Mitsubishi Heavy Industries SRK20ZIX-S Service Manual page 81

(7) Inspection procedures corresponding to detail of trouble
Sensor error
Is connector connection good?
YES
Is sensor resistance value good?
YES
Replace PCB.
◆ Discharge pipe sensor temperature characteristics
(Broken wire)
180
160
140
120
100
80
60
40
20
(Short circuit)
0
0 20
Indoor fan motor error
Is connector connection good?
YES
* Disconnect the fan motor
connector, then investigate
the fan motor and indoor
PCB separately.
Is the output of the indoor PCB
normal?
YES
Normal
NO
Correct connection.
NO
Replace sensor.
40 60 80 100 120
Temperature (˚C)
NO
Correct connector connection
Is fan motor resistance value good?
NO
Defective indoor PCB
◆ Sensor temperature characteristics (Room
temp., indoor heat exchanger temp., out-
door heat exchanger temp., outdoor air
temp.)
(Broken wire)
30
25
20
15
10
(Short circuit)
135
NO
YES
Replace indoor fan motor
Notes (1) See pages 85 for the fan motor and indoor PCB check pro-
cedure.
(2) After making sure the fan motor and indoor PCB are nor-
mal, connect the connectors and confirm that the fan motor
is turning.
(If power is turned on while one or the other is broken
down, it could cause the other to break down also.)
80
- -
Broken sensor wire,
connector poor connection
5
- 10
0 10 20 30 40
Temperature (˚C)
Defective fan motor, connector poor
connection, defective indoor PCB
50 60 70