oSIST prEN IEC 61558-2-23:2023

Safety of transformers, reactors, power supply units and combinations thereof - Part 2-23: Particular requirements and tests for transformers and power supply units for construction sites

Sicherheit von Transformatoren, Drosseln, Netzgeräten und entsprechenden Kombinationen - Teil 2-23: Besondere Anforderungen und Prüfungen für Transformatoren und Netzgeräte für Baustellen

Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et des combinaisons de ces élements - Partie 2-23: Règles particulières et essais pour les transformateurs et les blocs d'alimentation pour chantiers

Varnost transformatorjev, dušilk, napajalnikov in kombinacij teh elementov - 2-23. del: Posebne zahteve in preskusi za transformatorje in napajalnike za gradbišča

General Information

• Status: Not Published
• Public Enquiry End Date: 27-Feb-2023
• ICS: 29.180 - Transformers. Reactors
• ICS: 91.200 - Construction technology
• Technical Committee: I96 - Imaginarni 96
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 16-Dec-2022
• Due Date: 05-May-2023
• Completion Date: 19-Apr-2023
• Directive: 2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Ref Project: prEN IEC 61558-2-23:2022 - Safety of transformers, reactors, power supply units and combinations thereof - Part 2-23: Particular requirements and tests for transformers and power supply units for construction sites

Relations

• Revised: SIST EN 61558-2-23:2010 - Safety of transformers, reactors, power supply units and combinations thereof - Part 2-23: Particular requirements and tests for transformers and power supply units for construction sites (IEC 61558-2-23:2010)
• Effective Date: 06-Sep-2022

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN IEC 61558-2-23:2023
01-februar-2023
Varnost transformatorjev, dušilk, napajalnikov in kombinacij teh elementov - 2-23.
del: Posebne zahteve in preskusi za transformatorje in napajalnike za gradbišča
Safety of transformers, reactors, power supply units and combinations thereof - Part 2-
23: Particular requirements and tests for transformers and power supply units for
construction sites
Sicherheit von Transformatoren, Drosseln, Netzgeräten und entsprechenden
Kombinationen - Teil 2-23: Besondere Anforderungen und Prüfungen für
Transformatoren und Netzgeräte für Baustellen
Sécurité des transformateurs, bobines d'inductance, blocs d'alimentation et des
combinaisons de ces élements - Partie 2-23: Règles particulières et essais pour les
transformateurs et les blocs d'alimentation pour chantiers
Ta slovenski standard je istoveten z: prEN IEC 61558-2-23:2022
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
91.200 Gradbena tehnologija Construction technology
oSIST prEN IEC 61558-2-23:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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96/563/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:

IEC 61558-2-23 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:

2022-12-09 2023-03-03
SUPERSEDES DOCUMENTS:

96/553/RR

IEC TC 96 : TRANSFORMERS, REACTORS, POWER SUPPLY UNITS, AND COMBINATIONS THEREOF
SECRETARIAT: SECRETARY:
Germany Mr Wolfgang Reichelt
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

SC 3C,TC 14,TC 22,SC 22E,SC 34C,TC 51,TC
55,TC 61,SC 62A,TC 64,TC 66,TC 77,TC 85,TC
Other TC/SCs are requested to indicate their interest, if
97,TC 106,TC 108,TC 109,TC 111,TC 112
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:
Safety of transformers, reactors, power supply units and combinations thereof - Part 2-23:
Particular requirements and tests for transformers and power supply units for construction
sites

