Mitsubishi SRK50ZHX-S Technical Manual page 44

(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
Temperature (˚C) Resistance (kΩ)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
Indoor fan motor error
Is connector connection good?
YES
* Disconnect the fan motor
connector, then investigate
the DC fan motor and indoor
unit circuit board separately.
Is the output of the indoor unit's
printed circuit board normal?
YES
Normal
NO
NO
Temperature (˚C) Resistance (kΩ)
164 70
127 75
99 80
78 85
62 90
50 95
40 100
32 105
26 110
21 115
17 120
14 125
12 130
10 135
NO
Correct connector connection
Is DC fan motor resistance value good?
NO
Defective indoor PCB
Correct connection.
Replace sensor.
◆ Sensor temperature characteristics
8.7
7.3
6.2
5.3
(Broken wire)
4.5
3.9
3.3
2.9
2.5
2.2
1.9
(Shortcircuit)
1.6
1.4
1.3
YES
Replace indoor fan motor
Notes (1) See pages 45 for the DC fan motor and indoor unit circuit
(2) After making sure the DC fan motor and indoor unit circuit
41
- -
[Broken sensor wire,
connector poor connection]
(Room temp., indoor unit heat exchanger
temp., outdoor unit heat exchanger
temp., outdoor air temp.)
3 0
2 5
2 0
1 5
1 0
5
– 1 0 0 1 0 2 0 3 0
Temperature (˚C)
[Defective fan motor, connector
poor connection, defective PCB]
NO
board check procedure.
board are normal, 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.)
4 0 5 0 6 0 7 0