High-voltage switchgear and controlgear - Part 208: Methods to quantify the steady state, power-frequency electromagnetic fields generated by HV switchgear assemblies and HV/LV prefabricated substations, both for rated voltages above 1 kV and up to and including 52 kV

IEC 62271-208:2025 gives practical guidance for the evaluation and documentation of the external steady state power-frequency electromagnetic fields which are generated by HV switchgear and controlgear assemblies and prefabricated substations. Basic requirements to measure or calculate the electric and magnetic fields are summarised for assemblies covered by IEC 62271-200 and IEC 62271-201, and for prefabricated substations covered by IEC 62271-202.

NOTE 1？The methods described in this document refer to three-phase equipment. However, the methodology can be used correspondingly for any single- or multi-phase equipment covered by this document.

This document applies to equipment rated for voltages above 1 kV up to and including 52 kV and power-frequencies from 15 Hz to 60 Hz. The electromagnetic fields which are generated by harmonics or transients are not considered in this document. However, the methods described are equally applicable to the harmonic fields of the power-frequency.

Detailed generic information on requirements and measurements of low-frequency electromagnetic fields is given in IEC 61786-1 and IEC 61786-2.

This document covers evaluation under factory or labora