PROPOSED STABILITY DATE: 2025

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
3 FOREWORD. 3
4 INTRODUCTION . 5
5 1 Scope . 6
6 2 Normative references . 7
7 3 Terms and definitions . 7
8 4 General requirements . 8
9 5 General notes on tests . 8
10 6 Ratings . 8
11 7 Classification . 9
12 8 Marking and other information . 9
13 9 Protection against electric shock . 11
14 10 Change of input voltage setting . 11
15 11 Output voltage and output current under load . 11
16 12 No-load output voltage . 11
17 13 Short-circuit voltage . 13
18 14 Heating . 13
19 15 Short-circuit and overload protection . 13
20 16 Mechanical strength . 13
21 17 Protection against harmful ingress of dust, solid objects and moisture . 14
22 18 Insulation resistance, dielectric strength and leakage current . 14
23 19 Construction . 14
24 20 Components . 17
25 21 Internal wiring . 17
26 22 Supply connection and other external flexible cable or cords . 17
27 23 Terminals for external conductors . 17
28 24 Provisions for protective earthing . 17
29 25 Screws and connections . 17
30 26 Creepage distances, clearances and distances through insulation . 18
31 27 Resistance to heat, fire and tracking . 18
32 28 Resistance to rusting . 18
33 Annexes . 19
34 Bibliography . 20
35
36 Table 101 – Symbols indicating the kind of transformer . 10
37 Table 102 – Output voltage ratio for safety isolating transformers . 12
38 Table 103 – Output voltage ratio for isolating transformers . 12
39
40

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41 INTERNATIONAL ELECTROTECHNICAL COMMISSION
42 ____________
43
44 SAFETY OF TRANSFORMERS, REACTORS,
45 POWER SUPPLY UNITS AND COMBINATIONS THEREOF –
46
47 Part 2-23: Particular requirements and tests for transformers and
48 power supply units for construction sites
49
50
51 FOREWORD
52 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
53 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
54 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
55 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
56 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
57 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
58 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
59 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
60 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
61 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
62 consensus of opinion on the relevant subjects since each technical committee has representation from all
63 interested IEC National Committees.
64 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
65 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
66 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
67 misinterpretation by any end user.
68 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
69 transparently to the maximum extent possible in their national and regional publications. Any divergence between
70 any IEC Publication and the corresponding national or regional publication shall be clearl y indicated in the latter.
71 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
72 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
73 services carried out by independent certification bodies.
74 6) All users should ensure that they have the latest edition of this publication.
75 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
76 members of its technical committees and IEC National Committees for any personal injury, property damage or
77 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
78 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
79 Publications.
80 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
81 indispensable for the correct application of this publication.
82 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
83 rights. IEC shall not be held responsible for identifying any or all such patent rights.
84 International standard IEC 61558-2-23 has been prepared by IEC technical committee 96:
85 Transformers, reactors, power supply units and combinations thereof.
86 This third edition cancels and replaces the second edition published in 2010. This edition
87 constitutes a technical revision.
88 This edition includes the following significant technical changes with respect to the previous
89 edition:
90 a) Adjustment of structure and references in accordance with IEC 61558-1:2017
91 b) New symbol for power supply units with linearly regulated output voltage
92
93

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94 The text of this International Standard is based on the following documents:
Draft Report on voting
96/XXX/FDIS 96/XXX/RVD
95
96 Full information on the voting for its approval can be found in the report on voting indicated in
97 the above table.
98 The language used for the development of this International Standard is English.
99 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
100 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
101 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
102 described in greater detail at www.iec.ch/standardsdev/publications.
103 It has the status of a group safety publication in accordance with IEC Guide 104.
104 This International Standard is to be used in conjunction with IEC 61558-1:2017.
105 This document supplements or modifies the corresponding clauses in IEC 61558-1:2017, so as
106 to convert that publication into the IEC standard: Particular requirements and tests for
107 transformers and power supply units for construction sites.
108 A list of all parts in the IEC 61558 series published under the general title Safety of transformers,
109 reactors, power supply units and combinations thereof, can be found on the IEC website.
110 Future standards in this series will carry the new general title as cited above. Titles of existing
111 standards in this series will be updated at the time of the next edition.
112 Where this document states "addition", "modification" or "replacement", the relevant text of
113 IEC 61558-1:2017 is to be adopted accordingly.
114 In this document, the following print types are used:
115 − requirements proper: in roman type;
116 − test specifications: in italic type;
117 − explanatory matter: in smaller roman type.
118 In the text of this document, the words in bold are defined in Clause 3.
119 Subclauses, notes, figures and tables additional to those in IEC 61558-1:2017 are numbered
120 starting from 101; supplementary annexes are entitled AA, BB, etc.
121 The committee has decided that the contents of this document will remain unchanged until the
122 stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
123 the specific document. At this date, the document will be
124 • reconfirmed,
125 • withdrawn,
126 • replaced by a revised edition, or
127 • amended.

