Carrier 69NT40-541-505, Operation And Service Manual

Page: 32 / 143

T-368 4–2
4.1.1 Keypad
The keypad ( Figure 4.2 ) is mounted on the control box
door. The keypad consists of 11 push button switches
that act as the user’s interface with the controller.
Descriptions of the switch functions are provided in
Table 4–1 .
Figure 4.2 Keypad
4.1.2 Display Module
The display module ( Figure 4–3 ) consists of five digital
displays and seven indicator lights. Indicator lights
include:
1. COOL − White or Blue LED: Energized when
the refrigerant compressor is energized.
2. HEAT − Orange LED: Energized to indicate
heater operation in heat mode, defrost mode, or
dehumidification.
3. DEFROST − Orange LED: Energized when the
unit is in the defrost mode.
4. IN RANGE − Green LED: Energized when the
controlled temperature probe is within specified
tolerance of set point.
NOTE
The controlling probe in perishable range is the
SUPPLY air probe and the controlling probe in
frozen range is the RETURN air probe.
5. SUPPLY − Yellow LED: Energized when the
supply air probe is used for control. When this
LED is illuminated, the temperature displayed in
the AIR TEMPERATURE display is the reading
at the supply air probe. This LED will flash if
dehumidification or humidification is enabled.
6. RETURN − Yellow LED: Energized when the
return air probe is used for control. When this
LED is illuminated, the temperature displayed in
the AIR TEMPERATURE display is the reading
at the return air probe. This LED will flash if
dehumidification or humidification is enabled.
7. ALARM − Red LED: Energized when an active or
an inactive shutdown alarm is in the alarm queue.
CODE
SELECT
PRE
TRIP
ALARM
LIST
MANUAL
DEFROST/
INTERVAL
ENTER
BATTERY
POWER
ALT
MODE
RETURN
SUPPLY
C
F
Table 4–1 Keypad Function
KEY FUNCTION
CODE
SELECT
Accesses function codes.
PRE TRIP Displays the pre-trip selection menu.
Discontinues pre-trip in progress.
ALARM LIST Displays alarm list and clears the
alarm queue.
MANUAL
DEFROST /
INTERVAL
Displays selected defrost mode. De-
pressing and holding the Defrost inter-
val key for five seconds will initiate
defrost using the same logic as if the
optional manual defrost switch was
toggled on.
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 Down Change or scroll a selection down-
ward. Pre-trip repeat backward
RETURN /
SUPPLY
Displays non-controlling probe tem-
perature (momentary display).
Celsius /
Farenheit
Displays alternate English/Metric scale
(momentary display). When set to de-
grees Fahrenheit, pressure is dis-
played in psig and vacuum in “/hg. “P”
appears after the value to indicate psig
and “i” appears for inches of mercury.
When set to degrees Celsius, pres-
sure readings are in bars. “b” appears
after the value to indicate bars.
BATTERY
POWER
Initiate battery backup mode to allow
set point and function code selection if
AC power is not connected.
ALT MODE This key is pressed to switch the func-
tions from the temperature software to
the DataCORDER Software. The re-
maining keys function the same as de-
scribed above except the readings or
changes are made to the DataCORD-
ER programming.
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