Distribution Transformer Handbook

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

© Copyright 2003 ABB Ltd. All rights reserved.
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0.

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’sservice life, 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.Navigation through 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 onthe IEC is
available 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 latesteditions of the standards 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
0.
1.

FOREWORD

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0.1.

3

CONTENTS

2.

INTRODUCTION

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1.1.
1.2.

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ABB-GROUP
ABBPOWER TECHNOLOGY DISTRIBUTION TRANSFORMERS – PTDT

TRANSFORMER TYPES AND THEIR APPLICATION

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2.1.
2.2.
2.3.
2.4.

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2.5.

3.

LARGE DISTRIBUTION 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-typetransformers
OTHER TRANSFORMER TYPES
2.5.1. Single phase transformers
2.5.2. Drives transformers
2.5.3. Additional products

4.

INFORMATION REQUIRED WITH ENQUIRY AND ORDER

10

3.1.
3.2.
3.3.
3.4.

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NORMAL INFORMATION
SPECIAL INFORMATION
PARALLEL OPERATIONS
ACCESSORIES

INSTALLATION, OPERATION AND MAINTENANCE

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4.1.
4.2.

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4.3.

4.4.

5.

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. Earthing4.2.9. Protective equipment
4.2.10. Insulation resistance, off-circuit/on-load tap changer
4.2.11. Off-circuit/on-load tap changer
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 duringoperation
4.4.3. Inspection and maintenance during downtime
4.4.4. Investigation of transformer disturbances
4.4.5. Transformer liquid and insulation
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

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5.1.
5.2.
5.3.
5.4.
5.5.

6.

DISPOSAL AFTER USE...