Hitachi RAS-3.5UFESNH1 - Page 24

2.TROUBLESHOOTING
Fault
code
Fault description
Possible reasons for abnormality
How to deal with Remarks
12
Voltage absent phase
Three-phase power is abnormal;
The outdoor wiring is connected
improperly;
The outdoor control board fails.
1. Normal protection;
2. Check the wiring connection
referring to the wiring diagram;
3. Replace the outdoor control
board.
Application of
three-phase
power supply
models
13
Compressor overheat
protector device
1. The wiring of the overload
protector is connected loosely;
2. The overload protector fails;
3. The refrigerant is not enough;
4. The installation pipe is much
longer
than the normal one, but
extra refrigerant is not added;
5. The expansion v
alve fails;
6. The outdoor control board fails.
1. Reconnect the wiring of the
overload protector;
2. Replace the overload
protector;
3. Check the welding point of the
unit to confirm whether it is
leakage, and then recharge
the refrigerant;
4. Add the refrigerant;
5. Replace expansion valve;
6. Replace the outdoor control
board.
14
The high pressure
switch operation or
the unit is turned off
for high pressure
protection
1.
2.
The wiring of the high pressure
protector is connected loosely;
The high pressure protector
fails;
3.The outdoor control board is
abnormal;
4. Overload in cooling;
5. Overload in heating.
1.
2.
Reconnect the wiring of the
high pressure protector;
Replace the high pressure
protector;
3. Replace the outdoor control
board;
4.
Please refer to NOTE 3;
5.
Please refer to NOTE 4.
Applied to
models with
high
pressure
switch or
pressure
sensor
15
The low pressure
switch protection or
the unit is turned off
for low pressure
protection
1. The wiring of the low pressure
switch is connected loosely;
2. The low pre
ssure switch fails;
3. The refrigerant is not enough;
4. The expansion valve fails in
heating mode;
5. The outdoor control board is
abnormal.
1. Reconnect the wiring of the
low pr
essure s
witch;
2. Repl
ace the low pressure
switch;
3. Check
the weldi
ng po
int to
confirm whethe
r
the
unit leaks
,
and then add some refrigerant;
4. Replace the expansion valve;
5. Replace the outdoor control
board.
Applied to
models with
low pressure
switch or
pressure
sensor
16
Overload protection
in cooling mode
System overload
Please refer to NOTE 3.
17
Discharge
temperature sensor
fault
1.The wiring of the discharge tempe-
rature sensor is connected loosely;
3.The sampling circuit is abnormal.
1.Reconnect the wiring of the
discharge temperature sensor;
2. Replace the discharge
temperature sensor;
3.Replace the outdoor control
board.
18
AC voltage is
abnormal
1.The AC voltage>275V or <160V;
2.The AC voltage of sampling circuit
on the driver board is abnormal.
1. Normal protection, please
check the supply power;
2. Replace the driver board.
19
Suction temperature
sensor fault
1.The wiring of the suction tempe-
rature sensor is connected loose
ly;
2.The suction temperature sensor
fails;
3.The sampling circuit is abnormal.
1.Reconnect the wiring of the
suction temperature sensor;
2.Replace the suction
temperature sensor;
3.Replace the outdoor control
board.
22
The defrosting sensor
fault
1.The wiring of the defrosting sensor
is connected loosely;
2.The defrosting sensor fail
s;
3.The sampling circuit is abnormal.
1. Reconnect the wiring of the
defrosting sensor;
2. Replace the defrosting sensor;
3. Replace the outdoor control
board.
45 IPM fault
There are many reasons for this
failure. You can check the driver
board fault LED to further a
nalyze
the fault code of the drive board and
to learn about what leads to the fault
and how to operate it. Specific
information can be seen in table 5,
table 6.
See attached "analysis of the
driving board fault".
22
2. The discharge temperature sensor
fails;