scope:

Foreword 

Voltage fluctuations on electric power systems sometimes give rise to noticeable illumination changes from lighting equipment. The frequency of these voltage fluctuations is much less than the 50 Hz or 60 Hz supply frequency; however, they may occur with enough frequency and magnitude to cause irritation for people observing the illumination changes. This phenomenon is often referred to as flicker, lamp flicker, and sometimes voltage flicker. Often times, the terms have been used interchangeably. For many years, IEEE Std 141™-1993 and IEEE Std 519™-1992 have contained charts showing allowable voltage fluctuations. These charts in IEEE Std 141-1993 and IEEE Std 519-1992 show allowable voltage change magnitude on the vertical axis and frequency of occurrence on the horizontal axis. Although it is unclear, they appear to be based on 60 Watt, 120 Volt incandescent lamps subjected to rectangular voltage fluctuations. The advent of highpower electronic utilization equipment and mitigation equipment has given rise to some very complex voltage fluctuations that are not easily handled by IEEE Std 141-1993 and IEEE Std 519-1992. For this reason, the IEEE has worked in close cooperation with the International Union for Electroheat (UIE) and the International Electrotechnical Commission (IEC) to enhance existing standards to include a broader part of the world community.

This recommended practice is based on specifications that were prepared by the Disturbances Working Group of the UIE and published in 1992 with the international agreement for the 120 V power system published in the UIE congress in 1996. Consequently, the flickermeter specifications in this standard relate only to measurements of 230 V, 50 Hz and 120 V, 60 Hz inputs; specifications for other voltages and other frequencies are under consideration.

Scope

Voltage fluctuations on electric power systems sometimes give rise to noticeable illumination changes from lighting equipment. This phenomenon is often referred to as flicker, lamp flicker, and sometimes voltage flicker. This recommended practice provides specifications for measurement of this phenomenon and recommends acceptable levels for 120 V, 60 Hz and 230 V, 50 Hz AC electric power systems. It does not make any flicker emission specifications for certification of individual products manufactured for use on these systems.