This part of GB 1094 is applicable to oil-immersed transformers. It describes the effect of operation under various ambient temperatures and loading conditions on transformer life.
Note: for furnace transformers, the manufacturer shall be consulted in view of the special loading curve.
Foreword I Introduction III 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 Appendix A (Informative) Non-thermally and Thermally Upgraded Insulation Paper Appendix B (Informative) Example of Calculating and Presenting Overloading Data Appendix C (Informative) Practical Example of the Exponential Formulas Appendix D (Informative) Calculation of Winding and Oil Time Constant Appendix E (Informative) Illustration of the Differential Equation Solution Method Appendix F (Informative) Flowchart, Based on the Example in Appendix B References
