Manitowoc MLC300 Service And Maintenance Manual

Reference Only
Manitowoc Published 11-22-17, Control # 257-02 4-3
MLC300 SERVICE/MAINTENANCE MANUAL BOOM
4
Adjusting the Automatic Boom Stop
See Figure 4-3 for the following procedure.
The limit switch for the automatic boom stop was set at the
factory and should not require periodic adjustment.
Adjustment is necessary when:
• Parts are replaced
• The boom/luffing jib configuration is changed
The following instructions assume that the RCL/RCI is
installed and properly calibrated.
During the following procedure, the boom angle is monitored
on the working screen of the RCL/RCI and on a digital
protractor-level (14).
1. Park the crane on a firm level surface or level the crane
by blocking under the crawlers.
2. Make sure that the correct adjusting rod (2a or 2b) is
installed:
• Adjusting rod (2a) for 83° or 85° boom angle
• Adjusting rod (2b) for 86° boom angle
3. Boom up slowly while monitoring the boom angle on the
RCL/RCI working screen.
4. Stop boom up when the boom reaches the specified
maximum boom angle. (See Maximum Switch Boom
Angle table in View C.)
NOTE: The maximum switch boom angle is greater than
the maximum boom angle to allow for boom
deflection.
5. Verify the boom angle with an accurate digital protractor-
level (14) placed on the boom butt bottom chord (15).
The corresponding digital level angle (16) should appear
on the protractor-level:
• If the boom stops at the specified angle, further
adjustment is not needed.
• If the boom stops before reaching the specified
angle, go to step 6
.
• If the boom reaches the specified angle before it
stops, go to step 7
.
6. If the boom stops before reaching the specified angle,
perform the following procedure.
a. Loosen the jam nut (3).
b. Turn the adjusting rod (2a or 2b) all the way into the
coupling (4).
c. Boom up slowly until the boom reaches the
specified angle.
d. Turn the adjusting rod out against the boom butt
(1, View B) until the limit switch (6) clicks open.
e. Tighten the jam nut.
7. If the boom reaches the specified angle before it stops,
perform the following procedure.
a. Loosen the jam nut (3).
b. Turn the adjusting rod (2a or 2b) out against the
boom butt (1, View B) until the limit switch (6) clicks
open.
c. Tighten the jam nut.
8. Verify the position of the actuator rod (11) relative to the
limit switch roller to ensure there is overtravel (13).
9. Boom down and then boom back up. The boom must
stop at the specified maximum switch boom angle.
10. If the boom does not stop at the specified angle, repeat
step 3
through step 9.
Replacing the Boom Stop Limit Switch
Actuator Rod
See Figure 4-3 for the following procedure.
1. Disassemble the boom stop switch unit (5).
2. Assemble the boom stop switch using the following
instructions.
a. Position the actuator rod (11) so the tapered end
just touches the limit switch roller (see View B). The
actuator rod must not depress the limit switch.
b. Drill a 6,35 mm (1/4 in) hole through the spring
washer (7) and actuator rod.
c. Install the spring pin (8).
d. Push the actuator rod in until the limit switch clicks
open. Check the position of the limit switch roller to
ensure there is overtravel (13).
AUTOMATIC LUFFING JIB STOP
ADJUSTMENT AND MAINTENANCE
See the MLC300 Luffing Jib Operator Manual.
WARNING
Falling Attachment Hazard!
Do not operate the crane unless the boom stop limit
switch is properly adjusted and operational. Do not adjust
the maximum operating angle higher than specified. The
boom could be pulled over backward or collapse, causing
death or serious injury.

Manitowoc MLC300 Specifications

General

Brand	Manitowoc
Model	MLC300
Category	Construction Equipment
Language	English