STANDARDS

In the UK the ENGINEERING RECOMMENDATION G5/4-1 (2005) sets planning levels for harmonic voltage distortion to be used in the process for the connection of non-linear equipment and recommends the total harmonic distortion should be below 5%. The emission phenomena considered in this Recommendation are:

• Continuous harmonic, sub-harmonic and inter-harmonic voltage distortion within the range 0 to 2500Hz;
• Short burst of harmonic distortion
• Voltage notching

G5/4 superseded Engineering Recommendation G5/3 on 1st March 2001.

The Electricity Association web site is at http://www.electricity.org.uk
The ER G5/4-1 document can be ordered from http://www.ena-eng.org . Also see Managing Harmonics, A guide to ENA Engineering Recommendation G5/4-1(PDF)

In North America the INSTITUTE OF ELECTRICAL ENGINEERS recommends the standard IEEE 519-1992, which defines the maximum recommended voltage distortion (VTHD) for ‘general systems’ to be less 5%, with no more than 3% of any individual harmonic.

The Institute of Electrical Engineers web site is at http://www.ieee.org
The IEEE 519-1992 document can be purchased as a PDF download at http://shop.ieee.org/ieeestore/