Control Specification; Mode Hierarchy; Frequency Control - Daikin MKS-T Series Service Manual

Control Specification

4. Control Specification

4.1

Mode Hierarchy

Outline
The air conditioner control has normal operation mode, forced operation mode, and power
transistor test mode for installation and servicing.
Details
Notes
 Unless specified otherwise, dry operation command is regarded as cooling operation.
 Indoor fan operation cannot be made in multiple indoor units. A forced fan command is made
4.2

Frequency Control

Outline
Frequency corresponding to each room's capacity is determined according to the difference
between the target temperature and the temperature of each room thermistor.
Details
The compressor's frequency is determined by taking the following steps.
1. Determine command frequency
77
Air conditioner control mode
Forced operation mode
Power transistor test mode
Normal operation mode
during forced cooling operation.
When the shift of the frequency is less than zero (ΔF<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
Command frequency is determined in the following order of priority.
(1) Forced cooling
(2) Indoor frequency command
Forced cooling operation (for pump down operation)
Wiring error check operation
Fan
Cooling (includes drying)
Stop (indoor unit: OFF)
Discharging from capacitor
Stop
Input current control, etc.
FMAX
Skip control
FMIN
(R23672)
Dropping function
Upper limit function
Compressor protection function
Target frequency
Lower limit function
Part 4 Functions and Control
SiSG121917E
(R12230)