AMETEK MX CTSL - Manual (Page 19)

User Manual MX-CTSL Compliance Test System
California Instruments Revision J 19
2.4 The EN 61000-3-2:1998 Standard
This section covers the 1998 standard including amendments 1 and 2. This standard may be used to test
products until January 2004. After this date, only the 2000 revision of the standard including Amendment
14 should be used.
The purpose of enforcing the EN 61000-3-2 standard is to limit the amount of current harmonics produced
by electronic loads. Since harmonic currents caused by a load in turn produce voltage harmonics across
the public utilities impedance, they affect other equipment connected to the same circuit. In fact, most
public utilities exhibit voltage distortion caused by non-linear loads. Because harmonics can have serious
effects on many electrical devices, efforts to set standards to limit their presence date back to the 1930’s.
This resulted in the IEC’s Technical Committee (TC) setting standards dealing with current harmonics as
far back as 1977. These standards became the basis for IEC standards 1000-3-2 and 1000-3-3 adopted in
1993. Because of their long history, many people still refer to these standards as 555.2 and 555.3 although
there are some differences between the older and newer versions and tests performed today should be
done according to the new standards, not the old ones.
Another confusing issue that is rooted in history is the nature of the products that fall under these IEC
norms. While the original 555 specifications focused primarily on consumer products and excluded many
professional and industrial products, the new IEC 1000-3 norms expanded coverage to include all electrical
products with a rated input current up to 16 A rms per phase. Presently, only products with a line input
voltage of 220 V and above are included. Japan and the US are working towards similar requirements that
would cover products that require 100 Volts and up. Due to the original scope of the IEC 555 norms, many
manufacturers are still under the impression that their products are exempt since they are not considered
consumer products. Especially manufacturers of switching power supplies - some of the worst “offenders”
when it comes to generating harmonics currents - have been caught off guard.