2.19 BOOM TELESCOPING OPERATION

• Operate the boom telescoping lever as slowly as possible. Sudden lever operation especially while hoisting a load will cause the load to swing, giving a great impact to the machine, and thus may break the crane or overturn the machine.

• Do not pull the load horizontally or pull in the load by telescoping the boom.

• Extending the boom increases the working radius and the rated total load that can be hoisted decreases. Be extremely careful so that the load weight will not exceed an overload with the boom most extended when working by telescoping the boom.

• When the hook block is over-wound, such a condition is detected as an over hoist and operations including winching up, boom telescoping or boom raising are interrupted, also the Over hoist and moment limiter alarm buzzer beeps. When the buzzer beeps, immediately release control levers such as winch lever, boom telescoping lever or boom derricking lever to the NEUTRAL position so that all the crane operations are discontinued.

Caution

• The hook block is raised or lowered while telescoping the boom. Perform the winch operation at the same time to adjust the hook block height.

• When the boom is maintained extended for a long time, the boom slightly retracts due to the temperature change in the hydraulic oil. In this case, extend the boom as needed.

Perform the boom telescoping lever (2) as follows.

• Extend: Push the lever forward to the “EXTEND” side.

• Neutral: Release your hand from the lever. The lever returns to the NEUTRAL position and the boom telescoping stops.

• Retract: Pull the lever toward you to the “RETRACT” side.

Notes

Adjust the boom telescoping speed with the boom telescoping lever and the stroke of the acceleration lever.