SIST EN IEC 61557-11:2022

SLOVENSKI STANDARD
oSIST prEN IEC 61557-11:2019
01-julij-2019
Električna varnost v nizkonapetostnih razdelilnih sistemih izmenične napetosti do
1 kV in enosmerne napetosti do 1,5 kV - Oprema za preskušanje, merjenje ali
nadzorovanje zaščitnih ukrepov - 11. del: Učinkovitost naprav za nadzorovanje
preostalega toka (RCM) tipa A in tipa B v sistemih TT, TN in IT
Electrical safety in low voltage distribution systems up to 1000 V a.c. and 1500 V d.c. -
Equipment for testing, measuring or monitoring of protective measures - Part 11:
Effectiveness of residual current monitors (RCMs) type A and type B in TT, TN and IT
systems
Elektrische Sicherheit in Niederspannungsnetzen bis AC 1 000 V und DC 1 500 V -
Geräte zum Prüfen, Messen oder Überwachen von Schutzmaßnahmen - Teil 11:
Wirksamkeit von Differenzstrom-Überwachungsgeräten (RCMs) Typ A und Typ B in TT-,
TN- und IT-Systemen
Ta slovenski standard je istoveten z: prEN IEC 61557-11:2019
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
29.080.01 Električna izolacija na Electrical insulation in
splošno general
29.240.01 Omrežja za prenos in Power transmission and
distribucijo električne energije distribution networks in
na splošno general
oSIST prEN IEC 61557-11:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 61557-11:2019
85/676/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61557-11 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2019-04-26 2019-07-19
SUPERSEDES DOCUMENTS:
85/619/CD,85/641A/CC

IEC TC 85 : MEASURING EQUIPMENT FOR ELECTRICAL AND ELECTROMAGNETIC QUANTITIES
SECRETARIAT: SECRETARY:
China Mr Bo Chen
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

TC 23,TC 44,TC 64
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:
Electrical safety in low voltage distribution systems up to 1000 V a.c. and 1500 V d.c. - Equipment for
testing, measuring or monitoring of protective measures - Part 11: Effectiveness of residual current
monitors (RCMs) type A and type B in TT, TN and IT systems

PROPOSED STABILITY DATE: 2025

NOTE FROM TC/SC OFFICERS:

Copyright © 2019 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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IEC CDV 61557-11  IEC:2018 - 2 - 85/676/CDV
1 CONTENTS
2 FOREWORD . 3
3 1 Scope . 2
4 2 Normative references . 2
5 3 Terms and definitions . 2
6 4 Requirements . 4
7 4.1 General . 4
8 4.2 Functions . 4
9 4.2.1 Operating test . 4
10 4.2.2 Non-operating test . 6
11 4.2.3 Test of actuating time. 6
12 4.3 Fault voltages exceeding U . 7
L
13 4.4 Overvoltage . 7
14 4.5 Electromagnetic compatibility (EMC) . 7
15 5 Marking and operating instructions . 7
16 5.1 Markings . 7
17 5.2 Operating instructions . 8
18 5.2.1 General . 8
19 5.2.2 Information. 8
20 5.2.3 Warnings . 8
21 6 Tests . 8
22 6.1 General . 8
23 6.2 Operating uncertainty . 9
24 6.3 Test of protection against high fault voltages . 10
25 6.4 Test of overvoltage . 10
26 Annex A (informative) Differences between RCMs and RCDs . 11
27 A.1 Scope. 11
28 A.2 Reference documents and definition of function . 11
29 A.3 Requirements from product standards for testing RCMs . 11
30 A.4 Main technical differences between RCMs and RCDs . 12
31 A.5 Special considerations for testing RCMs in the installation . 13
32 Annex B (informative) Safety aspects, test methods and applications . 15
33 B.1 Safety aspects . 15
34 B.2 Test methods . 15
35 B.3 Applications of test methods . 15
36 Bibliography . 17
37
38 Figure 1 – Maximum steepness of stepwise rising smooth direct test current (I ) . 5
T
39 Figure 2 – Maximum increase of linearly increasing smooth direct test current (I ) . 5
T
40 Figure 3 – Example for linearly increasing smooth direct test current (I ): I = 30 mA . 6
T ∆n
41 Table 1 – Calculation of operating uncertainty . 9
42 Table A.2 – Requirements for testing RCMs according to product standard IEC 62020:1998 11
43 Table A.3 – Main technical differences between RCMs and RCDs . 12
44 Figure A.1 – Typical installation with a combination of RCDs and RCMs . 14
45

