FC101 Design Guide

3.4.4 Overview of Harmonics Emission
A frequency converter takes up a non-sinusoidal current
from mains, which increases the input current I
RMS
. A non-
sinusoidal current is transformed with a Fourier analysis
and split into sine-wave currents with dierent frequencies,
that is, dierent harmonic currents I
n
with 50 Hz basic
frequency:
I
1
I
5
I
7
Hz 50 250 350
Table 3.8 Harmonic Currents
The harmonics do not aect the power consumption
directly, but increase the heat losses in the installation
(transformer, cables). So, in plants with a high percentage
of rectier load, maintain harmonic currents at a low level
to avoid overload of the transformer and high temperature
in the cables.
175HA034.10
Figure 3.53 DC-link Coils
NOTICE!
Some of the harmonic currents might disturb communi-
cation equipment connected to the same transformer or
cause resonance with power factor correction batteries.
To ensure low harmonic currents, the frequency converter
is equipped with DC-link coils as standard. This normally
reduces the input current I
RMS
by 40%.
The voltage distortion on the mains supply voltage
depends on the size of the harmonic currents multiplied
by the mains impedance for the frequency in question. The
total voltage distortion THDv is calculated based on the
individual voltage harmonics using this formula:
THD
% = U
2
5
 + U
2
7
 + ... + U
2
N
(U
N
% of U)
3.4.5 Harmonics Emission Requirements
Equipment connected to the public supply network
Options Denition
1
IEC/EN 61000-3-2 Class A for 3-phase balanced
equipment (for professional equipment only up to
1 kW (1.3 hp) total power).
2
IEC/EN 61000-3-12 Equipment 16–75 A and profes-
sional equipment as from 1 kW (1.3 hp) up to 16 A
phase current.
Table 3.9 Connected Equipment
3.4.6 Harmonics Test Results (Emission)
Power sizes up to PK75 in T4 and P3K7 in T2 complies with
IEC/EN 61000-3-2 Class A. Power sizes from P1K1 and up to
P18K in T2 and up to P90K in T4 complies with IEC/EN
61000-3-12, Table 4.
Individual harmonic current I
n
/I
1
(%)
I
5
I
7
I
11
I
13
Actual 0.25–11
kW (0.34–15 hp),
IP20, 200 V
(typical)
32.6 16.6 8.0 6.0
Limit for R
sce
≥120
40 25 15 10
Harmonic current distortion factor (%)
THDi PWHD
Actual 0.25–11
kW (0.34–15 hp),
200 V (typical)
39 41.4
Limit for R
sce
≥120
48 46
Table 3.10 Harmonic Current 0.25–11 kW (0.34–15 hp), 200 V
Individual harmonic current I
n
/I
1
(%)
I
5
I
7
I
11
I
13
Actual 0.37–22
kW (0.5–30 hp),
IP20, 380–480 V
(typical)
36.7 20.8 7.6 6.4
Limit for R
sce
≥120
40 25 15 10
Harmonic current distortion factor (%)
THDi PWHD
Actual 0.37–22
kW (0.5–30 hp),
380–480 V
(typical)
44.4 40.8
Limit for R
sce
≥120
48 46
Table 3.11 Harmonic Current 0.37–22 kW (0.5–30 hp), 380-480 V
Product Overview
VLT
®
HVAC Basic Drive FC 101
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