Mitsubishi Heavy Industries FDT100VNAWVH Service Manual page 172

Error code
Indoor display
Remote control:
E57
Outdoor unit
1. Applicable model
All models
2. Error detection method
• Judge insufficient refrigerant
amount by detecting the
temperature differnce between
indoor heat exchanger (Th2)
and indoor room (Th1).
• It detects at initial startup in
cooling or dehumidifying
mode after power ON.
3. Condition of error displayed
Anomalous stop at initial
detection
4. Presumable cause
• Defective indoor heat
exchanger temperature sensor
• Defective indoor room
temperature sensor
• Defective indoor unit main
PCB
• Insufficient refrigerant amount
Note: Insufficient refrigerant amount preventive control makes compressor stopped, if it judges insufficient refrigerant amount by detecting the
temperature difference between indoor heat exchanger (Th2) and room temperature (Th1) for 1 minute after compressor ON in cooling or
dehumidifying mode and for 9 minutes after compressor ON in heating mode. [ in cooling mode: (Th1)-(Th2)>4degC, in heating mode:
(Th2)-(Th1)<4degC]
RUN light
7-time flash
Green LED
control PCB
Keeps flashing
5. Troubleshooting
service valve fully
connections of indoor
heat exchanger and/or room
temperature sensor
characteristics of indoor heat
exchanger and/or room
temperature sensor
pressure during operation
Indoor heat exchanger, room temperature sensor
Temperature-resistance characteristics
(Broken wire)
(Short-circuit)
TIMER light
Content
ON
Insufficient refrigerant amount
or detection of service valve closure
Red LED
1-time flash
Diagnosis
Is the
opened?
YES
Are the
connectors OK?
YES
Are the
OK?
YES
Is the low
normal?
15
10
5k at 25°C
5
0 10 20 30 40 50
Temperature (°C)
171
- -
'19 • PAC-SM-309
Countermeasure
Open fully.
NO
Correct indoor heat
NO
exchanger, room
temperature sensor
connector connections.
Defective indoor
NO
heat exchanger, room
temperature sensor ➞
Replace.
Charge refrigerant.
NO
Defective indoor unit
YES
control PCB ➞ Replace.
(Defective indoor
heat exchanger, room
temperature sensor input
circuits)