UNE-EN 60599:2016

Introduction
1 Scope
2 Normative references
3 Definitions and abbreviations
4 Mechanisms of gas formation
5 Identification of faults
6 Conditions for calculating ratios
7 Application to free gases in gas relays
8 Gas concentration levels in service
9 Recommended method of DGA interpretation (figure 1)
10 Report of results
Annex A (informative) Equipment application notes
Annex B (informative) Graphical representation of gas
                        ratios
Annex C (informative) Bibliography
Annex ZA (normative) Normative references to international
                        publications with their corresponding
                        European publications
Figure 1 - Flow chart
Figure B.1 - Graphical representation 1 of gas ratios
Figure B.2 - Graphical representation 2 of gas ratios
Figure B.3 - Graphical representation 3 of gas ratios -
             Duval's triangle

This International Standard is a guide describing how the concentrations of dissolved gases or free gases may be interpreted to diagnose the condition of oil-filled electrical equipment in service and suggest future action. This guide 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 (see annex A). The Guide may be applied only with caution to other liquid-solid insulating systems. In any case, the indications obtained should be viewed only as guidance and any resulting action should be undertaken only with proper engineering judgment.