2.9.3 EMC Test Results (Emission)
The following test results have been obtained using a system with a frequency converter (with options if relevant), a screened control cable, a
control box with potentiometer, as well as a motor and motor screened cable.
RFI filter type
Conducted emission.
Maximum shielded cable length.
Radiated emission
Industrial environment
Housing, trades
and light indus-
tries
Industrial environ-
ment
Housing, trades and
light industries
Standard
EN 55011 Class
A2
EN 55011
Class A1
EN 55011 Class B EN 55011 Class A1
EN 55011 Class B
H1
1.1-45 kW 200-240 V
T2
150 m
150 m
50 m
Yes
No
1.1-90 kW 380-480 V
T4
150 m
150 m
50 m
Yes
No
H2
1.1-3.7 kW 200-240 V
T2
5 m
No
No
No
No
5.5-45 kW 200-240 V
T2
25 m
No
No
No
No
1.1-7.5 kW 380-480 V
T4
5 m
No
No
No
No
11-90 kW 380-480 V
T4
25 m
No
No
No
No
110-1000 kW 380-480 V
T4
150 m
No
No
No
No
45-1400 kW 525-690 V
T7
150 m
No
No
No
No
H3
1.1-45 kW 200-240 V
T2
75 m
50 m
10 m
Yes
No
1.1-90 kW 380-480 V
T4
75 m
50 m
10 m
Yes
No
H4
110-1000 kW 380-480 V
T4
150 m
150 m
No
Yes
No
45-400 kW 525-690 V
T7
150 m
30 m
No
No
No
Hx
1.1-90 kW 525-600 V
T6
-
-
-
-
-
Table 2.1: EMC Test Results (Emission)
HX, H1, H2 or H3 is defined in the type code pos. 16 - 17 for EMC filters
HX - No EMC filters build in the frequency converter (600 V units only)
H1 - Integrated EMC filter. Fulfil Class A1/B
H2 - No additional EMC filter. Fulfil Class A2
H3 - Integrated EMC filter. Fulfil class A1/B (Frame size A1 only)
H4 - Integrated EMC filter. Fulfil class A1
2.9.4 General Aspects 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 trans-
formed by means of a Fourier analysis and split up into sine-wave
currents with different frequencies, i.e. different harmonic currents I
N
with 50 Hz as the basic frequency:
Harmonic currents
I
1
I
5
I
7
Hz
50 Hz
250 Hz
350 Hz
The harmonics do not affect the power consumption directly but increase
the heat losses in the installation (transformer, cables). Consequently, in
plants with a high percentage of rectifier load, maintain harmonic cur-
rents at a low level to avoid overload of the transformer and high
temperature in the cables.
NB!
Some of the harmonic currents might disturb communication equipment connected to the same transformer or cause resonance in
connection with power-factor correction batteries.
To ensure low harmonic currents, the frequency converter is equipped with intermediate circuit coils as standard. This normally reduces the input current
I
RMS
by 40%.
VLT
®
HVAC Drive Design Guide
2 Introduction to VLT HVAC Drive
MG.11.B9.02 - VLT
®
is a registered Danfoss trademark
41
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