Lighting power Quality Standards - A Brief International Overview
Lighting power Quality Standards - A Brief International Overview
Standards issued by the International Electrotechnical Commission (IEC) are recommendations and adopted as such by the national IEC committees. However, most European countries, as well as many non-European ones, have adopted the IEC recommendations as mandatory standards (See below under CENELEC).
The harmonic emission limits for lighting equipment are specified in the new standard IEC 1000-3-2, entitled "Harmonic limits for LV apparatus <16A", where lighting equipment is defined as "class C" equipment. IEC 1000-3-2 will replace the current IEC 555-2 standard, published in 1982.
According to IEC 1000-3-2, the harmonic current emissions from lighting equipment must not exceed the following limits:
| Harmonic order n | Maximum value expressed as a percentage of the input current at the fundamental frequency |
| 2 | 2 |
| 3 | 30*lambda |
| 5 | 10 |
| 7 | 7 |
| 9 | 5 |
| 11<n<39 | 3 | . | (lambda is the circuit power factor) |
Both the current IEC standards and the new ones replacing them will result in a current total harmonic distortion (THD) of less than 33% and a power factor (PF) of more than 0.95 for lighting equipment. However, no limits apply for self-ballasted lamps, dimmers, and so-called semi-luminaires with an active power of less than 25W. In practice, this means that there are still no emission limits for integral CFLs. Current discussions are addressing the questions of when and how to make integral CFLs and other lighting equipment with an active power below 25W subject to the standard. As for now, no agreement has been reached on the issue.
CENELEC (EN) STANDARDS
CENELEC is a European (not European Union!) standardization organisation. CENELEC's member states have agreed to adopt a standard as specified in the CENELEC Internal Regulation without alterations. The text of the IEC standard 1000-3-2 was approved by CENELEC as European Standard EN 61000-3-2.
CENELEC member states are Austria, Belgium, Denmark, Finland, France, Germany, Greece, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
The previous EN standard will be phased out gradually: Products launched on the market before January 1, 1997 can be sold under the old (EN 60555-2) standard until Dec. 31, 2000.
EUROPEAN UNION'S
EMC DIRECTIVE
The EU's Electromagnetic Compatibility (EMC) Directive also deals with harmonic emission levels. The European EMC Directive does not in itself specify emission levels being rather general. For lighting equipment, manufacturers must show that they comply with the EMC directive by giving reference to other standards which are listed in the EU's official journal. Currently, the Official Journal lists EN 60555-2, but it is expected that this standard will soon be replaced by EN 61000-3-2.
AMERICAN ANSI/IEEE STANDARDS
The US standards don't specify any emission limits for equipment. IEEE Standard 519-1992 "Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems" gives only the guidelines for permissible injections of harmonic currents from individual customers into the power system.
See also in IAEEL Newsletter 3-4/95: Power Quality and Lighting (overview article), and Power Quality For Beginners.
Nils Borg
Natan Gothelf