IEEE
IEEE C57.13-2016 is a published standard from the IEEE that sets requirements for instrument transformers, the current and voltage transformers that scale power system quantities down for meters, relays and other instruments. It gives manufacturers, utilities and testing engineers a shared basis for ratings, accuracy classes and verification.
Editions cited: IEEE C57.13-2016
The standard concerns current transformers and voltage transformers built to feed metering, protection and control equipment. It addresses how ratings are expressed, how accuracy classes are defined for metering and for relaying duty, the insulation and service conditions the devices must tolerate, the standard burdens against which accuracy is stated, and the tests that demonstrate conformance. Manufacturers build and prove products to it, utilities and industrial owners cite it in purchase specifications, and engineers rely on it to interpret nameplate data when they check ratio, polarity, burden or excitation characteristics in the field. Related guidance for field testing is published separately. This page describes the document in original words and does not reproduce it. For the requirements, classes and tables, obtain a licensed copy of IEEE C57.13-2016 from the publisher.