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128 INTRODUCTION
129 IEC/TC 96 has a group safety function in accordance with IEC Guide 104 for transformers other
130 than those intended to supply distribution networks, in particular transformers and power supply
131 units intended to allow the application of protective measures against electric shock as defined
132 by TC 64, but in certain cases including the limitation of voltage and horizontal safety function
133 for SELV, in accordance with IEC 60364-4-41.
134 The group safety function (GSF) is used because of responsibility for safety extra-low voltage
135 (SELV) in accordance with IEC 61140:2016, 5.2.6 and IEC 60364-4-41:2017, 414.3.1 or control
136 circuits in accordance with IEC 60204-1:2016, 7.2.4.
137 The group safety function is used for each part of IEC 61558-2 because different standards of
138 the IEC 61558 series can be combined in one construction but in certain cases with no limitation
139 of rated output power.
140 For example an auto-transformer in accordance with IEC 61558-2-13 can be designed with a
141 separate SELV-circuit in accordance with the particular requirements for IEC 61558-2-6 relating
142 to the general requirements of IEC 61558-1.
143

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144 SAFETY OF TRANSFORMERS, REACTORS,
145 POWER SUPPLY UNITS AND COMBINATIONS THEREOF –
146
147 Part 2-23: Particular requirements and tests for transformers and
148 power supply units for construction sites
149
150
151 1 Scope
152 Replacement
153 This part of IEC 61558 deals with the safety of transformers for construction sites and power
154 supply units incorporating transformers for construction sites. Transformers incorporating
155 electronic circuits are also covered by this document.
156 NOTE 1 Safety includes electrical, thermal and mechanical aspects.
157 Unless otherwise specified, from here onward, the term transformer covers transformers for
158 construction sites and power supply units incorporating transformers for construction sites.
159 This document is applicable to stationary or portable, single-phase or polyphase, air-cooled
160 (natural or forced) independent or associated transformers, being isolating or safety
161 isolating dry-type transformers for the use on construction sites. The windings can be
162 encapsulated or non-encapsulated.
163 For power supply units (linear) this document is applicable. For switch mode power supply
164 units, IEC 61558-2-16 is applicable together with this document. Where two requirements are
165 in conflict, the most severe take precedence.
166 The rated supply voltage does not exceed 1 000 V AC, and the rated supply frequency and
167 the internal operating frequencies do not exceed 500 Hz.
168 The rated output does not exceed:
169 − 25 kVA for single-phase transformers;
170 − 40 kVA for polyphase transformers.
171 This document is applicable to transformers without limitation of the rated output subject to
172 an agreement between the purchaser and the manufacturer.
173 NOTE 2 Transformers intended to supply distribution networks are not included in the scope.
174 Isolating transformers for construction sites have a no-load output voltage and a rated
175 output voltage exceeding 50 V AC and not exceeding 250 V AC.
176 Safety isolating transformers for construction sites have a no-load output voltage and a
177 rated output voltage not exceeding 50 V AC.
178 NOTE 3 This standard is applicable to transformers for the supply of electricity in locations as specified in
179 IEC 60364-7-704. The latter also specifies the protection by using an earthed midpoint or starpoint of the output
180 winding.
181 NOTE 4 Transformers covered by this document are used in applications where it is required by the installation
182 rules or by the appliance specification for protection purposes.
183 NOTE 5 When the transformers are incorporated into low voltage switchgear and controlgear assemblies for
184 construction sites as specified in IEC 60439-4, the additional requirements of IEC 60439-4 will apply to the
185 assembly.
186 NOTE 6 For transformers filled with liquid dielectric or pulverised material, such as sand, additional requirements
187 are under consideration.
188 Attention is drawn to the following if necessary:

