This Malaysian Standard constitutes an application guide and deals with the selection of insulationlevels 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 71-1 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 application guide.
It 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.
It covers phase-to-earth, phase-to-phase and longitudinal insulation.
This application guide is not intended to deal with routine tests. These are to be specified by
the relevant product committees.
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