Hitachi RWM-(H)FSN3E, Service Manual

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12 Troubleshooting
SMGB0070 rev. 1 - 08/2011
339
12
Alarm code
04
Abnormal transmission between Inverter PCB2 and outdoor PCB1
(RAS-(8-10)HRNME-AF)
• The RUN LED flickers 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 PCB2. 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.
Replace fuse if blown
No
Faulty PCB1
Disconnect CN6 of PCB1
Reconnect CN6 of PCB1
PCB2 is normal.
Check the wiring again
Disconnecting or
insufficient contact of
the wiring between
PCB2 and PCB1.
Faulty PCB2
Faulty PCB1
Disconnecting or
insufficient contact of
the wiring between
PCB2 and PCB1.
Faulty PCB2
Yes
No
Yes
No
No
Yes
Yes
N O T E
Investigate the cause of fuse blown
Is power fuse for
outdoor unit (EF1 or
EF2) normal?
Is LED2 (green)
on PCB1 flashing?
Is LED2 (green)
on PCB1 flashing?
Does flashing
speed become faster
than before?
PCB1: Control PCB in outdoor unit
PCB2: Inverter PCB
Inverter IPM RAS-(8-10)HRNME-AF