6. LENGTH READING PROBLEM
PROBLEM: Length displayed incorrect. Crane is not in "out of load chart" condition.
Check mechanical adjustment of length potentiometer in cable reel. When main boom is fully
retracted, adjust length potentiometer counter-clockwise until it reaches a soft stop.
Refer to Procedure 5 in Section 11.
Replace length potentiometer assembly, refer to Drawings 4,
11 in Section 10. Remove slip ring body from shaft and remove
gear wheel from potentiometer axle. Unscrew mounting plate and
remove potentiometer assembly from mounting plate. Remove
assembly wires from terminal block. Connect new assembly to
terminal block. Reinstall mounting plate, gear wheel and slip
rings. With boom fully retracted, reset potentiometer by turning
counter-clockwise until it reaches a soft stop. Refer to
Drawing 4, 11 in Section 10 and Procedure 5 in Section 11.
Check out clutch in big gear wheel of length potentiometer. Extend and
retract boom to ensure that clutch is not slipping on potentiometer axle.
Refer to Drawing 4 in Section 10 and Procedure 5 in Section 11.
Replace the gear wheel, clean length potentiometer
axle. Reset length potentiometer.
Refer to Drawing 4 Section 10 and
Procedure 5 in Section 11.
Check power supply to length potentiometer on connection board
In central unit, terminal X1:8 (ground) and X1:11 (-5V)
Refer to Drawing 2, 3, 16 in Section 10.
Main board in central unit defective. Replace
main board and reset pressure channel.
Refer to Drawing 3 in Section 10 and
Procedures 3 and 4 in Section 11.