Hitachi RAS-18FSXN - Page 188

Alarm code
04.
Abnormal transmission between the fan controller and the outdoor unit PCB.
• 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 an anomaly is maintained for 30 seconds after the normal transmission between PCB1
of the outdoor unit and the fan controller, and also if the anomaly is maintained for 30 seconds after the microcomputer
is automatically reset. The alarm is indicated when abnormal transmission is maintained for 30 seconds after the outdoor
unit is turned on.
PCB1: Control PCB in Outdoor Unit
PCB2: Inverter PCB
Yes
Disconnect CN14
of PCB1.
Check the wiring
between PCB1, PCB2
and Fan Controller.
Check
Fan Controller. *1)
Faulty PCB1.
No
Is LED2 (green) on
PCB1 flashing?
Yes
No
Is LED2 (green) on
PCB1 flashing?
Check Fan Controller.
<Outdoor Unit PCB1 Display Indication>
Abnormal Transmitting
of Fan Controller
Cause Check Item
Action
(Turn OFF Main Switch)
Phenomenon
Check continuity.
Check for looseness
of connection screws.
Replacing Wires,
Repairing and
Tightening Screws
Check connection Nos.
Correctly Connect
Wires
Check connections.
Repair wiring
connections.
Replace PCB if faulty.
Replace
fan controller. *1)
Replace power fuse,
power transistor, and
diode module.
Replace incoming
current limit resistance.
Between PCB1, PCB2
and Fan Controller
Disconnected
Wires, Insufficient
Contacting or
Incorrect
Connection
Check continuity of
wires.
Check for looseness
of connection screws.
Check connection No.
Replacing wires,
repairing, tightening
screws and incorrect
wiring.
Power Source Wiring
for Outdoor Unit
Disconnected Wires
to PCB
Faulty PCB
Melted Fuse
(Fan Controller)
Melted Power Fuse
Disconnected
Incoming Current Limit
Resistance
Check conductivity
of fuse.
Check conductivity
of power fuse, power
transistor, diode module.
Check resistance of
incoming current limit
resistance.
Disconnected Wires
Insufficient Contacting
Incorrect Wiring
Incorrect Wiring
Faulty PCB
PCB1 and PCB2
Fan Controller
Faulty Electrical
Components
Power Fuse,
Resistance
e
*1): The fan controller may be damaged if the fan controller fuse is blown. If so, replace the fan controller.
8 Troubleshooting
182
SMGB0065 rev. 1 - 12/2010