CLC/SR 28 - Insulation co-ordination

Gives guidance for the determination of the rated withstand voltages for ranges I and II of EN 60071-1 and justifies the association of these rated values with the standardized highest voltages for equipment. It covers phase-to-phase, phase-to-earth and longitudinal insulation of three-phase systems with nominal voltages above 1kV

Applies to three phase alternating current systems having a highest voltage for equipment above 1 kV. Specifies the procedures for the selection of the standard withstand voltages for the phase to earth, phase to phase and longitudinal insulation of the equipment and the installations of these systems.