Active Standard

IEEE C57.166-2026

IEEE Guide for Acceptance and Maintenance of Insulating Liquids in Transformers and Related Equipment

Recommendations regarding tests and evaluation procedures of insulating liquids are made in this guide. References are made in this guide to methods of reconditioning and reclaiming insulating liquids and the levels at which these methods become necessary. Assisting the power equipment operator in evaluating the serviceability of liquid insulation received in equipment, as received from the supplier for filling new equipment at the installation site and as processed into such equipment, and assisting the operator in maintaining the insulating liquid in serviceable condition are intended by this guide. Insulating liquids used in transformers, reactors, on-load tap changers, and step-voltage regulators are covered in this guide.

Standard Committee
PE/TR - Transformers
Status
Active Standard
PAR Approval
2018-03-08
Board Approval
2026-03-26
History
Published:
2026-09-15

Working Group Details

Society
IEEE Power and Energy Society
Standard Committee
PE/TR - Transformers
Working Group
WGC57.166 - Insulating Fluids - Consolidation of Insulating Liquid Guides
IEEE Program Manager
Patrycja Jarosz
Contact Patrycja Jarosz
Working Group Chair
Tom Prevost

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