Hitachi FSXN Series Service Manual page 221

8 Troubleshooting
3d
Alarm code
• The RUN indicator flashes and the ALARM indication is displayed on the remote control switch.
• The unit no., the alarm code and the unit code are alternatively displayed in the temperature setting section and the unit
no. and alarm code are displayed on the outdoor unit's PCB1 display.
* This alarm is indicated when the transmission to outdoor unit B or C is not maintained for thirty seconds ( alarm code
"31" will be indicated when the transmission to all the outdoor units connected to transmission terminal of the O.U. -
O.U. is not maintained).
Is LED1 turned ON on PCB1
of outdoor unit B and C?
Y es
Is operating line between
outdoor unit and outdoor unit
loosened or disconnected?
No
(Sub): Secondary unit(s).
215
SMGB0065 rev. 1 - 12/2010
Abnormal transmission between the main unit and the secondary unit(s).
No
Check the power supply
of outdoor unit.
Good
Is fuse of outdoor unit
PCB1 blown out?
No
Y es
PCB1: Control PCB in Outdoor Unit
O.U.: Outdoor Unit
Faulty
Turn ON the power supply.
Y es
Inspect the cause and
replace the fuse.
Replace the PCB1 of
outdoor unit B or C.
Correctly connect the
operating line between
outdoor unit and outdoor
unit. Also, reset
the power supply.
Replace the PCB1 of
outdoor unit B or C.
Outdoor Unit
Unit A Unit B
(Main) (Sub)
Unit C
(Sub)
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