SIST EN 61557-9:2009

Electrical safety in low voltage distribution systems up to 1 000 V ac and 1 500 V dc - Equipment for testing, measuring or monitoring of protective measures -- Part 9: Equipment for insulation fault location in IT systems

This part of IEC 61557 specifies the requirements for insulation fault location systems which localize insulation faults in any part of the system in unearthed IT a.c. systems and unearthed IT a.c. systems with galvanically connected d.c. circuits having nominal voltages up to 1 000 V a.c., as well as in unearthed IT d.c. systems with voltages up to 1 500 V d.c., independent of the measuring principle.

Elektrische Sicherheit in Niederspannungsnetzen bis AC 1000 V und DC 1500 V - Geräte zum Prüfen, Messen oder Überwachen von Schutzmaßnahmen – Teil 9: Einrichtungen zur Isolationsfehlersuche in IT-Systemen

Sécurité électrique dans les réseaux de distribution basse tension de 1 000 V c.a. et 1 500 V cc - Dispositifs de contrôle, de mesure ou de surveillance de mesures de protection -- Partie 9 : Dispositifs de focalisation de défauts d'isolement pour réseaux IT

La CEI 61557-9:2009 définit les exigences particulières applicables aux dispositifs de localisation de défauts d'isolement qui, indépendamment du principe de mesure, peuvent localiser les défauts d'isolement des parties de réseaux IT c.a. non mis à la terre et des réseaux IT c.a. non mis à la terre comprenant des circuits à courant continu reliés galvaniquement dont les tensions nominales sont égales ou inférieures à 1 000 V c.a., ainsi que dans des réseaux IT c.c. non mis à la terre dont les tensions nominales sont égales ou inférieures à 1 500 V c.c. Cette deuxième édition annule et remplace la première édition parue en 1999. Elle constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:  - le domaine d'application, les références normatives et les termes et définitions ont été complétés;  - les exigences, le marquage et les instructions de fonctionnement et l'Article 6 ont été révisés;  - le Tableau 1 a été révisé;  - les Annexes A, B et C ont été ajoutées.

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 - 9. del: Oprema za ugotavljanje mesta izolacijske okvare v sistemih IT (IEC 61557-9:2009)

General Information

• Status: Withdrawn
• Publication Date: 10-May-2009
• Withdrawal Date: 04-May-2023
• 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: MOV - Measuring equipment for electromagnetic quantities
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 05-May-2023
• Due Date: 28-May-2023
• Completion Date: 05-May-2023
• 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
• Ref Project: EN 61557-9:2009 - 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 9: Equipment for insulation fault location in IT systems

Relations

• Replaces: SIST EN 61557-9:2000 - 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 9: Equipment for insulation fault location in IT systems
• Effective Date: 01-Feb-2012
• Replaced By: SIST EN 61557-9:2015 - 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 9: Equipment for insulation fault location in IT systems (IEC 61557-9:2014)
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 61557-9:2009
01-junij-2009
1DGRPHãþD
SIST EN 61557-9:2000
(OHNWULþQDYDUQRVWYQL]NRQDSHWRVWQLKUD]GHOLOQLKVLVWHPLKL]PHQLþQHQDSHWRVWLGR
N9LQHQRVPHUQHQDSHWRVWLGRN92SUHPD]DSUHVNXãDQMHPHUMHQMHDOL
QDG]RURYDQMH]DãþLWQLKXNUHSRYGHO2SUHPD]DXJRWDYOMDQMHPHVWDL]RODFLMVNH
RNYDUHYVLVWHPLK,7,(&
Electrical safety in low voltage distribution systems up to 1 000 V ac and 1 500 V dc -
Equipment for testing, measuring or monitoring of protective measures -- Part 9:
Equipment for insulation fault location in IT systems
Elektrische Sicherheit in Niederspannungsnetzen bis AC 1000 V und DC 1500 V -
Geräte zum Prüfen, Messen oder Überwachen von Schutzmaßnahmen – Teil 9:
Einrichtungen zur Isolationsfehlersuche in IT-Systemen
Sécurité électrique dans les réseaux de distribution basse tension de 1 000 V c.a. et 1
500 V cc - Dispositifs de contrôle, de mesure ou de surveillance de mesures de
protection -- Partie 9 : Dispositifs de focalisation de défauts d'isolement pour réseaux IT
Ta slovenski standard je istoveten z: EN 61557-9:2009
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
SIST EN 61557-9:2009 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 61557-9:2009

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SIST EN 61557-9:2009

EUROPEAN STANDARD
EN 61557-9

NORME EUROPÉENNE
March 2009
EUROPÄISCHE NORM

ICS 25.040.40 Supersedes EN 61557-9:1999


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 9: Equipment for insulation fault location in IT systems
(IEC 61557-9:2009)


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 ou Geräte zum Prüfen, Messen oder
de surveillance de mesures de protection - Überwachen von Schutzmaßnahmen -
Partie 9: Dispositifs de localisation Teil 9: Einrichtungen zur
de défauts d'isolement pour réseaux IT Isolationsfehlersuche in IT-Systemen
(CEI 61557-9:2009) (IEC 61557-9:2009)




