Thermistor Or Related Abnormality (Indoor Unit) - Daikin D-Series Service Manual

SiBE12-522
5.6

Thermistor or Related Abnormality (Indoor Unit)

C4,
Remote
Controller
Display
Method of The temperatures detected by the thermistors are used to determine thermistor errors.
Malfunction
Detection
Malfunction When the thermistor input is more than 4.96 V or less than 0.04 V during compressor
operation∗.
Decision
∗ (reference)
Conditions
When above about 212°C (less than 120 ohms) or below about -50°C (more than 1,860 kohms).
Note: The values vary slightly in some models.
Supposed
Causes
Troubleshooting
Check No.06
Refer to P.215
C4 : Heat exchanger temperature thermistor
C9 : Room temperature thermistor
Service Diagnosis
C9
Faulty connector connection
Faulty thermistor
Faulty PCB
Be sure to turn off power switch before connect or disconnect connector,
Caution or parts damage may be occurred.
Check the connector connection.
Is it normal?
YES
Check No. 06
Thermistor resistance check
Is it normal?
YES
NO
NO
Troubleshooting
Correct the connection.
Replace the thermistor.
(Replace the indoor unit PCB.)
Replace the indoor unit PCB.
(R4696)
181