This Standard outlines principles which are intended to be used as the basis for determining the requirements for connecting large fluctuating loads (producing flicker) to public power systems. The primary objective is to provide guidance for engineering practices which will ensure adequate service quality for all connected consumers. Since the guidelines outlined in this Standard are necessarily based on certain simplifying assumptions, there is no guarantee that this approach will always provide the optimum solution for all flicker problems. The recommended approach should be used with flexibility and judgement as far as engineering is concerned, when applying the given assessment procedures in full or in part. The final decision regarding the connection of fluctuating installations will always rest with the utility. Problems related to voltage fluctuations fall into two basic categories: – flicker effect from light sources; – risk of the voltage magnitude being outside accepted tolerances. This Standard primarily focuses on controlling or limiting flicker, but a clause is included to address voltage magnitude changes and their effects. Appendices A, B, C, D, E, F and G are for information only. NOTES 1 This Standard uses the following terms for system voltage: – low voltage (LV) refers to UN <= 1 kV;– medium voltage (MV) refers to 1 kV < UN <= 35 kV;– high voltage (HV) refers to 35 kV < UN <= 230 kV;– extra high voltage (EHV) refers to 230 kV < UN.In the context of this Standard, the function of the network is more important than its rated voltage. For example, a HV system used for distribution may be given a "planning level" (see clause 3) which is situated between those of MV and HV systems. 2 The “load” is to be understood as the complete consumer’s load. 3 A list of principal letter symbols, subscripts and symbols is given in appendix F.

First published in Australia as AS 2279.4-1985.Second edition 1991.Jointly revised and redesignated as AS/NZS 61000.3.7:2001. First published in Australia as AS 2279.4-1985. Second edition 1991. Jointly revised and redesignated as AS/NZS 61000.3.7:2001.