New IEEE Standard - Superseded. The reporting and statistical analysis of reliability of power transformers and shunt reactors used on electric utility power systems are addressed. The following types and applications of transformers are covered: power transformers, autotransformers, regulating transformers, phase-shifting transformers, shunt reactors, HVDC converter transformers, substation transformers, transmission tie transformers, unit transformers, unit auxiliary transformers, and grounding transformers. The format for the collection and reporting of data is presented, and the kinds of reports that may be useful to both users and manufacturers of transformers are illustrated. (This standard has been superseded by IEEE C57.125-2015)