oSIST prEN IEC 61936-2:2022

SLOVENSKI STANDARD
oSIST prEN IEC 61936-2:2022
01-oktober-2022
Elektroenergetski postroji za izmenične napetosti nad 1 kV in enosmerne
napetosti nad 1,5 kV - 2. del: Enosmerna napetost
Power installations exceeding 1 kV AC and 1,5 kV DC - Part 2: DC
Installations électriques de puissance de tension supérieure à 1 kV en courant alternatif
et 1,5 kV en courant continu - Partie 2: Courant continu
Ta slovenski standard je istoveten z: prEN IEC 61936-2:2022
ICS:
29.240.01 Omrežja za prenos in Power transmission and
distribucijo električne energije distribution networks in
na splošno general
oSIST prEN IEC 61936-2:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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99/364/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61936-2 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2022-08-19 2022-11-11
SUPERSEDES DOCUMENTS:
99/324/CD, 99/359/CC

IEC TC 99 : INSULATION CO-ORDINATION AND SYSTEM ENGINEERING OF HIGH VOLTAGE ELECTRICAL POWER INSTALLATIONS ABOVE 1,0
KV AC AND 1,5 KV DC
SECRETARIAT: SECRETARY:
Australia Ms Erandi Chandrasekare
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

SC 22F,TC 115
Other TC/SCs are requested to indicate their interest, if any,
in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.

This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they
are aware and to provide supporting documentation.

TITLE:
Power installations exceeding 1 kV AC and 1,5 kV DC - Part 2: DC

PROPOSED STABILITY DATE: 2027

NOTE FROM TC/SC OFFICERS:


Copyright © 2022 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions. You
may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without permission
in writing from IEC.

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1 CONTENTS
2 CONTENTS . 2
3 FOREWORD . 5
4 INTRODUCTION . 7
5 1 Scope . 8
6 2 Normative references . 8
7 3 Terms and definitions . 9
8 Symbols and abbreviations . 11
9 4 Fundamental requirements . 12
10 4.1 General . 12
11 4.1.1 General requirements . 12
12 4.1.2 Agreements between supplier and user . 13
13 4.2 Electrical requirements . 14
14 4.2.1 Methods of DC neutral point earthing . 14
15 4.2.2 Voltage classification . 16
16 4.2.3 Current in normal operation . 16
17 4.2.4 Short-circuit current . 16
18 4.2.5 Rated frequency . 16
19 4.2.6 Corona . 17
20 4.2.7 Electric and magnetic fields . 17
21 4.2.8 Overvoltages . 17
22 4.2.9 Harmonics . 17
23 4.2.10 Electromagnetic compatibility . 18
24 4.2.11 Radio interference . 18
25 4.3 Mechanical requirements . 19
26 4.4 Climatic and environmental conditions . 19
27 4.4.1 General . 19
28 4.4.2 Normal conditions . 19
29 4.4.3 Special conditions . 20
30 4.5 Particular requirements . 22
31 4.5.1 Effects of small animals and micro-organisms. 22
32 4.5.2 Noise level . 22
33 4.5.3 Transport . 22
34 5 Insulation . 22
35 5.1 General . 22
36 5.2 Selection of insulation level. 22
37 5.2.1 General . 22
38 5.2.2 Consideration of methods of neutral earthing . 23
39 5.2.3 Consideration of rated withstand voltages for AC and specified
40 withstand voltages for DC . 23
41 5.3 Verification of withstand values . 23
42 5.4 Minimum clearances of live parts . 23
43 5.5 Minimum clearances between parts under special conditions . 23
44 5.6 Tested connection zones . 24
45 6 Equipment . 24
46 6.1 General requirements . 24
47 6.2 Specific requirements . 24

