Reference
Only
Manitowoc
Published 01-08-13, Control # 049-05
6-5
2250 MAX-ER 2000 OPERATOR’S MANUAL
MAINTENANCE
6
AUTOMATIC BOOM STOP ADJUSTMENT
Unless otherwise specified, see Figure 6-5 for following
instructions.
General
This crane is equipped with a maximum (MAX) boom angle
limit switch which automatically stops the boom hoist and
applies its brake when the boom is raised to a preset angle.
The limit switch must be set at one of the following angles,
depending on boom and luffing jib use:
•
83
°
for all #79 or #79-44 Boom Lengths with Luffing Jib
Removed.
•
85
°
for Less than 200 ft (61 m) of #79 Boom with #44
Luffing Jib Installed.
•
85
°
for Less than 220 ft (67,1 m) of #79-44 Boom with
#133 or 133A Luffing Jib Installed.
•
87° for 200 ft (61 m) or More of #79 Boom with #44
Luffing Jib Installed.
•
87
°
for 220 ft (67,1 m) or More of #79-44 Boom with
#133 or 133A Luffing Jib Installed.
Maintenance
At least once weekly, check that the automatic boom stop
stops the boom at the specified MAX angle; if not, replace
defective parts and/or adjust the boom stop.
Monthly, grease the fitting on the actuator bracket.
Adjustment
The automatic boom stop was adjusted and sealed at the
factory. Readjustment is required only when parts are
replaced and when installing or removing luffing jib. The
seals must be removed to allow readjustment.
1.
Make sure actuator bracket is securely fastened in
proper position on boom butt (Position A, B, or C).
2.
Check position of MAX limit switch with relation to
actuator bracket (View A).
3.
Loosen capscrews retaining MAX actuator to actuator
bracket.
4.
Rotate MAX actuator CLOCKWISE in its slots so it does
not contact limit switch roller when step 5 is performed.
5.
Raise boom:
a.
Slowly raise boom to specified angle – 85
°
or 87
°
–
while monitoring angle on digital display.
b.
Check boom angle using an accurate protractor-
level placed on centerline of boom butt (Figure 6-3,
View B).
c.
Boom up or down as required to position boom at
specified angle as indicated by protractor-level.
Angle on protractor-level should match angle on
digital display to within 1°.
6.
Rotate MAX actuator against limit switch roller until limit
switch just “clicks” open and hold.
7.
Check position of MAX actuator with relation to actuator
bracket (View B).
8.
Securely tighten capscrews for MAX actuator.
9.
Lower boom several degrees.
10. Slowly raise boom.
11. Boom must stop at specified angle; if not, repeat
adjustment steps.
12. Once adjustments are complete, drill and seal limit
switch spacer to mounting bracket and MAX actuator to
actuator bracket with dowel pins and lead wire seals as
shown in Figure 6-6.
WARNING
Falling Attachment Hazard!
Do not operate crane unless automatic boom stop is
properly adjusted and operational. Do not adjust MAX
operating angle higher than specified.
Boom can be pulled over backwards or collapse causing
death or serious injury.
Adjust boom angle indicator before adjusting automatic
boom stop (see procedure in this section).
FIGURE 6-6
Limit Switch
Spacer
Bracket
Actuator
Bracket
MAX
Actuator
Dowel Pin and Lead
Wire Seal (4 places)
A1162
