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

Si12-714
5.6

Thermistor or Related Abnormality (Indoor Unit)

C4 , C9
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
∗
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.219
C4
C9
Service Diagnosis
(reference)
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
: Indoor heat exchanger thermistor
: Room temperature thermistor
NO
NO
Troubleshooting
Correct the connection.
Replace the thermistor.
(Replace the indoor unit PCB.)
Replace the indoor unit PCB.
(R4696)
185