1-14
T-312
1.9 ELECTRONIC AUTOMATIC CONTROL DATA
FLOW
The system is supplied with 12 and 24 vdc power from
the coach power supply. The main controller receives
input from pressure transducers, temperature sensors,
condenser and evaporator fan motor overloads, high
pressure switch, fuses. It then processes these inputs to
control output devices enabling automatic control of
temperature conditions inside the coach. The driver
display provides a communication link between the
main controller and the rest of the system. The following
block diagram (Figure 1-13) indicates data flow through
the system. Refer to section 2 for more detailed
information on the theory of operation of the control
system and see section 5 for system electrical
schematics.
12 /24 VDC
POWER
SUPPLY
INPUT
DEVICES
(Transducers,
Sensors and
HP switch)
MAIN CONTROLLER
DRIVER
DISPLAY
EXPANSION
BOARD
OUTPUT DEVICES
(Heater Solenoid
Valves and RAM Air
Actuators)
12 VDC
POWER
SUPPLY
24 VDC
POWER
SUPPLY
Fan Motors,
Compressor,
Driver Control
Box
OUTPUT
DEVICES
(Solenoids,
Relays,
Clutch)
MAIN CONTROL BOX
24 VDC
POWER
SUPPLY
Figure 1-13. Electronic Automatic Control Data Flow Block Diagram