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Distribution Transformer Handbook
IEC / CENELEC related specifications ABB Ident # 1LAC000003

© Copyright 2003 ABB Ltd. All rights reserved. 1

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FOREWORD
The objective of this Distribution Transformer Handbook is to facilitate the selection, ordering and operation of distribution transformers. The target readers are personnel involved in the various stages of a transformer’s servicelife, from planning the investment to the disposal of the transformer after use. It may also be useful to ABB personnel. The handbook is arranged with the sections following the transformers life from planning through ordering, installation, operation, maintenance and scrapping. Other useful information, including more theoretical topics, may be found at the end of this handbook. Navigationthrough this handbook is facilitated through a three level contents following this foreword, and the index at the end. ABB Power Technologies Division thanks the International Electrotechnical Commission (IEC) for permission to reproduce information from its International Standards. All such extracts are copyright of IEC, Geneva, Switzerland. All rights reserved. Further information on the IEC isavailable from www.iec.ch. IEC has no responsibility for the placement and context in which the extracts and contents are reproduced by ABB Power Technologies Division; nor is IEC in any way responsible for the other content or accuracy therein." The standards, IEC, CENELEC, IEEE, mentioned in the text refer to the edition given in the list of standards. For practical use only latest editions of thestandards should be used. Extracts from the ABB Switchgear Manual are quoted by kind approval by the issuer. UK English has been selected for this document to comply with the text in IEC standards.

Distribution Transformer Handbook Page 2

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CONTENTS
FOREWORD
0.1. 1.1. 1.2. 2.1. 2.2. 2.3. 2.4. CONTENTS ABB-GROUP ABB POWER TECHNOLOGY DISTRIBUTION TRANSFORMERS – PTDT LARGEDISTRIBUTION TRANSFORMERS, LDT MEDIUM DISTRIBUTION TRANSFORMERS, MDT SMALL DISTRIBUTION TRANSFORMERS, SDT DRY-TYPE DISTRIBUTION TRANSFORMERS 2.4.1. Vacuum cast resin dry-type transformers 2.4.2. Resibloc® dry-type transformers OTHER TRANSFORMER TYPES 2.5.1. Single phase transformers 2.5.2. Drives transformers 2.5.3. Additional products NORMAL INFORMATION SPECIAL INFORMATION PARALLEL OPERATIONSACCESSORIES SAFETY PRECAUTIONS INSTALLATION 4.2.1. Transport 4.2.2. Transfer of responsibility (Incoterms) 4.2.3. Handling, lifting 4.2.4. Receiving the transformer at site 4.2.5. Storage prior to energizing 4.2.6. Erection at site 4.2.7. Network connection 4.2.8. Earthing 4.2.9. Protective equipment 4.2.10. Insulation resistance, off-circuit/on-load tap changer 4.2.11. Off-circuit/on-load tapchanger 4.2.12. Mechanical checks 4.2.13. Energizing OPERATION 4.3.1. Lifetime 4.3.2. Temperature rise and load capacity 4.3.3. Parallel operation 4.3.4. Frequency 4.3.5. Protection devices MAINTENANCE 4.4.1. Inspection during operation 4.4.2. Maintenance during operation 4.4.3. Inspection and maintenance during downtime 4.4.4. Investigation of transformer disturbances 4.4.5. Transformer liquid andinsulation 4.4.6. Bushings and joints 4.4.7. Off-circuit tap changer 4.4.8. On-load tap changer 4.4.9. Liquid conservator with rubber sack 4.4.10. Gaskets 4.4.11. Surface protection LOCAL REGULATIONS REUSE LANDFILL LIFE CYCLE ASSESSMENT (LCA) PCB-CONTAMINATED OIL INTRODUCTION CHOICE OF SYSTEM VOLTAGE BASIC PHYSICS OF THE TRANSFORMER EQUIVALENT DIAGRAM VOLTAGE RATIO AND VOLTAGE DROP (OR RISE)EFFICIENCY NO LOAD (MAGNETISING) CURRENT AND NO LOAD LOSSES LOAD LOSSES SHORT-CIRCUIT IMPEDANCE ABILITY TO WITHSTAND SHORT CIRCUIT CURRENTS TRANSFORMER SOUND CORE MATERIALS CONDUCTOR MATERIALS

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INTRODUCTION TRANSFORMER TYPES AND THEIR APPLICATION

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2.5.

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INFORMATION REQUIRED WITH ENQUIRY AND ORDER
3.1. 3.2. 3.3. 3.4.

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