oSIST prHD 60364-7-712:2023

Low voltage electrical installations - Part 7-712: Requirements for special installations or locations - Solar photovoltaic (PV) power supply systems

Installations électriques à basse tension - Partie 7-712: Exigences applicables aux installations ou emplacements spéciaux - Installations d'énergie solaire photovoltaïque (PV)

Nizkonapetostne električne inštalacije - 7-712. del: Zahteve za posebne inštalacije ali lokacije - Sončna fotonapetostna (PV) napajalna omrežja

General Information

• Status: Not Published
• Public Enquiry End Date: 28-Sep-2023
• ICS: 27.160 - Solar energy engineering
• ICS: 91.140.50 - Electricity supply systems
• Technical Committee: ELI - Electrical and communication installations
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 12-Jul-2023
• Due Date: 29-Nov-2023
• Ref Project: prHD 60364-7-712:2023 - Low voltage electrical installations - Part 7-712: Requirements for special installations or locations - Solar photovoltaic (PV) power supply systems

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prHD 60364-7-712:2023
01-september-2023
Nizkonapetostne električne inštalacije - 7-712. del: Zahteve za posebne inštalacije
ali lokacije - Sončna fotonapetostna (PV) napajalna omrežja
Low voltage electrical installations - Part 7-712: Requirements for special installations or
locations - Solar photovoltaic (PV) power supply systems
Installations électriques à basse tension - Partie 7-712: Exigences applicables aux
installations ou emplacements spéciaux - Installations d'énergie solaire photovoltaïque
(PV)
Ta slovenski standard je istoveten z: prHD 60364-7-712:2023
ICS:
27.160 Sončna energija Solar energy engineering
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
oSIST prHD 60364-7-712:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prHD 60364-7-712:2023

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oSIST prHD 60364-7-712:2023
64/2628/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60364-7-712 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-07-07 2023-09-29
SUPERSEDES DOCUMENTS:
64/2514/CD, 64/2620/CC

IEC TC 64 : ELECTRICAL INSTALLATIONS AND PROTECTION AGAINST ELECTRIC SHOCK
SECRETARIAT: SECRETARY:
Germany Mr Wolfgang Niedenzu
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
TC 8,SC 8B,TC 20,TC 22,SC 22F,SC 23E,SC
23K,SC 32B,SC 37A,TC 82,TC 85,TC 120,TC
Other TC/SCs are requested to indicate their interest, if any, in this
121,SC 121A,SC 121B,PC 128,SyC LVDC,SyC
CDV to the secretary.
Smart Energy
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.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some Countries”
clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for
submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Low voltage electrical installations - Part 7-712: Requirements for special installations or locations -
Solar photovoltaic (PV) power supply systems

PROPOSED STABILITY DATE: 2028

Copyright © 2023 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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NOTE FROM TC/SC OFFICERS:


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IEC CDV 60364-7-712 © IEC 2023 – 3 – 64/2628/CDV
1 CONTENTS
2
3 FOREWORD . 7
4 INTRODUCTION . 9
5 712 Solar photovoltaic (PV) power supply installations . 11
6 712.1 Scope . 11
7 712.2 Normative references . 11
8 712.3 Terms and definitions. 13
9 712.3.1 13
10 712.31 Purposes, supplies and structure . 19
11 712.31.101 PV installation configurations . 19
12 712.4 Protection for safety . 31
13 712.4.101 General . 31
14 712.41 Protection against electric shock . 31
15 712.410 Introduction . 31
16 712.410.3 General Requirements . 31
17 712.411 Protective measure: automatic disconnection of supply . 32
18 712.411.3 Requirements for fault protection . 32
19 712.412 Protective measure: double or reinforced insulation . 34
20 712.412.2 Requirements for basic protection and fault protection . 34
21 712.414 Protective measure: extra-low-voltage provided by SELV and PELV . 35
22 712.414.101 . 35
23 712.42 Protection against thermal effects . 35
24 712.421 Protection against fire caused by electrical equipment . 35
25 712.421.101 . 35
26 712.421.102 Provisions against the thermal effects due to insulation
27 faults on the DC side . 36
28 712.43 Protection against overcurrent . 37
29 712.430 . 37
30 712.430.3 General requirements . 37
31 712.432 Nature of protective devices . 38
32 712.432.101 . 38
33 712.433 Protection against overload current . 38
34 712.433.1 Coordination between conductors and overload protective devices . 38
35 712.433.2 Position of devices for overload protection . 41
36 712.433.101 Protection of PV array cable . 42
37 712.433.102 Protection of PV AC supply cable . 42
38 712.434 Protection against short-circuit currents . 42
39 712.434.101 . 42
40 712.44 Protection against voltage disturbances and electromagnetic disturbances . 42
41 712.443 Protection against transient overvoltages of atmospheric origin or due
42 to switching . 42
43 712.443.4 Overvoltage control . 42
44 712.443.5 Risk assessment method . 42
45 712.5 Selection and erection of electrical equipment . 43
46 712.51 Common rules . 43
47 712.51.101 43

