Refrigerant Shortage - Daikin FTXM-K Series Service Manual

Troubleshooting
4.6

Refrigerant Shortage

U0
Error Code
Method of Error 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.
Detection
Error Decision The following conditions continue for 7 minutes.
Conditions
20/25/35 class
42/50 class
Supposed
Causes
69
Input current × input voltage
Output frequency > C
A
(constant)
640/256
2813/256
If the error repeats, the system is shut down.
Reset condition: Continuous run for about 60 minutes without any other error
Disconnection of the discharge pipe thermistor, indoor or outdoor heat exchanger thermistor,
room or outdoor temperature thermistor
Closed stop valve
Refrigerant shortage (refrigerant leakage)
Poor compression performance of compressor
Defective electronic expansion valve
≤
A × output frequency + B
B (W) C (Hz)
0
50
SiBE041434E
55
50
Service Diagnosis