IEEE C57.111:1989 (R2009)

New IEEE Standard - Inactive-Reserved.
Tests and evaluation procedures for silicone transformer fluid are recommended. Criteria for maintenance and methods of reconditioning silicone fluid are described. The aim is to assist the transformer operator in evaluating the silicone insulating fluids in transformers, fluid received from the manufacturer for filling transformers at the installation site, and fluid processed into such transformers, as well as in maintaining the properties of silicone fluid in operating transformers.

This guide recommends standard tests and evaluation procedures for silicone transformer fluid. Criteria for maintenance and methods of reconditioning of silicone fluid are described. It is not the intent of this guide to cover the subject of retrofilling transformers with silicone fluids.
The purpose of this guide is to assist the transformer operator in evaluating the silicone insulating fluids in transformers, fluid received from the manufacturer for filling transformers at the installation site, and fluid processed into such transformers. It also assists the operator in maintaining the properties of silicone fluid in operating transformers.