Sensor Error - Mitsubishi Heavy Industries SRK50HE-S1 Technical Manual

(f) 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
Correct connection.
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
Replace indoor PCB
Replace sensor.
◆ Sensor temperature characteristics
(Room temp., indoor unit heat exchanger
temp., outdoor unit heat exchanger
temp., outdoor air temp.)
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
NO
YES
Replace indoor fan motor
Notes (1) See pages 208, 209 for the DC fan motor and indoor unit
(2) After making sure the DC fan motor and indoor unit circuit
206
- -
[Broken sensor wire,
connector poor connection]
30
25
20
15
10
5
–10 0 10 20 30
Temperature (˚C)
[Defective fan motor, connector
poor connection, defective PCB]
circuit 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.)
40 50 60 70