Daikin RXL25G2V1B, Service Manual

Page: 34 / 294

Main Functions SiENBE04-925_A
20 Function and Control
1. Main Functions
Note: The definitions of temperatures are classified as following.
Š
Room temperature: temperature of the lower part of the room
Š
Set temperature: temperature set by remote control
Š
Room thermistor temperature: temperature detected by room temperature thermistor
Š
Target temperature: temperature determined by microcomputer
1.1 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
Inverter Principle
To regulate the capacity, a frequency control is needed. The inverter makes it possible to vary
the rotation speed of the compressor. The following table explains the conversion principle:
Target temperature
Set temperature
Room temperature
Room thermistor temperature
(R12321)
Phase Description
1 The supplied AC power source is converted into the DC power source for the present.
2 The DC power source is reconverted into the three phase AC power source with variable
frequency.
„
When the frequency increases, the rotation speed of the compressor increases resulting
in an increased refrigerant circulation. This leads to a higher amount of the heat
exchange per unit.
„
When the frequency decreases, the rotation speed of the compressor decreases
resulting in a decreased refrigerant circulation. This leads to a lower amount of the heat
exchange per unit.
SIENBE04-925_A_FRONT.pdf 34 24/02/2011 13:53:51