IEEE Std C57.12.90-2021 PDF

Full title and description

IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers — methods for performing tests referenced in IEEE Std C57.12.00 and other IEEE transformer standards; covers test procedures, measurement techniques, and calculated data for liquid‑immersed transformers (excludes instrument transformers, voltage regulators, arc‑furnace, rectifier, specialty, grounding, and mine transformers).

Abstract

This standard (C57.12.90-2021) provides standardized test methods and procedures for evaluating electrical, dielectric, thermal, and acoustic performance of liquid‑immersed distribution, power, and regulating transformers. It defines how to perform resistance, polarity, ratio, no‑load (excitation) current and loss, impedance and load‑loss, dielectric (insulation) tests, temperature tests, short‑circuit tests, audible sound measurements, and how to compute and report calculated data.

General information

• Status: Active standard.
• Publication date: Board approval 9 November 2021; published 4 February 2022.
• Publisher: IEEE (IEEE Power & Energy Society / IEEE Standards Association).
• ICS / categories: Transformers / reactors (ICS 29.180).
• Edition / version: 2021 edition (designated C57.12.90-2021; revises C57.12.90-2015).
• Number of pages: 119 pages (typical published PDF length listed by standards distributors).

Scope

Describes methods for performing tests specified in IEEE Std C57.12.00 and other applicable standards for liquid‑immersed distribution, power, and regulating transformers. The standard is intended as a basis for consistent performance testing and reporting; it does not set performance limits or requirements for transformer design (those are in product or specification standards). Specific transformer types explicitly excluded are instrument transformers, step‑voltage and induction voltage regulators, arc furnace transformers, rectifier transformers, specialty transformers, grounding transformers, and mine transformers.

Key topics and requirements

• Standardized procedures for DC resistance measurements (winding resistance) and temperature compensation.
• Polarity and phase‑relation tests and ratio (turns) tests, including permissible test methods and accuracy requirements.
• No‑load loss and excitation current measurement methods and reporting conventions.
• Impedance and load‑loss measurement procedures, including short‑circuit test guidance.
• Dielectric tests (applied voltage, induced, and insulation withstand) and recommended instrumentation/conditioning.
• Temperature test methods (top‑oil and winding temperature rise measurements) and ambient/thermal corrections.
• Audible sound level measurement procedures and reporting metrics.
• Calculation and presentation of certified test data and recommended test report formats.

Typical use and users

Used by transformer manufacturers, independent test laboratories, utility test engineers, design and quality engineers, procurement/specification authors, and certification bodies to ensure consistent, repeatable testing and reporting of liquid‑immersed transformers. The standard supports factory acceptance testing, type testing, and verification testing called out in procurement specifications.

Related standards

Closely related to and referenced by IEEE Std C57.12.00 (general requirements for liquid‑immersed distribution, power, and regulating transformers), and product standards such as IEEE Std C57.12.10, C57.12.20, and C57.12.40. This 2021 revision supersedes IEEE C57.12.90‑2015 (and its corrigenda).

Keywords

transformer testing, liquid‑immersed transformers, test code, resistance measurement, ratio test, impedance, load loss, no‑load loss, dielectric test, temperature rise, sound level, IEEE C57.12.90.

FAQ

Q: What is this standard?

A: IEEE C57.12.90‑2021 is the IEEE test code that specifies standardized methods for testing liquid‑immersed distribution, power, and regulating transformers.

Q: What does it cover?

A: It covers the procedures and instrumentation for electrical, dielectric, thermal, mechanical (where applicable), and acoustic tests used to characterize transformer performance and to produce certified test data (resistance, ratio, no‑load, load‑loss/impedance, dielectric, temperature rise, short‑circuit, and sound).

Q: Who typically uses it?

A: Transformer manufacturers, utility and industrial test engineers, independent test labs, specification writers, and procurement/QA personnel use this standard to ensure repeatable, auditable test results.

Q: Is it current or superseded?

A: Current — C57.12.90‑2021 is an active standard (board approval 9 Nov 2021; published 4 Feb 2022) and it supersedes C57.12.90‑2015.

Q: Is it part of a series?

A: Yes — it is part of the IEEE C57.12 family of standards addressing liquid‑immersed transformer requirements and testing (see IEEE Std C57.12.00 and related product standards).

Q: What are the key keywords?

A: Transformer testing, liquid‑immersed, resistance, ratio, impedance, load loss, dielectric test, temperature rise, audible sound, IEEE C57.12.90.