Mitsubishi Electric SRK100VNPZJX, Technical Manual

Page: 434 / 509

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E28
Remote controller
temperature thermistor anomaly
– –
Keeps flashing Stays OFF
1. Applicable model
5. Troubleshooting
All models
Diagnosis Countermeasure
Correct.
Defective remote controller
temperature thermistor
➞
Replace.
Defective remote controller
PCB
➞
Replace.
(Defective remote
controller temperature
thermistor input circuit)
2. Error detection method
Detection of anomalously low
temperature (resistance) of
remote controller temperature
thermistor (Thc)
3. Condition of Error displayed
When the temperature
thermistor detects -50°C
or lower for 5 seconds
continuously, the compressor
stops. After 3-minutes delay,
the compressor starts again
automatically, but if this error
occurs again within 60 minutes
after the initial detection.
4. Presumable cause
• Faulty connection of remote
controller temperature
thermistor
• Defective remote controller
temperature thermistor
• Defective remote controller
PCB
Note:
After 10 seconds has passed since remote controller thermistor was switched from valid to invalid, E28 will not be displayed even if the
thermistor harness is disconnected. At same time the thermistor, which is effective, is switched from remote controller thermistor to indoor return
air temperature thermistor. Even though the remote controller thermistor is set to be Effective, the return air temperature displayed on remote
controller for checking still shows the value detected by indoor return air temperature thermistor, not by remote controller temperature thermistor.
NO
YES
NO
YES
Is the remote
controller temperature thermistor
connected properly?
Are the
characteristics of
remote controller temperature
thermistor OK?
Is the thermistor wire
OK?
Resistance-temperature characteristics of remote controller temperature thermistor (ThC)
0
1
2
4
6
8
10
12
Temperature (°C)
65
62
59
53
48
44
40
36
14
16
18
20
22
24
26
28 33
30
27
25
23
21
19
18
30
32
34
36
38
40
42
44 16
15
14
13
12
11
9.9
9.2
46
48
50
52
54
56
58
60 8.5
7.8
7.3
6.7
6.3
5.8
5.4
5.0
Resistance value (k
Ω
) Temperature (°C) Resistance value (k
Ω
)
NO
YES
NO
YES
Is the remote
controller temperature thermistor
connected properly?
Are the
characteristics of
remote controller temperature
thermistor OK?
Is the thermistor wire
OK?
Resistance-temperature characteristics of remote controller temperature thermistor (ThC)
0
1
2
4
6
8
10
12
Temperature (°C)
65
62
59
53
48
44
40
36
14
16
18
20
22
24
26
28 33
30
27
25
23
21
19
18
30
32
34
36
38
40
42
44 16
15
14
13
12
11
9.9
9.2
46
48
50
52
54
56
58
60 8.5
7.8
7.3
6.7
6.3
5.8
5.4
5.0
Resistance value (k
Ω
) Temperature (°C) Resistance value (k
Ω
)
Error code
Remote controller:
Indoor
display
RUN light TIMER light
Green LED Red LED
Outdoor
control PCB
Content
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'12 • PAC-T-174