Carrier 69NT40--541--200 TO 299 Operation And Service page 41

Cd22 Compressor Speed
Cd23 Evaporator Fan
Controlled
Cd24
Atmosphere State
Compressor Run
Cd25 Time Remaining Un-
til Defrost
Defrost Temperature
Cd26
Sensor Reading
Function codes Cd27 through Cd37 are user-selectable functions. The operator can change the value of
these functions to meet the operational needs of the container.
Defrost Interval
Cd27
(Hours or Automatic)
Temperature Units
Cd28
(_C or _F)
Failure Action
Cd29
(Mode)
Cd30 In-Range Tolerance
Table 3-5 Controller Function Codes (Sheet 2 of 4)
The status of the compressor is displayed (high, low or off).
Displays the current evaporator fan state (high, low or off).
Not used in this application
This code displays the time remaining until the unit goes into defrost (in tenths of
an hour). This value is based on the actual accumulated compressor running
time.
Defrost temperature sensor reading is displayed.
Configurable Functions
NOTE
There are two modes for defrost initiation, either user--selected timed intervals or
automatic control. The user--selected values are (OFF), 3, 6, 9, 12, or 24 hours
while the factory default is 12 hours. Automatic defrost starts with an initial de-
frost at 3 hours and then adjusts the interval to the next defrost based on the ac-
cumulation of ice on the evaporator coil. Following a start--up or after termination
of a defrost, the time will not begin counting down until the defrost temperature
sensor (DTS) reading falls below set point. If the reading of DTS rises above set
point any time during the timer count down, the interval is reset and the count-
down begins over. If DTS fails, alarm code AL60 is activated and control switches
over to the the return temperature sensor. The controller will act in the same man-
ner as with the DTS except the return temperature sensor reading will be used.
Defrost Interval Timer Value (Configuration variable CnF23): If the software is
configured to "SAv" (save) for this option, then the value of the defrost interval
timer will be saved at power down and restored at power up. This option prevents
short power interruptions from resetting an almost expired defrost interval, and
possibly delaying a needed defrost cycle.
The defrost interval timer counts only during compressor run time.
This code determines the temperature units (_C or _F) which will be used for all
temperature displays. The user selects _C or _F by selecting function code Cd28
and pushing the ENTER key. The factory default value is Celsius units.
This function code will display "--- --- --- --- ---" if Configuration Variable CnF34 is
set to _F.
If all of the control sensors are out of range (alarm code AL26) or there is a probe
circuit calibration failure (alarm code AL27), the unit will enter the shutdown state
defined by this setting. The user selects one of four possible actions as follows:
A -- Full Cooling (stepper motor SMV at maximum allowed opening)
B -- Partial Cooling (stepper motor SMV 11% open)
C -- Evaporator Fan Only
D -- Full System Shutdown -- Factory Default
The in-range tolerance will determine the band of temperatures around the set
point which will be designated as in-range. If the control temperature is in-range,
the in-range light will be illuminated. There are four possible values:
1 = ¦ 0.5_C (¦ 0.9_F)
2 = ¦ 1.0_C (¦ 1.8_F)
3 = ¦ 1.5_C (¦ 2.7_F)
4 = ¦ 2.0_C (¦ 3.6_F) -- Factory Default
NOTE
NOTE
3-15
T-317