Carrier 69NT20-531-300 manual KEY Function

3.1.1 Key Pad

The key pad (Figure 3- 2) is mounted on the right-hand side of the control box. The key pad consists of eleven push button switches that act as the user’s interface with the controller. Descriptions of the switch functions are provided in Table 3-1.

CODE	PRE
SELECT	TRIP
ALARM	DEFROST
LIST	INTERVAL
ENTER
RETURN	_C
SUPPLY	_F
BATTERY	ALT.
POWER	MODE

Figure 3- 2 Key Pad

COOL	HEAT DEFROST IN RANGE ALARM		SUPPLY RETURN
	SETPOINT/Code	AIR TEMPERATURE/Data

Figure 3- 3 Display Module 3.1.2 Display Module

The display module (Figure 3- 3) consists of two backlighted five digit LCD displays and seven indicator lights. The indicator lights include:

1.Cool - White LED: Energized when the refrigerant compressor is energized.

2.Heat - Orange LED: Energized to indicate heater op- eration in the heat or defrost mode.

3.Defrost - Orange LED: Energized when the unit is in the defrost mode.

4.In-Range - Green LED: Energized when the con- trolled temperature probe is within specified toler- ance of set point.

	Table 3-1 Key Pad Function
KEY		FUNCTION
Code Select		Accesses function codes.
Pre-Trip		Displays the pre-trip selection menu. Dis-
		continues pre-trip in progress.
Alarm List		Displays alarm list and clears the alarm
		queue.
Defrost		Displays selected defrost interval.
Interval
Enter		Confirms a selection or saves a selection
		to the controller.
Arrow Up		Change or scroll a selection upward Pre-
		trip advance or test interruption.
Arrow		Change or scroll a selection downward.
Down		Pre-trip repeat backward.
Return/		Displays non-controlling probe tempera-
Supply		ture (momentary display).
		Displays alternate English/Metric scale
		(momentary display). When set to _F,
		pressure is displayed in psig and vacuum
		in “/hg. “P” appears after the value to in-
_C/_F		dicate psig and “i” appears for inches of
		mercury.
		When set to _C. pressure readings are in
		bars. “b” appears after the value to indi-
		cate bars.
Battery		Initiate battery backup mode to allow set
		point and function code selection if AC
Power
		power is not connected.
		This key is pressed to switch the functions
		from the temperature software to the Da-
ALT Mode		taCORDER Software. The remaining keys
		function the same as described above ex-
		cept the readings or changes are made to
		the DataCORDER programming..
		NOTE

The controlling probe in the perishable range will be the SUPPLY air probe and the control- ling probe in the frozen range will be the RETURN air probe.

5.Supply - Yellow LED: Energized when the supply air probe is used for control. When this LED is illumi- nated, the temperature displayed in the AIR TEMPER- ATURE display is the reading at the supply air probe. This LED will flash if dehumidification or humidifi- cation is enabled.

6.Return - Yellow LED: Energized when the return air probe is used for control. When this LED is illumi- nated, the temperature displayed in the AIR TEM- PERATURE display is the reading at the return air pro- be. This LED will flash if dehumidification or humidification is enabled.

7.Alarm - Red LED: Energized when there is an active or an inactive shutdown alarm in the alarm queue

T-309 3-2