Mitsubishi Electric SRK100VNPZJX, Technical Manual

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E57
1. Applicable model
5. Troubleshooting
All models
Diagnosis Countermeasure
NO
YES
NO
YES
Is the
service valve fully
opened?
Are the
connections of indoor
heat exchanger and/or return air
temperature thermistor
connectors OK?
NO
YES
NO
YES
Are the
characteristics of indoor heat
exchanger and/or return air
temperature thermistor
OK?
Is the low
pressure during operation
normal?
Indoor heat exchanger, return air temperature thermistor
Temperature-resistance characteristics
15
10
5
0 10 30 40 20 50
Temperature thermistor resistance (k
Ω
)
Temperature (°C)
5k
Ω
at 25°C
(Broken wire)
(Short circuit)
Open fully.
Correct indoor heat
exchanger, return air
temperature thermistor
connector connections.
Defective indoor heat
exchanger, return air
temperature thermistor
➞
Replace.
Charge refrigerant.
Defective indoor control
PCB
➞
Replace. (Defective
indoor heat exchanger,
return air temperature
thermistor input circuits)
2. Error detection method
• Judge insufficient refrigerant
amount by detecting the
temperature differnce between
indoor heat exchanger (ThI-R)
and indoor return air (ThI-A).
• 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
thermistor
• Defective indoor return air
temperature thermistor
• Defective indoor control PCB
• Insufficient refregerant
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 (ThI-R) and return air temperature (ThI-A) for 1 minute after compressor ON in
cooling or dehumidifying mode and for 9 minutes after compressor ON in heating mode. [ in cooling mode: (ThI-A)-(ThI-R)>4degC, in
heating mode: (ThI-R)-(ThI-A)<4degC]
Error code
Remote controller:
Content
1 time flash Keeps flashing
Keeps flashing
ON 7 times flash
Indoor display
RUN light TIMER light
Green LED
Yellow LED
Red LED
Outdoor
control PCB
Outdoor
inverter PCB
Insufficient refrigerant amount
or detection of service valve closure
-
450
-
'12 • PAC-T-174