Outdoor Air Thermistor Error - Daikin VAM 500EJ Service Manual

Si-93
1.5

Outdoor Air Thermistor Error

Remote Controller
Error Code
LCD Display
LED Indication
Remote Controller
Error Detection
Temperature detected by outside air temperature sensor is used to detect errors.
Method
Error Generating
When value detected by outside air temperature sensor is -40ºC or below (open circuit) or 70ºC or higher
Conditions
(shorting).
I Faulty sensor
Possible Causes
I Broken wire
I Faulty control PCB
I Faulty contact in connector
Troubleshooting
Note: Note 1:
Refer to the thermistor temperature - resistance conversion table when measuring resistance.
Thermistor temperature - resistance conversion table
Thermistor
temperature
-10ºC or less
If measured value deviates significantly from above values, thermistor is faulty.
Use tester to check resistance
Troubleshooting
6 6 6 6 5 5 5 5
—
Inspection
4
Main Unit
Remove outdoor air
thermistor (R2T) from
X13A (2P) on control
PCB, and measure
resistance.
Is
thermistor
normal?
Note 1
Sensor resistance
108kΩ or more
-5ºC Approx. 85kΩ
0ºC Approx. 66kΩ
5ºC Approx. 51kΩ
10ºC Approx. 40kΩ
14ºC Approx. 33kΩ
16ºC Approx. 30kΩ
18ºC Approx. 27kΩ
20ºC Approx. 25kΩ
5
Unit No.
5
NO
YES
Thermistor
temperature
22ºC
24ºC
26ºC
28ºC
30ºC
35ºC
40ºC
50ºC or more
Continuity check
(HL028)
Troubleshooting
Replace outdoor
air thermistor.
If there is no faulty
contact, replace
control PCB.
(HF004)
Sensor resistance
Approx. 23kΩ
Approx. 21kΩ
Approx. 19kΩ
Approx. 18kΩ
Approx. 16kΩ
Approx. 13kΩ
Approx. 11kΩ
7kΩ or less
35