Control Specification; Mode Hierarchy; Frequency Control - Daikin FTXG20LV1BW Service Manual

Control Specification

3. Control Specification

3.1

Mode Hierarchy

Outline The air conditioner control has normal operation mode, forced operation mode, and power
transistor test mode for installation and servicing.
Detail
Note: Unless specified otherwise, a dry operation command is regarded as cooling operation.
3.2

Frequency Control

Outline The compressor frequency is determined according to the difference between the room
thermistor temperature and the target temperature.
Detail 1. Determine command frequency
37
Air conditioner control mode
Forced operation mode
Power transistor test mode
Normal operation mode
When the shift of the frequency is less than zero (∆F<0) by PI control,
the target frequency is used as the command frequency.
Upper limit frequency
Command frequency Limit frequency
Lower limit frequency
Initial frequency
PI control
Defrost control
Command frequency is determined in the following order of priority.
1. Limiting defrost control time
2. Forced cooling
3. Indoor frequency command
Forced cooling operation (for pump down operation)
Fan
Cooling (includes drying)
Heating
Heating
Defrosting
Stop (indoor unit: OFF)
Preheating operation
Discharging from capacitor
Stop
Input current control, etc.
FMAX
Skip control
FMIN Four way valve operation compensation, etc.
(R19522)
Dropping function
Upper limit function
Compressor protection function
Target frequency
Lower limit function
Function and Control
SiBE041401E
(R18023)