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46 INTERNATIONAL ELECTROTECHNICAL COMMISSION
47 ____________
48
49 ELECTRICAL SAFETY IN LOW VOLTAGE DISTRIBUTION
50 SYSTEMS UP TO 1 000 V AC AND 1 500 V DC –
51 EQUIPMENT FOR TESTING, MEASURING OR
52 MONITORING OF PROTECTIVE MEASURES –
53
54 Part 11: Effectiveness of residual current monitors (RCMs)
55 in TT, TN and IT systems
56
57 FOREWORD
58 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
59 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
60 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
61 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
62 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
63 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
64 in the subject dealt with may participate in this preparatory work. International, governmental and non-
65 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
66 with the International Organization for Standardization (ISO) in accordance with conditions determined by
67 agreement between the two organizations.
68 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
69 consensus of opinion on the relevant subjects since each technical committee has representation from all
70 interested IEC National Committees.
71 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
72 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
73 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
74 misinterpretation by any end user.
75 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
76 transparently to the maximum extent possible in their national and regional publications. Any divergence
77 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
78 the latter.
79 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
80 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
81 services carried out by independent certification bodies.
82 6) All users should ensure that they have the latest edition of this publication.
83 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
84 members of its technical committees and IEC National Committees for any personal injury, property damage or
85 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
86 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
87 Publications.
88 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
89 indispensable for the correct application of this publication.
90 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
91 patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
92 International Standard IEC 61557-11 has been prepared by IEC technical committee TC85:
93 Measuring equipment for electrical and electromagnetic quantities
94 This second edition cancels and replaces the first edition published in 2009. This edition
95 constitutes a technical revision.
96 This edition includes the following significant technical changes with respect to the previous
97 edition:
98 a) Subtitle includes all types of RCMs;
99 b) Terms aligned with IEC 60050;
100 c) addition of requirements for testing new types of RCM;
101 d) moving of requirements for RCM type B from former Annex A to standard text;
102 e) addition of Annex B on recommended tripping times;

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103 f) alignment of the structure with that of the whole IEC 61557 series.
104
105 The text of this standard is based on the following documents:
FDIS Report on voting
XX/XX/FDIS XX/XX/RVD
106
107 Full information on the voting for the approval of this standard can be found in the report on
108 voting indicated in the above table.
109 This part of IEC 61557 shall be used in conjunction with IEC 61557-1 1.
110 A list of all parts in the IEC 61557 series, published under the general title Electrical safety in
111 low voltage distribution systems up to 1 000 V AC and 1 500 V DC – Equipment for testing,
112 measuring or monitoring of protective measures, can be found on the IEC website.
113 The committee has decided that the contents of this publication will remain unchanged until
114 the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
115 related to the specific publication. At this date, the publication will be
116 – reconfirmed,
117 – withdrawn,
118 – replaced by a revised edition, or
119 – amended.
120 The National Committees are requested to note that for this publication the stability date
121 is 2025
122 THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE
123 DELETED AT THE PUBLICATION STAGE.
124
125
126

