SiBE121021_C
Control Specification
Function and Control
115
PI Control (Determine Frequency Up / Down by
∆
D Signal)
1. P 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.
2. I control
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.
3. Limit of frequency variation width
When the difference between input current and input current drooping value is less than 1.5
A, the frequency increase width must be limited.
4. Frequency management when other controls are functioning
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.
5. Upper and lower limit of frequency by PI control
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.