Insufficient Gas - Daikin B-Series Service Manual

Si04-306E

4.20 Insufficient Gas

U0
Remote
Controller
Display
Method of Gas shortage detection I :
Malfunction A gas shortage is detected by checking the CT-detected input current value and the compressor
running frequency.
Detection
Gas shortage detection II :
A gas shortage is detected by checking the difference between indoor unit heat exchanger
temperature and room temperature as well as the difference between outdoor unit heat
exchanger temperature and room temperature.
Malfunction Gas shortage detection I :
DC current × DC voltage <
Decision
However, when the status of running frequency > 55 (Hz) is kept on for a certain time.
Conditions
Note : The values are different from model to model.
R-410A
R-22
2YC63
Gas shortage detection II :
If a gas shortage error takes place 4 times successively, the system will be shut down. The error
counter will reset itself if this or any other error does not occur during the following 60-minute
compressor running time (total time).
Supposed
Causes
Service Diagnosis
1756 / 256
2600 / 256
2420 / 256
Refrigerant shortage (refrigerant leakage)
Poor compression performance of compressor
Discharge pipe thermistor disconnected, or indoor unit or outdoor unit heat exchanger
thermistor disconnected, room or outside air temperature thermistor disconnected
Stop valve closed
Electronic expansion valve defective
(A/Hz) × Compressor running frequency +
–50
–300
55
Troubleshooting
139