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189 − for transformers intended to be used in vehicles, on board ships, and aircraft, additional
190 requirements (from other applicable standards, national rules, etc.);
191 − measures to protect the enclosure and the components inside the enclosure against
192 external influences such as fungus, vermin, termites, solar-radiation, and icing;
193 − the different conditions for transportation, storage, and operation of the transformers;
194 − additional requirements in accordance with other appropriate standards and national rules
195 can be applicable to transformers intended for use in special environments.
196 Future technological development of transformers can necessitate a need to increase the
197 upper limit of the frequencies. Until then this document can be used as a guidance document.
198 This group safety publication focusing on safety guidance is primarily intended to be used as a
199 product safety standard for the products mentioned in the scope, but is also intended to be used
200 by technical committees in the preparation of publications for products similar to those
201 mentioned in the scope of this group safety publication, in accordance with the principles laid
202 down in IEC Guide 104 and lSO/lEC Guide 51.
203 One of the responsibilities of a technical committee is, wherever applicable, to make use of
204 basic safety publications and/or group safety publications in the preparation of its publications.
205
206 2 Normative references
207 This clause of IEC 61558-1 is applicable, except as follows:
208 Addition
209 IEC 60068-2-27:2008, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
210 IEC 60439-4:2012, Low-voltage switchgear and controlgear assemblies – Part 4: Particular
211 requirements for assemblies for construction sites (ACS)
212 IEC 61558-1:2017, Safety of transformers, reactors, power supply units and combinations
213 thereof – Part 1: General requirements and tests
214 IEC 61558-2-16:2021, Safety of transformers, reactors, power supply units and combinations
215 thereof – Part 1: Particular requirements and tests for switch mode power supply units and
216 transformers for switch mode power supply units for general applications
217
218 3 Terms and definitions
219 For the purposes of this document, the terms and definitions given in IEC 61558-1 apply.
220 ISO and IEC maintain terminological databases for use in standardization at the following
221 addresses:
222 • IEC Electropedia: available at http://www.electropedia.org/
223 • ISO Online browsing platform: available at http://www.iso.org/obp
224
225
226 3.2 General terms
227 Addition

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228 3.2.101
229 low voltage switchgear and controlgear assembly for construction sites (ACS)
230 combination of one or several transforming or switching devices with associated control,
231 measuring, signalling, protective and regulating equipment complete with all their internal
232 electrical and mechanical connections and structural parts, designed and built for use on all
233 construction sites, indoors or outdoors
234
235 4 General requirements
236 This clause of IEC 61558-1 is applicable.
237
238 5 General notes on tests
239 This clause of IEC 61558-1 is applicable.
240
241 6 Ratings
242 This clause of IEC 61558-1 is applicable except as follows:
243 Addition
244 6.101 The rated output voltage shall not exceed:
245 − 250 V AC for isolating transformers with a non-earthed mid-point (single-phase) or a
246 non-earthed star-point (three-phase) or delta connection (three-phase);
247 − 115 V AC for isolating transformers with a mid-point (single-phase) earthed in the
248 construction or a star-point (three-phase) earthed in the construction;
249 − 50 V AC for safety isolating transformers.
250 The rated output voltage shall exceed:
251 − 50 V AC for isolating transformers
252 Preferred values for the rated output voltage are
253 − 115 V and 230 V for portable, single-phase isolating transformers;
254 − 72 V, 115 V and 230 V for other isolating transformers;
255 − 6 V, 12 V, 24 V, 42 V and 48 V for safety isolating transformers.
256
257 6.102 The rated output shall not exceed:
258 − 25 kVA for single-phase isolating and safety isolating transformers;
259 − 40 kVA for polyphase isolating and safety isolating transformers;
260
261 Preferred values for the rated output are
262 − 25 VA, 40 VA, 63 VA, 100 VA, 160 VA, 250 VA, 400 VA, 630 VA, 1 000 VA, 1 600 VA,
263 2 500 VA, 4 000 VA, 6 300 VA, 10 kVA, 16 kVA and 25 kVA for single-phase
264 transformers;

