EMC requirements in Europe

SCHURTER products are suitable for audio/video, IT and communication technology equipment according to the new application standard IEC / UL 62368-1, which replaces IEC 60065 for audio and video equipment and IEC 60950-1 for IT and communication equipment. For filters we recommend a version with bleed resistor for an application according to IEC/UL 62368-1. The correct use of the SCHURTER component must be checked for conformity to the standard in the end application.

The most important safety standards for equipment/installations are listed in the following:

IEC / UL 62368-1 Safety of audio, video, information technology, and office equipment IEC / UL 62368-1

IEC 60335 Safety of household and similar electrical appliances IEC 60335

IEC 61010-1 Safety requirements for electronic measuring apparatus IEC 61010-1

IEC 60601 Safety requirements for electro-medical equipment 60601

There are basically 2 types of emitted disturbances: conducted and radiated. Line interferences are high-frequency noise signals which are superimposed on the useful signals on input and output lines. Interference signals can be of common- or differential mode type. The significance of line interference is reduced dramatically above a frequency of 30 MHz. From here radiated interference increases greatly. On the following pages we will nevertheless deal with conducted interference only.

RFI Testing station

EN 55011: Boundary values and measuring systems for RF suppression for industrial, scientific, and medical high-frequency equipment (ISM), 1991 (see also CISPR 11 or VDE 0871)

Boundary values complying with EN 55011

Quasipeak (QP) and Average (AV) are two limits, neither of which must be exceeded and which are measured by two different test receivers. The test arrangement remains the same. These boundary values replace the boundary values given by the old standards for broadband and narrowband noise generators.

Boundary values are divided into classes A and B.

Into class A fall those devices which should not be operated in residential buildings and should not be connected to power supplies that also supply these areas. Class A boundary values shall not be exceeded.

Into class B fall devices for which the above restrictions do not apply. Class B boundary values shall not be exceeded.

EN 55022: Boundary values and measuring systems for RF suppression for information technology installations (Telecommunications) 1987 (see also CISPR 22 or VDE 0878).

Boundary values complying with EN 55022

Into class A fall all units which should be used in a commercial environment and should be used with a safety distance of 30 m to other units.

Into class B fall all units which have no restrictions on their use.

EN 55013: Boundary value and measuring techniques for RF suppression characteristics of radio receivers and connected applications.

EN 55014: Boundary values and measuring systems for RF suppression for electrical household appliances, handheld electrical tools and similar electrical products, 1993 (see also CISPR 14).

EN 55015: Boundary values and measuring systems for RF suppression for fluorescent lamps and lighting, 1993 (see also CISPR 13).

(EN 61000-3-2, IEC 61000-3-2)

Current harmonics represent a distortion of the normal sine wave provided by the utility. When a product such as an SCR switched load or a switching power supply distorts the current, harmonics at multiples of the power line frequency are generated. Two significant consequences arise as a result of harmonic generation. First, because of finite impedances of power lines, voltage variations are generated that other equipment on the line must tolerate. Second, when generated in a three-phase system, harmonics may cause overheating of neutral lines.

Power line harmonics are generated when a load draws a non-linear current from a sinusoidal voltage. The harmonic component is an element of a Fourier series that can be used to define any periodic waveshape. The harmonic order or number is the integral number defined by the ratio of the frequency of the harmonic to the fundamental frequency (e.g., 150 Hz is the third harmonic of 50 Hz; n = 150/50).

After multiple postponements finish at 1.1. 2001 the transition period for the EN 61000-3-2, frequently called “PFC-Norm”. It applies to all electrical and electronic devices with input current up to max. 16 A per phase, which is designed to connect to the general low voltage mains. Limits are set only for 220/380 V, 230/400 V, and 240/415 V at 50 Hz.

This standard distinguishes four classes of equipment.

A Symmetric three phase equipment and all other equipment not in other classes

B Portable tools

C Lighting equipment

D Equipment has special waveshape (see EN 61000-3-2, paragraph 4 picture 1)

A harmonics test to conform to the standards must include an analysis of the incoming current up to the 40th harmonic (for fN = 50 Hz, fH = 2 kHz).

The IEC 61642 "Industrial a.c. networks affected by harmonics- application of filters and shunt capacitors" gives guidance for the use of passive a.c. harmonic filters and shunt capacitors for the limitation of harmonics and power factor correction intended to be used in industrial applications, at low and high voltages.

(EN61000-3-3, IEC 61000-3-3, IEC 61000-3-5)

The appearance of flicker effects and voltage fluctuations on the main supply is caused by varying loads connected to the mains. The most critical are the effects of voltage fluctuations on equipment such as lights and illumination. Here the light output and thereby the intensity is an exponential function of the supplied voltage. This fluctuation in light intensity is called flicker. Many people experience dizziness and headaches as a result.

There are various limit values depending on the type of voltage fluctuation (square, sinusoidal, and mixed or erratic voltage fluctuation).

Flickers are measured by so-called flicker meters (arranged in compliance with EN 60808).

(EN 61000-4-2, IEC 61000-4-2)

One of the main interference sources, along with switching through radio interference, is electrostatic discharge from people and equipment.

(EN 61000-4-4, IEC 61000-4-4)

One of the most common and most dangerous sources of interference are transient disturbances such as those originating from switching transients (interruption of inductive loads, relay contact bounce, etc.). The burst test measures the resistance of the device to repetitive fast transients.

(EN 61000-4-5, IEC 61000-4-5)

This test procedure measures the behavior of a device when subjected to high-energy pulses. Sources of such pulses are switching events due to lightning strikes, short circuits, or switching cycles which vary in time and place. Surge tests on SCHURTER filters is according to IEC 60939.

Specification of the burst test impulse to IEC 61000-4-4

Surge voltage forms in an open circuit

Guideline for the selection of ESD test levels

Recommended test levels for Fast Transient/Burst (acc. IEC 61000-4-4)

*EFT/B: Electrical Fast Transient/Burst

Installation classification for Surge Immunity test (acc. IEC 61000-4-5)

Compared to the IEC standard, the surge load test according to ANSI or DOE is not carried out under the same test conditions. SCHURTER, therefore, tests e.g. fuses with increased pulse resistance according to these ratings to ensure that these products meet the local requirements.

1) 1.2×50μs Voltage 8×20μs Current Combination Wave