Daikin FTXS30HVJU, Service Manual

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Troubleshooting SiUS04-924
102 Service Diagnosis
4.23 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 :
DC current

(A/Hz) Output fre
However, when the status of running frequency > 40 (Hz) is kept on for a certain time.
Note : The values are different from model to model.
Gas shortage detection II :
Electronic expansion valve opening
 
(pulse)
Discharge pipe temperature(°C)

target discharge pipe temperature(°C) + (°C)
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
30/36 class 27 / 1000 2
30/36 class 480 128/128 Cooling: 50, Heating: 45