Daikin FTK Series Service Manual page 41

Control Specification
Initial Frequency When starting the compressor, the frequency is initialized according to the ΔD value of the
indoor unit.
ΔD signal: Indoor frequency command
The difference between the room thermistor temperature and the target temperature is taken as
the ΔD value and is used for ΔD signal of frequency command.
In Cooling Mode
Temperature
difference (°C)
Temperature
difference (°F)
PI Control 1. P control
2. I control
3. Frequency control when other controls are functioning
4. Upper and lower limit of frequency by PI control
36
ΔD signal
-1.5 0
-1.0 1
-0.5 2
0.0 3
0.5 4
1.0 5
1.5 6
2.0 7
2.5
8
3.0
ΔD signal
-2.7 0
-1.8 1
-0.9 2
0.0 3
0.9 4
1.8 5
2.7 6
3.6 7
4.5
8
5.4
ΔD value is calculated in each sampling time (20 seconds), and the frequency is adjusted
according to its difference from the frequency previously calculated.
If the operating frequency does not change for more than a certain fixed time, the frequency
is adjusted according to ΔD value.
When ΔD is low, the frequency is lowered.
When ΔD is high, the frequency is increased.
 When frequency is dropping:
Frequency control is carried out only when the frequency drops.
 For controlling lower limit:
Frequency control is carried out only when the frequency rises.
The frequency upper and lower limits are set according to the command of the indoor unit.
When the indoor unit quiet operation command comes from the indoor unit, the upper limit
frequency is lower than the usual setting.
In Heating Mode
Temperature
ΔD signal
difference (°C)
-1.5 0
-1.0 1
-0.5 2
0.0 3
0.5 4
1.0 5
1.5 6
2.0 7
2.5 8
3.0
3.5
9
4.0
Temperature
ΔD signal
difference (°F)
-2.7 0
-1.8 1
-0.9 2
0.0 3
0.9 4
1.8 5
2.7 6
3.6 7
4.5 8
5.4
6.3
9
7.2
DAMA-SM-21-001
In Dry Mode
Temperature
ΔD signal
difference (°C)
-1.5 0
-1.0 1
-0.5 2
0.0 3
0.5 4
1.0 5
1.5 6
2.0 7
2.5 8
Temperature
ΔD signal
difference (°F)
-2.7 0
-1.8 1
-0.9 2
0.0 3
0.9 4
1.8 5
2.7 6
3.6 7
4.5 8
Functions and Control