Immunity Requirements - Danfoss VLT AQUA Drive Design Manual

2. Introduction to VLT AQUA Drive
NB!
To ensure low harmonic currents, the frequency converter is equipped with intermediate circuit coils as standard. This normally reduces
the input current I
2
The voltage distortion on the mains supply depends on the size of the harmonic currents multiplied by the mains impedance for the frequency in question.
The total voltage distortion THD is calculated on the basis of the individual voltage harmonics using this formula:
2 2
THD % = U + U
5 7
2.10.5. Harmonics Emission Requirements
Equipment connected to the public supply network:
2.10.6. Harmonics Test Results (Emission)
I
RMS
I
1
I
5
I
7
I
11-49
Table 2.2: Harmonic currents compared to the RMS input current
Power sizes up to PK75 in T2 and T4 complies with IEC/EN 61000-3-2 Class A. Power sizes from P1K1 and up to P18K in T2 and up to P75K in T4 complies
with IEC/EN 61000-3-12. Table 4, R
S SC R SCE U line
= 3 × ×
at the interface point between the user's supply and the public system.
It is the responsibility of the installer or user of the equipment to ensure, by consultation with the distribution network operator if necessary, that the
equipment is connected only to a supply with a short-circuit power S
Other power sizes can be connected to the public supply network by consultation with the distribution network operator.

2.11. Immunity Requirements

2.11.1. Immunity Requirements
The immunity requirements for frequency converters depend on the environment where they are installed. The requirements for the industrial environment
are higher than the requirements for the home and office environment. All frequency converters comply with the requirements for the industrial envi-
ronment and consequently comply also with the lower requirements for home and office environment with a large safety margin.
In order to document immunity against electrical interference from electrical phenomena, the following immunity tests have been made on a system
consisting of a frequency converter (with options if relevant), a screened control cable and a control box with potentiometer, motor cable and motor.
The tests were performed in accordance with the following basic standards:
• EN 61000-4-2 (IEC 61000-4-2): Electrostatic discharges (ESD): Simulation of electrostatic discharges from human beings.
34
by 40%.
RMS
2
+ ... + U
N
>= 120, THD <= 48% provided that the short-circuit power of the supply S
sce
I equ
× = 3 × 120 × 400 ×
MG.20.N4.02 - VLT
(U % of U)
N
Op- Definition:
tions:
1 IEC/EN 61000-3-2 Class A for 3-phase balanced
equipment (for professional equipment only up
to 1 kW total power).
2 IEC/EN 61000-3-12 Equipment 16A-75A and
professional equipment as from 1 kW up to 16A
phase current.
Input current
I equ
greater than or equal to specified above.
sc
®
is a registered Danfoss trademark
®
VLT AQUA Drive Design Guide
1.0
0.9
0.4
0.2
< 0.1
is greater than or equal to:
sc