News | August 11, 2011

IEEE Approves Projects To Revise Standards For Evaluating And Reconditioning Transformers

Piscataway Township Society Hill, NJ - IEEE, the world's largest professional association advancing technology for humanity, recently announced that the IEEE Standards Association (IEEE-SA) Standards Board has approved two projects for the revision of standards for evaluating and reconditioning transformers.

When completed, IEEE PC57.12.34 – Standard for Requirements for Pad-Mounted, Compartmental Type, Self Cooled, Three Phase Distribution Transformers, 10 MVA and Smaller; High Voltage, 34.5kV Nominal System Voltage and Below; Low Voltage, 15kV Nominal System Voltage and Below – will address certain electrical, dimensional and mechanical characteristics and safety features of transformers that are generally used for step-down or step-up purposes from an underground primary cable supply. The standard covers the connector, bushing and terminal arrangements for radial or loop-feed systems, as well as certain critical dimensions for these items necessary for proper safety and operational considerations. The standard's scope is being revised to account for the increasing size of step-up and step-down transformers in distribution systems.

IEEE PC57.140 – Guide for Evaluation and Reconditioning of Liquid Immersed Power Transformers – will review and update a comprehensive document intended to aid users in selecting the proper approaches to upgrading, reconditioning, refurbishing or other activities in extending the useful life of transformers. Guidelines are provided for insulating oil maintenance and diagnostics, oil reclamation, testing methods for the determination of remaining insulation (paper) life and upgrades of auxiliary equipment such as bushings, gauges, de-energized tap changers (DETCs), load tap changers (LTCs) where applicable and coil "reclamping."

*Additional details on these projects can be found on the IEEE PC57.12.34 web page ( and the IEEE PC57.140 web page (

SOURCE: The IEEE Standards Association