DAMA-SM-21-001
Control Specification
Functions and Control
35
3.2 Frequency
Control
Outline
The compressor frequency is determined according to the difference between the room
thermistor temperature and the target temperature.
*
Only applicable for heat-pump model
Details
For Cooling Only model:
1. Determine command frequency
Command frequency is determined in the following order of priority.
(1) Forced cooling
(2) Indoor frequency command
2. Determine upper limit frequency
The minimum value is set as the upper limit frequency among the frequency upper limits of
the following functions:
Compressor protection, input current, discharge pipe temperature, freeze-up protection.
3. Determine lower limit frequency
The maximum value is set as the lower limit frequency among the frequency lower limits of
the following function:
Pressure difference upkeep.
4. Determine prohibited frequency
There is a certain prohibited frequency such as a power supply frequency.
For Heat-pump model:
1. Determine command frequency
Command frequency will be determined in the following order of priority.
1.1 Limiting frequency by drooping function
Input current, discharge pipes, peak cutting, freeze-up protection, dew prevention, fin
thermistor temperature.
1.2 Limiting defrost control time
1.3 Forced cooling
1.4 Indoor frequency command
2.
Determine upper limit frequency
Set a minimum value as an upper limit frequency among the frequency upper limits of the
following functions:
Compressor protection, input current, discharge pipes, peak cutting, freeze-up protection,
defrost.
3.
Determine lower limit frequency
Set a maximum value as an lower limit frequency among the frequency lower limits of the
following functions:
Four way valve operating compensation, draft prevention, pressure difference upkeep.
4.
Determine prohibited frequency
There is a certain prohibited frequency such as a power supply frequency.
Initial frequency
PI control
Defrost control*
Lower limit function
Four way valve operating compensation, etc*
Command frequency
Lower limit frequency
FMIN
Upper limit frequency
FMAX
Limit frequency
Skip control
Target frequency
Upper limit function
Compressor protection function
Dropping function
Input current control, etc.
When the shift of the frequency is less than zero (
∆
F<0) by PI control,
the target frequency is used as the command frequency.
Summary of Contents for FTK Series
Page 2: ......
