Danfoss VLT Flow Drive FC 111 Design Manual page 34

VLT® Flow Drive FC 111
Design Guide
Table 10: EMC Emission Test Results, H13–H14
RFI filter type Conduct emission. Maximum shielded cable length [m
(ft)]
EN 55011 Class B Housing,
trades and light
industries
EN/IEC
Category C1
61800-3
First environ-
ment home and
office
H2 RFI filter (EN 55011 A2, EN/IEC 61800-3 C3)
110–315 kW No
(150– 450 hp)
3x380–480 V
IP20
3.4.4 Harmonics Emission
A drive takes up a non-sinusoidal current from mains, which increases the input current I
formed with a Fourier analysis and split into sine-wave currents with different frequencies, that is, different harmonic currents I
with 50 Hz basic frequency:
Table 11: Harmonic Currents
Hz
The harmonics do not affect the power consumption directly, but increase the heat losses in the installation (transformer, cables).
So, in plants with a high percentage of rectifier load, maintain harmonic currents at a low level to avoid overload of the transformer
and high temperature in the cables.
Illustration 23: DC-link Coils
Some of the harmonic currents might disturb communication equipment connected to the same transformer or cause resonance
with power factor correction batteries.
To ensure low harmonic currents, the drive is equipped with DC-link coils as standard. This normally reduces the input current I
by 40%.
The voltage distortion on the mains supply voltage depends on the size of the harmonic currents multiplied by the mains impe-
dance for the frequency in question. The total voltage distortion THDv is calculated based on the individual voltage harmonics us-
ing this formula:
2 2
+ U + ... + U
THD % = U
5 7
(U % of U)
N
3.4.4.1 Harmonics Emission Requirements
Equipment is connected to the public supply network.
34 | Danfoss A/S © 2021.04
Class A Group 1 Class A Group 2
Industrial envi- Industrial envi-
ronment ronment
Category C2 Category C3
First environ- Second environ-
ment home and ment industrial
office
No 150 m (492 ft)
I
1
50
N O T I C E
2
N
Radiated emission
Class B Hous-
ing, trades
and light in-
dustries
Category C1
First environ-
ment home
and office
No
RMS
I
5
250
Product Overview
Class A Group Class A Group
1 Industrial 2 Industrial
environment environment
Category C2 Category C3
First environ- First environ-
ment home ment home
and office and office
No Yes
. A non-sinusoidal current is trans-
I
7
350
AJ363928382091en-000101 / 130R0983
n
RMS