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48 712.510 Introduction . 43
49 712.510.3 General . 43
50 712.511 Compliance with standards . 43
51 712.511.1 43
52 712.512 Operational conditions and external influences . 44
53 712.512.1 Operational conditions . 44
54 712.513 Accessibility . 45
55 712.513.101 . 45
56 712.514 Identification . 45
57 712.514.101 Safety marking . 45
58 712.514.102 Live parts marking . 46
59 712.514.103 Isolation marking . 46
60 712.514.104 Equipment marking . 46
61 712.514.105 Requirements for signs . 46
62 712.514.106 Labelling of disconnection devices . 46
63 712.514.107 Documentation . 46
64 712.514.2 Wiring systems . 46
65 712.515 Prevention of mutual detrimental influence . 47
66 712.515.101 . 47
67 712.515.102 Selection and erection of PV modules in relation with
68 external influences . 47
69 712.52 Wiring systems . 48
70 712.521 Types of wiring systems . 48
71 712.521.101 Type . 48
72 712.521.102 . 48
73 712.521.103 General . 48
74 712.521.104 Wiring loops . 49
75 712.521.105 String wiring and DCU string wiring . 49
76 712.521.106 String wiring harness . 49
77 712.522 Selection and erection of wiring systems in relation to external
78 influences . 51
79 712.522.101 Installation method . 51
80 712.523 Current-carrying capacities . 51
81 712.523.101 . 51
82 712.524 Cross-sectional areas of conductors . 51
83 712.524.1 51
84 712.526 Electrical connections . 53
85 712.526.101 . 53
86 712.526.102 Connectors on the DC side . 53
87 712.526.103 Wiring installation in combiner boxes . 53
88 712.527 Selection and erection of wiring systems to minimize spread of fire . 53
89 712.53 Devices for protection for safety, isolation, switching, control and monitoring . 53
90 712.531 Equipment for protection against electric shock . 53
91 712.531.2 Devices for automatic disconnection of supply . 53
92 712.532 Devices and precautions for protection against thermal effects . 54
93 712.532.101 Protection against thermal effects due to insulation faults
94 which includes the use of an IMD . 54
95 712.533 Devices for protection against overcurrent . 54
96 712.533.1 General requirements . 54

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97 712.534 Devices for protection against transient overvoltages . 55
98 712.534.1 General . 55
99 712.534.4 Selection and erection of SPDs . 55
100 712.536 Isolation and switching . 56
101 712.536.2 Isolation. 56
102 712.537 Monitoring . 58
103 712.537.1 General . 58
104 712.54 Earthing arrangements and protective conductors . 60
105 712.542 Earthing arrangements . 60
106 712.542.101 Separate earth electrode . 60
107 712.542.102 Bonding of PV metal structures . 60
108 712.544 Protective bonding conductors . 60
109 712.544.2 Protective bonding conductors for supplementary bonding . 60
110 712.55 Other equipment . 61
111 712.55.101 Measures to prevent DC on-load interruption . 61
112 712.55.102 Blocking diodes . 61
113 712.6 Inspection and testing . 61
114 Annex A (normative) Calculation of U and I . 62
OC MAX SC MAX
115 A.1 Calculation of U . 62
OC MAX
116 A.2 Calculation of I . 63
SC MAX
117 Annex B (informative) Examples of signs . 64
118 B.1 General . 64
119 Annex C (informative) Performance issues . 65
120 Annex D (informative) Further examples of architecture configurations . 66
121 D.1 General . 66
122 Annex E (informative) Current carrying capacities of PV cables - Temperature
123 correction factors . 67
124 Annex F (informative) List of notes concerning certain countries . 69
125 Bibliography . 70
126
127 Figure 1 – General functional configuration of a PV installation with energy storage . 20
128 Figure 2 – DCU string circuit: defined by output of DC/DC converters in serial
129 connection (purple) . 21
130 Figure 3 – PCE using an external transformer . 22
131 Figure 4 – Example of PV array diagram – single string case . 24
132 Figure 5 – Example of PV array diagram – multiple parallel string case . 25
133 Figure 6 – Example of PV array diagram – multiple parallel DCU string case . 26
134 Figure 7 – Example of PV array diagram – multiple parallel string case with array
135 divided into subarrays . 27
136 Figure 8 – Example of PV array using a PCE with multiple separate DC inputs . 28
137 Figure 9 – Example of PV array using a PCE with multiple DC inputs internally
138 connected to a common DC bus . 29
139 Figure 10 – Example of fault protection on DC bus circuit using an IT system . 33
140 Figure 11 – Example of fault protection on DC bus circuit with non-separated PCE
141 connected to a TT or TN system . 33
142 Figure 12 – Example of fault protection on DC bus circuit with separated PCE using a
143 TT or TN system . 34

