SiUS091133
Main Functions
Function and Control
28
1. Main Functions
1.1
Temperature Control
Definitions of
Temperatures
The definitions of temperatures are classified as following.
Room temperature: temperature of lower part of the room
Set temperature: temperature set by remote controller
Room thermistor temperature: temperature detected by room temperature thermistor
Target temperature: temperature determined by microcomputer
The illustration is for FTXS series as representative.
Temperature
Control
The temperature of the room is detected by the room temperature thermistor. However, there is
difference between the “temperature detected by room temperature thermistor” and the
“temperature of lower part of the room”, depending on the type of the indoor unit or installation
condition. Practically, the temperature control is done by the “target temperature appropriately
adjusted for the indoor unit” and the “temperature detected by room temperature thermistor”.
1.2
Frequency Principle
Main Control
Parameters
The compressor is frequency-controlled during normal operation. The target frequency is set by the
following 2 parameters coming from the operating indoor unit:
The load condition of the operating indoor unit
The difference between the room thermistor temperature and the target temperature
Additional
Control
Parameters
The target frequency is adapted by additional parameters in the following cases:
Frequency restrictions
Initial settings
Forced cooling operation
Target temperature
Set temperature
Room temperature
Room thermistor temperature
(R12321)
