IEC 61000-3-2: Limits - Limits for Harmonic Current Emissions (equipment input current up to and including 16 A per phase)

EN 61000-3-2: April 1998 is the current standard for harmonics in conjunction with amendments A1 and A2. It covers all equipment connected to the power lines, not just appliances as before.

EN 61000-3-2 is described by the IEC as one that “specifies limits for harmonic current emissions applicable to electrical and electronic equipment having an input current up to and including 16 A per phase and intended to be connected to public low-voltage distribution systems.” The tests according to this standard are type tests. Test conditions for particular equipment are given in annex C. For systems with nominal voltages less than 220 V (line to neutral), the limits have not yet been considered.

Work on the latest revision to the document still is unfinished. Document Provisional A14 will contain the latest revisions and recommendations to the standard. This document is out for vote and should be ready for use by September 2000.

When it is adopted, there will likely be a three-year transition in which you can use EN 61000-3-2 alone or in conjunction with A14. After that, use of A14 will be mandatory. Following are some changes that will be introduced by A14:

• No limits for equipment using 75 W or less.
• No limits for professional equipment over 1,000 W.
• New class D for PCs, monitors, and TVs.
• Test confirmation mode with expected maximum THD (no worst-case search).
• Limits applying only to the power lines, not to the neutral.
• IEC 61000-4-7 Guide replacing Annex B.
• New measurement method for fluctuating loads.

The A14 amendment provides a temporary solution to many of the problems with the standard. It gives legislation the means to apply the standard in conjunction with the amendments after Jan. 1, 2001. However, there still is a major hurdle to overcome. The IEC has not agreed to the content of A14, so the EN A14 document may cause problems for manufacturers that sell their products internationally.