Service manual

Troubleshooting by Indication on the Remote Controller SiUS28-902_a
113 Troubleshooting
3.22 “H9” Outdoor Unit: Malfunction of Thermistor (R1T) for
Outdoor Air
Remote
Controller
Display
H9
Applicable
Models
RZQ18~30PVJU
Method of
Malfunction
Detection
Malfunction is detected from the temperature detected by the outdoor air thermistor.
Malfunction
Decision
Conditions
When the outside air temperature thermistor has short circuit or open circuit.
Supposed
Causes
 Defect of thermistor (R1T) for outdoor air
 Defect of outdoor unit P.C.B. (A1P)
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.
Resistance
is normal when
measured after
disconnecting the thermistor
(R1T) from the outdoor
unit P.C.B.
(3.5kΩ to
360kΩ)
Connector is
connected to X11A of
outdoor P.C.B.
(A1P).
Replace the outdoor unit P.C.B.
(A1P).
Connect the connector and turn
on again.
NO
NO
Replace the thermistor (R1T).
YES
YES