MXS Service Manual

SiUS121736EA Common Functions
Functions and Control 48
1. Common 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 wall mounted type as representative.
Temperature
Control
The temperature of the room is detected by the room temperature thermistor. However, there is a
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. In
practice, 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
Control
Parameters
The frequency of the compressor is controlled by the following 2 parameters:
 The load condition of the operating indoor unit
 The difference between the room thermistor temperature and the target temperature
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)