Hitachi RAS-3.0TNESNH1 - Page 25

2
2
.
.
T
T
R
R
O
O
U
U
B
B
L
L
E
E
S
S
H
H
O
O
O
O
T
T
I
I
N
N
G
G
Fault
code
Fault Description Possible Reason of Abnormality How to Deal With Remarks
7
The
communication
fault between the
indoor unit and
outdoor unit
1.The connection cable connect wrong
between the indoor unit and outdoor
unit;
2.The communication cable connect
loose;
3.The communication cable is fault;
4.The indoor control board is fault;
5.The outdoor control board is fault;
6.Communication circuit fuse open;
7.The specification of communication
cable is incorrect.
1.Reconnect the connection cable refer
to the wiring diagram;
2.Reconnect the communication cable;
3.Replace the communication cable;
4.Replace the indoor control board;
5.Replace the outdoor control board;
6.Check the communication circuit,
adjust the DIP switch and the
short-circuit fuse.
7.Choose suitable communication cable
refer to the user manual
12
voltage absent
phase
1.Three-phase power is abnormal;
2.The outdoor wiring connect wrong;
3.The outdoor control board is failure.
1. Normally protection
2. Check the wiring connection refer 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
connect loose.
2. The overload protector is failure .
3. The refrigerant is not enough;
4. The installation pipe is too long than
normal, but not add the enough
refrigerant;
5. The expansion valve is failure;
6. The outdoor control board is failure
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 operate or
the unit turn off for
high pressure
protection
1.The wiring of the high pressure
protector connect loose;
2.The high pressure protector is failure;
3.The outdoor control board is abnormal;
4. Overload in cooling;
5. Overload in heating.
1.Reconnect the wiring the high
pressure protector;
2. Replace the high pressure protector;
3. Replace the outdoor control board;
4. Please refer to the Note 3;
5. Please refer to the Note 4.
Applied to
models
with high
pressure
switch or
pressure
sensor
15
the low pressure
switch protection
or the unit turn off
for low pressure
protection
1.The wiring of the low pressure switch
connect loose ;
2.The low pressure switch is failure;
3.The refrigerant is not enough;
4.The expansion valve failure in heating
mode;
5.The outdoor control board is abnormal.
1. Reconnect the wiring of the low
pressure switch;
2. Replace the low pressure switch;
3.Check the welding point to confirm
whether the unit is leakage, 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 the Note 3.
17
Discharge
temperature
sensor fault
1.The wiring of the discharge
temperature sensor connect loose;
2.The discharge temperature sensor is
failure;
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.
22