Insufficient Gas - Daikin FTKS20D3VMW Service Manual

SiENBE12-713

5.25 Insufficient Gas

U0
Remote Control
Display
Outdoor Unit LED
A
Display
Method of Gas shortage detection I:
Malfunction Gas shortage is detected by checking the input current value and the compressor running
frequency. If the gas is short, the input current is smaller than the normal value.
Detection
Gas shortage detection II:
Gas shortage is detected by checking the discharge temperature and the opening of the
electronic expansion valve. If the gas is short, the discharge temperature tends to rise.
Malfunction
Gas shortage detection I (typical value):
Decision The following conditions continue for 7 minutes.
$ DC current
Conditions
$ Output frequency > 55 (Hz)
Gas shortage detection II:
The following conditions continue for 80 seconds.
$ Target opening of the electronic expansion valve ≥ 450 (pulse)
$ Cooling: discharge temperature > 255 / 256 × target discharge temperature +20 (°C)
If a gas shortage error takes place 4 times straight, 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).
" Refrigerant shortage (refrigerant leakage)
Supposed
" Poor compression performance of compressor
Causes
" Discharge pipe thermistor disconnected, or indoor unit or outdoor unit heat exchanger
" Stop valve closed
" Electronic expansion valve defective
Service Diagnosis
5 1 1 2 1 3 4 4
≤
0.035 × output frequency + 0.5
Heating: discharge temperature > 255 / 256 × target discharge temperature +40 (°C)
thermistor disconnected, room or outside air temperature thermistor disconnected
4
Troubleshooting
271