Refrigerant Shortage - Daikin J Series Service Manual

Troubleshooting

4.24 Refrigerant Shortage

U0
Remote
Controller
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:
The following conditions continue for 7 minutes.
Decision
Conditions
<20/25/35/42 class>
20/25/35 class
42 class
<50 class>
50 class
Refrigerant shortage detection II :
The following conditions continue for 80 seconds.
20/25/35 class
42 class
50 class
117
Input current × input voltage
Output frequency > C
A
(–)
640/256
3446/256
≤
Input current D × output frequency + E
Output frequency > F
D
(–)
18/1000
Opening of the electronic expansion valve ≥ G
Discharge pipe temperature > H × target discharge pipe temperature + J
G (pulse)
480
450
480
≤
A × output frequency + B
B (W) C (Hz)
0
–346
E F
(A)
0.7
H (–)
128/128
128/128
128/128 cooling: 20, heating: 45
55
48
(Hz)
55
J (°C)
30
40
Service Diagnosis
SiBE041101