IEC TS 61936-2:2015

Power installations exceeding 1 kV a.c. and 1,5 kV d.c. - Part 2: d.c.

IEC TS 61936-2:2015(E) provides, in a convenient form, common rules for the design and the erection of electrical power installations in systems with nominal voltages above 1,5 kV d.c., so as to provide safety and proper functioning for the use intended.

General Information

• Status: Replaced
• Publication Date: 04-Mar-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.020 - Electrical engineering in general
• ICS: 29.080.01 - Electrical insulation in general
• Technical Committee: TC 99 - Insulation co-ordination and system engineering of high voltage electrical power installations above 1,0 kV AC and 1,5 kV DC
• Drafting Committee: WG 5 - TC 99/WG 5

Relations

• Revised: IEC 61936-2:2023 - Power installations exceeding 1 kV AC and 1,5 kV DC - Part 2: DC
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TS 61936-2 ®
Edition 1.0 2015-03
TECHNICAL
SPECIFICATION
colour
inside
Power installations exceeding 1 kV a.c. and 1,5 kV d.c. –
Part 2: d.c.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]

CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

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The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
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IEC TS 61936-2 ®
Edition 1.0 2015-03
TECHNICAL
SPECIFICATION
colour
inside
Power installations exceeding 1 kV a.c. and 1,5 kV d.c. –

Part 2: d.c.
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020; 29.080.01 ISBN 978-2-8322-2304-8

– 2 – IEC TS 61936-2:2015 © IEC 2015

CONTENTS
FOREWORD . 5

INTRODUCTION . 8

1 Scope . 9

2 Normative references . 9

3 Terms and definitions . 10

4 Fundamental requirements . 12

4.1 General . 12
4.1.1 General requirements . 12
4.1.2 Agreements between supplier (manufacturer) and user . 12
4.2 Electrical requirements . 12
4.2.1 Methods of d.c. neutral point earthing . 12
4.2.2 Voltage classification . 13
4.2.3 Current in normal operation . 13
4.2.4 Short-circuit current . 13
4.2.5 Rated frequency . 13
4.2.6 Corona . 13
4.2.7 Electric and magnetic fields . 14
4.2.8 Overvoltages . 14
4.2.9 Harmonics . 14
4.2.10 Galvanic separation between a.c. and d.c. systems . 14
4.3 Mechanical requirements . 14
4.4 Climatic and environmental conditions . 14
4.4.1 General . 14
4.4.2 Normal conditions . 15
4.4.3 Special conditions . 15
4.5 Special requirements . 15
5 Insulation . 15
5.1 General . 15
5.2 Selection of insulation level. 15
5.2.1 Consideration of methods of neutral earthing . 15
5.2.2 Consideration of rated withstand voltages . 15
5.3 Verification of withstand values . 16

5.4 Minimum clearances of live parts . 16
5.5 Minimum clearances between parts under special conditions . 18
5.6 Tested connection zones . 18
6 Equipment . 18
6.1 General requirements . 18
6.2 Specific requirements . 18
6.2.1 Switching devices . 18
6.2.2 Reactors . 18
6.2.3 Prefabricated type-tested switchgear . 19
6.2.4 Surge arresters . 19
6.2.5 Capacitors . 19
6.2.6 Line traps . 19
6.2.7 Insulators . 19
6.2.8 Insulated cables . 19

6.2.9 Conductors and accessories . 20

6.2.10 Rotating electrical machines . 20

6.2.11 Static converters . 20

6.2.12 Fuses . 20

6.2.13 Electrical and mechanical Interlocking . 20

6.2.14 Electronic valve devices . 20

6.2.15 Valve cooling system . 20

7 Installations . 21

7.1 General requirements . 21

7.1.1 Circuit arrangement . 21
7.1.2 Documentation . 21
7.1.3 Transport routes . 21
7.1.4 Aisles and access areas . 21
7.1.5 Lighting . 21
7.1.6 Operational safety . 21
7.1.7 Labelling . 21
7.2 Outdoor installations of open design . 21
7.2.1 Protective barrier clearances . 22
7.2.2 Protective obstacle clearances . 22
7.2.3 Boundary clearances . 22
7.2.4 Minimum height over access area . 22
7.2.5 Clearances to buildings . 23
7.2.6 External fences or walls and access doors . 25
7.3 Indoor installations of open design . 25
7.4 Installation of prefabricated type-tested switchgear . 25
7.5 Requirements for buildings . 25
7.5.1 General . 25
7.5.2 Structural provisions . 25
7.5.3 Rooms for switchgear . 26
7.5.4 Maintenance and operating areas . 26
7.5.5 Doors . 26
7.5.6 Draining of insulating liquids . 26
7.5.7 Air conditioning and ventilation . 26
7.5.8 Buildings which require special consideration . 27
7.6 High voltage/low voltage prefabricated substations . 27

7.7 Electrical installations on mast, pole and tower . 27
8 Safety measures . 27
8.1 General . 27
8.2 Protection against direct contact . 27
8.2.1 Measures for protection against direct contact . 27
8.2.2 Protection requirements . 27
8.3 Means to protect persons in case of indirect contact . 28
8.4 Means to protect persons working on electrical installations . 28
8.5 Protection from danger resulting from arc fault . 28
8.6 Protection against direct lightning strokes . 28
8.7 Protection against fire . 28
8.8 Protection against leakage of insulating liquid . 28
8.9 Identification and marking .
...

