scope:

This section of IEC 1000-3 is concerned with the emission of disturbances due to voltage fluctuations and flicker.

The recommendations in this Technical Report are applicable to electrical and electronic equipment intended to be connected to a public low-voltage a.c. distribution system, where the equipment has a rated input current exceeding 16 A per phase, or has a lower rated current, but requires the special consent of the supply authority.

The recommendations that specify the information required to enable a supply authority, manufacturer, or consumer to assess equipment and appropriate questionnaires are included as annexes A and B.

Guidance is also given on emission values of voltage fluctuations produced by equipment which has been type tested to the specified conditions given in IEC 1000-3-3.

NOTE 1 - The limits recommended in this report are mainly based on the subjective severity of the flicker of the light output from 230 V/60 W coiled-coil filament tamps as a result of fluctuation of the supply voltage. For systems with nominal voltages less than 220 V, line-to-neutral, limits, and reference circuit values have not yet been considered.

The authorization to connect equipment to the supply depends on the levels of disturbance caused by the equipment and the load flow conditions in the network.

NOTE 2 - For equipment requiring authorization, only general recommendations for the assessment of disturbances can be given. There is no guarantee that the connection of equipment complying with the recommendations in clause 3 will be allowed in all cases, as system loading must not exceed plant ratings (transformers, cables, etc.).

The methods of assessment may be applied also to private consumer installations.