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6 − 17 T-364
3. Values will be entered from right to left. Press the UP
or DOWN ARROW key to increase or decrease the
values. ENTER will enter the information for the cur-
rent field and move to the next value; CODE
SELECT will allow modification of the previous
value.
4. When the last value is entered, press the ENTER
key to enter the information to the controller; the
CODE SELECT key will allow modification of the
previous value.
6.21.4 Removing and Installing a Controller
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 − 13) and lift up and
out.
3. Disconnect the back connectors and remove
module.
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 (see Figure 6
− 13)
are 0.23 mkg (20 inch-pounds). Torque value for the
connectors is 0.12 mkg (10 inch-pounds).
6.21.5 Battery Replacement
CAUTION
Use care when cutting wire ties to avoid
nicking or cutting wires.
a. Turn unit power OFF and disconnect power supply.
b. Disconnect battery wire connector from control box.
c. Slide out and remove old battery and bracket. (See
Figure 3 − 4, Item 8.)
d. Slide new battery pack and bracket into the control
box slot.
e. Reconnect battery wire connector to control box and
replace wire ties that were removed.
6.22 TEMPERATURE SENSOR SERVICE
Service procedures for the return recorder, return tem-
perature, supply recorder, supply temperature, ambi-
ent, defrost temperature, evaporator temperature, and
compressor discharge temperature sensors are pro-
vided in the following sub paragraphs.
6.22.1 Sensor Checkout Procedure
To verify that accuracy of a temperature sensor:
a. Remove the sensor and place in a 0
C (32 F)
ice-water 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 filling voids between ice with water and
agitating until mixture reaches 0 C (32 F) measured
on a laboratory 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.
e. Using the plug connector marked “EC” that is con-
nected to the back of the controller, locate the sensor
wires (RRS, RTS, SRS, STS, AMBS, DTS, or CPDS
as required). Follow those wires to the connector and
using the pins of the plug, measure the resistance.
Values are provided in Table 6 − 2 and Table 6 − 3.
Due to the variations and inaccuracies in ohmmeters,
thermometers or other test equipment, a reading
within 2% of the chart value would indicate a good
sensor. If a sensor is defective, the resistance read-
ing will usually be much higher or lower than the resis-
tance values given.