EN 61557-3:2007

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. - Equipment for testing, measuring or monitoring of protective measures -- Part 3: Loop impedanceSécurité électrique dans les réseaux de distribution basse tension de 1 000 V c.a. et 1 500 V c.c. - Dispositifs de contrôle, de mesure ou de surveillance de mesures de protection -- Partie 3: Impédance de boucleElektrische Sicherheit in Niederspannungsnetzen bis AC 1 000 V und DC 1 500 V - Geräte zum Prüfen, Messen oder Überwachen von Schutzmaßnahmen -- Teil 3: SchleifenwiderstandTa slovenski standard je istoveten z:EN 61557-3:2007SIST EN 61557-3:2007en29.240.01Power transmission and distribution networks in general29.080.01VSORãQRElectrical insulation in general17.220.20Measurement of electrical and magnetic quantitiesICS:SIST EN 61557-3:20001DGRPHãþDSLOVENSKI
STANDARDSIST EN 61557-3:200701-september-2007

EUROPEAN STANDARD EN 61557-3 NORME EUROPÉENNE
EUROPÄISCHE NORM March 2007
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61557-3:2007 E
ICS 17.220.20; 29.080.01; 29.240.01 Supersedes EN 61557-3:1997
English version
Electrical safety in low voltage distribution systems
up to 1 000 V a.c. and 1 500 V d.c. -
Equipment for testing, measuring or monitoring
of protective measures -
Part 3: Loop impedance (IEC 61557-3:2007)
Sécurité électrique dans les réseaux
de distribution basse tension
de 1 000 V c.a. et 1 500 V c.c. -
Dispositifs de contrôle, de mesure
ou de surveillance de mesures
de protection -
Partie 3: Impédance de boucle (CEI 61557-3:2007)
Elektrische Sicherheit
in Niederspannungsnetzen
bis AC 1 000 V und DC 1 500 V -
Geräte zum Prüfen,
Messen oder Überwachen
von Schutzmaßnahmen -
Teil 3: Schleifenwiderstand (IEC 61557-3:2007)
This European Standard was approved by CENELEC on 2007-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.

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Foreword The text of document 85/292/FDIS, future edition 2 of IEC 61557-3, prepared by IEC TC 85, Measuring equipment for electrical and electromagnetic quantities, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61557-3 on 2007-03-01. This European Standard supersedes EN 61557-3:1997. The following changes were made with respect to EN 61557-3:1997: – definitions complemented; – revision of some requirements; – addition of information on operating instructions; – addition of new influence quantities E9 and E10. This standard is to be used in conjunction with EN 61557-1. The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop)
2007-12-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2010-03-01 Annex ZA has been added by CENELEC. __________ Endorsement notice The text of the International Standard IEC 61557-3:2007 was approved by CENELEC as a European Standard without any modification. __________

- 3 - EN 61557-3:2007 Annex ZA
(normative)
Normative references to international publications with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
NOTE
When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.
Publication Year Title EN/HD Year
IEC 61010-1
Safety requirements for electrical equipment for measurement, control, and laboratory
use -
Part 1: General requirements EN 61010-1 + corr. June
2001 2002
IEC 61557-1 -1) Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. - Equipment for testing, measuring or monitoring of protective measures -
Part 1: General requirements EN 61557-1 20072)
1) Undated reference. 2) Valid edition at date of issue.

NORME INTERNATIONALECEIIEC INTERNATIONAL STANDARD 61557-3Deuxième éditionSecond edition2007-01 Sécurité électrique dans les réseaux
de distribution basse tension de 1 000 V c.a.
et 1 500 V c.c. –
Dispositifs de contrôle, de mesure ou de surveillance de mesures de protection –
Partie 3: Impédance de boucle
Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring
or monitoring of protective measures –
Part 3: Loop impedance
Pour prix, voir catalogue en vigueur For price, see current catalogue© IEC 2007
Droits de reproduction réservés
⎯
Copyright - all rights reserved Aucune partie de cette publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit de l'éditeur. 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 the publisher. International Electrotechnical Commission,
3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch
Web: www.iec.ch CODE PRIX PRICE CODE K Commission Electrotechnique InternationaleInternational Electrotechnical Commission

61557-3 © IEC:2007 – 3 –
CONTENTS
FOREWORD.5
1 Scope.9 2 Normative references.9 3 Terms and definitions.9 4 Requirements.11 5 Marking and operating instructions.15 5.1 Marking.15 5.2 Operating instructions.15 6 Tests.17
Bibliography.19
Table 1 – Calculation of operating uncertainty.13

61557-3 © IEC:2007 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION ___________
ELECTRICAL SAFETY IN LOW VOLTAGE DISTRIBUTION SYSTEMS UP TO 1 000 V a.c. AND 1 500 V d.c. – EQUIPMENT FOR TESTING, MEASURING OR MONITORING OF PROTECTIVE MEASURES –
Part 3: Loop impedance
FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 61557-3 has been prepared by IEC technical committee 85: Measuring equipment for electrical and electromagnetic quantities. This second edition cancels and replaces the first edition published in 1997. This edition constitutes a technical revision. The following changes were made with respect to the previous edition: a) definitions complemented; b) revision of some requirements;
c) addition of information on operating instructions;
d) addition of new influence quantities E9 and E10.

61557-3 © IEC:2007 – 7 –
The text of this standard is based on the following documents: FDIS Report on voting 85/292/FDIS 85/302/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. This part of IEC 61557 shall be used in conjunction with Part 1. A list of all parts of the IEC 61557 series, published under the general title Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring or monitoring of protective measures, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will be
• reconfirmed; • withdrawn; • replaced by a revised edition, or • amended.

61557-3 © IEC:2007 – 9 –
ELECTRICAL SAFETY IN LOW VOLTAGE DISTRIBUTION SYSTEMS UP TO 1 000 V a.c. AND 1 500 V d.c. – EQUIPMENT FOR TESTING, MEASURING OR MONITORING OF PROTECTIVE MEASURES –
Part 3: Loop impedance
1 Scope This part of IEC 61557 specifies the requirements applicable to equipment for measuring the loop impedance between a phase conductor and the protective conductor or between a phase conductor and neutral or between two phase conductors by using the voltage drop when the circuit under test is loaded. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 61010-1:2001, Safety requirements for electrical equipment for measurement, control, and laboratory use – Part 1: General requirements IEC 61557-1, Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring or monitoring of protective measures – Part 1: General requirements 3 Terms and definitions For the purposes of this document, the definitions given in IEC 61557-1 and the following definitions apply. 3.1
loading method method of loading a circuit within a distribution system to cause a voltage drop 3.2
loading equipment equipment causing a voltage drop in a circuit 3.3
test current current that causes a voltage drop in a circuit

61557-3 © IEC:2007 – 11 –
3.4
system phase angle angle between loop impedance and loop resistance of the distribution system 3.5
loop impedance
Zs sum of the impedances in a current loop comprising the impedance of the source of the current, the impedance of the phase conductor (e.g. protective conductor, earth electrode and earth) from the point of measurement to the ot
...