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2 2
2-2
T-312
inside or outside temperature. The inside tempera-
ture is obtained by averaging the curb and road side
return air sensors (located in the return air ducts). If
one sensor is not functioning the display will read
only the functioning sensor, if both are not function-
ing, the display will show ’--40’. The outside temper-
ature sensor is located in the condenser assembly.
When the key is toggled to display the inside temper-
ature, the inside LED will be illuminated. When the
key is toggled to display the outside temperature, the
outside LED will be illuminated. When the key
toggles to show set point, both inside and outside
LEDs are turned off.
9. Fresh Air -- The Fresh Air Button has two selection
LEDs, Fresh Air and Circulation. If the fresh air
damper door is open, the Fresh Air LED is illumi-
nated, if the fresh air damper door is closed, the Cir-
culation LED will be illuminated.
After start--up, the fresh air selection is in AUTO, the
controller will control the fresh air damper door.
When the key is toggled the damper selection will
move to the next step an Auto--Closed--Open--Auto
sequence. The Auto selection allows controller to
operate the damper, the Closed or Open being the
closed or open damper door selections with the
damper door held in those respective positions until
the button is toggled again.
10.Fan Speed -- After start--up, the display obtains the
the current fan speed status from the controller. If the
controller is in AUTO no fan speed LEDs will be illu-
minated. When a fan speed is selected the appropri-
ate LED will be illuminated.
11.
_
F/
_
C -- Key combination is used to select
_
F or
_
C.
When the display is showing temperature, press and
hold the Inside/Outside Temperature selection
key(8.) and press the UP key(2.), the display will
show in the
_
F scale. When the display is showing
temperature, press and hold the Inside/Outside
Temperature selection key(8.) and press the DOWN
key(3.), the display will show in the
_
C scale.
Figure 2-2. Parcel Rack On/Off
d. The Parcel Rack Switch (Figure 1-9) controls the liq-
uid line solenoid valve and the blower motors of the
parcel rack evaporators. The driver controls the par-
cel rack evaporator function with this switch. The par-
cel rack evaporators will function only after the main
evaporator is operating.
Figure 2-3. Driver A/C
e. The Driver A/C Switch (Figure 2-3) allows the driver
to control cooling with the driver’s evaporator. When
the switch is in AUTO, the driver’s area cooling is
controlled by the microprocessor controller. When
the switch is in COOL, the driver’s area is demanding
cooling, even if the microprocessor is calling for heat-
ing in the passenger area.
2.1.2 HVAC Power to Controller
Before starting the system, electrical power must be
available from the coach power supply.
2.1.3 Starting
The Driver Display Panel consists of a display and a
keypad (Figure 2-1), which allows the user to modify
and observe system operating parameters.
On start--up a self test will execute. While the test is
being executed the display will show its programing
revision number in the format of X.X, where X is a digit
from 1 to 9 (ex. 1.4). At his time three possible error
messages may also appear on the display. Refer to
Table 3-2 for definitions.
a. If the engine is not running, start the engine. The
HVAC system will restart in the AUTO mode. All sys-
tem controls will operate automatically in heating,
cooling or ventilating mode, as required.
b. CONTROL PANEL (Figure 2-1)
It is suggested the system be started in the automatic
mode.
1. The Driver Display Panel may be programmed to
display the set point temperature or return air tem-
perature. To determine which display temperature is
programmed, press the TEMPERATURE button so
that the OUT SIDE AIR indicator is illuminated. If the
controller cycles back to the INSIDE AIR indicator,
than the controller is programmed to display return
air temperature. If the controller does not automati-
cally cycle back to the return air indicator, than the
controller is programmed to display set point temper-
ature.
2. The Control Panel will signal the controller to perform
start up when the ON/OFF button is pushed. Ensure
the AUTO button indicator is illuminated. If not, press
the AUTO button to place the system in the automat-
ic mode.
3. If cooling only, heating only or ventilation only is de-
sired, press the corresponding button (refer to
Figure 2-1) to illuminate the indicator light and manu-
ally place the system in that mode of operation.
4. If low or high speed evaporator fan speed is desired,
press the FAN SPEED button to illuminate the indi-
cator light and bring speed to the desired level.