Daikin FTKD50BVM, Service Manual

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Troubleshooting Si04-306
120 Service Diagnosis
4.19 Insufficient Gas
Remote
Controller
Display
U0
Method of
Malfunction
Detection Gas shortage detection I : A gas shortage is detected by checking the CT-detected input current
value and the compressor running frequency.
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
Decision
Conditions Gas shortage detection I :
Input current <
(A/Hz) x Compressor running frequency × V
However, when the status of running frequency > 55 (Hz) is kept on for a certain time.
Note : The values are different from model to model.
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
„
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
R410A 1756 / 256 –50
R22 2600 / 256 –300
RXD71BVMA 2420 / 256 55