Daikin E Series, Service Manual

Page: 340 / 453

SiAU18-715 Troubleshooting for RA Indoor Unit
Troubleshooting 327
4.4 Thermistor or Related Abnormality (Indoor Unit)
Remote
Controller
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.329
C4
: Heat exchanger temperature thermistor
C9
: Room temperature thermistor
YES
(R7134)
NO
Check No. 06
Check the thermistor resistance
value.
YES
NO
Caution
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.
Is it normal?
Is it normal?
Check the connector connection.