Zoomlion ZT20J, Service And Maintenance Manual

Page: 81 / 113

5- 22
c. Calibrate the zero position of the boom length sensor, and record the initial value of the boom length
on the display screen.
d. Extend the boom 1m, record the length of the boom on the display screen.
e. Compare the boom length values twice. The absolute value should be 1m.
5.6 Check of Wire Rope Damage Indication System
a. A limit switch is installed at the end of the boom to detect the loose state of the wire rope.
b. When the wire rope is loose, the limit switch will be triggered, and the wire rope will be alarmed.
c. When the steel wire rope is loose and alarmed, the telescopic function of the operation boom is:
The boom is forbidden to extend, only the turtle can retract quickly.
d. Tighten the steel wire rope according to the tightening requirements.
e. Make sure that there is no alarm for loose wire rope on the display. At this time, the boom telescopic
function can be operated normally.
5.7 Beyond the stowed position-limited speed check
a. Start the unit in platform mode and adjust the device to the favorite position.
b.
Select “ground rabbit speed” for engine speed, turn the function speed knob to rabbit speed.
c. Operate the travel function. At this time, the two-speed valve will open to enable the high-speed
travel function.
d. Retracted the boom to the stowed position, and the turntable is turned to the stowed position.
e. Raise the boom beyond the stowed position (the boom lifting angle exceeds 7 °).
f. Operate the travel function, at this time the two-speed valve will be closed, and the high-speed travel
function cannot be enabled.
g. Operate the boom to retract to the stowed position, and lower the boom to the stowed position.
h. Turn the turntable beyond the rear wheel position.
i. Operate the travel function, at this time the two-speed valve will be closed, and the high-speed travel
function cannot be enabled.
j. Lower the boom to the stowed position, and the turntable is turned to the stowed position.
k. Extend the boom over 1m/3.28ft.
l. Operate the travel function, at this time the two-speed valve will be closed, and the high-speed travel
function cannot be enabled.