Service manual

T -318
3-- 2
3.1.1 Keypad
The keypad (Figure 3-2) is mounted on the right-hand
side of the control box. 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 3-1.
ENTER
BATTERY
POWER
MANUAL
DEFROST/
INTERVAL
CODE
SELECT
PRE
TRIP
ALARM
LIST
ALT.
MODE
RETURN
SUPPLY
_C
_F
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 five digital
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: Energiz ed when th e con-
trolled tem perature probe is within specified tolerance
of set point.
Table 3-1 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 in-
terval 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).
DegreesC/-
Degrees F
Displays alternate English/Metric
scale (momentary display). When set
to degrees Fahrenheit, pressure is
displayed in psig and vacuum in “/hg.
“P” appears after the value to indi-
cate psig and “i” appears for inches
of mercury.
When set to degrees Celsius, pres-
sure readings are in bars. “b” ap-
pears 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
functions from the temperature soft-
ware to the DataCORDER Software.
The remaining keys function the
same as described above except 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 controlling
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 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 en-
abled.
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 en-
abled.
7. Alarm -- Red LED: Energized when there is an active
or an inactive shutdown alarm in the alarm queue.