Service manual

Troubleshooting by Indication on the Remote Controller SiUS28-902_a
99 Troubleshooting
3.12 “CA” Indoor Unit: Malfunction of Thermistor for
Discharge Air
Remote
Controller
Display
CA
Applicable
Models
AII indoor unit models
Method of
Malfunction
Detection
Malfunction detection is carried out by temperature detected by discharge air temperature
thermistor.
Malfunction
Decision
Conditions
When the discharge air temperature thermistor becomes disconnected or shorted while the unit
is running.
Supposed
Causes
 Defect of indoor unit thermistor for air outlet
 Defect of indoor unit P.C.B.
Troubleshooting
∗ Refer to thermistor resistance / temperature characteristics table on P.166.
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Replace the indoor unit P.C.B.
Connect the thermistor and turn
on again.
NO
NO
Replace the thermistor.
YES
YES
Connector
is connected to the indoor
unit P.C.B.
Resistance
is normal when
measured after
disconnecting the thermistor
from the indoor unit
P. C . B .
(7.2kΩ~
112kΩ)