3. Diagnostic Trouble Code (monitor display

97

Option Circuits

Breaker circuit (independent operation)

By operating the option remote control valve to the breaker side, the pilot pressure oil is fed to the control valve pa2 port and switches the option spool.

The discharge oil from hydraulic pump A1 is fed from the control valve P1 port through the parallel oil path and fed to the option spool. Switching the spool lets the oil flow from the relief valve A port through the B port and into the breaker.

The breaker set pressure is set by this relief valve.

At this time, the option pilot pressure switch signal is detected, the P1 flow control proportional valve is controlled by the output signals from the computer A to adjust the discharge flow.

The return oil from the breaker goes through the manifold and returns to the hydraulic oil tank.

Because the breaker operating flow can be set to 5 levels on the service support screen of the monitor display with the ON signal from the breaker switch in the cab, the optimum operating flow can be selected.

Pressure line Tank line Pilot pressure line Pilot tank line Electric line

1 Control valve 12 Console lever lock switch 2 Manifold 13 Lever lock 3 Relief valve 14 5 stack solenoid valve 4 Breaker 15 P1 pressure sensor 5 Travel pilot pressure sensor 16 P2 pressure sensor 6 Upper pilot pressure sensor 17 N1 negative control pressure sensor 7 Computer A 18 N2 negative control pressure sensor 8 Monitor display 19 P1 flow control proportional valve 9 Breaker switch 20 Hydraulic pump 10 Option remote control valve 21 Check valve 11 Option pilot pressure switch 22 Oil cooler