SiBE121021_C
Troubleshooting for Outdoor Unit
Service Diagnosis
349
7.12 Thermistor or Related Abnormality (Outdoor Unit)
Remote
Controller
Display
H9
,
J3
,
J6
,
J8
,
J9
,
P4
Outdoor Unit LED
Display
A
j
1
i
2
i
3
h
4
h
5
h
Method of
Malfunction
Detection
This type of error is detected by checking the thermistor input voltage to the microcomputer.
A thermistor error is detected by checking the temperature sensed by each thermistor.
Malfunction
Decision
Conditions
The thermistor input is above 4.96 V or below 0.04 V with the power on.
J3
error is judged if the discharge pipe temperature is lower than the heat exchanger
temperature.
The system is shut down if all the units are judged as the
J8
error.
Supposed
Causes
Disconnection of the connector for the thermistor
Defective thermistor
Defective outdoor unit PCB
Defective indoor unit PCB
Defective heat exchanger thermistor in the case of
J3
error (outdoor heat exchanger
thermistor in cooling mode, or indoor heat exchanger thermistor in heating mode)
Troubleshooting
In case of “
P4
”
Replace the outdoor unit PCB.
P4
: Radiation fin thermistor
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
