Hydraulic Circuit - Komatsu PC300LC-8 Operation & Maintenance Manual

MACHINE READY FOR ATTACHMENT

HYDRAULIC CIRCUIT

NOTICE
It is necessary to return the return circuit directly to the return filter when a breaker is used, so use only the B mode. Do not
use any other mode.
When the machine is shipped from the factory, the standard set pressure of the safety valve in the service valve is set as
follows:
When B mode is selected: 21.6 MPa (220 kg/cm
When P or E mode is selected: 24.5 MPa (250 kg/cm
The set pressure may have to be adjusted depending on the attachment. In such cases, please ask your Komatsu distributor
to carry out the adjustment.
Switching Hydraulic Circuit
Depending on the type of attachment, set the working mode on the monitor as follows.
The set pressure of the safety valve in the service valve and the hydraulic circuit switch is according to the working
mode selected.
Attachment
Breaker or other attachment
with one-way circuit
Crusher or other attachment
with two-way circuit
Adjusting Oil Flow
Depending on the attachment, it is necessary to change the oil flow in the service circuit.
For details of setting the oil flow, see "ATTACHMENT OPERATIONS (PAGE 6-17)".
Switching Between Breaker and General Attachment
If an attachment is installed as an option, and the mode is set to B mode:
(1) The system is set to the breaker operation circuit (1-way circuit).
(2) The hydraulic oil flowing to the breaker circuit flows to the additional filter for the breaker.
(3) The relief pressure valve is set to low pressure.
Set pressure when machine is shipped from factory: 21.6 MPa (220 kg/cm
(4) It is possible to use the selector mode to adjust the maximum oil flow.
If an attachment is installed as an option, and the mode is set to P or E mode:
(1) The system is set to the crusher operation circuit (2-way circuit).
(2) The hydraulic oil flowing to the crusher circuit does not flow to the additional filter for the breaker.
(3) The relief pressure valve is set to high pressure.
Set pressure when machine is shipped from factory: 24.5 MPa (250 kg/cm
(4) It is possible to use the selector mode to adjust the maximum oil flow.
6 - 8
2 , 3,124 PSI)
2
, 3,550 PSI).
Working
Hydraulic circuit
mode
Return circuit automatically
B mode switched so that it does not
pass through control valve
Return circuit automatically
P mode or
switched so that it passes
E mode
through control valve
ATTACHMENTS AND OPTIONS
Set pressure of safety valve in
service valve
When shipped from factory :
2
21.6 MPa (220 kg/cm , 3124 PSI)
When shipped from factory :
2
24.5 MPa (250 kg/cm , 3550 PSI)
2
, 3,124 PSI)
2
, 3,550 PSI)