Frequency Principle - Daikin FTK25JVE9 Service Manual

Si04-115
1.3

Frequency Principle

Main control The compressor is frequency-controlled during normal operation. The target frequency is set by
the following 2 parameters coming from the operating indoor unit:
parameters
"
"
Additional The target frequency is adapted by additional parameters in the following cases:
"
control
"
parameters
"
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:
1
2
Drawing of The following drawing shows a schematic view of the inverter principle:
inverter
Main Function
the load condition of the operating indoor unit
the difference between the room temperature and the set temperature.
frequency limits
initial settings
forced cooling/heating operation.
Phase
The single phase power supply in AC is converted into DC.
The single phase power supply DC is converted into a three phase chopped DC voltage
with a 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.
Amount of heat
exchanged (large)
Amount of heat
exchanged (small)
A
Min. frequency
Cooling
Heating
Description
Refrigerant circulation rate (high)
*
max. freq.= Hz
high f
low f
)
min. freq.= Hz
50 Hz
freq=
freq=variable
constant
60 Hz
Refrigerant circulation rate (low)
J type Max. frequency
34
34
General Functionality
high speed
Amount of heat
exchanged (large)
Amount of heat
exchanged (small)
low speed
capacity=
variable
B
Cooling
Heating
(R1900)
J type
98
98
21