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48 6.2.1 Switching devices . 24
49 6.2.2 Power transformers and reactors . 24
50 6.2.3 Prefabricated type-tested switchgear . 25
51 6.2.4 Instrument Transformers . 25
52 6.2.5 Surge arresters . 25
53 6.2.6 Capacitors . 25
54 6.2.7 Line traps . 25
55 6.2.8 Insulators . 25
56 6.2.9 Insulated cables . 25
57 6.2.10 Conductors and accessories . 26
58 6.2.11 Rotating electrical machines . 26
59 6.2.12 Generating units . 26
60 6.2.13 Generating unit main connections . 26
61 6.2.14 Static converters . 26
62 6.2.15 Fuses . 26
63 6.2.16 Electrical and mechanical Interlocking . 26
64 6.2.17 Resistors . 26
65 6.2.18 Cooling system . 26
66 7 Installations . 27
67 7.1 General . 27
68 7.1.1 Common requirements . 27
69 7.1.2 Circuit arrangement . 27
70 7.1.3 Documentation . 27
71 7.1.4 Transport routes . 27
72 7.1.5 Aisles and access areas . 27
73 7.1.6 Lighting . 27
74 7.1.7 Operational safety . 27
75 7.1.8 Labelling . 27
76 7.2 Outdoor DC installations of open design . 27
77 7.2.1 General . 27
78 7.2.2 Protective barrier clearances . 28
79 7.2.3 Protective obstacle clearances . 28
80 7.2.4 Boundary clearances . 28
81 7.2.5 Minimum height over access area . 28
82 7.2.6 Clearances to buildings . 29
83 7.2.7 External fences or walls and access doors . 31
84 7.3 Indoor DC installations of open design . 31
85 7.4 Installation of prefabricated type-tested switchgear . 31
86 7.5 Requirements for buildings . 31
87 7.5.1 General . 31
88 7.5.2 Structural provisions . 31
89 7.5.3 Rooms for switchgear . 32
90 7.5.4 Maintenance and operating areas . 32
91 7.5.5 Doors . 32
92 7.5.6 Draining of insulating liquids . 32
93 7.5.7 Heating, ventilation and air conditioning (HVAC) . 32
94 7.5.8 Buildings which require special consideration . 32
95 7.6 High voltage/low voltage prefabricated substations . 33
96 7.7 Electrical installations on mast, pole and tower . 33

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97 8 Safety measures . 33
98 8.1 General . 33
99 8.2 Protection against direct contact . 33
100 8.2.1 General . 33
101 8.2.2 Measures for protection against direct contact . 33
102 8.2.3 Protection requirements . 33
103 8.3 Means to protect persons in case of indirect contact . 34
104 8.4 Means to protect persons working on electrical installations . 34
105 8.5 Protection from danger resulting from arc fault . 34
106 8.6 Protection against direct lightning strokes . 34
107 8.7 Protection against fire . 34
108 8.8 Protection against leakage of insulating liquid and SF . 34
6
109 8.9 Identification and marking . 34
110 9 Protection, control and auxiliary systems . 34
111 9.1 Protection systems. 34
112 9.2 Automation systems . 35
113 9.3 Auxiliary systems . 35
114 9.4 Basic rules for electromagnetic compatibility of control systems . 35
115 10 Earthing systems . 35
116 10.1 General . 35
117 10.2 Fundamental requirements . 35
118 10.2.1 Safety criteria . 35
119 10.2.2 Functional requirements . 36
120 10.2.3 High and low voltage earthing systems . 37
121 10.3 Design of earthing systems . 37
122 10.3.1 General . 37
123 10.3.2 Power system faults. 37
124 10.3.3 Lightning and transients. 38
125 10.4 Construction of earthing systems . 38
126 10.5 Measurements . 38
127 10.6 Maintainability . 38
128 10.6.1 Inspections . 38
129 10.6.2 Measurements . 38
130 11 Inspection and testing . 38
131 11.1 General . 38
132 11.2 Verification of specified performances . 38
133 11.3 Tests during installation and commissioning . 38
134 11.4 Trial running . 38
135 12 Operation and maintenance manual . 38
136 Annex A (informative) Example of typical DC voltages with possible insulation levels
137 and corresponding air clearances . 39
138 Annex B (normative) Method of calculating the voltage limit . 42
139 Bibliography . 43
140
141 Figure 1 - Simplified VSC scheme layout showing . 12
142 Figure 2- Simplified LCC bipole scheme layout showing . 12
143 Figure 3 - Neutral point earthing for various DC configurations . 15
144 Figure 4 – Approaches with buildings (within closed electrical operating areas) . 30
145 Figure 5 – Touch voltage limit DC . 36

