IEEE
IEEE C57.12.00-2021 is a published standard from the IEEE that sets out general requirements for liquid-immersed distribution, power and regulating transformers. It is the common base document that manufacturers, utilities and testing engineers refer to when they need a shared definition of how these transformers are rated, built and proven.
Editions cited: IEEE C57.12.00-2021
The document is the general-requirements foundation for liquid-immersed transformers. It deals with the way ratings are expressed, the service conditions a unit is expected to withstand, the construction and marking expected of the finished product, and the set of routine and design verifications that show a unit meets its rating. Other standards in the same family build on it with specific tables, test codes and application guidance. Manufacturers use it when specifying and proving new units, utilities and owners use it when writing purchase specifications and judging factory results, and field engineers consult it to understand what a nameplate promises and which verification tests, such as turns ratio checks, are tied to that promise. This page describes the document in original words and does not reproduce it. For the actual requirements, tables and limits, obtain a licensed copy of IEEE C57.12.00-2021 from the publisher.