Manitowoc Grove RT770E Operator's Manual page 106

OPERATING CONTROLS AND PROCEDURES
Lowering and Raising the Hoist Cable
Crushing Hazard!
Keep the area beneath the load clear of all obstructions
and personnel when lowering or raising the cable (load).
Do not jerk the control lever when starting or stopping the
hoist. Jerking the lever causes the load to bounce, which
could result in possible damage to the crane.
NOTE: When the load is stopped at the desired height, the
automatic brake will engage and hold the load as
long as the control lever remains in neutral.
Lowering the Cable
Push the Main or Aux hoist control lever forward, away from
the operator, and hold until the hook or load is lowered to the
desired height.
Raising the Cable
Pull the Main or Aux hoist control lever back, toward the
operator, and hold until the hook or load is raised to the
desired height.
Hoist Speed Range Selection
CAUTION
Equipment Damage!
Do not change the hoist speed range with the hoist
rotating.
To change the speed range of the hoist(s), position the
applicable switch (Main Hoist Speed or optional Aux Hoist
Speed) to HIGH or LOW as applicable
Operational Aids
Unexpected Operation Hazard!
Electronic equipment on this crane is intended as an aid
to the operator. Under no condition should it be relied
upon to replace the use of capacity charts and operating
instructions. Sole reliance upon these electronic aids in
place of good operating practices can cause an accident.
Rated Capacity Limiter (RCL) System
The Rated Capacity Limiter (RCL) is an electro-mechanical
sensing system designed to alert the crane operator of
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DANGER
WARNING
Published 04-04-2017, Control # 446-09
RT770E OPERATOR MANUAL
impending capacity when the system has been properly
preset by the operator. The control panel is mounted in the
front console of the operator cab. When an overload
condition is sensed, the system provides the operator with a
visual and audible warning, and locks out the control levers
to prevent lowering the boom, extending the boom, or raising
the main or auxiliary hoist cables.
Three additional features are included within the RCL
system:
• Swing Angle Set Limitation
• Work Area Definition
• Anti-two Block Device
Swing Angle Set Limitation allows left and right swing
angle to be preset. When the preset angle is reached, the
system will provide an audible warning.
Work Area Definition allows the crane operator to describe
the crane's working area by setting up "virtual walls". They
are referred to as virtual walls because they exist in the
system and are not real walls. The virtual walls represent
obstacles (i.e. buildings, towers, poles, etc.) in the crane's
working range. They are set by defining points along the
outer limits of the working area with the tip of the boom. Once
the working area has been defined, the system will provide a
visual and an audible warning if the boom approaches a
virtual wall.
CAUTION
Possible Machine Damage!
When defining virtual wall(s), always allow a safe working
distance to any obstacles. Never work outside a safe
working area as defined by common practice, standards,
and manuals.
Risk of Unexpected Operation!
There are no machine cutouts associated with the swing
angle set limitation or the work area definition features.
An Anti-Two Block Device is also incorporated into the
system to prevent the hook block or headache ball from
coming into contact with the boom nose or boom extension.
This condition will cause a lockout of hoist up, boom down,
and telescope out, and also provide a visual and an audible
alarm.
Refer to the RCL Operator Handbook for more detailed
information on the function of the RCL system.
WARNING