SiBE041012_B
Troubleshooting
Service Diagnosis
75
4.7
Refrigerant Shortage
Error Code
U0
Method of Error
Detection
Refrigerant shortage detection I:
Refrigerant shortage is detected by checking the input current value and the compressor
running frequency. If the refrigerant is short, the input current is lower than the normal value.
Refrigerant shortage detection II:
Refrigerant shortage is detected by checking the discharge pipe temperature and the opening of
the outdoor electronic expansion valve. If the refrigerant is short, the discharge pipe
temperature tends to rise.
Refrigerant shortage detection III:
Refrigerant shortage is detected by checking the difference between suction and discharge
temperature.
Error Decision
Conditions
Refrigerant shortage detection I:
The following conditions continue for 7 minutes.
<25/35 class, RXG50K3V1B>
Input current × input voltage
≤
A
× output fre
B
Output frequency >
C
<RXG50K2V1B>
Input current
≤
D
× output fre
E
Output frequency >
F
Refrigerant shortage detection II:
The following conditions continue for 80 seconds.
Opening of the outdoor electronic expansion valve
≥
G
Discharge pipe temperature >
H
× target discharge pipe tempe
J
A
(–)
B
(W)
C
(Hz)
25/35 class
640/256
0
55
RXG50K3V1B
2000/256
–181
55
D
(–)
E
(A)
F
(Hz)
RXG50K2V1B
18/1000
0.7
55
G
(pulse)
H
(–)
J
(°C)
25/35 class
480
128/128
30
RXG50K2V1B
480
128/128
cooling: 20, heating: 45
RXG50K3V1B
480
128/128
cooling: 60, heating: 45
