Telescoping the Boom

Controls

[NOTICE]

◆ The extended boom retracts, though slightly, in course of time, due to hydraulic oil temperature change. For example, 15 ft (5 m) extended boom retract by approx. 1.6 in (40 mm) along with lowering of temperature by 50°F (10°C). Besides temperature, the boom’s telescoping conditions, boom angle, lubrication, etc. affect the amount of retraction. For boom retraction prevention, use the following precautions:

• Do not extend the boom when the hydraulic oil is extremely high.

• Manipulate the telescoping control lever slightly to the EXTEND direction to mitigate the oil effect.

• Fully extend the 2nd boom section for working with this section.

Extending and Retracting the Boom

Warning

Moving the control levers abruptly is dangerous because it causes the load to bounce and swing. Operate levers slowly and carefully.

When the boom is extended, the load radius increases. Be alert to any sign of overloading when extending the boom.

A boom telescoped incorrectly can collapse if a lift is made in this condition. Watch out for any error in the boom section telescoping sequence while operating the crane.

Do not push or pull the load by telescoping the boom. This practice can damage the crane and lead to an accident.

The boom consists of four sections. The telescoping of these boom sections is controlled by using the boom telescoping control lever, the boom telescoping control pedal and the 3rd/top boom extending switch. The telescoping speed can be controlled by changing the amount the boom telescoping control lever and the boom telescoping control pedal are moved and by using the accelerator pedal.

To extend:Push the lever forward.

To retract:Pull the lever rearward.

To stop:Return the lever to neutral position.

(Full retracted) (2nd boom section full extened) (Full extended)

Extension

1. Push the boom telescoping control lever forward. The 2nd boom section will extend.

2. After the 2nd boom section has fully extended, press the 3rd/top boom extending switch. The 3rd and the top boom sections go extending simultaneously. Keep the lever pushed in this while.

◆ When the 3rd boom section begins to extend, release the switch.

3. Once the boom has extended to the desired length, return the boom telescoping control lever to the neutral position.

Retraction

1. Pull the boom telescoping control lever rearward. The boom will begin to retract. When retracting a fully extended boom, first the 3rd and top boom sections will retract simultaneously. After the 3rd and top boom sections have completely retracted, the 2nd section will retract.

2. Once the boom has retracted to the desired length, return the boom telescoping control lever to the neutral position.

Boom Telescoping Control Pedal

To extend

To stop

To retract

Boom telescoping control pedal

T20918E