21
ENG
ir33+ VCC
+040000058 - rel. 1.2 - 15.02.2018
3.3 Advanced
VCC
confi guration
To verify that the VCC compressor has shutdown, the inverter needs to be sent a certain frequency (called the
switch-off frequency) that is lower than the compressor’s minimum operating frequency, yet not 0. ir33+ VCC
uses the following default values:
•
switch-off frequency = 30 Hz
(equivalent to 0 rpm compressor speed)
•
maximum rotation frequency = 150 Hz
(equivalent to 4500 rpm compressor speed)
If a certain model of VCC compressor uses values other than those set as default on ir33+ VCC for the switch-off
frequency and maximum rotation frequency, the following parameters can be set:
•
cMI = switch-off frequency (expressed in tens of Hz);
•
cMA = maximum rotation frequency (expressed in tens of Hz).
Note:
the switch-off frequency (
cMI
) and the maximum rotation frequency (
cMA
) must not be confused
with the following parameters used to adapt VCC compressor capacity to the actual needs of the application:
•
cmf = minimum control frequency; default value = 52 Hz (1560 rpm)
•
cMf = maximum control frequency; default value = 100 Hz (3000 rpm)
Requested
Motor speed
(RPM)
Frequency and Motor Speed
Fin Frequency (Hz)
cMI
cmF
cMF cMA
0
0
St
op
Fig. 3.l
Code Parameter
UOM
Dis.
Def. Max Min
cMI
Compressor switch-off frequency (expressed in tens of Hz)
Hz x10
C
3
250
0
cMA
Maximum compressor rotation frequency (expressed in tens of Hz)
Hz x10
C
15
250
0
cmF
Minimum compressor control frequency
Hz
C
52
255
0
cMF
Maximum compressor control frequency
Hz
C
140
255
0
Tab. 3.t
All the parameters used to confi gure the VCC compressor are expressed as frequency (Hz). The corresponding
compressor rotation speed (rpm) is determined based on the following relationship:
Compressor speed (rpm) = Frequency (Hz) * 30
If a certain model of VCC uses a value other than the default (30) set on ir33+ VCC for converting from frequency
to compressor speed, the following parameter can be set:
cuF = conversion from Hz to rpm (expressed in tenths);
The compressor speed will thus be:
Compressor speed (rpm) = Frequency (Hz) * cuF
Code
Parameter
UOM
Dis.
Def.
Max
Min
cuF
VCC Hz to RPM conversion factor expressed in tenths
0.1 Hz
H
300
999
0
Tab. 3.u