E39 Discharge Pipe Temperature Thermistor Anomaly - Mitsubishi Electric FDT125VNVF Technical Manual

Error code
Indoor control PCB
E39
Remote controller:
Outdoor control PCB
Outdoor inverter
1. Applicable model
All models
2. Error detection method
Detection of anomalously low
temperature (resistance) on
the discharge pipe temperature
thermistor
3. Condition of Error displayed
When the temperature thermistor
detects -10°C or lower for 5
seconds continuously within
10 minutes to 10 minutes 20
seconds after the compressor
ON, the compressor stops. After
3-minutes delay, the compressor
starts again automatically, but
if this anomalous temperature
is detected 3 times within 40
minutes.
4. Presumable cause
• Defective outdoor control
PCB
• Broken thermistor harness or
temperature sensing section
(Check molding.)
• Disconnected wire connection
(connector)
Note:
LED Green
Keeps flashing
Keeps flashing
Yellow LED or Red LED Green LED
PCB
Keeps flashing
5. Troubleshooting
Is the
discharge pipe
temperature thermistor
connector connected
properly?
YES
Are the
characteristics
of discharge pipe
temperature
thermistor
OK?
Temperature-resistance characteristics
(Broken wire)
200
100
温 180
〔T 80 〕
度
160
T 80
セ
140
ン
サ 120
抵
100
50
抗
80
60
(k)
40
20
0
0
0 20
0
(Short circuit)
Red
Content
Stays OFF
1 time flash
temperature thermistor anomaly
Keeps flashing
Diagnosis
NO
For the characteristics of discharge pipe
temperature thermistor, see the following graph.
NO
YES
10
〔T 80 〕
T 80
5
0
40 60 80 100 120 140
50 80 100
温 度〔 Ｔ〕 （ ）
Temperature (°C)
392
- -
'12 • PAC-T-174
Discharge pipe
Countermeasure
Correct connector.
Defective discharge pipe
temperature thermistor ➞
Replace.
Defective outdoor control
PCB ➞ Replace.
(Defective temperature
thermistor input circuit)
温
度
セ
ン
サ
抵
抗
(k)
160