5. MAIN RELIEF PRESSURE CHANGE CIRCUIT 5.
MAIN RELIEF PRESSURE CHANGE CIRCUIT ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR ps1 ps2 T3 T1 T2 T4 TRAVEL MOTOR Auto power boost TRAVEL P T (2) (1) (4) (3) pb6 pa1 pb1 pa6 T1 T2 PUMP A1 PUMP A2 PILOT PUMP P T T3 dr# (4) POWER MAX SOLENOID VALVE PH (MCV) F (T/JOINT) j1 A1 A2 A5 P4 Pi(D/C VALVE) P pb9 pb5 T PS P2 P3 P(2-EPPR) PP(MCV) Td# pa9 pc1 pa5 pa8 pa11 pb8 A B C pa3 (Td#) P1 LINE FILTER HYDRAULIC TANK pc6 pb3 pb7 pc2 pa7 480A3HC06 When the power max switch on the left control lever is pushed ON, the power max solenoid valve is actuated, the discharged oil from the pilot pump into PH port of the main relief valve of main control valve ; Then the setting pressure of the main control valve is raises from 330 kgf/cm 2 to 360 kgf/cm 2 for increasing the digging power.
And even when press continuously, it is canceled after 8 seconds. Also, the auto power boost function is selected to enable on the cluster, the pressure of the main relief valve is automatically increased to 360 kgf/cm 2 as working condition by the MCU. It is also operated max 8 seconds. 3-11 3-11 A5 pb5 ARM 1 pa5 B4 A4 pb4 pa4 OPTION A3 B3 pb3 B2 pa3 BOOM 2 A2 (RH) TRAVEL(LH TRAVEL STRAIGHT A6 pb6 pa6 ) P3 P2 T ARM (2) (4) D E (3) B (3) (1) (2) F G H J c b PS pa2 d1 d e2 e f PS PS PS 1 f g g1 h PS h1 j j PS CRO P1 P2 P3 P1 P2