Mitsubishi Electric SRK100VNPZJX, Technical Manual

Page: 407 / 509

-
406
-
'12 • PAC-T-174
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:
LED Green Red
Outdoor control PCB
Outdoor inverter
PCB
1 time flash Keeps flashing
Yellow LED or Red LED Green LED
Indoor control PCB Stays OFF Keeps flashing
Keeps flashing
Content
Keeps flashing
Insufficient refrigerant amount
or detection of service valve