1) Set the crane operation switch to the "ON" position.
2) Set the boom extension/retraction switch to the "boom section 2" side.
3) Check that the main and auxiliary hooks are lowered sufficiently below the boom.
4) Release the lock of the boom extension/retraction pedal to move the pedal to the extension side.
(2) Retracting the boom section 2
1) Set the crane operation switch to the "ON" position.
2) Set the boom extension/retraction switch to the "boom section 2" side.
3) Check that the main and auxiliary hooks are not lowered more than necessary below the boom. 4) Release the lock of the boom extension/retraction pedal to move the pedal to the retraction side.
boom sections 3 and 4 side.
Extend : Set the crane operation switch to the "ON" position and depress the boom extension/retraction pedal forward.
Retract : Set the crane operation switch to the "ON" position and depress the boom extension/retraction pedal backward.
If the boom section 2 is not fully extended, the boom sections 3 and 4 cannot extend even if the boom extension/retraction switch is set to the boom sections 3 and 4 side.
(611A-0045-0E)
(1) Extending the boom sections 3 and 4
1) Set the crane operation switch to the "ON" position. 2) Fully extend the boom section 2.
3) Set the boom extension/retraction switch to the boom sections 3 and 4 side. 4) Check that the main and auxiliary hooks are lowered sufficiently below the boom. 5) Move the boom extension/retraction pedal to the extension side.
(2) Retracting the boom sections 3 and 4
1) Set the crane operation switch to the "ON" position.
2) Set the boom extension/retraction switch to the boom sections 3 and 4 side.
3) Check that the main and auxiliary hooks are not lowered more than necessary below the boom. 4) Move the boom extension/retraction pedal to the retraction side.
5) If you wish to go on to retract the boom section 2, first confirm that the boom sections 3 and 4 are completely retracted then return the pedal briefly to the neutral position before switching the boom extension/retraction switch to the boom section 2 side to retract the boom section 2.
When extending the boom, confirm that the boom sections 2 is fully extended before going on to extend the boom sections 3 and 4.
If you extend the only boom sections 3 and 4 and proceed to lift a load, the boom could break. When you extend the only boom sections 3 and 4 for periodic inspection such as greasing the boom etc., do so with the outriggers fully extended and no suspended load.
(541A-0222-1E)
・ If you extend or derrick the boom while the hydraulic oil is hot and then leave it to rest, the extended cylinder may retract as the oil cools. This is because the volume of oil has reduced and is not a malfunction.
The degree of cylinder retraction depends on the amount of change in the oil temperature and the cylinder stroke position and can be as much as several percent of the cylinder's stroke. This phenomenon is most pronounced in the long telescopic cylinder or derrick cylinder and can lower the hook position, so take care to avoid problems due to this effect. Take necessary precautions in the following situations.
(1) If you wait with a load suspended from a long boom, avoid extending the boom further than necessary and correct the boom length (extend it) from time to time.
(2) If the boom angle is low and the load is close to the rated lifting capacity, correct the boom angle (by derricking) before the ACS alerts you to danger.
・ When extending the boom, make sure the hooks are far enough below the boom top to avoid overhoisting.
・ If it is not possible to retract the boom sections 3 and 4, move the boom extension/retraction emergency switch to the "release" position, set the boom extension/retraction switch to the boom sections 3 and 4 side and depress the boom extension/retraction pedal backward to retract the boom sections 3 and 4.
(611A-0075-0E) NOTE
: Set the crane operation switch to the "ON" position and push the left control lever left to slew the crane left. : Set the crane operation switch to the "ON" position and push the left control lever right to slew the crane right.
(1) Set the crane operation switch to the "ON" position. (2) Release the slewing lock lever.
(3) Set the slewing free/lock switch to free or lock as necessary for the operation to be carried out. (4) Set the slewing brake switch to the "release" position.
(5) Press the slewing alarm button on the left control lever to sound the horn to warn nearby workers that you are about to slew the crane.
(6) Check again for safety around the crane and operate the left control lever to slew the crane right or left.
Precautions when slewing ・ Do not use slewing to drag a load sideways.
・ Check the safety before slewing and pay attention to people and obstacles nearby while slewing.
・ When operating the crane with the outriggers at anything other than full extension, refer to the rated lifting capacity chart and work according to the applicable value in the chart.
・ If the ACS sound alarm is emitted during slewing operation, slow to a slewing speed which will allow you to stop quickly and safely at any time or stop slewing immediately and take emergency action such as reversing the slewing direction, derricking or retracting the boom, or lowering the load to the ground while watching the safety level indicator lamps until it reverts to the green zone.
(611A-0076-0E) NOTE
During "inching" and other fine positioning movements, the slewing free/lock switch should be set to "lock", but if "lock" is in use and the slewing lever is returned suddenly to neutral, the superstructure stops suddenly, causing the load to swing and affecting the structure of the crane adversely, so work carefully in this case.