Carrier 69NT40-541-300, Операция и обслуживание

Страница: 110 / 152

6 − 22 T − 318
6.23.5 Battery Replacement
Standard Battery Location
(Standard Cells):
a. Turn unit power OFF and disconnect power supply.
b. Slide bracket out and remove old batteries. (See
Figure 3-4, Item 8.)
c. Install new batteries and slide bracket into control box
slot.
CAUTION
Use care when cutting wire ties to avoid
nicking or cutting wires.
Standard Battery Location (Rechargeable Cells):
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.
Secure Battery Option (Rechargeable Cells Only):
a. Turn unit power OFF and disconnect power supply.
b. Open control box door and remove both the high volt-
age shield and clear plastic rain shield (if installed).
c. Disconnect the battery wires from the “KA” plug posi-
tions 14, 13, 11.
d. Using Driver Bit, Carrier Transicold part number
07 − 00418 − 00, remove the 4 screws securing the dis-
play module to the control box. Disconnect the ribbon
cable and set the display module aside.
NOTE
The battery wires must face toward the right.
e. Remove the old battery from the bracket and clean
bracket surface. Remove the protective backing from
the new battery and assemble to the bracket. Secure
battery by inserting the wire tie from the back of the
bracket around the battery, and back through the
bracket.
f. Reconnect the ribbon cable to display and re − install
the display.
g. Route the battery wires from the battery along the dis-
play harness and connect the red battery wire and
one end of the red jumper to “KA14,” the other end of
the red jumper wire to “KA11,” and the black wire to
“KA13.”
h. Replace wire ties that were removed.
6.24 TEMPERATURE SENSOR SERVICE
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.
6.24.1 Sensor Checkout Procedure
To verify that accuracy of a temperature sensor:
a. Remove the sensor from the bracket and place in a
0 ° C (32 ° F) ice-water bath. The ice-water bath is pre-
pared 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) mea-
sured 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 6.23 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, CPDS
OR CPSS as required). Follow those wires to the con-
nector and using the pins of the plug, measure the
resistance. Values are provided in Table 6-2.
Table 6-2 Sensor Temperature/Resistance Chart
Temperature
Centigrade
Temperature
Fahrenheit
Resistance
(Ohms)
RRS, RTS, SRS and STS:
0 32 32,650 +/ − 91
25 77 10,000 +/ − 50
AMBS and DTS
0 32
32,650 +1720
-1620
25 77
10,000 +450
-430
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.
6.24.2 Sensor Replacement
a. Turn unit power OFF and disconnect power supply.
b. For two wire sensors, cut cable 5cm (2 inches) from
shoulder of defective sensor and discard the defec-
tive sensor only. For 3-wire sensors, cut at 23cm (9
inches). Slide the cap and grommet off well mounted
sensor and save for possible reuse. Do not cut the
grommet.