HARNESS AS-SWITCH 3009957 - Caterpillar

Illustration 1 g03870214
Medium Pressure (Load Sensing Valve)
(1) Main control valve
(2) Oil cooler
(3) Hydraulic tank
(4) Pilot manifold
(5) Retract solenoid valve "A3"
(6) Extend solenoid valve "A3"
(7) Auxiliary control valve
(8) Line relief valves
(9) Motor for rotation
(10) Main relief valve
(11) Unload valve
(12) Idler pump
(13) Auxiliary pump
(14) Pilot pump
(15) Drive pump Medium pressure is designed to provide oil to the work tool for tool rotation. An attachment valve is used to control the oil flow. This valve is shifted with proportional reducing valves that allow the operator complete electronic control over the tool rotation. An auxiliary pump is used to supply oil flow for medium pressure. A typical example of a work tool that will use medium pressure is a shear.Reference: Refer to Testing and Adjusting, "Work Tool Parameter - Program" for the tool control system to change the settings for work tool operation.Reference: Refer to Testing and Adjusting, "Medium Pressure: Default Value of Work Tool Parameters" for the Tool Control System to reference the factory settings.
Table 1
Operation Lever List
Control Extension Retraction
Left Joystick Thumb Wheel Push Forward Push Backward
Electric Foot Pedal Push Forward Push Backward Attachment Valve Extended
When the device for activation is operated in the extend position, proportional reducing valve (6) receives a modulated signal from the machine ECM. Proportional reducing valve (6) allows pilot oil to flow to attachment control valve (7). This shifts attachment control valve (7) allowing medium pressure oil from auxiliary pump (13) to hydraulic rotator motor (9).Oil returning from the rotator motor flows through attachment control valve (7), oil cooler (2), and back to the hydraulic tank.The working pressure for rotation is limited by the main relief valve (10).Attachment Valve Retracted
When the device for activation is operated in the retract position, proportional reducing valve (5) receives a modulated signal from the machine ECM. Proportional reducing valve (5) allows pilot oil to flow to attachment control valve (7). This shifts attachment control valve (7) allowing medium pressure oil from the auxiliary pump (13) to hydraulic rotator motor (9).Oil returning from the rotator motor flows through attachment control valve (7), oil cooler (2), and back to the hydraulic tank.The working pressure for rotation is limited by the main relief valve (10).