Daikin Super Multi NX FFQ25B8V1B Service Manual page 127

SiBE121021_C
PI Control (Determine Frequency Up / Down by ∆ D Signal)
1. P control
2. I control
3. Limit of frequency variation width
4. Frequency management when other controls are functioning
5. Upper and lower limit of frequency by PI control
Function and Control
A total of 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.
If the operating frequency is not change more than a certain fixed time, the frequency is
adjusted according to the Σ∆ D value.
When the Σ∆ D value is small...lower the frequency.
When the Σ∆ D value is large...increase the frequency.
When the difference between input current and input current drooping value is less than 1.5
A, the frequency increase width must be limited.
When each frequency is drooping;
Frequency management is carried out only when the frequency droops.
For limiting lower limit
Frequency management is carried out only when the frequency rises.
The frequency upper and lower limits are set depending on the total of S values of a room.
When low noise commands come from the indoor unit more than one room or when outdoor
unit low noise or quiet commands come from all the rooms, the upper limit frequency must
be lowered than the usual setting.
Control Specification
115