONTROLS AND PROCEDURES MLC165-1 OPERATOR MANUAL
3-42
Published 08-06-19, Control # 237-09_v1
Drum 1 or Drum 2 Free Fall Operation
1. In the RCL/RCI display, select the correct crane
configuration and capacity chart, if not already done.
2. To turn on free fall for the desired load drum:
a. Park the load drums.
b. Move the desired free fall selector valve handle (1 or
2, Figure 3-12
) to the ON position.
c. Latch down the corresponding free fall brake pedal.
This will close a safety switch to allow free fall to be
enabled.
See Free Fall Brake Pedals on page 3-9
for
operation of the brake pedals.
d. Turn off the drum park switch for the desired drum to
be operated.
e. Use the free fall enable/
disable key switch to turn on
free fall drum for the desired
drum. The corresponding
amber light will come on to
indicate that free fall is
enabled for the selected
drum.
3. Increase the engine speed to the desired rpm with the
hand throttle. Press the foot throttle to momentarily
increase engine speed when more power is required.
4. To raise the load, unlatch the brake pedal and pull the
Drum 1 (or Drum 2) handle back.
As the load nears the desired position, begin to apply the
brake and slowly move the drum handle toward center to
slow down the load. Then fully apply the brake to stop
and hold the load.
5. The load can be lowered in one of two ways: with the
brake pedal only or with normal hydraulic power plus the
brake pedal.
To lower a load with the brake pedal only: leave the
drum handle at center and slowly release the brake
pedal to lower the load at the desired speed.
As the load nears the desired position, increase foot
pressure on the brake pedal to slow down the load. Then
fully apply the brake to stop the load and hold it in
position.
To lower the load with hydraulic power: while the
brake pedal is held down, push the drum handle forward
from center and slowly release the brake. Lowering
speed is now controlled by drum handle movement and
any desired pressure on the brake pedal.
As the load nears the desired position, slowly move the
Figure 3-12. Free Fall Valves
Item Description
1 Drum 1 (Front) Free Fall Selector Valve
2 Drum 2 (Rear) Free Fall Selector Valve
3 Free Fall OFF (typical both handles)
4 Free Fall ON (typical both handles)
Right Side Enclosure
CAUTION
Avoid Gearbox Damage
While a load is being lowered using the free fall brake,
leave the drum handle at center. Before using the control
handle, use the free fall brake to bring the drum to a
complete stop.
Moving the control handle off-center while a load is free
falling will immediately engage the motor shaft to the
planetary gears, which can result in extensive equipment
damage.
WARNING
Falling Load Hazard
In free fall mode, the load will fall uncontrolled when the
drum handle is centered unless the brake pedal is
applied.
Always be ready to apply the brake pedal so lowering
speed can be controlled.
If this is not done, the load can fall, possibly resulting in
injury or death.
To prevent the load from falling when free fall is selected,
latch down the free fall brake pedal.
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