Daikin FTKS20D3VMW, Service Manual

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Control Specification SiENBE12-713
96 Function and Control
3.12 Malfunctions
3.12.1 Sensor Malfunction Detection
Sensor malfunction may occur either in the thermistor or current transformer (CT) system.
Relating to Thermistor Malfunction
1. Outdoor heat exchanger thermistor
2. Discharge pipe thermistor
3. Fin thermistor
4. Gas pipe thermistor
5. Outdoor air temperature thermistor
6. Liquid pipe thermistor
Relating to CT Malfunction
When the output frequency is more than 55 Hz and the input current is less than 0.5A, carry out
abnormal adjustment.
3.12.2 Detection of Overload and Over Current
Outline
In order to protect the inverter, detect an excessive output current, and for protecting
compressor, monitor the OL operation.
Detail
$
If the OL (compressor head) temperature exceeds 130°C (2YC45), the compressor
gets interrupted.
3.12.3 Insufficient Gas Control
Outline
If a power consumption is below the specified value in which the frequency is higher than the
specified frequency, it must be regarded as gas insufficient.
In addition to such conventional function, if the discharge temperature is higher than the target
discharge pipe temperature, and more than the specified temperature, and the electronic
expansion valve is fully open (450 pulses) more than the specified time, it is considered as an
insufficient gas.
With the conventional function, a power consumption is weak comparing with that in the normal
operation when gas is insufficient, and gas insufficiency is detected by checking a power
consumption.
When operating with insufficient gas, although the rise of discharge pipe temperature is great
and the electronic expansion valve is open, it is presumed as an insufficient gas if the discharge
pipe temperature is higher than the target discharge pipe temperature.
Frequency
Power consumption
Insufficient gas zone
55 Hz
(R6960)
(R1391)
Gas insufficient
zone