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144 Figure 13 – Example of a PV array diagram where strings are grouped under one
145 OCPD per group . 41
146 Figure 14 – Example of a sign indicating the presence of a photovoltaic installation . 45
147 Key: 49
148 Figure 15 – PV string wiring and DCU string wiring with minimum loop area . 49
149 Figure 16 – String wiring harness. 50
150 Figure B.1 – Example of sign required on PV array combiner boxes . 64
151 Figure D.1 – Further architecture configurations of the DC bus . 66
th
152 Figure E.1 – IEC TS 63126:2020 Figure A.3 98 percentile temperature for an open-
153 rack, or thermally unrestricted, glass superstrate, polymer backsheet module . 68
th
154 Figure E.2 – IEC TS 63126:2020 Figure A.4 98 percentile temperature for a close-
155 roof mounted glass superstrate, polymer backsheet module . 68
156
157 Table 1 – Calculation of the critical length L . 43
crit
158 Table 2 – Minimum current rating of circuits . 52
159 Table 3 – Isolation devices in PV array installations . 57
160 Table 4 – Minimum insulation resistance thresholds for detection of failure of
161 insulation to earth . 58
162 Table 5 – Response time limits for sudden changes in residual current . 59
163 Table E.1 – IEC 62930:2017 Table A.3 current carrying capacity of PV cables . 67
164 Table E.2 – IEC 62930:2017 Table A.4 current rating conversion factors for different
165 ambient temperatures . 67
166 Table F.1 – List of notes concerning certain countries . 69
167
168

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169 INTERNATIONAL ELECTROTECHNICAL COMMISSION
170 ____________
171
172
173 LOW VOLTAGE ELECTRICAL INSTALLATIONS –
174
175 Part 7-712: Requirements for special installations or locations –
176 Solar photovoltaic (PV) power supply installations
177
178 FOREWORD
179 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
180 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
181 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
182 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
183 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
184 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
185 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
186 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
187 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
188 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
189 consensus of opinion on the relevant subjects since each technical committee has representation fro m all
190 interested IEC National Committees.
191 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
192 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of I EC
193 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
194 misinterpretation by any end user.
195 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
196 transparently to the maximum extent possible in their national and regional publications. Any divergence between
197 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
198 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
199 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
200 services carried out by independent certification bodies.
201 6) All users should ensure that they have the latest edition of this publication.
202 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
203 members of its technical committees and IEC National Committees for any personal injury, property damage or
204 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
205 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
206 Publications.
207 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
208 indispensable for the correct application of this publication.
209 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
210 rights. IEC shall not be held responsible for identifying any or all such patent rights.
211 IEC 60364-76712 has been prepared by IEC technical committee 64: electrical installations and
212 protection against electric shock. It is an International Standard.
213 This third edition cancels and replaces the second edition published in 2017. This edition
214 constitutes a technical revision.
215 This edition includes the following significant technical changes with respect to the previous
216 edition:
217 a) The technical content has been extensively revised and expanded, taking into account
218 experience gained in the construction and operation of PV installations, and developments
219 made in technology, since the second edition of this standard was published.
220 b)
221 The text of this International Standard is based on the following documents:

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Draft Report on voting
XX/XX/FDIS XX/XX/RVD
222
223 Full information on the voting for its approval can be found in the report on voting indicated in
224 the above table.
225 The language used for the development of this International Standard is English.
226 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
227 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
228 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
229 described in greater detail at www.iec.ch/publications.
230 The committee has decided that the contents of this document will remain unchanged until the
231 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
232 specific document. At this date, the document will be
233 • reconfirmed,
234 • withdrawn,
235 • replaced by a revised edition, or
236 • amended.
237

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238 INTRODUCTION
239
240 For the purpose of this part of IEC 60364 (IEC 60364-7-712), the requirements of the general
241 parts 1 to 6 and part 8 of IEC 60364 apply.
242 The IEC 60364-7-7XX parts of IEC 60364 contain particular requirements for special
243 installations or locations which are based on the requirements of the general parts of IEC 60364
244 (IEC 60364-1 to IEC 60364-6 and IEC 60364-8). These IEC 60364-7-7XX parts are considered
245 in conjunction with the requirements of the general parts.
246 The particular requirements of this part of IEC 60364 supplement, modify or replace certain of
247 the requirements of the general parts of IEC 60364 being valid at the time of publication of this
248 part. The absence of reference to the exclusion of a part or a clause of a general part means
249 that the corresponding clauses of the general part are applicable (undated reference).
250 Requirements of other 7XX parts being relevant for installations covered by this part also apply.
251 This part may therefore also supplement, modify or replace certain of these requirements valid
252 at the time of publication of this part.
253 The clause numbering of this part follows the pattern and corresponding references of
254 IEC 60364. The numbers following the particular number of this part are those of the
255 corresponding parts, or clauses of the other parts of the IEC 60364 series, valid at the time of
256 publication of this part, as indicated in the normative references of this document (dated
257 reference). If requirements or explanations additional to those of the other parts of the
258 IEC 60364 series are needed, the numbering of such items appears as 712.101, 712.102,
259 712.103, etc.
260 Numbering of figures and tables takes the number of this part followed b
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