A procedure to be used to perform a failure analysis is recommended. The procedure is primarily focused on power transformers used on electrical utility systems, although it may be used for an investigation into any ac transformer failure. This document provides a methodology by which the most probable cause of any particular transformer failure may be determined. This document is also intended to encourage the establishment of routine and uniform data collection procedures, consistency of nomenclature and compatibility with similar efforts by otherre organizations, and cooperative effects by users and manufacturers during the failure analysis.

This guide recommends a procedure to be used to perform a failure analysis. Although the procedure may be used for an investigation into any ac transformer failure, it is primarily focused on power transformers used on electric utility systems.

This document was intended for the following purposes: (1) To provide a methodology by which the most probable cause of any particular trans-former failure may be determined (2) To provide sufficient guidelines, examples, and case histories to promote uniformity in the analysis of transformer failures (3) To encourage the establishment of routine and uniform data collection so that valuable facts are not lost or destroyed (4) To encourage consistency of nomenclature and compatibility with similar efforts by otherre organizations such as CIGRE, EEl, IEC, NEMA, and AEIC (5) To encourage cooperative efforts by users and manufacturers during the failure analysis