Carrier 69NT40-561-019, Operation And Service Manual

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T-359 7–26
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 4.4 , 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.
7.18 VENT POSITION SENSOR SERVICE
The fresh air vent position sensor alarm (AL50) will occur if the sensor reading is not stable for four minutes or if the
sensor is outside of its valid range (shorted or open). This can occur if the vent is loose or the panel is defective. To
confirm a defective panel, assure that the wing nut is secure and then power cycle the unit. If the alarm immedi-
ately reappears as active, the panel should be replaced.
The alarm should immediately go inactive, check the 4-minute stability requirement. If the alarm reoccurs after the
four minutes and the panel was known to have been stable, then the sensor should be replaced.
In order to replace the VPS, the panel must be removed and replaced with another upper fresh air panel equipped
with VPS.
Upon installation, a new vent position sensor assembly requires calibration as follows:
1. Rotate the vent to the 0 CMH / CFM position.
2. Code select 45 will automatically display. Press the Enter key and hold for five seconds.
3. After the enter key has been pressed the display will read CAL (for calibration).
4. Press the ALT MODE key and hold for five seconds.
5. After the calibration has been completed, Code 45 will display 0 CMH / CFM.
a. Lower Vent Position Sensor Calibration
Calibration of the Lower VPS is only required when the air makeup slide, motor or sensor has been repaired
or serviced.
The VPS is calibrated using the keypad:
1. Remove the two nuts that secure the air makeup panel slide to the unit.
2. Rotate the gear clockwise until it stops.
3. Rotate the gear 1/4 turn counterclockwise.
4. Carefully reposition the slide onto the air makeup panel, given that the gear is engaged with the rail
and has not moved.
5. Position slide panel to the fully closed position.
6. Code select Cd45 will automatically be shown on the left display.
7. Depress the ENTER key and hold for five seconds. CAL for calibration is displayed.
8. Depress the ALT MODE key on the keypad and hold for five seconds.
9. When calibration has been completed, Cd45 causes 0 CMH/CFM to be shown on the right display.
10. Secure the air makeup panel slide to the unit with the two nuts; stake threads.
7.19 TEMPERATURE SENSOR SERVICE
Procedures for service of the return recorder, return temperature, supply recorder, supply temperature, ambient,
defrost temperature, evaporator temperature, and compressor discharge temperature sensors are provided in the
following sub paragraphs.