SiBE041401E
Control Specification
Function and Control
38
2. Determine upper limit frequency
The minimum value is set as an upper limit frequency among the frequency upper limits of
the following functions:
Compressor protection, input current, discharge pipe temperature, heating peak-cut, freeze-
up protection, defrost.
3. Determine lower limit frequency
The maximum value is set as a lower limit frequency among the frequency lower limits of the
following functions:
Four way valve operation compensation, draft prevention, pressure difference upkeep.
4. Determine prohibited frequency
There is a certain prohibited frequency such as a power supply frequency.
Initial Frequency
When starting the compressor, the frequency is initialized according to the
∆
D value and the Q
value of the indoor unit.
<
∆
D signal: Indoor Frequency Command>
The difference between the room thermistor temperature and the target temperature is taken as
the
∆
D signal and is used for frequency command
∗
OFF = Thermostat OFF
<Q value>
Q value is the indoor unit output determined from indoor heat exchanger volume and airflow rate
set by remote controller.
PI Control
1. P control
The
∆
D value is calculated in each sampling time (15 ~ 20 seconds), and the frequency is
adjusted according to its difference from the frequency previously calculated.
2. I control
If the operating frequency does not change for more than a certain fixed time, the frequency
is adjusted according to the
∆
D value.
When the
∆
D value is low, the frequency is lowered.
When the
∆
D value is high, the frequency is increased.
3. Frequency control when other controls are functioning
When frequency is dropping;
Frequency control is carried out only when the frequency drops.
For controlling lower limit;
Frequency control is carried out only when the frequency rises.
4. Upper and lower limit of frequency by PI control
The frequency upper and lower limits are set according to the command of the indoor unit.
When the indoor or outdoor unit quiet operation command comes from the indoor unit, the
upper limit frequency is lower than the usual setting.
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
–2.0
∗
OFF
0
4
2.0
8
4.0
C
–1.5
1
0.5
5
2.5
9
4.5
D
–1.0
2
1.0
6
3.0
A
5.0
E
–0.5
3
1.5
7
3.5
B
5.5
F
Summary of Contents for FTXG20LV1BW
Page 12: ...SiBE041401E 1 List of Functions Part 1 List of Functions 1 Functions 2...
Page 14: ...SiBE041401E 3 Specifications Part 2 Specifications 1 Specifications 4...
Page 60: ...SiBE041401E 49 Remote Controller Part 5 Remote Controller 1 Remote controller 50...
Page 113: ...SiBE041401E Check Service Diagnosis 102 50 class Diode bridge R19944...
Page 127: ...Revision History Month Year Version Revised contents 03 2014 SiBE041401E First edition...
