Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 36

1102 (U2): Compressor temperature trouble
Abnormal points and detection methods
• TH4 falls into either of the following temperature condi-
tions:
- over 230°F (110°C) continuously for 5 minutes
- over 257°F (125°C)
• The saturation temperature converted from the pressure
detected by the high pressure sensor exceeds 104°F
(40°C) during defrosting, and TH4 exceeds 230°F
(110°C)
TH4:
Thermistor <Compressor>
LEV:
Linear expansion valve
Diagnosis of failure
Is the error code 5101 displayed when
restarted?
Is the outdoor stop valve (liquid/gas)
fully open?
Is there refrigerant leak?
Check the connection for thermistor wiring and
indoor controller board connector.
Is there any abnormality on connec-
tors/wires such as disconnection,
half-disconnection or breakage?
Continue to the next page.
OCH800A_36
Yes
(5101)
No
(1102)
No
Yes
Yes
No
Yes
No
Causes and checkpoints
• Malfunction of stop valve
• Over-heated compressor operation caused by shortage
of refrigerant
• Defective thermistor
• Defective outdoor multi controller circuit board
• LEV performance failure
• Defective indoor controller board
• Clogged refrigerant system caused by foreign object
• Refrigerant shortage (Refrigerant liquid accumulation in
compressor while indoor unit is OFF/thermo-OFF.)
Refer to the diagnosis of error code 5101.
Open the stop valve (liquid/gas) fully.
Repair the refrigerant leakage.
Connect the connector properly
(Repair or replace it in the case of breakage).
Chart 1 of 2