Table of Contents

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviations
5 Effect of loading beyond nameplate rating
6 Relative ageing rate and transformer insulation life
7 Limitations
8 Determination of temperatures
9 Influence of tap-changers
Annex A (informative) - Insulation life expectancy and relative
        ageing rate considering oxygen and water effect
Annex B (informative) - Core temperature
Annex C (informative) - Specification of loading beyond rated
        power
Annex D (informative) - Description of Q, S and H factors
Annex E (informative) - Calculation of winding and oil time
        constant
Annex F (informative) - Thermal model parameters
Annex G (informative) - Oil and winding exponents
Annex H (informative) - Practical example of the exponential
        equations method
Annex I (informative) - Application of the difference equation
        solution method
Annex J (informative) - Flowchart, based on the example in
        Annex H
Annex K (informative) - Example of calculating and presenting
        overload data
Annex L (informative) - Geomagnetic induced currents
Annex M (informative) - Alternative oils
Bibliography

Abstract

Defines the effect of operation under various ambient temperatures and load conditions on transformer life.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	International Electrotechnical Committee
Pages
ISBN
Committee	TC 14