Hitachi RAS-(3-6)HVRNM2E - Abnormal Transmission between Inverter PCB and Outdoor PCB1 for IVX Series

8 Troubleshooting
218
SMGB0064 rev.0 - 08/2011
Alarm code
04
Abnormal transmission between Inverter PCB and Outdoor PCB1 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 is displayed when the abnormal operation is maintained for 30 seconds after the normal transmission
between the outdoor unit PCB1 and inverter PCB. Also, the abnormal operation is maintained for 30 seconds after
the micro-computer is automatically reset. The alarm is displayed when the abnormal transmission is maintained
for 30 seconds from the starting of the outdoor unit.
Is power fuse for outdoor unit
(EF1 or EF2) normal?
Replace fuse if blown
No
Yes
Note: Investigate the cause of
fuse blown
Disconnect CN6 of PCB1
Is LED2 (green) on PCB1
flashing?
Faulty PCB1
No
Yes
Reconnect CN6 of PCB1
Is LED2 (green) on PCB1
flashing?
Faulty inverter PCB
No
Yes
Disconnecting or
insufficient contact of the
wiring between inverter
PCB and PCB1.
Does flashing speed become
faster than before?
Faulty PCB1
No
Disconnecting or
insufficient contact of the
wiring between inverter
PCB and PCB1.
Yes
Inverter PCB is normal.
Check the wiring again
Faulty inverter PCB
PCB1: Control PCB in outdoor unit
Inverter dipIPM RAS-(3-6)HVRNM(1)E
Inverter ISPM RAS-(4-6)HRNM1E
Inverter IPM RAS (8-12HRNM)