Refrigerant Shortage - Daikin FTXL20G2V1B Service Manual

Troubleshooting

4.24 Refrigerant Shortage

U0
Remote Control
Display
Method of Refrigerant shortage detection I:
Malfunction Refrigerant shortage is detected by checking the input current value and the compressor
running frequency. If the refrigerant is short, the input current is smaller than the normal value.
Detection
Refrigerant shortage detection II:
Refrigerant shortage is detected by checking the discharge pipe temperature and the opening of
the 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.
Malfunction
Refrigerant shortage detection I:
Decision The following conditions continue for 7 minutes.
Conditions
<20/25 class>
Š Input current × input voltage
Š Output frequency >
20 class
25 class
<35 class>
Š Input current
Š Output frequency >
35 class
Refrigerant shortage detection II :
The following conditions continue for 80 seconds.
Š Opening of the electronic expansion valve ≥
Š Discharge pipe temperature >
20 class
25 class
35 class
112
≤
× output frequency +
(–) (W)
640/256 0
3446/256 –346
≤
× output frequency +
(–) (A)
18/1000 0.7
× target discharge pipe temperature +
(pulse) (–)
480 128/128
450 128/128
480 128/128
SiENBE04-925_A
(Hz)
55
48
(Hz)
55
(°C)
30
40
cooling: 20, heating: 45
Service Diagnosis