EN 61557-8:2015

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 61557-8:2014 specifies the requirements for insulation monitoring devices (IMD) which permanently monitor the insulation resistance RF to earth of unearthed a.c. IT systems, of a.c. IT systems with galvanically connected d.c. circuits having nominal voltages up to 1 000 V a.c., as well as of unearthed d.c. IT systems with voltages up to 1 500 V d.c. independent from the method of measuring. IT systems are described in IEC 60364-4-41 amongst other literature. Additional data for the selection of devices in other standards should be noted. IMDs according to this part of IEC 61557 can also be used for de-energized TT, TN and IT systems or appliances. This third edition cancels and replaces the second edition published in 2007. This edition constitutes a technical revision which includes the following significant technical changes with respect to the previous edition: - terms and definitions have been complemented; - abbreviations are listed and explained; - requirements have been revised; - mandatory and optional functions and their terminology have been adapted from IEC 61557-15; - mechanical requirements have been added; - information on operating instructions has been added; - type tests and routine tests have been complemented; - an Annex C: 'Insulation monitoring devices for photovoltaic systems (PV-IMD)' has been added; and - an Annex D: 'Insulation monitoring function of a photovoltaic inverter (PV-IMF) or in a charge controller' has been added.

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: Contrôleur permanent d¿isolement pour réseaux IT

L'IEC 61557-8:2014 spécifie les exigences applicables aux contrôleurs d'isolement (CPI) destinés à surveiller en permanence, et quelle que soit la méthode de mesure, la résistance d'isolement RF par rapport à la terre de réseaux IT à courant alternatif non mis à la terre, ou de réseaux IT à courant alternatif comprenant des circuits à courant continu reliés galvaniquement dont les tensions nominales sont au plus égales à 1 000 V en courant alternatif, et de réseaux IT à courant continu non mis à la terre dont les tensions nominales sont au plus égales à 1 500 V en courant continu. Les réseaux IT sont décrits entre autres dans l'IEC 60364-4-41. Il convient de noter que, pour le choix des appareils, des indications supplémentaires sont données dans d'autres normes. Les CPI conformes à la présente partie de l'IEC 61557 peuvent également être utilisés dans des systèmes ou appareils hors tension du type TT, TN et IT. Cette troisième édition annule et remplace la deuxième édition parue en 2007. Cette édition constitue une révision technique qui inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: - les termes et définitions ont été complétés; - énumération et explication des abréviations; - révision des exigences; - adaptation des fonctions obligatoires et facultatives et leur terminologie à l'IEC 61557-15; - ajout d'exigences mécaniques; - ajout d'informations relatives aux instructions de fonctionnement; - les essais de type et essais individuels de série ont été complétés; - ajout de l'Annexe C: 'Contrôleurs d'isolement pour systèmes photovoltaïques (PV-CPI)'; et - ajout de l'Annexe D: 'Fonction de surveillance de défaut d'isolement d'un onduleur photovoltaïque (PV-IMF) ou dans un contrôleur de charge'.

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 - 8. del: Naprave za nadzorovanje izolacije v IT sistemih (IEC 61557-8:2014)

Ta del standarda IEC 61557 določa zahteve za naprave za nadzorovanje izolacije (IMD), ki omogočajo stalen nadzor upornosti izolacije (RF) na ozemljitev pri neozemljenih IT-sistemih na izmenični tok, IT-sistemih na izmenični tok z galvansko povezanimi tokokrogi enosmernega toka z nominalnimi vrednostmi izmenične napetosti do 1000 V ter neozemljenih IT-sistemih na enosmerni tok z vrednostmi enosmerne napetosti do 1500 V, neodvisno od metode merjenja.
IT-sistemi so med drugim opisani tudi v standardu IEC 60364-4-41. Upoštevali naj bi dodatne podatke za izbiro naprav v drugih standardih.
OPOMBA: uporabo naprav za nadzorovanje izolacije v IT-sistemih določajo različni standardi. V teh primerih je namen opreme opozoriti na padec upornosti (RF) pod najnižjo dovoljeno raven.
Naprave za nadzorovanje izolacije v skladu s tem delom standarda IEC 61557 je mogoče uporabiti tudi za sisteme ali naprave TT, TN in IT v breznapetostnem stanju.

