Control Specification; Mode Hierarchy; Frequency Control - Daikin FTX20JV1B Service Manual

SiBE041010EA

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 Frequency is determined according to the difference between the room thermistor temperature
and the target temperature.
Detail How to Determine Frequency
The compressor's frequency is determined by taking the following steps.
Function and Control
Air conditioner control mode
Forced operation mode
Forced cooling operation (for pump down operation)
Power transistor test mode
Normal operation mode
Fan
Cooling (includes drying)
Heating
Stop (indoor unit: OFF)
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
Initial frequency Lower limit frequency
PI control
Defrost control
Heating
Defrosting
Preheating operation
Discharging from capacitor
Stop
Dropping function
Input current control, etc.
FMAX
Skip control
FMIN Four way valve operation compensation, etc.

Control Specification

(R17533)
Upper limit function
Compressor protection function
Target frequency
Lower limit function
(R18023)
30