Komatsu PC200-8M0 Shop Manual page 291

600 Electrical system
Electrical control system
1) Swing lock and swing holding brake func-
tion
q The swing lock function (manual) is used to
lock machine from swinging at any position.
The swing holding brake function (automatic)
is used to prevent hydraulic drift after the
machine stops swinging.
q Operation of swing lock switch and swing lock/
holding brake
Lock Lock
Function
switch lamp
Swing
OFF OFF holding
brake
Swing
ON ON
lock
Swing holding brake cancel switch
q If the controller, etc. has a problem, the swing
holding brake does not work normally, and the
machine cannot swing, the swing lock can be
reset with the swing holding brake cancel
switch.
Swing
ON
holding
(when controller has
brake cancel
trouble)
switch
Swing lock
ON
switch
Swing
Swing brake lock is
turned on. canceled.
q Even if the swing holding brake cancel switch
is turned on, if the swing lock switch is placed
in the ON position, the swing brake is not
released.
q If the swing lock is reset, only the hydraulic
brake is applied by the safety valve. Note that
if swinging is stopped on a slope, the upper
structure may swing by its gravity.
PC200, 200LC, 220, 220LC-8M0
Operation
If swing lever is set in neu-
tral, swing brake operates
in about 5 sec. If swing
lever is operated, brake is
released and machine can
swing freely.
Swing lock operates and
machine is locked from
swinging. Even if swing
lever is operated, swing
lock is not reset and
machine does not swing.
OFF
(when controller is
normaly)
OFF ON OFF
Swing
Swing Swing
holding
lock is lock is
brake is
turned on.
turned on.
2) Quick hydraulic oil warm-up function when
swing lock switch is turned on
q If swing lock switch (2) is turned on, the pump
cut-off function is cancelled and the relief pres-
sure rises from 34.8 MPa {355 kg/cm
2
MPa {380 kg/cm }.
If the work equipment is relieved under this
condition, the hydraulic oil temperature rises
quickly and the warm-up time can be short-
ened.
SEN06123-00
2
} to 37.2
25
10-600