Carrier 69NT20-531-300 Defrost temperature sensor reading is displayed, Sensor Reading, Unit

		Table 3-5 Controller Function Codes (Sheet 2 of 3)ff
Cd22	Compressor State		The status of the compressor is displayed (Off, On).
Cd23	Evaporator Fan		Displays the current evaporator fan state (high, low or off).
Cd24	Controlled		Not used in this application
	Atmosphere State
	Compressor Run		This code displays the time remaining until the unit goes into defrost (in tenths of
Cd25	Time Remaining
			an hour). This value is based on the actual accumulated compressor running time.
	Until Defrost
Cd26	Defrost Temperature		Defrost temperature sensor reading is displayed.
	Sensor Reading

Configurable Functions

NOTE

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.

		The defrost interval is the time between defrost cycles. Five selectable values are
		available: 3, 6, 9, 12 or 24 hours. The factory default value is 12 hours. Follow-
		ing 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 countdown begins over. If DTS fails, alarm code
		AL60 is activated and control switches over to the the return temperature sensor.
	Defrost Interval	The controller will act in the same manner as with the DTS except the return tem-
Cd27		perature sensor reading will be used.
	(Hours)	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.
		NOTE
		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
Cd28	Temperature Units	and pushing the ENTER key. The factory default value is Celsius units.
	(_C or _F)	NOTE
		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 fol-
		lows:
	Failure Action	A - Full Cooling (compressor is on, economized operation. SMV subject to pressure
Cd29		and current limit.)
	(Mode)	B - Partial Cooling (Compressor is on, standard operation. SMV subject to pressure
		and current limit.)
		C - Evaporator Fan Only (Compressor is off, evaporator fans on high speed, not ap-
		plicable with frozen set points.
		D - Full System Shutdown - Factory Default (shut down every component in the
		unit)
		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,
Cd30	In-Range Tolerance	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

3-15 T-309