Insulation co-ordination - Part 2: Application guidelines

This part of IEC 60071 constitutes application guidelines and deals with the selection of insulation levels of equipment or installations for three-phase electrical systems. Its aim is to give guidance for the determination of the rated withstand voltages for ranges I and II of IEC 60071-1 and to justify the association of these rated values with the standardized highest voltages for equipment. This association is for insulation co-ordination purposes only. The requirements for human safety are not covered by this document. This document covers three-phase systems with nominal voltages above 1 kV. The values derived or proposed herein are generally applicable only to such systems. However, the concepts presented are also valid for two-phase or single-phase systems. This document covers phase-to-earth, phase-to-phase and longitudinal insulation. This document is not intended to deal with routine tests. These are to be specified by the relevant product committees.