STT113 TOWER CRANE OPERATION AND SERVICE MANUAL
3B
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5
g) The speed was selected by the weight of load. Heavy load selected low speed
(PV) and light load selected high speed (GV).
h) Stop moving before operating the stroke limiter.
i) Don’t put the hook on ground.
j) Loosen the wire rope slowly to avoid rope winding when placing load.
(3) Operating the slewing mechanism
a) Select the slewing speed according to the shift to be reached.
b) Every time use the max. speed as long as the angle allowed.
c) If the slewing mechanism suddenly changes its speed, it may cause the mast
twisting and jib swing. So acceleration and deceleration operation should be
done gradually.
d) It is forbidden to stop the jib by slewing brake. It should decelerate first, and
then release the control lever, so that the brake can brake in minor slewing
speed.
e) The slewing brake can only be used in windy condition, it can keep jib in its
position.
f) When slewing the jib, it is recommended to operate the lifting movement and
lowering movement at the same time to avoid distorting of the wire rope and it
is convenient for the rope swivel to work.
g) Stop the slewing movement before
slewing limiter start to work.
(4) Operating the trolley winch
a) The trolley speed is selected by the distance of the trolley.
b) It must accelerate or decelerate gradually to avoid swing when suddenly
changing the shift of trolley operation.
c) Stop the trolley movement before operating the trolley limiter.
