Service manual

Main Functions SiBE07-724_B
30 Function and Control
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, the 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 Cooling
Operation
Refer to “Forced operation mode” on page
199
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)
freq=
constant
50 Hz
60 Hz
capacity=
variable
Amount of heat
exchanged air (small)
AC
power
DC
power
Amount of heat
exchanged air (large)
Amount of heat
exchanged air (small)
Frequency Functions
Low  Four way valve operation compensation. Refer to page 44.
High  Compressor protection function. Refer to page 44.
 Discharge pipe temperature control. Refer to page 45.
 Input current control. Refer to page 46.
 Freeze-up protection control. Refer to page 47.
 Heating peak-cut control. Refer to page 47.
 Defrost control. Refer to page 49.