Komatsu PC1250-11, Original Instructions Manual

Page: 162 / 452

MACHINE PUSH-UP SWITCH
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WARNING
Set the machine push-up switch in high-pressure set when stepping down the bench by supporting the
machine body with the boom pushing the ground. Otherwise, the machine may suddenly fall and tip
over.
Machine push-up switch is used to set the safety valve pres-
sure on the head side of the boom circuit to 2 stages.
(a) Low-pressure set
Since the bracing force of the boom is decreased, the machine
is less moved up during digging work and the operator can dig
smoothly.
Use this position for the general normal operation for ordinary
soil, soft rocks, blasted rocks, etc.
(b) High-pressure set
Since the bracing force of the boom is increased, the machine
can easily escape from soft ground.
STAIRCASE LIGHTING SWITCH
Use the staircase lighting switch when getting off the machine
in the night.
• Turn the staircase lighting switch to ON position (a), and
the staircase lighting lights up for approximately 60 sec-
onds.
• The staircase lighting lights up for approximately 60 sec-
onds by pressing the staircase lighting switch even when
the starting switch key is in OFF position.
BOOM SHOCK ABSORBING CONTROL SWITCH
The boom shock absorbing control switch is used to control the
vibration of the work equipment during the boom stopping oper-
ation.
Effect
• The vibration of the machine body and dropping of the
load from the bucket reduce.
• Operator's fatigue in a long time operation reduces for saf-
er operation.
REMARK
• If stopping operation is performed when the switch is in
ON position (a), the boom moves rather larger until it is
stopped. Operate it carefully until you get used to it.
• Be sure to set this switch to OFF position (b) when per-
forming the lifting work. Otherwise, the boom overrun in
lowering occurs and the positioning of boom becomes diffi-
cult.
EXPLANATION OF COMPONENTS OPERATION
3-96