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146
147 INTERNATIONAL ELECTROTECHNICAL COMMISSION
148 ____________
149
150 POWER INSTALLATIONS EXCEEDING 1 kV AC and 1,5 kV DC –
151
152 Part 2: DC
153
154 FOREWORD
155 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
156 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
157 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
158 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
159 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
160 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
161 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
162 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
163 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
164 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
165 consensus of opinion on the relevant subjects since each technical committee has representation from all
166 interested IEC National Committees.
167 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
168 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
169 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
170 misinterpretation by any end user.
171 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
172 transparently to the maximum extent possible in their national and regional publications. Any divergence between
173 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
174 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
175 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
176 services carried out by independent certification bodies.
177 6) All users should ensure that they have the latest edition of this publication.
178 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
179 members of its technical committees and IEC National Committees for any personal injury, property damage or
180 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
181 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
182 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
183 indispensable for the correct application of this publication.
184 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
185 rights. IEC shall not be held responsible for identifying any or all such patent rights.
186 International Standard IEC 61936-2 has been prepared by technical committee 99: Insulation
187 co-ordination and system engineering and erection of electrical power installations above 1 kV
188 AC and 1,5 kV DC.
189 The text of this International Standard is based on the following documents:
Enquiry draft Report on voting
99/XX/XX 99/XX/XX
190
191 Full information on the voting for the approval of this International Standard can be found in the
192 report on voting indicated in the above table.
193 This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
194 A list of all parts in the IEC 61936 series, published under the general title Power installations
195 exceeding 1 kV AC and 1,5 kV DC, can be found on the IEC website.

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196 Notes concerning particular conditions in certain countries are provided in Annex G of IEC
197 61936-1: 2021.
198 The committee has decided that the contents of this publication will remain unchanged until
199 the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
200 related to the specific publication. At this date, the publication will be
201 • reconfirmed,
202 • withdrawn,
203 • replaced by a revised edition, or
204 • amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
205
206
207

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208 INTRODUCTION
209 There are few national laws, standards and internal rules dealing with the matter coming within
210 the scope of this standard, and these practices have been taken as a basis for this work.
211 This part of IEC 61936 contains the minimum requirements and some additional information
212 which ensures an acceptable reliability of an installation and its safe operation.
213 The publication of this International Standard is believed to be a decisive step towards the
214 gradual alignment all over the world of the practices concerning the design and erection of high
215 voltage power installations.
216 Particular requirements for transmission and distribution installations as well as particular
217 requirements for power generation and industrial installations are included in this standard.
218 The relevant laws or regulations of an authority having jurisdiction takes precedence.
219

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220
221 POWER INSTALLATIONS EXCEEDING 1 kV AC and 1,5 kV DC –
222
223 Part 2: DC
224
225
226 1 Scope
227 This part of IEC 61936 provides, in a convenient form, requirements for the design and the
228 erection of DC installations in systems with nominal voltages above 1,5 kV DC, so as to provide
229 safety and proper functioning for the use intended.
230 For the purpose of interpreting this standard, a DC installation is considered to be one of the
231 following:
232 a) A converter station or DC switching station;
233 b) one (or more) DC generating or storage unit(s), such as solar farms or battery storage units,
234 located on a single site, the DC installation includes DC equipment and cables with all
235 associated power electronics, controlgear, switchgear and all electrical auxiliary systems.
236 Connections between DC generating or storage units located on different sites are excluded;
237 c) DC installation erected on offshore facilities for the purpose of generation, transmission,
238 distribution and/or storage of electricity; or
239 d) DC transition station (between overhead lines and underground cable or between different
240 sections of underground cables).
241 This International Standard does not apply to the design and erection of any of the following:
242 – overhead and underground lines between separate installations;
243 – electric railways;
244 – mining equipment and installations;
245 – installations on ships according to IEC 60092 series and offshore units according to IEC
246 61892 series, which are used in the offshore petroleum industry for drilling, processing and
247 storage purposes;
248 – electrostatic equipment (e.g. electrostatic precipitators, spray-painting units);
249 – test sites;
250 – medical equipment, e.g. medical X-ray equipment;
251 – valve hall or converter hall.
252 This International Standard does not apply to the requirements for carrying out live working on
253 electrical installations.
254 This International Standard does not apply to the design of factory-built, type-tested thyristor
255 valves, VSC valves and switchgear for which separate IEC standards exist.
256 2 Normative references
257 The following documents, in whole or in part, are normatively referenced in this document and
258 are indispensable for its application. For dated references, only the edition cited applies. For
259 undated references, the latest edition of the referenced document (including any amendments)
260 applies.
261 IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
262 IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules

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263 IEC 60071-2:2018, Insulation co-ordination – Part
...