Daikin FTKS50BVMB, Service Manual

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Troubleshooting for RA Indoor Unit SiEN18-622
328 Troubleshooting
4.4 Thermistor or Related Abnormality (Indoor Unit)
Remote Control
Display
C4, C9
Method of
Malfunction
Detection
The temperatures detected by the thermistors are used to determine thermistor errors.
Malfunction
Decision
Conditions
When the thermistor input is more than 4.96 V or less than 0.04 V during compressor
operation
∗
.
∗
(reference)
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 „
Faulty connector connection
„ Faulty thermistor
„
Faulty PCB
Troubleshooting
Check No.06
Refer to P.331
C4
: Heat exchanger temperature thermistor
C9
: Room temperature thermistor
Check the connector connection.
YES
Is it normal?
Is it normal?
(R4696)
NO
Check No. 06
Thermistor resistance check
YES
NO
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Correct the connection.
Replace the thermistor.
(Replace the indoor unit PCB.)
Replace the indoor unit PCB.
Caution