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127 ELECTRICAL SAFETY IN LOW VOLTAGE DISTRIBUTION
128 SYSTEMS UP TO 1 000 V AC AND 1 500 V DC –
129 EQUIPMENT FOR TESTING, MEASURING OR
130 MONITORING OF PROTECTIVE MEASURES –
131
132 Part 11: Effectiveness of residual current monitors (RCMs)
133 in TT, TN and IT systems
134
135
136 1 Scope
137 This part of IEC 61557 specifies the requirements for testing equipment applied to the testing of the
138 effectiveness of residual current monitors (RCMs), which are already installed in distribution systems.
139 This test equipment can be used in any kind of network like a TN, TT or IT system. The test
140 equipment may also be used for testing directionally discriminating RCMs in IT systems.
141 2 Normative references
142 The following documents, in whole or in part, are normatively referenced in this document and are
143 indispensable for its application. For dated references, only the edition cited applies. For undated
144 references, the latest edition of the referenced document (including any amendments) applies.
145 IEC 61010-1:2010, AMD1:2016, Safety requirements for electrical equipment for measurement,
146 control, and laboratory use – Part 1: General requirements
147 IEC 61326-2-2, Electrical equipment for measurement, control and laboratory use – EMC
148 requirements – Part 2-2: Particular requirements – Test configurations, operational conditions and
149 performance criteria for portable test, measuring and monitoring equipment used in low-voltage
150 distribution systems
151 IEC 61557-1:2018, Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V
152 DC – Equipment for testing, measuring or monitoring of protective measures – Part 1: General
153 requirements
154 IEC 62020:1998, amd.1:2003, Electrical accessories – Residual current monitors for household and
155 similar uses (RCMs)
156 3 Terms and definitions
157 For the purposes of this document, the terms and definitions given in IEC 61557-1, IEC 61557-6 and
158 the following apply.
159 ISO and IEC maintain terminological databases for use in standardization at the following addresses:
160 – IEC Electropedia: available at http://www.electropedia.org/
161 – ISO Online browsing platform: available at http://www.iso.org/obp
162 3.1
163 earth fault current
164 current flowing to earth due to an insulation fault
165 [SOURCE: IEC 60050-442:1998, 442-01-23]
166 3.2
167 test current
168 I
T
169 test current superimposed by the test equipment for testing the effectiveness of the RCM

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170 3.3
171 residual current
172 I
∆
173 RMS value of the vector sum of the currents flowing through the main circuit of the residual current
174 device due to an insulation fault
175 [SOURCE: IEC 60050-442:1998, 442-05-19, modified: ‘due to an insulation fault’ is added.]
176 3.4
177 rated residual operating current
178 I
∆n
179 value of residual operating current assigned to the RCM by the manufacturer at which the RCM
180 operates under specified conditions
181 [SOURCE: IEC 60050-442:1998, 442-05-20, modified: relating to RCM and to the values given by the
182 manufacturer]
183 3.5
184 residual operating current
185 I
∆o
186 value of residual current which causes the residual current monitoring device to operate under
187 specified conditions
188 [SOURCE: IEC 60050-442:1998 442-05-20, modified: ‘residual current monitoring device’ instead of
189 ‘residual current device’]
190 3.6
191 residual non-operating current
192 value of residual current at which (and below which) the RCM does not operate under specified
193 conditions
194 [SOURCE: IEC 60050-442:1998 442-05-21, modified: ‘residual current monitoring device’ instead of
195 ‘residual current device’]
196 3.7
197 actuating time
198 t
a
199 time taken for a residual current monitoring device to change from the non-alarm state to the alarm
200 state in response to the sudden appearance of a residual current which exceeds the preset level
201 [SOURCE: IEC 62020:1998, definition 3.3.12]
202 3.8
203 residual current monitor (RCM)
204 device or association of devices which monitors the residual current in an electrical installation and
205 which activates an alarm when the residual current exceeds the operating value of the device
206 [SOURCE: IEC 62020.1998; definition 3.3.1]
207 3.9
208 residual current monitor (RCM) type A
209 type of RCM for which monitoring is ensured for residual sinusoidal alternating currents and residual
210 pulsating direct currents, whether suddenly applied or slowly rising
211 [SOURCE: IEC 62020, definition 3.3.8, modified: the word ‘monitoring’ is used for ‘actuation’]
212 3.10
213 residual current monitor (RCM) type B
214 type of RCM for which monitoring is ensured for residual sinusoidal alternating currents, with residual
215 pulsating direct currents and smooth residual direct currents independent of polarity, whether
216 suddenly applied or slowly rising

