Harmonic Input Chokes - Siemens MICROMASTER Eco Reference Manual
Hvac-frequency inverter
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Also See for MICROMASTER Eco:
- Reference manual (183 pages) ,
- Operating instructions manual (23 pages)
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Inverter type
Harmonic
Supply Voltage
number
208-240V 3ac
Fundamental
Type ECO1-2200/2
and below
208-240V 3ac
Fundamental
Type ECO1-3000/2
and above
380/500V 3ac
Fundamental
Type ECO1-4500/3
and below
380/500V 3ac
Fundamental
Type ECO1-5500/3
and above
HARMONIC INPUT CHOKES
Mains Harmonics
When the inverter is operating it draws a non-
sinusoidal current from the mains supply which
includes harmonics of the fundamental 50/60Hz
current. The approximate percentage of the
fundamental of these harmonics, based on a 1%
mains impedance, is shown in the table below.
The amplitude of the harmonics can be reduced
by fitting input chokes. The order numbers of
suitable chokes providing an additional
impedance of 2% or 4% are shown in the tables
below.
15-14
Typical harmonic
current with 1%
mains impedance
(%)
100%
5
72.9
7
48.4
11
10.6
13
5.5
100%
5
32
7
9.6
11
7.8
13
3.7
100%
5
72.5
7
52.6
11
17.0
13
7.2
100%
5
42.7
7
17.7
11
6.7
13
4.0
Supply Impedance
The impedance of the mains supply should not
be less than 0.5%. This means that the voltage
drop when the inverter is fully loaded should be
greater than or equal to 0.5% of the nominal
voltage. If the mains impedance is below this
value the lifetime of the electrolytic capacitors
could be reduced. To overcome this effect, 2%
input chokes should be fitted. If a further
reduction of harmonic currents is required, 4%
input chokes can be fitted.
ECO REFERENCE MANUAL
Typical harmonic
Typical harmonic
current with 2%
current with 4%
mains impedance
mains impedance
(%)
100%
56.3
31.3
6.6
6.6
100%
29.2
7.9
7.0
3.6
100%
62.0
36.7
7.4
6.2
100%
37.8
13.2
7.1
3.5
(%)
100%
39.4
14.7
6.9
3.4
100%
26.0
6.9
5.9
3.4
100%
41.0
16.5
7.3
3.2
100%
32.6
9.2
6.9
3.3
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