EN 61557-8:2007

SLOVENSKI STANDARD
01-december-2007
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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 8:
Insulation monitoring devices for 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 8:
Isolationsüberwachungsgeräte für IT-Systeme
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 8: Contrôleurs d'isolement pour réseaux IT
Ta slovenski standard je istoveten z: EN 61557-8:2007
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
29.080.01 (OHNWULþQDL]RODFLMDQD Electrical insulation in
VSORãQR general
29.240.01 2PUHåMD]DSUHQRVLQ Power transmission and
GLVWULEXFLMRHOHNWULþQHHQHUJLMH distribution networks in
QDVSORãQR general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61557-8
NORME EUROPÉENNE
July 2007
EUROPÄISCHE NORM
ICS 17.220.20; 29.080.01; 29.240.01 Supersedes EN 61557-8:1997

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 8: Insulation monitoring devices for IT systems
(IEC 61557-8:2007 + corrigendum May 2007)

Sécurité électrique dans les réseaux  Elektrische Sicherheit
de distribution basse tension in Niederspannungsnetzen
de 1 000 V c.a. et 1 500 V c.c. - bis AC 1 000 V und DC 1 500 V -
Dispositifs de contrôle, de mesure Geräte zum Prüfen,
ou de surveillance de mesures Messen oder Überwachen
de protection - von Schutzmaßnahmen -
Partie 8: Contrôleurs d'isolement Teil 8: Isolationsüberwachungsgeräte
pour réseaux IT für IT-Systeme
(CEI 61557-8:2007 (IEC 61557-8:2007
+ corrigendum May 2007) + corrigendum May 2007)

This European Standard was approved by CENELEC on 2007-04-11. 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.

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 61557-8:2007 E
Foreword
The text of document 85/296/FDIS, future edition 2 of IEC 61557-8, 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 61557-8 on 2007-04-11.
This European Standard supersedes EN 61557-8:1997.
The following changes were made with respect to EN 61557-8:1997:
– definitions complemented;
– revision of some requirements;
– addition of information on operating instructions;
– sections “type tests” and “routine tests” complemented;
– modification of Table 1;
– addition of Annexes A and B.
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) 2008-02-01
– latest date by which the national standards conflicting
(dow) 2010-05-01
with the EN have to be withdrawn
Annexes ZA and ZB have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61557-8:2007, including the corrigendum May 2007, was
approved by CENELEC as a European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60364-4-41 NOTE  Harmonized as HD 60364-4-41:2007 (modified).
IEC 61140 NOTE  Harmonized as EN 61140:2002 (not modified).
__________
- 3 - EN 61557-8:2007
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 60364-7-710 2002 Electrical installations of buildings - - -
(mod) Part 7-710: Requirements for special
installations or locations - Medical locations

1) 2)
IEC 60664-1 - Insulation coordination for equipment within EN 60664-1 2007
low-voltage systems -
Part 1: Principles, requirements and tests

1) 2)
IEC 60664-3 - Insulation coordination for equipment within EN 60664-3 2003
low-voltage systems -
Part 3: Use of coating, potting or moulding for
protection against pollution
IEC 60691 2002 Thermal-links - Requirements and application EN 60691 2003
guide
1) 2)
IEC 60721-3-1 - Classification of environmental conditions - EN 60721-3-1 1997
Part 3: Classification of groups of
environmental parameters and their
severities - Section 1: Storage

1) 2)
IEC 60721-3-2 - Classification of environmental conditions - EN 60721-3-2 1997
Part 3: Classification of groups of
environmental parameters and their
severities - Section 2: Transportation

1) 2)
IEC 60721-3-3 - Classification of environmental conditions - EN 60721-3-3 1995
Part 3: Classification of groups of
environmental parameters and their
severities - Section 3: Stationary use at
weatherprotected locations
1) 2)
IEC 60947-5-1 - Low-voltage switchgear and controlgear - EN 60947-5-1 2004
Part 5-1: Control circuit devices and switching + corr. July 2005
elements - Electromechanical control circuit
devices
1) 2)
IEC 60947-5-4 - Low-voltage switchgear and controlgear - EN 60947-5-4 2003
Part 5-4: Control circuit devices and switching
elements - Method of assessing the
performance of low-energy contacts - Special
tests
1)
Undated reference.
2)
Valid edition at date of issue.

Publication Year Title EN/HD Year
IEC 61010-1 2001 Safety requirements for electrical equipment EN 61010-1 2001
for measurement, control, and + corr. June 2002
laboratory use -
Part 1: General requirements
1) 2)
IEC 61326-2-4 - Electrical equipment for measurement, EN 61326-2-4 2006
control and laboratory use - EMC
requirements -
Part 2-4: Particular requirements - Test
configurations, operational conditions and
performance criteria for insulation monitoring
devices according to IEC 61557-8 and for
equipment for insulation fault location
according to IEC 61557-9
1) 2)
IEC 61557-1 - Electrical safety in low voltage distribution EN 61557-1 2007
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
1) 2)
IEC 61810-2 - Electromechanical elementary relays - EN 61810-2 2005
Part 2: Reliability
1) 2)
CISPR 11 (mod) - Industrial scientific and medical (ISM) radio- EN 55011 2007
frequency equipment - Electromagnetic
disturbance characteristics - Limits and
methods of measurement
- 5 - EN 61557-8:2007
Annex ZB
(informative)
A-deviations
A-deviation: National deviation due to regulations, the alteration of which is for the time being outside the
competence of the CENELEC member.
This European Standard falls under Directive 2006/95/EC.
NOTE (from CEN/CENELEC IR Part 2:2006 , 2.17)  Where standards fall under EC Directives, it is the view of the Commission of
the European Communities (OJ No C 59, 1982-03-09) that the effect of the decision of the Court of Justice in case 815/79
Cremonini/Vrankovich (European Court Reports 1980, p. 3583) is that compliance with A-deviations is no longer mandatory and that
the free movement of products complying with such a standard should not be restricted except under the safeguard procedure
provided for in the relevant Directive.
A-deviations in an EFTA-country are valid instead of the relevant provisions of the European Standard in
that country until they have been removed.
Clause Deviation
A.3.5 Spain
(REBT ITC-BT-38)
The device shall include monitoring of the isolation value to verify the alarm and the test
device.
__________
NORME CEI
INTERNATIONALE
IEC
61557-8
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
2007-01
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 8: Contrôleurs d'isolement pour réseaux IT

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 8: Insulation monitoring devices
for IT systems
© IEC 2007 Droits de reproduction réservés ⎯ Copyright - all rights reserved
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61557-8 © IEC:2007 – 3 –
CONTENTS
FOREWORD.5

1 Scope.9
2 Normative references .9
3 Terms and definitions .11
4 Requirements .15
5 Marking and operating instructions .19
5.1 Marking .19
5.2 Operating instructions .21
6 Tests .21
6.1 Type tests .21
6.2 Routine tests .25

Annex A (normative) Medical insulation monitoring devices (IMDs) .29
Annex B (informative) Monitoring of overload and high temperature.37

Bibliography.41

Table 1 – Requirements applicable to insulation monitoring devices .17
Table A.1 – Additional requirements applicable to medical insulation monitoring
devices (IMDs).33
Table A.2 – Emission test for medical insulation monitoring devices (IMDs) .35

61557-8 © 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 8: Insulation monitoring devices for IT systems

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 a
...