Maeda MC305C-3 - Page 119

M A E D A Mini-Crawler Crane Section 4 – CRANE OPERATION
3/2019 MC305C-3 4-55
67B66BBoom Derricking Operation
WARNING!
• Operate the boom derricking lever as slowly
as possible.
Sudden lever operation especially while
hoisting a load will cause the load to slew,
giving a great impact to the machine, and
thus may break the crane or overturn the
machine.
• Lowering the boom increases the working
radius and the rated total load that can be
hoisted decreases. Be extremely careful so
that the load weight will not be overloaded
with the boom most lowered when working
by boom lift the boom.
Operate the boom derricking lever (4) as follows.
Fig. 4-151
• Lower: Push the lever forward to the "LOWER"
side.
• Neutral: Release your hand from the lever.
The lever goes back to the "Neutral"
position and the boom lift stops.
• Raise: Pull the lever toward you to the
"RAISE" side.
NOTICE: Adjust the boom lift speed with the boom
derricking lever and the stroke of the acceleration
pedal.
68B67BBoom Telescoping Operation
WARNING!
• Operate the boom telescoping lever as
slowly as possible.
Sudden lever operation especially while
hoisting a load will cause the load to slew,
giving a great impact to the machine, and
thus may break the crane or overturn the
machine.
• Do not pull the load horizontally or pull in
the load by telescoping the boom.
• Extending the boom increases the working
radius and the rated total load that can be
hoisted decreases. Be extremely careful so
that the load weight will not be overloaded
with the boom most extended when working
by telescoping the boom.
• When the boom is extended, the hook block
is raised.
If the alarm buzzer of the over winding
detector and the audible message of "Hook
Over Hoisted" are heard during the boom
extending operation, return the boom
telescoping lever immediately to the
"Neutral" position and stop the boom
extending operation.
CAUTION:
• The hook block is raised or lowered while
telescoping the boom. Perform the winch
operation at the same time to adjust the
hook block height.
• The hook block is raised or lowered while
telescoping the boom. Perform the winch
operation at the same time to adjust the
hook block height.
• When the boom is maintained extended for a
long time, the boom slightly retracts due to
the temperature change in the hydraulic oil.
In this case, extend the boom as needed.
Perform the boom telescoping lever (2) as follows.
Fig. 4-152
• Extend: Push the lever forward to the
"EXTEND" side.
• Neutral: Release your hand from the lever.
The lever returns to the "Neutral"
position and the boom telescoping
stops.
• Retract: Pull the lever toward you to the
"RETRACT" side.
NOTICE: Adjust the boom telescoping speed with
the boom telescoping lever and the stroke of the
acceleration pedal.