This European Standard was approved by CENELEC on 2009-02-01. 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.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: avenue Marnix 17, B - 1000 Brussels


© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61557-9:2009 E

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SIST EN 61557-9:2009
EN 61557-9:2009 - 2 -
Foreword
The text of document 85/337/FDIS, future edition 2 of IEC 61557-9, 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 61557-9 on 2009-02-01.
This European Standard supersedes EN 61557-9:1999.
EN 61557-9:2009 includes the following significant technical changes with respect to EN 61557-9:1999:
– scope complemented;
– normative references complemented;
– terms and definitions of Clause 3 complemented;
– revision of requirements;
– revision of marking and operating instructions;
– revision of Clause 6 “Tests”;
– revision of Table 1;
– addition of Annex A;
– addition of Annex B;
– addition of Annex C.
This standard is to be used in conjunction with EN 61557-1:2007.
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) 2009-11-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2012-02-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61557-9:2009 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 60364-5-53 NOTE  Clause 534 (in IEC/A1:2002) harmonized as HD 60364-5-534:2008 (modified).
IEC 60947-5-1 NOTE  Harmonized as EN 60947-5-1:2004 (not modified).
IEC 60947-5-4 NOTE  Harmonized as EN 60947-5-4:2003 (not modified).
IEC 61810-2 NOTE  Harmonized as EN 61810-2:2005 (not modified).
__________

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SIST EN 61557-9:2009
- 3 - EN 61557-9:2009
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 60364-4-41 2005 Low-voltage electrical installations - HD 60364-4-41 2007
(mod) Part 4-41: Protection for safety - Protection + corr. July 2007
against electric shock


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


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


2)
IEC 61010-1 2001 Safety requirements for electrical EN 61010-1 2001
equipment 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)
Undated reference.
2)
Valid edition at date of issue.

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SIST EN 61557-9:2009
EN 61557-9:2009 - 4 -
Publication Year Title EN/HD Year

IEC 61557-1 2007 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


IEC 61557-8 2007 Electrical safety in low voltage distribution
+ corr. May 2007 systems up to 1 000 V a.c. and 1 500 V d.c. - EN 61557-8 2007
Equipment for testing, measuring or
monitoring of protective measures -
Part 8: Insulation monitoring devices for IT
systems

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SIST EN 61557-9:2009
IEC 61557-9
®
Edition 2.0 2009-01
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 9: Equipment for insulation fault location in 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 9: Dispositifs de localisation de défauts d'isolement pour réseaux IT

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
S
CODE PRIX
ICS 25.040.40 ISBN 2-8318-1023-7
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 7 ----------------------

SIST EN 61557-9:2009
– 2 – 61557-9 © IEC:2009
CONTENTS
FOREWORD.4
1 Scope.6
2 Normative references .6
3 Terms and definitions .7
4 Requirements .8
4.1 Equipment for insulation fault location .8
4.2 Response sensitivity.8
4.3 Warning device .8
4.4 Locating current I .8
L
4.5 Locating voltage U .9
L
4.6 Indication of the insulation value .9
4.7 PE connection .9
4.8 Clearances and creepage distances .9
4.9 Electromagnetic compatibility (EMC) .9
4.10 Additional requirements.9
5 Marking and operating instructions .10
5.1 Marking .10
5.2 Operating instructions .11
6 Tests .11
6.1 Type test .12
6.1.1 Response sensitivity of the insulation fault location system .12
6.1.2 Locating current I .12
L
6.1.3 Locating voltage U .13
L
6.1.4 Warning device.13
6.1.5 Equipment for indication of the insulation value .13
6.1.6 Locating current injector .13
6.1.7 Dielectric test .13
6.1.8 Electromagnetic compatibility (EMC) .13
6.1.9 Loss of locating current sensor connection .13
6.1.10 Additional requirements .13
6.1.11 Marking and operating instructions .13
6.1.12 Record of the type test .13
6.2 Routine tests .13
6.2.1 General .13
6.2.2 Response sensitivity.13
6.2.3 Warning device.14
6.2.4 Self-test function .14
6.2.5 Dielectric test .14
6.2.6 Marking and operating instructions .14
Annex A (normative) Equipment for insulation fault location in medical locations .15
Annex B (normative) Portable equipment for insulation fault location .18
Annex C (informative) Example of an insulation fault location system and explanation of
upstream / downstream leakage capacitances .20
Bibliography.23

Figure C.1 – Example of an insulation fault location system.21

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SIST EN 61557-9:2009
61557-9 © IEC:2009 – 3 –
Figure C.2 – Explanation of upstream/downstream leakage capacitance.22

Table 1 – Requirements for Insulation Fault Location Systems (IFL) .10
Table A.1 – Additional requirements applicable to equipment for insulation fault location
in medical locations .17
Table A.2 – Emission test for equipment for insulation fault location in medical locations.17

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SIST EN 61557-9:2009
– 4 – 61557-9 © IEC:2009
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 9: Equipment for insulation fault location in 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 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 61557-9 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 1999. It is a technical
revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) scope complemented;
b) normative references complemented;
c) terms and definitions of Clause 3 complemented;
d) revision of requirements;
e) revision of marking and operating instructions;
f) revision of Clause 6 “Tests”;

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SIST EN 61557-9:2009
61557-9 © IEC:2009 – 5 –
g) revision of Table 1;
h) addition of Annex A;
i) addition of Annex B;
j) addition of Annex C.
The text of this standard is based on the following documents:
FDIS Report on voting
85/337/FDIS 85/341/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 is to be used in conjunction with IEC 61557-1:2007.
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.

