T039890E
Swinging the Boom
1. Place the swing free/lock selector switch to either the FREE or LOCK position, depending on the job to be performed. “FREE”: The swing continues even after the swing control lever has been returned to the neutral position due to the effects of inertia. Keep this in mind when returning the lever to the neutral position. This position is useful when the boom is used short to lift a heavy load and the load is not located directly below the hook block. When a hoist up operation is started with the switch in the “FREE” position, the boom swings toward the load, making it possible to lift the load vertically. “LOCK”: When the switch is in this position, the swing stops as soon as the swing control lever is returned to the neutral position. Be sure to return the swing control lever to the neutral position slowly. ◆The position of the switch must not be changed during a swing operation. ◆ The indicator lamp is lit while the switch is in the “FREE” position.
WARNING Be sure to move the swing control lever slowly and carefully. Moving the lever abruptly is dangerous because it causes the load to bounce and swing. This practice could result in injury or death and may also damage the crane. During a swing operation, the crane will not be stopped even if it is in an overload condition. When swinging a load from the over-front area to an over-side area during on-rubber operation, be extremely careful not to have the crane become overloaded. If the alarm buzzer sounds and a message appears on the AML moment display during a swing, stop the swing immediately. Then lower the load or swing the boom back to avoid an accident. Do not try to pull the load inward or sideways by swinging the boom. This practice can damage the crane, leading to an accident. Before swinging the load, make sure that the work area is clear of obstructions which the boom or jib could hit. Before swinging the load, press the horn switch to alert people in the work area around the crane.
OFF
Indicator lamp
REAR
AML
50℃
JIB LOCK
85℃
ON
H
FREE
UEL
INT
(FREE) (LOCK)
ON
L
F
Swing free/lock selector switch
Use the swing control lever to swing the crane. The swing speed can be controlled by changing the amount you move the swing control lever and by using the accelerator pedal. ◆When the swing free/lock selector switch is in the FREE position, be sure to take into account the effect of inertia on the swing when you stop the swing. ◆Be sure to set the swing brake switch “ON” after a swing operation. ◆When leaving the cab, center the boom to the front and position the swing lock lever in the “LOCK” position.
Swinging the Boom
ON
AML
T24754E
82
Swinging the Boom
