Removing And Installing A Module; Temperature Sensor Service; Sensor Checkout Procedure; Figure 6-19 Sensor Types - Carrier 69NT20-551-300 TO 399 Operation And Service

6. Press the ENTER key on the keypad.
7. The Display will show the message "Pro SoFt." This
message will last for up to one minute.
6. Press the ENTER key on the keypad.
8. The Display module will go blank briefly, then read
"Pro donE" when the software loading has loaded. (If
a problem occurs while loading the software: the Dis-
play will blink the message "Pro FAIL" or "bad 12V".
Turn start-stop switch OFF and remove the card.)
9. Turn unit OFF, via start-stop switch (ST).
10.Remove the PCMIA card from the programming/
software port and return the unit to normal operation
by placing the start-stop switch in the ON position.
11. Turn power on, and wait 15 seconds -- The status
LED will flash quickly, and there will be no display.
The controller is loading the new software into
memory. This takes about 15 seconds.
To load new software into the module, the programming
card is inserted into the programming/software port.
b. Procedure for loading Configuration Software
1. Turn unit OFF using start-stop switch (ST).
2. Insert software/programming PCMCIA card contain-
ing the following (example) files into the program-
ming/software port. (See Figure 6-18):
menuDDMM.ml3, this file allows the user to select
the file/program to upload into the controller.
cfYYMMDD.ml3, multi--configuration file
scrl55XX.ml3, controller software program for scroll
units.
3. Turn unit ON using start-stop switch (ST).
4. The Display module will display the message ruN
COnFG. (If a defective card is being used the Dis-
play will blink the message "bAd CArd". Turn start-
stop switch OFF and remove the card.)
5. Press the ENTER key on the keypad.
6. The Display module will go blank briefly and then dis-
play "551 00". Based on the operational software
installed.
7. Press the UP or DOWN ARROW key to scroll
through the list to obtain the proper model dash num-
ber. (If a defective card is being used, the Display will
blink the message "bAd CArd". Turn start-stop
switch OFF and remove the card.)
8. Press the ENTER key on the keypad.
9. When the software loading has successfully com-
pleted, the Display will show the message "EEPrM
donE." (If a problem occurs while loading the soft-
ware, the Display will blink the message "Pro FAIL"
or "bad 12V." Turn start-stop switch OFF and remove
the card.)
10.Turn unit OFF using start-stop switch (ST).
11. Remove the PCMIA card from the programming/
software port and return the unit to normal operation
by placing the start-stop switch in the ON position.
12.Confirm correct model configuration using the key-
pad to choose code select 20 (CD20). The model
displayed should match the unit serial number plate.

6.21.4 Removing and Installing a Module

a. Removal:
1. Disconnect all front wire harness connectors and
move wiring out of way.
2 The lower controller mounting is slotted, loosen the
top mounting screw (see Figure 6-18) and lift up and
out.
3 Disconnect the back connectors and remove mod-
ule.
4 When removing the replacement module from its
packaging , note how it is packaged. When returning
the old module for service, place it in the packaging
in the same manner as the replacement. The pack-
aging has been designed to protect the module from
both physical and electrostatic discharge damage
during storage and transit.
b.Installation:
Install the module by reversing the removal steps.
Torque values for mounting screws (item 2, see
Figure 6-18) are 2 Nm (20 inch-pounds). Torque value
for the connectors is 11 Nm (10 inch-pounds).

6.22 TEMPERATURE SENSOR SERVICE

Procedures for service of the Return Recorder, Return
Temperature, Supply Recorder, Supply Temperature,
Ambient, Defrost Temperature, Compressor Discharge
and Compressor Suction temperature sensors are
provided in the following sub paragraphs.

6.22.1 Sensor Checkout Procedure

Mounting Stud Type
Sensor
Bulb Type
Sensor
40 mm (1-1/2 inches)
Dual Sensor

Figure 6-19 Sensor Types

To check a sensor reading, do the following:
a. Remove the sensor and place in a 0_C (32_F) ice-wa-
ter bath. The ice-water bath is prepared by filling an
insulated container (of sufficient size to completely
immerse bulb) with ice cubes or chipped ice, then fill-
ing voids between ice with water and agitating until
mixture reaches 0_C (32_F) measured on a labora-
tory thermometer.
b. Start unit and check sensor reading on the control
panel. The reading should be 0_C (32_F). If the read-
ing is correct, reinstall sensor; if it is not, continue with
the following.
c. Turn unit OFF and disconnect power supply.
d. Refer to paragraph 6.21 and remove controller to gain
access to the sensor plugs.
6-15
40 mm (1 1/2 inch)
6.3 mm (1/4 inch)
40 mm (1-1/2 inches)
)
6.3 mm (1/4 inch
)
6.3 mm (1/4 inch
T-322