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265 − 630 VA, 1 000 VA, 1 600 VA, 2 500 VA, 4 000 VA, 6 300 VA, 10 kVA, 16 kVA, 25 kVA
266 and 40 kVA for polyphase transformers.
267 Intermittent duty cycle can be assigned only to portable transformers having a rated output
268 not exceeding 6,3 kVA.
269 Transformers without limitation of the rated output shall be subject to agreement between the
270 purchaser and the manufacturer.
271
272 6.103 The rated supply frequency shall not exceed 500 Hz.
273
274 6.104 The rated supply voltage shall not exceed 1 000 V AC.
275
276 6.105 Transformers with intermittent duty cycle shall be intended for a rated operating time
277 of 5 min "on" and a resting time of 15 min "off".
278
279 6.106 The supply current is limited to a maximum of 125 A, and in the case of flexible cable or
280 socket outlet, to 63 A.
281 Compliance with 6.101 to 6.106 is checked by inspection of the marking.
282
283 7 Classification
284 This clause of IEC 61558-1 is applicable, except as follows:
285
286 Replacement
287 7.5 Transformers are classified in accordance with their duty type:
288 − continuous duty;
289 − intermittent duty cycle.
290
291 8 Marking and other information
292 This clause of IEC 61558-1 is applicable, except as follows:
293
294 8.1 h)
295 Replacement of the content up to the first semi-colon by the following:
296 relevant graphical symbols shown in Table 101 that indicate the kind of transformer
297
298 8.11
299 Addition
300 The symbol for linear power supply units shall be used in conjunction with the symbol
301 indicating the kind of transformer.
302

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303 Table 101 – Symbols indicating the kind of transformer
Symbol or
Explanation or title Identification
graphical
symbol
Isolating transformer for construction sites, fail-safe IEC 60417-6010-1:2007-02

Safety isolating transformer for construction sites, fail-safe IEC 60417-6010-2:2007-02

Isolating transformer for construction sites, fail-safe, IEC 60417-6010-3:2007-02
mid-point or star-point earthed

Isolating transformer for construction sites, IEC 60417-6010-4:2007-02
non-short-circuit proof

Safety isolating transformer for construction sites, IEC 60417-6010-5:2007-02
non-short-circuit proof

Isolating transformer for construction sites, IEC 60417-6010-6:2007-02
non-short-circuit proof, mid-point or star-point earthed

Isolating transformer for construction sites, IEC 60417-6010-7:2007-02
short-circuit proof (inherently or non-inherently)

Safety isolating transformer for construction sites, IEC 60417-6010-8:2007-02
short-circuit proof (inherently or non-inherently)

Isolating transformer for construction sites, IEC 60417-6010-9:2007-02
short-circuit proof (inherently or non-inherently), mid-point or star-
point earthed

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Power supply unit, linear IEC 60417-6210:2013-10
To identify the electronic device incorporating transformer(s) and
L
electronic circuitry(ies), that converts electrical power into single
or multiple power outputs, the output voltage is linearly regulated.
The internal operating frequency does not exceed 500 Hz.
304
305 9 Protection against electric shock
306 This clause of IEC 61558-1 is applicable.
307
308 10 Change of input voltage setting
309 This clause of IEC 61558-1 is applicable.
310
311 11 Output voltage and output current under load
312 This clause of IEC 61558-1 is applicable.
313
314 12 No-load output voltage
315 This clause of IEC 61558-1 is applicable except as follows:
316 Addition
317 12.101 The no-load output voltage shall not exceed:
318 − 250 V AC for isolating transformers with a non-earthed mid-point (single-phase) or a
319 non-earthed star-point (three-phase) or delta connection (three-phase);
320 − 115 V AC for isolating transformers with a mid-point (single-phase) earthed in the
321 construction or a star-point (three-phase) earthed in the construction;
322 − 50 V AC for safety isolating transformers.
323 For independent transformers, the no-load output voltage limitation applies even when
324 output windings, not intended for interconnection, are connected in series.
325 The no-load output voltage shall exceed:
326 − 50 V AC for isolating transformers.
327
328 12.102 The difference between the no-load output voltage and the output voltage under
329 load shall not be excessive.
330 The ratio between the no-load output voltage measured in Clause 12 and the output voltage
331 under load measured during the test of Clause 11, expressed as a percentage of the latter
332 voltage, shall not exceed the values shown in Table 102 or Table 103.
333 The ratio is determined by Formula (1):
𝑈 − 𝑈
no−load load
× 100 (%)
(1)
𝑈
load
334 where
335 𝑈 is the no-load output voltage, expressed in V
no−load

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336 𝑈 is the output voltage under load, expressed in V
load
337
338 Table 102 – Output voltage ratio for safety isolating transformers
Type of transformer Ratio between no-load output voltage and output
voltage under load
Rated output
%
VA
Inherently short-circuit proof transformers:
− up to and including 63 100
− over 63 up to and including 630 50
−
...