
10 Troubleshooting
Troubleshooting procedure
SMGB0091 rev.2 - 11/2015
215
10
Alarm code
07
Decrease of discharge gas superheat
• When the temperature at the top of compressor remains lower than the condensing temperature during 30
continuous minutes, the compressor stops and performs a retry operation 3 minutes later. If this occurs 2 more times
within 120 minutes, an alarm code is shown.
• This alarm code is indicated in situations such as damaged compressor due to lock shaft, when the detection of
synchronism loss is not possible.
No
Faulty thermistor
Yes
Yes
Heating
No
Is the thermistor on top of
compressor normal?
Install it correctly
Heating operation
Cooling
Cooling operation
Check the IU expansion valve opening and
the temperature on the top of compressor by
the RASC unit PCB.
Plug the
connectors
properly
No
Replace RASC fan
motor
Charge correct
refrigerant volume
No
No
Repair leaks of gas.
Correctly charge refrigerant.
Check the expansion
valve or remove the
cause of discharge air
short-circuit at indoor
and RASC units.
Is the thermistor
installed correctly on the
compressor?
Is it at cooling or
heating mode when the
alarm has occurred?
Indoor unit
expansion valve opening
lower than 300 pulses?
Yes
Check the OU expansion valve opening and
the temperature on the top of compressor by
the RASC unit PCB.
RASC unit
expansion valve opening
lower than 70 pulses?
Yes
No
No
Yes
Yes
No
No
Is the temperature
on the top of compressor
less than estimated condensation
temperature?
Is the temperature
on the top of compressor
less than estimated condensation
temperature?
Are the connectors for the
indoor expansion valve connected
properly?
- Connector on IU PCB for expansion valve
- Junction connector for expansion
valve
No
Yes
Is the RASC fan
motor normal? (*2)
Yes
Is the refrigerant
correctly charged?
Yes
Is gas leaking?
Yes