General Information

• Status: Published
• Publication Date: 12-Feb-2015
• Withdrawal Date: 14-Jan-2018
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.080.01 - Electrical insulation in general
• ICS: 29.240.01 - Power transmission and distribution networks in general
• Technical Committee: CLC/TC 85X - Measuring equipment for electrical and electromagnetic quantities
• Drafting Committee: IEC/TC 85 - IEC_TC_85
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 13-Feb-2015
• Completion Date: 13-Feb-2015
• Directive: 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)
• 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
• Directive: 2014/53/EU - Directive 2014/53/EU of The European Parliament and of the Council of 16 April 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment and repealing Directive 1999/5/EC
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Ref Project: SIST EN 61557-8:2015 - 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 61557-8:2014)

Relations

• Replaces: EN 61557-8:2007 - 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
• Effective Date: 28-Jan-2023
• Corrected By: EN 61557-8:2015/AC:2016-06 - 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
• Effective Date: 23-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2015
1DGRPHãþD
SIST EN 61557-8:2007
(OHNWULþQDYDUQRVWYQL]NRQDSHWRVWQLKUD]GHOLOQLKVLVWHPLKL]PHQLþQHQDSHWRVWLGR
N9LQHQRVPHUQHQDSHWRVWLGRN92SUHPD]DSUHVNXãDQMHPHUMHQMHDOL
QDG]RURYDQMH]DãþLWQLKXNUHSRYGHO1DSUDYH]DQDG]RURYDQMHL]RODFLMHY,7
VLVWHPLK,(&
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 61557-8:2014)
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 (IEC 61557-8:2014)
Ta slovenski standard je istoveten z: EN 61557-8:2015
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
EUROPÄISCHE NORM February 2015
ICS 17.220.20; 29.240.01; 29.080.01 Supersedes EN 61557-8:2007
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 61557-8:2014)
Sécurité électrique dans les réseaux de distribution basse Elektrische Sicherheit in Niederspannungsnetzen bis AC 1
tension de 1 000 V c.a. et 1 500 V C:C - Dispositifs de
000 V und DC 1 500 V - Geräte zum Prüfen, Messen oder
contrôle, de mesure ou de surveillance de mesures de Überwachen von Schutzmaßnahmen - Teil 8:
protection - Partie 8: Contrôleur permanent d'isolement Isolationsüberwachungsgeräte für IT-Systeme
pour réseaux IT (IEC 61557-8:2014)
(CEI 61557-8:2014)
This European Standard was approved by CENELEC on 2015-01-15. 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 CEN-CENELEC
Management Centre 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 CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61557-8:2015 E
Foreword
The text of document 85/485/FDIS, future edition 3 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 approved by CENELEC as EN 61557-8:2015.

The following dates are fixed:
(dop) 2015-10-15
 latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
 latest date by which the national (dow) 2018-01-15
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61557-8:2007.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights.

This standard covers the Principle Elements of the Safety Objectives for Electrical Equipment Designed for
Use within Certain Voltage Limits (LVD).

Endorsement notice
The text of the International Standard IEC 61557-8:2014 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.
IEC 60664-1 NOTE Harmonized as EN 60664-1.
IEC 60664-3 NOTE Harmonized as EN 60664-3.
IEC 61140 NOTE Harmonized as EN 61140.
IEC 60027-7 NOTE Harmonized as EN 60027-7.
IEC 61557-9 NOTE Harmonized as EN 61557-9.
IEC 60364-7-712 NOTE Harmonized as HD 60364-7-712.

