scope:

The purpose of this guide is to give guidance and explanatory comments on the existing procedures for lightning and switching impulse testing of power transformers to supplement the requirements of IEC Publication 76-3: Power Transformers, Part 3: Insulation Levels and Dielectric Tests. The contents of this guide are also generally applicable to the testing of reactors, see IEC Publication 289: Reactors, modifications to power transformer procedures being indicated where required. Information is given on wave-shapes, test circuits including test connections, earthing practices, failure detection methods, test procedures, measuring techniques and interpretation of results. Where applicable, the test techniques are as recommended in IEC Publication 60: Highvoltage Test Techniques.