IEC TS 61936-2 ®
Edition 1.0 2015-03
TECHNICAL
SPECIFICATION
colour
inside
Power installations exceeding 1 kV a.c. and 1,5 kV d.c. –
Part 2: d.c.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC TS 61936-2 ®
Edition 1.0 2015-03
TECHNICAL
SPECIFICATION
colour
inside
Power installations exceeding 1 kV a.c. and 1,5 kV d.c. –

Part 2: d.c.
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020; 29.080.01 ISBN 978-2-8322-2304-8

– 2 – IEC TS 61936-2:2015 © IEC 2015
CONTENTS
FOREWORD . 5
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 Fundamental requirements . 12
4.1 General . 12
4.1.1 General requirements . 12
4.1.2 Agreements between supplier (manufacturer) and user . 12
4.2 Electrical requirements . 12
4.2.1 Methods of d.c. neutral point earthing . 12
4.2.2 Voltage classification . 13
4.2.3 Current in normal operation . 13
4.2.4 Short-circuit current . 13
4.2.5 Rated frequency . 13
4.2.6 Corona . 13
4.2.7 Electric and magnetic fields . 14
4.2.8 Overvoltages . 14
4.2.9 Harmonics . 14
4.2.10 Galvanic separation between a.c. and d.c. systems . 14
4.3 Mechanical requirements . 14
4.4 Climatic and environmental conditions . 14
4.4.1 General . 14
4.4.2 Normal conditions . 15
4.4.3 Special conditions . 15
4.5 Special requirements . 15
5 Insulation . 15
5.1 General . 15
5.2 Selection of insulation level. 15
5.2.1 Consideration of methods of neutral earthing . 15
5.2.2 Consideration of rated withstand voltages . 15
5.3 Verification of withstand values . 16
5.4 Minimum clearances of live parts . 16
5.5 Minimum clearances between parts under special conditions . 18
5.6 Tested connection zones . 18
6 Equipment . 18
6.1 General requirements . 18
6.2 Specific requirements . 18
6.2.1 Switching devices . 18
6.2.2 Reactors . 18
6.2.3 Prefabricated type-tested switchgear . 19
6.2.4 Surge arresters . 19
6.2.5 Capacitors . 19
6.2.6 Line traps . 19
6.2.7 Insulators . 19
6.2.8 Insulated cables . 19

6.2.9 Conductors and accessories . 20
6.2.10 Rotating electrical machines . 20
6.2.11 Static converters . 20
6.2.12 Fuses . 20
6.2.13 Electrical and mechanical Interlocking . 20
6.2.14 Electronic valve devices . 20
6.2.15 Valve cooling system . 20
7 Installations . 21
7.1 General requirements . 21
7.1.1 Circuit arrangement . 21
7.1.2 Documentation . 21
7.1.3 Transport routes . 21
7.1.4 Aisles and access areas . 21
7.1.5 Lighting . 21
7.1.6 Operational safety . 21
7.1.7 Labelling . 21
7.2 Outdoor installations of open design . 21
7.2.1 Protective barrier clearances . 22
7.2.2 Protective obstacle clearances . 22
7.2.3 Boundary clearances . 22
7.2.4 Minimum height over access area . 22
7.2.5 Clearances to buildings . 23
7.2.6 External fences or walls and access doors . 25
7.3 Indoor installations of open design . 25
7.4 Installation of prefabricated type-tested switchgear . 25
7.5 Requirements for buildings . 25
7.5.1 General . 25
7.5.2 Structural provisions . 25
7.5.3 Rooms for switchgear . 26
7.5.4 Maintenance and operating areas . 26
7.5.5 Doors . 26
7.5.6 Draining of insulating liquids . 26
7.5.7 Air conditioning and ventilation . 26
7.5.8 Buildings which require special consideration . 27
7.6 High voltage/low voltage prefabricated substations . 27
7.7 Electrical installations on mast, pole and tower . 27
8 Safety measures . 27
8.1 General . 27
8.2 Protection against direct contact . 27
8.2.1 Measures for protection against direct contact . 27
8.2.2 Protection requirements . 27
8.3 Means to protect persons in case of indirect contact . 28
8.4 Means to protect persons working on electrical installations . 28
8.5 Protection from danger resulting from arc fault . 28
8.6 Protection against direct lightning strokes . 28
8.7 Protection against fire . 28
8.8 Protection against leakage of insulating liquid . 28
8.9 Identification and marking . 28
9 Protection, control and auxiliary systems .
...