Hitachi RAS-5.0UFESMH1 - Page 27

2.TROUBLESHOOTING
Fault
code
Fault description
Possible reasons f or abnormality
How to deal with
Remarks
74
Indoor EEPROM
Data 2 fault
EE in MCU is fails, the unit
can run, but the function user
has set is ineffective.
Replace EE data in MCU.
81
Indoor ambient
Temperature
Sensor Fault
1.
The cable of
the room
temperature sensor is connected
loosely;
2. The room temperatur
e sensor
fails;
3. The sampling circuit is abnormal.
1. Reconnect the cable of the
room temperature sensor;
2. Replace the room temperature
sensor;
3. Replace the indoor control
board.
83
Evaporator Middle
Temperature
Sensor Fault
1.The cable of the coil temperature
sensor of the evaporator fails
;
2.The coil temperature sensor of
the evaporator fails;
3.The sampling circuit is abnormal.
1. Reconnect the cable of the
coil temperature sensor of the
evaporator;
2. Replace the coil
temperature sensor of the
evaporator;
3. Replace the indoor
control board.
FE
(254)
Communication
between main
control board &
Wired controller
Fault (display on
wired controller)
1. The wired controller and the
indoor control board are
connected loosely;
2. The sequence of the wiring
between the wired controller
to th
e indoor control board is
wrong;
3. The wiring between the
wired controller to the indoor
control board fails;
4.
The wired controller fai
ls;
5. The indoor control
board
is abnormal.
1.
2.
Reconnect the wiring between
the wired controller to the
indoor control board;
Replace the wiring between
the wired controller to the
indoor control
board;
3. Replace the wiring between
the wired controller to the
indoor control board;
4. Replace the wired controller;
5. Replace the indoor c
ontrol
board.
ER
Communication
between main
control board
& display board
Fault (displays on
display board)
1.The wiring between the display
board to the indoor control
board is connected loosely;
2.The sequence of the wiring
between the display board to
the
indoor control board is wrong;
3.The wiring between the display
board to the indoor control
board fails;
4.The display board fails;
5.The indoor control board fails.
1. Reconnect the wiring
between the display board
to the indoor control board;
2. Replace the wiring between
the display board to the
indoor control board;
3. Replace the wiring between
the display board to the
indoor control
board;
4. Replace the display board;
5. Replace the indoor control
board.
25