Electronic Accelerator And Retard Pedals; Typical Electronic Pedal - Komatsu 930E-2 Shop Manual

ELECTRONIC ACCELERATOR AND
RETARD PEDALS
The accelerator pedal provides a signal to the Truck
Control Interface (TCI) when the operator requests
power. The retard pedal provides a signal to the Pro-
pulsion System Controller (PSC) when the operator
requests retarding. The pedal signals are processed
by the analog card in the respective panel for use by
the system controllers to provide the desired mode of
operation.
As the operator depresses the pedal, the internal
potentiometer's wiper is rotated by a lever. The output
voltage signal increases in proportion to the angle of
depression of the pedal.
Repair and initial adjustment procedures are dis-
cussed in the following. Refer to "AC Drive System
Checkout Procedure" for final calibration of the pedal
potentiometer after installation in the truck.
Removal
NOTE: Repair procedures for the retard and accelera-
tor pedal are identical. The retard pedal is mounted on
the brake pedal. Refer to Section "J" for instructions
for removing and installing the electronic pedal on
brake actuator.
Note routing and clamp location of wire harness.
Proper wire routing is critical to prevent damage during
operation after reinstallation.
1. Disconnect pedal wire harness from truck harness
connector.
2. Remove mounting capscrews, lockwashers and
nuts and remove pedal assembly.
Installation
1. Install pedal assembly using hardware removed
in step 2, "Removal". Connect potentiometer to
wiring harness.
2. Calibrate pedal potentiometer per instructions in
"AC Drive System Checkout Procedure - Setting
Pedal Percentages".
Disassembly
1. Remove screws on cable clamps (1, Figure 2-9)
and potentiometer cover (6).
2. Remove potentiometer mounting screws (5) and
grommet (3). Remove potentiometer (4).
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1. Cable Clamp
2. Electrical Harness
3. Grommet
Assembly
Electrical Propulsion System Components
FIGURE 2-9. TYPICAL ELECTRONIC PEDAL
1. Position new potentiometer with the flat side
toward the potentiometer cover and install on
shaft as follows:
a. Align cutouts in shaft with the potentiometer
drive tangs.
b. Press potentiometer onto shaft until it bottoms
against the housing.
2. Install screws (5) and lockwashers but do not
tighten.
3. Rotate potentiometer counterclockwise until
mounting slots contact the mounting screws and
tighten screws (5) to 15 in. lbs. (1.70 N.m) torque.
4. Install grommet (3) and potentiometer cover.
Tighten screws to 15 in. lbs. (1.70 N.m) torque.
5. Install cable clamps and tighten screws to 40 in.
lbs. (4.21 N.m) torque.
6. Inspect assembly and verify proper wiring clear-
ance during operation of pedal throughout the
range of travel.
4. Potentiometer
5. Adjustment Screw
6. Cover
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