Frequency Principle; Main Control Parameters; Additional Control Parameters; Inverter Principle - Daikin Altherma EKHBH Series Service Manual

Outdoor Unit Functional Concept
3.2

Frequency Principle

1
Main control
parameters
2
Additional control
parameters
3

Inverter principle

4
5
Drawing of inverter
2–12
The compressor is frequency-controlled during normal operation. The target frequency is set by the
following 2 parameters coming from the operating hydro-box:
The load condition of the operating hydro-box
The difference between the water temperature and the set temperature
The target frequency is adapted by additional parameters in the following cases:
Frequency restrictions
Initial settings
Forced cooling operation
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:
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 varia-
ble 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.
The following drawing shows a schematic view of the inverter principle:
Amount of heat
exchanged (large)
Amount of heat
exchanged (small)
Refrigerant circulation rate (high)
high speed
high f
low f
low speed
freq=
50 Hz
freq=variable
constant
Refrigerant circulation rate (low)
Amount of heat
exchanged (large)
Amount of heat
exchanged (small)
capacity=
variable
Part 2 – Functional Description
ESIE06-03