Manitowoc National Crane NBT40 Series, Руководство по обслуживанию

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CRANE INSTALLATION NBT40 SERVICE MANUAL
9-30
Published 8-01-2017 Control # 287-11
7. Over the rear:
• Assemble the second stability test load as
described above near the crane
• Measure the load radius from the center of rotation
directly to the rear of the machine.
• Extend the boom to the specified boom length and
lift the stability test load just slightly off the ground
(not above 1 ft 0.3 m).
• Boom down while hoisting up to move the stability
test load out to the load radius.
• Move the load very slowly when approaching the
load radius so the stability test load does not swing
out past the load radius. If the stability test load can
be kept from contacting the ground at the load
radius, the unit is stable over the rear of the unit.
• Slowly rotate the stability test load 360° to ensure
that the load is stable directly over both sides, the
back, and the front.
8. If unit is unstable, counterweight needs to be added.
• Add weight at the front bumper or at the front of the
subbase, if the crane is unstable over the rear.
• Add weight close to the centerline of rotation if the
crane is unstable over the side.
COUNTERWEIGHT
Each NBT40 and NBT45 model crane is equipped with a
different removable counterweight combination. See
Figure 9-20 and the following counterweight table for the
proper crane counterweight combination.
T h e N B T 3 6 m o d e l c r a n e i s n o t e q u i p p e d w i t h a
counterweight.
Use only the counterweight plate combinations as shown in
the following counterweight table and Figure 9-20.
Each counterweight plate can be identified by the part
number and weight steel stamped (1, Figure 9-19) into the
side of the plate.
Counterweight Removal
1. Position the crane on a firm, level surface. Fully extend
and set the outriggers.
2. Position the superstructure over the front of the machine
and engage the turntable lock.
3. Install two threaded lifting bolts into the 1.25 x 7 UNC lift
inserts (2, Figure 9-19). Using a proper lifting device,
attach lifting straps to the bolts. After straps are attached
remove slack from the straps.
4. Remove the two bolts (1, Figure 9-20), lockwashers (2)
nuts (3) securing the counterweight to the crane support
weldment. Lift and remove the counterweight from
crane.
DANGER
Do not add material to or change the configuration of the
counterweights to increase the crane capacity.
Serious injury or death may occur if lifting weight above
the crane rated capacity or using a weight combination
not shown in the counterweight table and Figure 9-20.
DANGER
Do not stand near or underneath the counterweight when
removing or installing it.
Serious injury or death may occur when removing or
installing the counterweight if the counterweight falls from
the lifting device.
FIGURE 9-19
1
2
2
7471
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Reference Only