Main Functions; Frequency Principle - Daikin CTXS09GVJU Service Manual

Main Functions

1. Main Functions

Note: Check the list of functions applicable to different models.
1.1

Frequency Principle

Main Control
The compressor is frequency-controlled during normal operation. The target frequency is set by the
Parameters following 2 parameters coming from the operating indoor unit:
Additional
The target frequency is adapted by additional parameters in the following cases:
Control
Parameters
Inverter Principle
To regulate the capacity, frequency control is needed. The inverter makes it possible to vary the
rotation speed of the compressor. The following table explains the conversion principle:
Phase
Drawing of
The following drawing shows a schematic view of the inverter principle:
Inverter
24
The load condition of the operating indoor unit
The difference between the room temperature and the set temperature
Frequency restrictions
Initial settings
Forced cooling / heating operation
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 increased refrigerant circulation. This leads to a higher amount of heat exchange per
unit.
When the frequency decreases, the rotation speed of the compressor decreases
resulting in decreased refrigerant circulation. This leads to a lower amount of the heat
exchange per unit.
Amount of heat
exchanged air (large)
Amount of heat
exchanged air (small)
freq=
constant
Description
Refrigerant circulation rate (high)
high speed
high f
low f
low speed
50 Hz
capacity=
freq=variable
60 Hz
variable
Refrigerant circulation rate (low)
SiUS12-814
Amount of heat
exchanged air (large)
Amount of heat
exchanged air (small)
(R2812)
Function and Control