- 3 - EN 61557-8:2015
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60068-2-1 -  Environmental testing -- Part 2-1: Tests - Test EN 60068-2-1 -
A: Cold
IEC 60068-2-2 -  Environmental testing -- Part 2-2: Tests - Test EN 60068-2-2 -
B: Dry heat
IEC 60068-2-6 -  Environmental testing -- Part 2-6: Tests - Test EN 60068-2-6 -
Fc: Vibration (sinusoidal)
IEC 60068-2-27 -  Environmental testing -- Part 2-27: Tests - EN 60068-2-27 -
Test Ea and guidance: Shock
IEC 60364-7-710 2002 Electrical installations of buildings -- Part 7- HD 60364-7-710 2012
(mod) 710: Requirements for special installations or
locations - Medical locations
+AC 2013
IEC 60691 -  Thermal-links - Requirements and application - -
guid
IEC 60721-3-1 -  Classification of environmental conditions -- EN 60721-3-1 -
Part 3: Classification of groups of
environmental parameters and their severities
-- Section 1: Storage
IEC 60721-3-2 -  Classification of environmental conditions -- EN 60721-3-2 -
Part 3: Classification of groups of
environmental parameters and their severities
-- Section 2: Transportation
IEC 60721-3-3 -  Classification of environmental conditions -- EN 60721-3-3 -
Part 3: Classification of groups of
environmental parameters and their severities
-- Section 3: Stationary use at
weatherprotected locations
IEC 60947-5-1 -  Low-voltage switchgear and controlgear -- EN 60947-5-1 -
Part 5-1: Control circuit devices and switching
elements - Electromechanical control circuit
devices
+EN 60947-5- 2005
1:2004/corrigendum
Jul. 2005
+EN 60947-5- 2004
1:2004/corrigendum
Nov. 2004
IEC 60947-5-4 -  Low-voltage switchgear and controlgear -- EN 60947-5-4 -
Part 5-4: Control circuit devices and switching
elements - Method of assessing the
performance of low-energy contacts - Special
tests
IEC 61010-1 2010 Safety requirements for electrical equipment EN 61010-1 2010
for measurement, control and laboratory use -
- Part 1: General requirements
IEC 61010-2- -  Safety requirements for electrical equipment - -
030:2010/corrigendu for measurement, control and laboratory use -
m May 2011 - Part 2-030: Particular requirements for
testing and measuring circuits
IEC 61326-2-4 -  Electrical equipment for measurement, control EN 61326-2-4 -
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 61557-8
IEC 61557-1 -  Electrical safety in low voltage distribution EN 61557-1 -
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
IEC 61810-2 -  Electromechanical elementary relays -- Part EN 61810-2 -
2: Reliability
IEC 62109-2 2011 Safety of power converters for use in EN 62109-2 2011
photovoltaic power systems -- Part 2:
Particular requirements for inverters
CISPR 11 -  Industrial, scientific and medical equipment - EN 55011 -
Radio-frequency disturbance characteristics -
Limits and methods of measurement

IEC 61557-8 ®
Edition 3.0 2014-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
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

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: Contrôleur permanent d’isolement pour réseaux IT

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 17.220.20; 29.080.01; 29.240.01 ISBN 978-2-8322-1973-7

– 2 – IEC 61557-8:2014 © IEC 2014
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviations . 9
3.1 Terms and definitions . 9
3.2 Abbreviations . 13
4 Requirements . 13
4.1 General requirements . 13
4.2 Types of IMDs . 14
4.2.1 General . 14
4.2.2 Mandatory functions provided by IMDs . 14
4.2.3 Mandatory service function provided by the IMD – Test function . 15
4.3 Optional functions provided by IMD . 15
4.3.1 General . 15
4.3.2 Local transformer monitoring warning (LTMW) . 15
4.3.3 Remote transformer monitoring warning (RTMW) . 15
4.3.4 Remote enabling and disabling command (REDC) . 16
4.4 Performance requirements . 16
4.4.1 Specified response value R . 16
an
4.4.2 System leakage capacitance C . 16
e
4.4.3 Relative percentage uncertainty A of the specified response value R . 16
an
4.4.4 Response time t . 17
an
4.4.5 Measuring voltage U and measuring current I . 17
m m
4.4.6 Internal d.c. resistance R and internal impedance Z . 17
i i
4.4.7 Indication of the value of the insulation resistance R . 18
F
4.4.8 Permanently admissible nominal voltage U . 18
n
4.4.9 Permanently admissible extraneous d.c. voltage U . 18
fg
4.4.10 Supply voltage U . 18
S
4.5 Electromagnetic compatibility (EMC) . 18
4.6 Safety requirements . 18
4.6.1 General . 18
4.6.2 Clearances and creepage distances . 19
4.6.3 Protection class and earth connection of an IMD . 19
4.7 Climatic environmental conditions .
...