Si04-115
Trouble shooting
Service Diagnosis
69
5.4
Operation Halt Due to Detection of Thermistor or Related
Abnormality
Remote
Controller
Display
C4,
C4,
C4,
C4, C9,
C9,
C9,
C9, CA
CA
CA
CA
Indoor unit LED
Display
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
Ω
) or below about -50°C (more than 1,860 k
Ω
).
Note:
The values vary slightly in some models.
Supposed
Causes
"
Faulty connector connection
"
Faulty thermistor
"
Faulty PCB
Troubleshooting
Check No.5
Refer to P.88
C4
: Heat exchanger temperature thermistor
C9
: Suction air thermistor
CA
: Discharge air thermistor
Check the connector connection.
YES
Correct the connection.
Replace the thermistor.
(Replace the indoor unit PCB.)
Replace the indoor unit PCB.
Is it normal?
Is it normal?
(R1947)
NO
Check No. 5
Thermistor resistance check
YES
NO
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
