Sequence Of Operation; Perishable Mode; Frozen Mode; Configuration - Carrier 40 Operation & Service Manual

2.8 SEQUENCE OF OPERATION

General operation sequences for cooling, null, and
heating are provided in the following subparagraphs.

2.8.1 Perishable Mode

The unit operates in the perishable mode with set points
above 10°F (--12°C)
a. With supply air temperature above set point and de-
creasing, the unit will be cooling with the compressor
and evaporator fans operating. The condenser fan
will operate for the first three minutes after start up
then operate under the control of the condenser pres-
sure switch (HP2). the green unit operating data led
will be flashing then go to a steady illumination as set
point is approached.
b. Once temperature decreases to the control point, the
unit will enter the null mode with no components oper-
ating. If the unit is operating on standby, a 5 minute
delay is required before restart is allowed.
c. If temperature increases during the null mode, the unit
will restart in cooling.
d. If temperature continues to decrease the unit will en-
ter the heating mode with the with the compressor
and evaporator fans operating and the hot gas valve
(SV4 energized open). The condenser fan and con-
denser pressure control valve will operate under the
control of the condenser pressure switch (HP2). If the
heat option is installed, those heaters will also be en-
ergized.
COOL
UNIT STOPPED
HEAT
Figure 2-2
Operating Sequence - - Perishable Mode

2.8.2 Frozen Mode

The unit operates in the frozen mode with set points at or
below 10°F (--12°C). Operation in the frozen mode is the
same as in the perishable mode except the heat relays
are locked out and no hot gas or electric heating takes
place.
62-10630
+1_C (+1.8_F)
or +2_C (+3.6_F)
or +3_C (+5.4_F)
SET-POINT
--1_C (--18_F)
or --2_C (--3.6_F)
or --3_C (--5.4_F)
(setting)
2-4
COOL
UNIT STOPPED

2.9 CONFIGURATION

To access the configuration menu, press the
configuration button (see Figure 2-3) located on the
rear of Cab Command. Press the button once only to
enter the menu.
Configuration
button

Figure 2-3 Configuration Button

NOTE
If when settings are adjusted, no key is acti-
vated within 5 sec. the system reverts to dis-
playing the box temperature. All changes
made are recorded with OFF/ON.
TEMPERATURE UNIT
Ut_ _ _ _ C : Celsius degree display
Ut_ _ _ _ F : Fahrenheit degree display
Press the + and -- keys to change Ut_C
or Ut_F.
Press the SET key to validate.
+1_C (+1.8_F)
or +2_C (+3.6_F)
or +3_C (+5.4_F)
SET-POINT
--1_C (--18_F)
or --2_C (--3.6_F)
or --3_C (--5.4_F)
(setting)
Change 07/03