Traction Circuit-Theory Of Operation - Textron JACOBSEN Eclipse 2 Technical/Repair Manual

Traction Circuit—Theory of Operation
Traction Circuit Components
Main Control Unit
The main control unit (MCU) manages all machine
functions based on user input and programmed settings.
Throttle Potentiometer
The throttle potentiometer (R1) is supplied 5 VDC from
MCU.
The throttle potentiometer provides a 0–5 VDC input
voltage to the MCU terminal J2-16.
Bail Potentiometer
The bail potentiometer (R2) is supplied 5 VDC from
MCU.
The bail potentiometer provides a 0–5 VDC input voltage
to the MCU terminal J2-32.
Traction Motor Controller Unit
The traction motor controller (U2) is supplied 48 VDC
from the MCU.
The traction motor controller provides an AC output and
5 VDC output to the traction motor. The traction motor
controller manages motor speed based on input from the
MCU.
Traction Motor
Traction motor (M2) is supplied AC current from the
traction motor controller.
The traction motor hall effect sensors provides the
traction motor controller an input voltage to communicate
motor speed.
The traction motor maintains speed via regenerative
braking.
When the traction motor is slowed, energy is created.
The traction motor controller rectifies this energy and
places it back on the 48 VDC power circuit.
Traction Circuit Operation
See Figures 4-14 and 4-15.
Main control unit (MCU) terminal J1-2 provides +48 VDC
to traction motor controller terminal J9-1.
MCU terminal J2-15 provides +5 VDC to throttle
potentiometer terminal 3.
When the throttle potentiometer is adjusted, a 0–5 VDC
reference voltage is provided from throttle potentiometer
terminal 2 to the MCU speed input terminal J2-16.
MCU terminal J2-31 provides +5 VDC to bail
potentiometer terminal 3.
When the bail potentiometer is adjusted, a 0–5 VDC
reference voltage is provided from bail potentiometer
terminal 2 to the MCU bail pot Input terminal J2-32.
4262930-Rev A
The traction motor controller (U2) provides +5 volts and a
signal ground to the traction motor (M2), powering the
motor hall effect and temp sensors.
The hall A, B, and C sensor output terminals provide a
signal to the traction motor controller hall A, B, and C
input terminals through the traction motor terminals
J13-2, J13-3, and J13-4.
The traction motor controller, motor tach output terminal
J8-1 provides an AC signal to MCU traction motor tach
input terminal J2-6. The AC signal is used to indicate
motor speed. The tach signal is based on the traction
motor hall sensor signals provided to the traction motor
controller.
The traction motor temp sensor provides a 0–5 VDC
reference voltage to the traction motor controller temp
input terminal J13-6. The traction motor controller, motor
temp output terminal J8-2 provides the temperature value
to the MCU traction motor temp terminal J2-11.
The MCU provides a ground (low) signal output from
traction motor enable terminal J2-19 to traction motor
controller terminal J8-5. This ground (low) enables motor
operation.
The MCU provides an open/high or approximately 8 VDC
from the traction motor direction terminal J2-20 to traction
motor controller terminal J8-4. The 8 VDC signal turns
the motor shaft in the CCW direction for forward travel.
The traction motor controller provides three-phase AC
voltage to the traction motor through terminals phase A,
B, and C.
The MCU traction motor speed output terminal J2-5
provides a 0–5VDC reference voltage to the traction
motor controller motor speed input terminal J8-3.
Depending on the value of the signal provided from the
MCU, the traction motor controller will operate the
traction motor at the speed requested.
The MCU will display the traction motor controller fault
icon on the LCD display when a problem is detected in
the traction motor controller. The traction motor will not
operate until the problem is resolved.
The MCU will also display the traction motor fault icon on
the LCD display when a traction motor short circuit is
detected or the traction motor current draw exceeds a
constant 25 amps. The traction motor will not operate
until the problem is resolved.
ELECTRICAL
4
4-27