IEC/IEEE 60214-2:2019

Tap-changers - Part 2: Application guidelines

IEC/IEEE 60214-2:2019 is published as an IEC/IEEE Dual Logo standard and is intended to assist in the selection of tap-changers designed in accordance with IEC 60214-1 or IEEE Std C57.131 for use in conjunction with the tapped windings of transformers or reactors. Requirements, references and definitions relevant to either IEC 60214-1 or IEEE Std C57.131 are given and their use is described in Clause 4. It is also intended to assist in understanding the various types of tap-changers and their associated equipment available. These application guidelines cover on-load tap-changers (resistor and reactor types) and de-energized tap-changers. This second edition cancels and replaces the first edition published in 2004. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) title has been updated from "Application guide" to "Application guidelines";
b) tap-changers for gas-filled transformers have been added;
c) description of typical circuits for regulation has been added;
d) description of basic arrangements of tapped windings with on-load tap-changers and de-energized tap-changers has been added;
e) types of tap-changers are explained in more detail (e.g. vacuum type on-load tap-changer) and new types have been added (e.g. step-voltage regulator, advance retard switch (ARS), on-load tap-changers for distribution transformers);
f) selection of tap-changers (on-load and de-energized) are described in more detail with respect to applications and parameters, which have to be considered (e.g. current wave shapes, operating pressure, temperature conditions, overloading conditions, continuous consecutive operations);
g) storage and installation has been considered;
h) field service, including commissioning, operation, maintenance and monitoring, has been considered;
i) safety aspects have been updated.
Keywords: tap-changers

General Information

• Status: Published
• Publication Date: 13-Jun-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: TC 14 - Power transformers
• Drafting Committee: MT 60214 - TC 14/MT 60214
• Current Stage: PPUB - Publication issued
• Start Date: 26-Apr-2019
• Completion Date: 14-Jun-2019

Relations

• Revises: IEC 60214-2:2004 - Tap-changers - Part 2: Application guide
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC/IEEE 60214-2 ®
Edition 2.0 2019-06
INTERNATIONAL
STANDARD
TAP-changers –
Part 2: Application guidelines

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IEC/IEEE 60214-2 ®
Edition 2.0 2019-06
INTERNATIONAL
STANDARD
TAP-changers –
Part 2: Application guidelines

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.180 ISBN 978-2-8322-6722-6

– 2 – IEC/IEEE 60214-2:2019 © IEC/IEEE 2019
CONTENTS
FOREWORD . 7
INTRODUCTION . 10
1 Scope . 11
2 Normative references . 11
2.1 IEC references . 11
2.2 IEEE references . 12
3 Terms, definitions and abbreviated terms . 12
3.1 Terms and definitions . 12
3.2 Abbreviated terms . 13
4 Use of normative references . 13
5 Application of tap-changers for transformers and reactors . 14
5.1 General . 14
5.2 Typical circuits for regulation . 14
5.3 Basic arrangements of tapped windings with on-load tap-changers . 16
5.4 Basic arrangements of tapped windings with step-voltage regulator on-load
tap-changers . 17
5.5 Basic arrangements of tapped windings with de-energized tap-changers . 17
5.5.1 Bridging contact scheme for DETC . 17
5.5.2 Linear contact scheme for DETC . 18
5.5.3 WYE (star) contact scheme for DETC . 18
5.5.4 Most common basic arrangements for different combinations . 18
6 Types of tap-changers . 19
6.1 On-load tap-changers (OLTCs) . 19
6.1.1 General . 19
6.1.2 Principles of operation . 20
6.1.3 Physical layouts . 27
6.2 De-energized tap-changers (DETCs) . 32
6.2.1 General . 32
6.2.2 Types of DETC . 32
6.2.3 Location of DETC in the transformer tank or enclosure . 32
6.3 Tap-changer environment . 34
6.3.1 Liquid immersed tap-changers . 34
6.3.2 Dry-type tap-changers (OLTC and DETC) . 35
6.3.3 Gas-immersed tap-changers (SF -insulated tap-changers) . 36
6.4 Other types . 38
6.4.1 General . 38
6.4.2 Electronic tap-changers . 38
6.4.3 Step-voltage regulators . 38
6.4.4 Advance retard switch (ARS) . 38
6.4.5 OLTCs for distribution transformers . 39
7 On-load tap-changers . 39
7.1 General . 39
7.2 Selection of OLTCs . 39
7.2.1 Basic parameters . 39
7.2.2 Additional data. 45
7.3 Application of OLTCs . 45

7.3.1 General . 45
7.3.2 OLTCs for application in special transformers with non-sinusoidal
currents (HVDC, rectifier transformers, converter transformers, etc.) . 45
7.3.3 OLTCs for PSTs . 46
7.3.4 OLTCs for arc furnace transformers . 47
7.3.5 OLTCs for shunt reactors . 47
7.3.6 OLTCs for series reactors . 48
7.3.7 OLTCs for unit auxiliary transformers. 48
7.3.8 OLTCs for railway supply transformers . 48
7.3.9 Transformers and phases out-of-step condition . 48
7.4 Other important parameters for OLTCs . 49
7.4.1 Current wave shapes other than sinusoidal . 49
7.4.2 Operating pressure . 49
7.4.3 Operational life of breaking and making contacts . 50
7.4.4 Tap-changer mechanical life . 51
7.4.5 Motor-drive mechanism . 51
7.4.6 Pressure and vacuum test . 51
7.4.7 Temperature conditions . 52
7.4.8 Overloading conditions . 52
7.4.9 Continuous consecutive operations . 53
7.4.10 Preventive autotransformer circuit (reactor type tap-changer only) . 53
8 De-energized tap-changers. 54
8.1 General . 54
8.2 Selection of DETCs . 54
8.2.1 Currents . 54
8.2.2 Rated step voltage . 55
8.2.3 Insulation level . 55
8.2.4 Number of tap positions . 55
8.3 Application of DETCs . 55
8.3.1 General . 55
8.3.2 Frequencies . 55
8.3.3 Application involving non-sinusoidal currents (HVDCs, rectifier
transformers, converter transformers, etc.) . 56
8.3.4 DETCs for arc furnace transformers and other high load cycle
applications . 56
8.3.5 DETCs for peaking pulsing loads . 56
8.4 Other important parameters for DETCs . 56
8.4.1 Tap-changer mechanical life . 56
8.4.2 Motor-drive . 56
8.4.3 Paralleling de-energized tap-changers/current splitting . 56
9 Protective devices for OLTCs . 57
9.1 General . 57
9.2 Increase of pressure within diverter or selector switch liquid compartments . 58
9.2.1 General . 58
9.2.2 Liquid flow controlled relay . 58
9.2.3 Overpressure relay . 58
9.2.4 Sudden pressure relay . 59
9.2.5 Pressure relief device . 59
9.3 Increase of pressure within a diverter or selector switch in SF . 59
– 4 – IEC/IEEE 60214-2:2019 © IEC/IEEE 2019
9.3.1 General . 59
9.3.2 Pressure gauge (compound gauge) . 59
...