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217 3.11
218 directionally discriminating RCM
219 type of RCM with the manufacturer’s declaration about having the ability to discriminate between
220 supply side and load side residual currents
221 Note 1 to entry: Directionally discriminating RCM are described in IEC 62020.
222 4 Requirements
223 4.1 General
224 In addition to the requirements of IEC 61557-1:2018, Clause 4, the requirements of Clause 4 of this
225 document shall apply.
226 4.2 Functions
227 4.2.1 Operating test
228 The testing equipment shall be capable of verifying that the residual operating current of a RCM type
229 A tested with an AC test current is lower or equal to the value of the rated residual operating current.
230 Testing of RCMs type A shall be conducted with a suddenly applied calibrated AC current at zero
231 crossing.
232 The tests shall be carried out with a sinusoidal, or mains-derived quasi sinusoidal, test current.
233 If the test equipment is capable of producing half-wave test currents, testing of residual current
234 monitors (RCMs) type A may be carried out alternatively with half-wave test currents and/or AC
235 current with superimposed ±6 mA DC according to IEC 62020.
236 In case of pulsed DC current, the test equipment shall be capable of testing in both polarities.
237 When testing RCMs of type B with a DC test current, it shall be verified that the residual operating
238 current is lower or equal to 2 times the value of the rated residual operating current.
239 Testing of RCMs type B shall be conducted separately with a suddenly applied, calibrated AC current
240 and a continuously rising smooth direct current.
241 The steepness of the continuous rate of rising shall not be higher than 2 times I / 5 s.
∆n
242 If the continuous rate of rising is simulated by a stepwise or linearly increasing test current, the
243 increase shall not be higher than 2 times I / 30 (see Figures 1 to 3).
∆n
244 In both cases the starting current shall be below 0,2 times I .
∆n
245 The operating uncertainty of the increasing test current I shall not exceed ±10 % of the rated residual
T
246 operating current I .
∆n
247 The operating uncertainty of the calibrated test current I shall not exceed 0 % to +10 %.
T
248 The test period shall be adapted to the set actuating time of the RCM and it shall be possible to
249 extend the test period up to 10 s.
250

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I
T
∆I
T
∆t
t
IEC  2359/08
251
252

253 Figure 1 – Maximum steepness of stepwise rising smooth direct test current (I )
T
254

I

T
∆I

T
∆t
t
IEC  2360/08
255
256
257 Figure 2 – Maximum increase of linearly increasing smooth direct test current (I )
T
258

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I
T
∆I
T
∆t
t
IEC  2361/08
259
260
261 Figure 3 – Example for linearly increasing smooth direct test current (I ): I = 30 mA
T ∆n
262 Key (for Figures 1 to 3)
263 t time
264 I rated residual operating current
∆n
265 I smooth direct test current
T
266 ∆I  steepness of continuous rising test current or steps of stepwise rising test current
T
267 ∆t  time for one step for stepwise rising test current or time for steepness of continuous rising test
268 current
269 A slow continuous or stepwise increase of the DC test current is required to prevent the AC sensitive
270 part of the RCM type B from operating during the DC test.
271 Example for ∆I  = 2 mA: ∆t ≥ (2 mA × 5 s) / (2 × 30 mA) ≥ 167 ms
T
272 Example for ∆I  = 0,5 mA:   ∆t ≥ (0,5 mA × 5 s) / (2 × 30 mA) ≥ 42 ms
T
273 NOTE 1 Existing leakage currents downstream may influence the verification.
274 NOTE 2 The actual rise time depends on the system capacitance and the resistive load of the test equipment.
275 NOTE 3 Smooth DC test current refers to direct current with AC ripple up to 10 % (peak to peak).
276 4.2.2 Non-operating test
277 When a test at 50 % or less of the rated residual operating current to test the reliability of the RCM is
278 included, the minimum test period shall be 10 s. The alarm shall not be activated.
279 When a non-operating test at 50 % or less of the rated residual operating current is included, the
280 operating uncertainty of the calibrated test current shall not exceed 0 % to –10 % of the specified non-
281 operating test current.
282 NOTE Existing leakage currents downstream can influence the verification.
283 4.2.3 Test of actuating time
284 If the set actuating time of the RCM is being tested with the test equipment, the setting of the test
285 period on the test device shall have a resolution of minimum 0,5 s ranging up to 10 s. The setting

