Daikin FTXS30HVJU - Fault Diagnosis and Error Codes; Retrieving Fault Codes

Control Specification SiUS04-924
Function and Control 29
Indoor Frequency Command (D signal)
The difference between the room temperature and the temperature set by the remote controller will
be taken as the “D signal” and is used for frequency command.
Th OFF = Thermostat OFF
Frequency Initial Setting
Outline
When starting the compressor, or when conditions are varied due to the change of the room, the
frequency must be initialized according to the total of a maximum D value of the indoor unit and
the Q value of the indoor unit.
Q value: Indoor unit output determined from indoor unit volume, airflow rate and other factors.
PI Control (Determine Frequency Up/Down by D Signal)
1. P control
Calculate D value in each sampling time (20 seconds), and adjust the frequency according to
its difference from the frequency previously calculated.
2. I control
If the operating frequency is not changed more than a certain fixed time, adjust the frequency up
and down according to the D value, obtaining the fixed D value.
When the D value is small...lower the frequency.
When the D value is large...increase the frequency.
3. Limit of frequency variation width
When the difference between input current and input current dropping value is less than 1.0 A,
the frequency increase width must be limited.
4. Frequency management when other controls are functioning
 When frequency is dropping;
Frequency management is carried out only when the frequency drops.
 For limiting lower limit
Frequency management is carried out only when the frequency rises.
5. Upper and lower limit of frequency by PI control
The frequency upper and lower limits are set depending on indoor unit.
When low noise commands come from the indoor unit or when outdoor unit low noise or quiet
commands come from indoor unit, the upper limit frequency must be lower than the usual
setting.
Temperature
difference
°F(°C)
D
signal
Temperature
difference
°F(°C)
D
signal
Temperature
differenc
°F(°C)
D
signal
Temperature
difference
°F(°C)
D
signal
0 Th
OFF
3.6 (2.0) 4 7.2 (4.0) 8 10.8 (6.0) C
0.9 (0.5) 1 4.5 (2.5) 5 8.1 (4.5) 9 11.7 (6.5) D
1.8 (1.0) 2 5.4 (3.0) 6 9.0 (5.0) A 12.6 (7.0) E
2.7 (1.5) 3 6.3 (3.5) 7 9.8 (5.5) B 13.5 (7.5) F