scope:

This insulation coordination standard applies to three-phase alternating current (ac) systems above 15 kV. This standard specifies the procedure for selection of withstand voltages [basic lightning impulse insulation level (BIL) and basic switching impulse insulation level (BSL)] for equipment phase-to-ground and phaseto- phase insulation systems. It also identifies a list of standard insulation levels, based on the voltage stress to which the equipment is being exposed. Although the principles of this standard also apply to transmission line insulation systems, the insulation levels may be different from those identified as standard insulation levels.

The guide to this standard, IEEE Std 1313.2™-1999, is an application guide with practical examples, intended to provide guidance in the determination of the withstand voltages and to suggest calculation methods and procedures.¹

NOTE-IEEE Std 1313.2-1999 will be revised as IEEE Std C62.82.2™ with its next revision.²

Purpose

The purpose of this standard is to

a) Define applicable terms

b) Outline insulation coordination procedures

c) Identify standard insulation levels

¹ Information on references can be found in Clause 2.

² Notes in text, tables, and figures of a standard are given for information only and do not contain requirements needed to implement this standard.