Model 8210/8250 Maintenance Manual Section 8. Theory of Operation
Traction System
Publication:1146945/001, Revised: 25 Sep 2018 8-7
• The drive wheel starts to rotate in the
requested direction at a speed
proportional to the voltage at the traction
motor.
Emergency Reverse
If the emergency reverse button (belly button)
hall effect switch is closed with the control arm
lowered in travel mode (SW2 closed), the control
system activates an immediate, rapid
acceleration in the reverse (forks-first) direction.
The following occurs:
• The emergency reverse travel instruction is
transmitted through the CAN-bus to the
traction amplifier.
• Travel and speed inputs to the traction
amplifier are ignored.
• The traction amplifier provides maximum
torque inputs to the traction motor
immediately after the emergency reverse
button is activated.
• Travel in reverse (forks-first) direction
continues until the emergency reverse
button is released.
When the emergency reverse mode is activated,
the TA ceases to respond to the normal travel
command from the directional/speed control.
To reset the truck for normal travel, return the
directional/speed control to the neutral
position and cycle the brake ON/OFF.
Electric Brake Release Switch
A manually activated Electric Brake Release
Switch (SW3) has been added. Arm angle
proximity switch SW2 is supplied B– at SW2-3
any time the battery is plugged in. SW3 is
supplied with B+ from fuse FU2 any time the
battery is plugged in and the Main ON/OFF
switch (SW1) is in the ON position. To release
the brake, SW2 must be open with low voltage
at brake switch inputs, JP1-9 and JP1-24 (logic
low). A rising edge at JP1-33 while JP1-9 and
JP1-24 are at logic low is required to enter
brake release mode. The brake release mode
cannot be entered if SW3 is closed during
key-on or while the brake switch inputs are at
logic high (control handle is in the driving
position). While in brake release mode, the arm
angle proximity switch (SW2) still controls the
brake. The brake is released when the brake
switch inputs, JP1-9 and JP1-24, are at logic
high (tiller in driving position). The brake is
engaged with the brake switch inputs, JP1-9
and JP1-24, are at logic low (tiller in brake
position). To exit brake release mode at any
time, open the brake override switch (SW3).
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