Hitachi ZW180 Technical Manual page 64

Neutral Control
Purpose: To protect transmission by restricting clutch
connection despite operation of FNR lever or
FNR switch while applying the parking
brake.
Operation:
1. When either of the signal from FNR lever, forward
signal or reverse signal of the FNR switch is
transmitted to MC, MC confirms the detected
value of the parking brake pressure sensor.
2. When the parking brake pressure is higher than
the set pressure, MC transmits the signal to the
clutch solenoid valve. When the parking brake
pressure is lower than the set pressure, MC does
not transmit the signal to the clutch solenoid valve.
NOTE: When the pilot pressure is transmitted, the
parking brake of the vehicle body is re-
leased.
NOTE: In case short-circuiting takes place inside
the FNR lever, the transmission is made
neutral forcedly.
NOTE: In case electric abnormality takes place
involving the FNR switch, traveling by the
FNR lever is possible as an emergency
measure.
NOTE: The FNR switch does not transmit the neu-
tral signal. In case of no electric current
from the FNR switch, the controller judges
that the switch is neutral (N).
SYSTEM / Control System
T2-1-22
IMPORTANT: Be careful that in case the parking
brake pressure sensor is abnormal,
traveling is possible even if the
parking brake switch is ON and the
parking brake is applied as the
parking brake indicator is kept OFF
(release).