Manitowoc Published 11-20-19, Control # 234-19 3-69
MLC300 OPERATOR MANUAL OPERATING CONTROLS AND PROCEDURES
Luffing Hoist Operation
The location of the boom and luffing jib control handles
varies depending on the crane’s configuration. Refer to
Drum and Control Handle Identification on page 3-54
.
1. If not already done, perform the crane Startup
Procedure on page 3-63
.
2. Select the correct capacity chart and crane configuration
using the RCL/RCI Display. For detailed instructions,
see the RCL/RCI Operation Manual.
3. Luffing hoist speed can be adjusted between 25% and
100% to meet operator needs. See the Speed and
Limits Screen topic in the Main Display Operation
Manual for detailed instructions.
4. Make sure the automatic boom stop is set at the proper
angle. For detailed instructions, see the Automatic
Boom Stop Adjustment topic in Section 4 of MLC300
Service Manual.
5. Make sure the automatic jib stops are set at the proper
angles. For detailed instructions, see the Automatic Jib
Stop Adjustment topic in the MLC300 Luffing Jib
Operator Manual.
6. Turn off the luffing hoist park switch. It may be
necessary to raise the luffing jib slightly to disengage the
luffing hoist pawl.
7. Increase the engine speed to the desired RPM with the
hand throttle. Press the foot throttle to momentarily
increase the engine speed when more power is
required.
8. Pull the luffing jib control handle BACK from off to RAISE
the luffing jib.
Push the luffing jib control handle FORWARD from off to
LOWER the luffing jib.
Continued on next page
WARNING
Avoid Death or Serious Injury
Read and understand the instructions in the Luffing Jib
Operator Manual and the Luffing Jib Raising Procedure
chart in the Luffing Jib Capacity Chart Manual before
attempting to raise or lower the luffing jib from or to the
ground.
Use extreme care when operating the luffing hoist and the
boom hoist at the same time. The maximum or minimum
operating radius will be reached quickly when operating
both hoists at the same time.
CAUTION
Avoid Rigging Damage
Check that the luffing hoist wire rope is reeved through all
sheaves and spooled properly onto the luffing hoist drum
before raising the boom and luffing jib from the ground.
• For wire rope and reeving specifications, see the
Luffing Jib Assembly Drawing in the MLC300 Luffing
Jib Operator Manual.
• For instructions on attaching wire rope to the luffing
hoist drum, see the Wire Rope Installation topic in
Section 4 of MLC300 Operator Manual.
Drum 6 – Luffing Hoist
Figure 3-19. Luffing Jib Control Handle
CAUTION
Avoid Boom or Luffing Jib Damage
Do not turn on the luffing hoist park switch while raising or
lowering the luffing jib. The brake will bring the luffing jib to
an abrupt stop. This action could cause shock load
damage to the boom and jib. Bring the luffing jib to a
smooth stop with the control handle and then turn on the
park switch.
WARNING
Avoid Two-Blocking Hazard
Pay out the load lines while lowering the boom. The load
may contact the boom point or the jib point sheaves if this
step is not taken. The wire rope or other parts could break
allowing load to fall.