Hitachi RAS-(3-6)HVRNM2E - Abnormal Operation of Thermistor for Fresh Outdoor Air (Econofresh)

8 Troubleshooting
239
SMGB0064 rev.0 - 08/2011
8
Alarm code
15
Abnormal operation of thermistor for fresh outdoor air (Econofresh)
• 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 displayed when the thermistor is short-circuited (less than 0.24 kΩ) or cut (greater than 840 kΩ)
during the cooling process or the heating process. The system is automatically restarted when the fault is removed.
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
Faulty fresh outdoor air (Econof-
resh) thermistor
Fault Check the resistance Replace the thermistor if faulty
Incorrect connection Check the connection
Repair the wiring and the connec-
tions
Faulty PCB
Replace PCB and
check the operation
Replace PCB if faulty
N O T E
• This data is applicable to the following thermistors:
- Indoor unit discharge air temperature
- Indoor unit liquid refrigerant temperature
- Indoor unit air inlet temperature
- Outdoor temperature
- Outdoor unit evaporating temperature
- Indoor unit gas piping