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2-1
T-312
SECTION 2
OPERATION
H
L
W
O
H
G
I
HEAT
H
L
W
O
H
G
I
DEF
Down (Decrease) Selection
Up (Increase) Selection
Fresh Air
Heat Only
Cooling
Only
Vent Only
On/Off
Fan Speed
Display
Inside/Outside
Temperature
Automatic Control
Defrost (Driver’s Evap Blower)
Heat (Driver’s Evap Coolant Valve)
(
1.
)
(
a.
)
(
b.
)
(
2.
)
(
3.
)
(
4.
)
(
5.
)
(
6.
)
(
7.
)
(
8.
)
(
9.
)
(
10.
)
Driver Display Panel (
c.
)
Figure 2-1. System Operating Controls
(upper left hand switch panel)
2.1 STARTING, STOPPING AND OPERATING
INSTRUCTIONS
2.1.1 Operating Controls
There are five operating controls (Figure 2-1) used to
control the functions of this system. They are as follows:
a. The Defrost Switch controls the driver evaporator
blower motor speeds. With this switch the driver con-
trols the amount of air discharged to the windshield.
This function is independent of any other HVAC func-
tion in the coach.
b. The Heat Switch controls the coolant valve to the driv-
er’s evaporator. With this switch the driver controls
the amount of engine coolant flowing thru the driver’s
evaporator heater core, hence increasing or decreas-
ing the temperature of air that is discharged to the
windshield. This function is independent of any other
HVAC function in the coach.
c. The Driver Display Panel controls the Carrier Trans-
icold microprocessor controller which in turn controls
the operation of the heating and air conditioning sys-
tem. With this control the driver controls the tempera-
ture of air to the passenger area and cooling to the
driver area. The panel has 10 keys whose functions
are described as follows:
1. On/Off -- Pressing this key will change the display
state from inactive to active. If the controller is active
the display will illuminate and the other keypad LEDs
will be active.
2. Up (Increase Selection) -- If the set point is displayed
when the Up key is pressed, the display will increase
set point 1
_
F
(0.5
_
C).
3. Down (Decrease Selection) -- If the set point is dis-
played when the Down key is pressed, the display
will decrease set point 1
_
F
(0.5
_
C).
4. Auto (Auto Control Selection) -- Pressing the Auto
button illuminates the AUTO LED and signals the
controller to automatically cycle to the control set
point. If the AUTO LED is illuminated, the manual
modes will be de--activated, the COOL, VENT, and
HEAT LED’s will not be illuminated.
5. Cool (Cool Mode Selection) -- If the COOL button is
pressed, the COOL LED is illuminated, the system
will only cool to control set point. The AUTO, VENT,
and HEAT LED’s will not be illuminated.
6. Vent (Ventilation Mode Selection) -- If the VENT but-
ton is pressed, the VENT LED is illuminated, only the
system fans will operate. The AUTO, COOL, and
HEAT LED’s will not be illuminated.
7. Heat (Heat Mode Selection) -- If the HEAT button is
pressed, the HEAT LED is illuminated, the system
will operate in the heat mode only, cycling the coolant
control valves as needed to maintain set point. The
AUTO, COOL, and VENT LED’s will not be illumi-
nated.
8. Inside/Outside Temperature -- After start--up, the
display shows set point. The temperature display
selection button will toggle the display to show bus