AS 2374.2-1997

1 - AS 2374.2-1997 POWER TRANSFORMERS - TEMPERATURE RISE
4 - PREFACE
6 - CONTENTS
7 - 1 Scope
7 - 2 Normative references
7 - 3 Identification symbols according to cooling method
9 - 4 Temperature-rise limits
9 - 4.1 General
9 - 4.2 Normal temperature-rise limits at continuous rated power
11 - 4.3 Modified requirements because of unusual service conditions
12 - 4.4 Temperature rise during a specified load cycle
12 - 5 Test of temperature rise
12 - 5.1 General
13 - 5.2 Test methods for temperature-rise determination
16 - 5.3 Determination of oil temperatures
17 - 5.4 Determination of average winding temperature
18 - 5.5 Determination of winding temperature before shutdown
18 - 5.6 Corrections
19 - Annex A - Note on oil temperature in transformers with forced oil circulation
21 - Annex B - Transient loading – Mathematical model and testing
21 - B.1 General
21 - B.2 Mathematical model for temperature distribution in a winding of an oil-immersed transformer - The hot-spot concept
23 - B.3 Variable loading or cooling. Thermal time-constants
23 - B.4 Recommendations for temperature-rise test with transient load
25 - Annex C - Techniques used in temperature-rise testing of oil-immersed transformers
25 - C.1 Truncation of a test to steady state
28 - C.2 Procedure for winding resistance measurement after shutdown
29 - C.3 Extrapolation of winding temperature to the instant of shutdown
32 - C.4 Gas-in-oil analysis
33 - APPENDIX ZZ - LIST OF VARIATIONS BETWEEN THIS STANDARD AND IEC 76-2
34 - APPENDIX ZA - TYPICAL HEAT SINK

Specifies temperature-rise limits and methods of test for measuring temperature rise. Based on but not equivalent to, and has been reproduced from IEC 76-2:1993. Includes Australian variations.

This part of International Standard IEC 76 identifies transformers according to their cooling methods, defines temperature-rise limits and details the methods of test for temperature-rise measurements. It applies to transformers as defined in the scope of IEC 76-1.

First published as part of AS C61-1931.
Second edition 1946.
Third edition 1963.
Fourth edition 1970.
Revised and redesignated in part as AS 2374.2-1982.
Second edition 1997.