3.12 Malfunctions - Daikin D Series Service Manual

Control Specification

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 thermistor
6. Liquid pipe thermistor
Relating to CT Malfunction
When the output frequency is more than 68 Hz and the input current is less than 1.25A, 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
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 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.
Detail Judgment by Input Current
When an output frequency is exceeds 61 Hz and the input current is less than specified value,
the adjustment is made for insufficient gas.
Judgment by Discharge Pipe Temperature
When discharge pipe temperature is 20°C higher than target value and the electronic expansion
value opening is 450 plus (max.), the adjustment is made for insufficient gas.
66
If the OL (compressor head) temperature exceeds 120~130°C (depending on the
model), the compressor gets interrupted.
If the inverter current exceeds 22 A, the compressor gets interrupted too.
Insufficient gas zone
61 Hz Frequency
(R3037)
Gas insufficient
zone
(R1391)
SiBE12-519
Function and Control