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286 uncertainty shall not exceed 0 % to –10 % of the set value. The test shall solely be performed with
287 calibrated AC test current.
288 Other methods for the acquisition of the actuating time via optical recognition or interfacing are
289 permissible.
290 NOTE The general function of RCMs is not the disconnecting of the power supply when a residual current above the value
291 of the rated residual operating current occurs. The RCM indicates the increase of the residual current above the residual
292 operating current with a signalling device, for example a lamp, buzzer, contact relay or interface-signal. Thus the response
293 time may only be tested via the visual or additional electrical detection of this signal.
294 According to IEC 62020 the response time of RCMs may only amount to a maximum of 10 s. The
295 response time shall be specified by the manufacturer or shall be adjustable on the device.
296 If the RCM is being used for the purpose of disconnection, the tests covered by IEC 61557-6 shall
297 apply.
298 4.3 Fault voltages exceeding U
L
299 Prevention of danger due to fault voltages exceeding U within the system under test shall be ensured
L
300 during measurement. This can be achieved as follows:
301 – automatic disconnection in accordance with IEC 61010-1:2010, Figure 1, if the residual voltage is
302 above 50 V AC or 120 V DC;
303 – application of test current I , gradually or permanently adjustable, where the test starts a maximum
T
304 current of 3,5 mA AC or 15 mA DC in accordance with IEC 61010-1:2010, 6.3.2 b), including
305 parallel test circuits, is permitted. The possibility to change the test current I without generating a
T
306 dangerous residual voltage shall be clearly identifiable, for instance on a voltmeter.
307 – In special locations the touch voltage limit is 25 V AC or 60 V DC
308 – The operating uncertainty for the detection of the fault voltage shall not exceed 0 % to –20 % of
309 the limit.
310 4.4 Overvoltage
311 If the system is connected to 120 % of the nominal voltage of the system for which the test equipment
312 is designed, neither the operator shall be harmed nor the device be damaged. Protective devices shall
313 not be activated. If the device is intended to be used in IT systems, the nominal voltage of the test
314 equipment is the line-to-line voltage.
315 If the test equipment is accidentally connected to 173 % of the nominal voltage in TN or TT systems
316 for which the test equipment is designed for the duration of 1 min, neither the operator shall be
317 harmed nor the device be damaged. In this case, protective devices may be activated.
318 4.5 Electromagnetic compatibility (EMC)
319 The electromagnetic compatibility shall be in accordance with IEC 61326-2-2.
320 5 Marking and operating instructions
321 5.1 Markings
322 In addition to the requirements of IEC 61557-1;2018, 5.1, the following information shall be provided
323 on the measuring equipment.
324 Rated residual operating current or rated residual operating currents of the RCM for which the test
325 equipment has been designed for an actuating time of 10 s.
326 NOTE Other rated residual operating currents for lower actuating times may be marked in addition.
327 The maximum voltage to earth and the rated measuring category shall be marked.

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328 5.2 Operating instructions
329 5.2.1 General
330 In addition to IEC 61557-1:2018, 5.2, the the operating instructions shall include the following
331 information.
332 5.2.2 Information
333 a) Information about special test configurations to avoid unintended tripping of RCDs (see Annex B);
334 b) information to avoid unintended influences on the operation of the system;
335 c) information for recalibration cycles and safety tests of the test equipment after repair and
336 instructions for periodical tests.
337 5.2.3 Warnings
338 d) If the detecting circuit for the fault voltage has no probe and if a possible voltage between the
339 protective conductor and earth influences the measurements, a warning shall be included.
340 e) Where the detecting circuit for the fault voltage uses the N-conductor as a probe, a warning shall
341 be given to test the connection between the neutral point of the distribution system and earth
342 before the test is started; a possible voltage between the N-conductor and earth may influence the
343 measurements.
344 f) A warning that leakage currents in the circuit following the RCM may influence measurements and
345 test results.
346 g) The earth electrode resistance of a detecting circuit for the fault voltage with a probe shall not
347 exceed the value stated by the manufacturer.
...