General recommendations for measuring voltage transients in dry-type distribution and power transformers are provided. Recurrent surge voltage generator circuitry, instrumentation, test sample, test point location, mounting the test coil, conducting the test, and reporting results are covered.

This guide applies to the equipment setup, measurement, and analysis of the transient voltage response of a dry-type transformer coil to impulse voltage.

Transient voltage analysis is used to determine the response of various parts of the coil to a 1.2 x 50 microsecond impulse wave. This analysis can be made on specially designed prototype coils with embedded voltage leads. This testing uses significantly lower voltages than the rated Basic Lightning Impulse Insulation Level (BIL) to expedite the test time for each data point required.