Komatsu PC490-11, Installation And Instruction Manual

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The additional lamps switch is used to turn on the cab front
lamps, cab rear lamps and extra boom lamps (If fitted by cus-
tomer)
(a) ON
Lamps light up.
(b) OFF
Lamps go out.
MACHINE PUSH-UP SWITCH
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.
CONTROL LEVERS AND PEDALS
(1) Lock lever
(2) Travel levers (with pedal and auto-deceleration
system)
(3) L.H. work equipment control lever (with auto-decel-
eration system)
(4) R.H. work equipment control lever (with auto-de-
celeration system)
EXPLANATION OF COMPONENTS OPERATION
3-98