Daikin FTKB09AXVJU - Page 38

Algorithm & Control
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2.24.1 Initial Frequency
Whenstartingthecompressor,thefrequencyisinitializedaccordingtothe∆Dvalueoftheindoorunit.
<∆Dsignal:Indoorfrequencycommands>
Thedifferencebetweentheroomthermistortemperatureandthetargettemperatureisrecognizedasthe∆D
signal and is used for frequency command.
Temperature
difference
∆D
signal
Temperature
difference
∆D
signal
Temperature
difference
∆D
signal
Temperature
difference
∆D
signal
-2.0°C(-3.6°F) *OFF 0°C(0°F) 4 2.0°C(3.6°F) 8 4.0°C(7.2°F) C
-1.5°C(-2.7°F) 1 0.5°C(0.9°F) 5 2.5°C(4.5°F) 9 4.5°C(8.1°F) D
-1.0°C(-1.8°F) 2 1.0°C(1.8°F) 6 3.0°C(5.4°F) A 5.0°C(9.0°F) E
-0.5°C(-0.9°F) 3 1.5°C(2.7°F) 7 3.5°C(6.3°F) B 5.5°C(9.9°F) F
*OFF = Thermostat OFF
2.24.2 PI Control
1. P control
The∆Dvalueiscalculatedineachsamplingtime(20seconds),andthefrequencyisadjustedaccordingto
its difference from the frequency previously calculated.
2. I control
Iftheoperatingfrequencydoesnotchangeformorethanacertainxedtime,thefrequencyisadjusted
accordingto∆Dvalue.
Whenthe∆Dvalueislow,thefrequencyislowered.
Whenthe∆Dvalueishigh,thefrequencyisincreased.
3. Frequency control when other controls are functioning
•Whenfrequencyisdropping;
Frequency control is carried out only when the frequency drops.
•Forlimitinglowerlimit;
Frequency control is carried out only when the frequency rises.
4. Upper and lower limit of frequency by PI control
The frequency upper and lower limits are set according to the command of the indoor unit. When the indoor
or outdoor unit quiet operation command comes from the indoor unit, the upper limit frequency is lower than
the usual setting.
ON
<Cooling / Dry>
OFF
A
B
C
-1.5°C (-2.7 °F)
Room thermistor temperature - target temperature
Cooling : -0.5°C (-0.9 °F)
Dry : -0.5°C (-0.9 °F)
Cooling : -2.0°C (-3.6 °F)
Dry : -2.5 - 2.0°C (-4.5 - 3.6 °F)
ON
<Heating>
OFF
A
B
C
1.5°C (2.7 °F)
Room thermistor temperature - target temperature
2.0°C (3.6 °F)
0.5°C (0.9 °F)