Daikin FTXS20G2V1B - Refrigerant Shortage

SiENBE04-808_A Troubleshooting
Service Diagnosis 140
4.24 Refrigerant Shortage
Remote Control
Display
U0
Method of
Malfunction
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 smaller than the normal value.
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
Decision
Conditions
Refrigerant shortage detection I:
The following conditions continue for 7 minutes.
<20/25/35/42 class>

Input current × input voltage ≤ × output frequency +

Output frequency >
<50 class>

Input current
≤ × output frequency +

Output frequency >
Refrigerant shortage detection II :
The following conditions continue for 80 seconds.

Opening of the electronic expansion valve ≥

Discharge pipe temperature > × target discharge pipe temperature +
(–)
(W) (Hz)
20/25/35 class 640/256 0 55
42 class 3446/256 –346 48
(–) (A) (Hz)
50 class 18/1000 0.7 55
(pulse) (–) (°C)
20/25/35 class 480 128/128 30
42 class 450 128/128 40
50 class 480 128/128 cooling: 20, heating: 45
SiENBE04-808_A.pdf 152 21/02/2011 13:20:03