TM 5-2410-240-23-1
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ELECTRO-HYDRAULIC CONTROLS CONTINUED
8. Left Counterrotate Turn
The machine ECM (Figure 15, Item 2) interprets two signals and determines that the joystick (Figure 15, Item 1) is
in the FORWARD and COUNTERROTATE LEFT position. The machine ECM sets the duty cycle for the motor
displacement control solenoids (Figure 15, Items 7 and 8) between 33% and 70%. These solenoids are located in
the left and right hydrostatic drive motors, respectively.
The machine ECM (Figure 15, Item 2) also sets the duty cycle for the reverse solenoid (Figure 15, Item 6) at less
than 23.5% and the duty cycle for the forward solenoid (Figure 15, Item 4) between 26% and 88.5%. These
solenoids adjust the proportional solenoid valves in the right side hydrostatic pump.
The machine ECM (Figure 15, Item 2) also sets the duty cycle for the reverse solenoid (Figure 15, Item 5) between
23.5% and 86% and the duty cycle for the forward solenoid (Figure 15, Item 3) at less then 26%. These solenoids
adjust the proportional solenoid valves in the left side hydrostatic pump.
N OT E
The duty cycles determine the angle of the pump and motor swashplates. The machine
ECM (Figure 15, Item 2) varies the duty cycles based on signals received from the travel
speed switch in joystick (Figure 15, Item 1). The machine ECM also adjusts the duty
cycles based on signals received from the engine speed sensor (Figure 15, Item 11) and
motor speed sensors (Figure 15, Items 9 and 10) in order to prevent an overspeed,
underspeed, or stall condition, and to ensure the machine is tracking in a straight line.
Figure 15. Machine ECM Inputs and Outputs for Left Counterrotate Turn.
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