AMETEK CTS 3.0 - Manual (Page 24)

Compliance Test System 3.0 User Manual
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2.4 The IEC 61000-3-2 Ed 2.2:2004 Standard
This section covers the 2004 standard which incorporates amendments 1 and 2 and amendment
14. This standard must be to test products since January 2004..
The purpose of enforcing the IEC 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.