SiBE121135
Indoor Unit Control (RA Models)
Function and Control
77
Drawing of
Inverter
The following drawing shows a schematic view of the inverter principle:
Inverter Features
The inverter provides the following features:
The regulating capacity can be changed according to the changes in the outdoor
temperature and cooling / heating load.
Quick heating and quick cooling
The compressor rotational speed is increased when starting the heating (or cooling). This
enables to reach the set temperature quickly.
Even during extreme cold weather, high capacity is achieved. It is maintained even when the
outdoor temperature is 2°C.
Comfortable air conditioning
A fine adjustment is integrated to keep the room temperature constant.
Energy saving heating and cooling
Once the set temperature is reached, the energy saving operation enables to maintain the
room temperature at low power.
Frequency Limits
The following functions regulate the minimum and maximum frequency:
Forced Operation
Refer to page 405 for detail.
Refrigerant circulation rate (high)
high f
low f
freq=variable
Refrigerant circulation rate (low)
high speed
low speed
(R2812)
Amount of heat
exchanged air (large)
Amount of heat
exchanged air (small)
freq=
constant
capacity=
variable
AC
po
w
er
DC
po
w
er
Amount of heat
exchanged air (large)
Amount of heat
exchanged air (small)
50 Hz
60 Hz
Frequency
Functions
Low
Four way valve operation compensation. Refer to page 111.
High
Compressor protection function. Refer to page 112.
Discharge pipe temperature control. Refer to page 112.
Input current control. Refer to page 113.
Freeze-up protection control. Refer to page 113.
Heating peak-cut control. Refer to page 114.
Defrost control. Refer to page 116.
