scope:

Commented versions are a valuable improvement upon the conventional IEC Redline Version (RLV). These versions are designed to facilitate a clearer understanding of the revisions made between the prior and current editions of a publication. This enhanced product package incorporates both the most recent edition of the document and the annotated redline version. This combined offering provides users with an easily accessible means to track and comprehend the alterations and additions that have been made, thereby enhancing the utility and effectiveness of the publication for its intended audience.

This document describes how the concentrations of dissolved gases or free gases can be interpreted to diagnose the condition of oil-filled electrical equipment in service and suggest future action.

This document is applicable to electrical equipment filled with mineral insulating oil and insulated with cellulosic paper or pressboard-based solid insulation. Information about specific types of equipment such as transformers (power, instrument, industrial, railways, distribution), reactors, bushings, switchgear and oil-filled cables is given only as an indication in the application notes.

This document can be applied, but only with caution, to other liquid-solid insulating systems.

In any case, the indications obtained are given only as guidance with resulting action undertaken only with proper engineering judgment.