Refrigerant Shortage - Daikin FVXG25K2V1B Service Manual

SiBE061121_A
4.7

Refrigerant Shortage

U0
Error Code
Method of Error Refrigerant shortage detection I:
Refrigerant shortage is detected by checking the input current value and the compressor
Detection
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 Refrigerant shortage detection I:
The following conditions continue for 7 minutes.
Conditions
<25/35 class, RXG50K3V1B>
25/35 class
RXG50K3V1B
<RXG50K2V1B>
RXG50K2V1B
Refrigerant shortage detection II:
The following conditions continue for 80 seconds.
25/35 class
RXG50K2V1B
RXG50K3V1B
Service Diagnosis
Input current × input voltage
Output frequency > C
A
(–)
640/256
2000/256
≤
Input current D × output frequency + E
Output frequency > F
D
(–)
18/1000
Opening of the outdoor electronic expansion valve ≥ G
Discharge pipe temperature > H × target discharge pipe temperature + J
G (pulse)
480
480
480
≤
A × output frequency + B
B (W) C (Hz)
0
–181
E F
(A)
0.7
H (–)
128/128
128/128 cooling: 20, heating: 45
128/128 cooling: 60, heating: 45
Troubleshooting
55
55
(Hz)
55
J (°C)
30
71