Hitachi RAS-(4-12)HRNM(2)(E) - Decrease of Discharge Gas Superheat for IVX Series

8 Troubleshooting
230
SMGB0064 rev.0 - 08/2011
Alarm code
07
Decrease of Discharge Gas Superheat for IVX Series
• The RUN LED ickers and “ALARM” is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section. The unit
number and the alarm code are displayed on the display of the outdoor unit PCB.
• This alarm code is indicated as follows:
- When the temperature at the top of the compressor is lower than condensing temperature and indoor expansion
valve opening is lower than 300 pulse for 30 minutes in cooling operation, retry operation will be performed once.
When outdoor expansion valve opening is lower than 70 pulse for 30 minutes in heating operation, retry operation
will be performed once. If these occurs again within 120 minutes after the retry, the alarm code will be indicated.
Is the thermistor on top of
compressor normal?
Faulty thermistor
No
Yes
Is the thermistor installed
correctly on the compressor?
Install it correctly
No
Yes
Is it at cooling or heating mode
when the alarm has occurred?
Heating operation
Heating
Cooling
Cooling operation
Check the I.U. expansion valve opening and the
temperature on the top of the compressor by the outdoor
unit PCB.
Check the O.U. expansion valve opening and the
temperature on the top of the compressor by the outdoor
unit PCB.
I.U. expansion
valve opening <300pls
O.U. expansion
valve opening <70pls
Is the temperature on the top of compressor
less than estimated condensation temp.?
Is the temperature on the top of compressor less
than estimated condensation temp.?
Are the connectors for the indoor expansion valve connected properly?
– Connector on I.U. PCB for ex. valve
– Junction connector for ex. valve
Plug the connectors
properly
Is the refrigerant corectly
charged?
Is gas leaking?
Replace fan motor
Charge correct
refrigerant volume.
Check the ex. valve.
Or remove the cause of
discharge air short-circuit
at indoor and outdoor
units.
Repair leaks of gas.
Correctly charge refrigerant.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
I.U.: Indoor Unit
O.U.: Outdoor Unit
Is the outdoor fan normal?