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SIST EN 61557-9:2009
– 6 – 61557-9 © IEC:2009
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 9: Equipment for insulation fault location in IT systems



1 Scope
This part of IEC 61557 specifies the requirements for insulation fault location systems which
localize insulation faults in any part of the system in unearthed IT a.c. systems and unearthed IT
a.c. systems with galvanically connected d.c. circuits having nominal voltages up to 1 000 V a.c.,
as well as in unearthed IT d.c. systems with voltages up to 1 500 V d.c., independent of the
measuring principle.
NOTE 1 IT systems are described in IEC 60364-4-41 amongst other literature. Additional data for a selection of
devices in other standards should be noted.
NOTE 2 Further information on insulation fault location can be found in the following standards:
IEC 60364-4-41:2005, 411.6, and IEC 60364-5-53:2001, 531.3.
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 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-3, Insulation coordination for equipment within low-voltage systems – Part 3: Use of
coating, potting or moulding for protection against pollution
IEC 60721-3-1, Classification of environmental conditions – Part 3: Classification of groups of
environmental parameters and their severities – Section 1: Storage
IEC 60721-3-2, Classification of environmental conditions – Part 3: Classification of groups of
environmental parameters and their severities – Section 2: Transportation
IEC 60721-3-3, Classification of environmental conditions – Part 3-3: Classification of groups of
environmental parameters and their severities – Stationary use at weatherprotected locations
IEC 61010-1:2001, Safety requirements for electrical equipment for measurement, control, and
laboratory use – Part 1: General requirements
IEC 61326-2-4, Electrical equipment for measurement, 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

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SIST EN 61557-9:2009
61557-9 © IEC:2009 – 7 –
IEC 61557-1:2007, 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 1:
General requirements
IEC 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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61557-1, in
IEC 61557-8 and the following apply.
3.1
insulation fault location system
device or combination of devices used for insulation fault location in IT systems. The insulation
fault location system is used in addition to an insulation monitoring device. It injects a locating
current between the electrical system and earth and locates insulation faults
NOTE The requirements for insulation monitoring devices are defined in IEC 61557-8.
3.2
locating current
I
L
r.m.s. value of the current that is injected by the locating current injector during the location
process. The locating current can be generated by
– an independent locating voltage source, or
– an independent locating current source, or
– it can be driven directly from the system to be monitored
3.3
locating voltage
U
L
r.m.s. value of the voltage present at the measuring terminals of the locating current injector
during the measurement when the device has an independent locating voltage or current source
NOTE In a fault-free, de-energized system, this represents the voltage present between the terminals of the locating
device to the system to be monitored and the terminals for the connection to the PE conductor.
3.4
response sensitivity
value of the evaluating current or insulation resistance at which the evaluator responds under
specified conditions
NOTE Response sensitivity can either be a fixed threshold or a response curve.
3.5
insulation fault locator
device or part of a device for the location of the insulation fault
3.6
locating current sensor
sensor for the detection of the locating current used for the location of the insulation fault
3.7
locating current injector
device or part of a device, which function it is to inject the locating current in the IT system in
order to locate the insulation fault

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SIST EN 61557-9:2009
– 8 – 61557-9 © IEC:2009
3.8
passive locating current injector
locating current injector that generates the locating current directly from the system to be
monitored
3.9
active locating current injector
locating current injector that generates the locating current from a locating voltage source which
is independent from the system to be monitored
4 Requirements
The following requirements as well as those given in IEC 61557-1 shall apply.
4.1 Equipment for insulation fault location
Equipment for insulation fault location shall be capable of localizing symmetrical as well as
asymmetrical insulation faults in an IT system and to give a warning, if the insulation resistance
in a part of the installation falls below the response sensitivity.
If equipment for insulation fault location has a self-test function, the self-test shall not produce
an insulation fault to earth.
NOTE 1 See also IEC 61557-8:2007, 4.1.
NOTE 2 Insulation monitoring devices may be deactivated during the location process.
NOTE 3 Warning indication can be done by a lamp, a buzzer or by any other kind of indication.
NOTE 4 Insulation fault locating systems may have a self-test function. Checking the response sensitivity is not
necessary.
NOTE 5 Insulation fault location systems with an active locating current source may also be used for insulation fault
location in de-energized systems.
4.2 Response sensitivity
Insulation fault location systems shall be designed in such a manner that the response
sensitivity stated by the manufacturer will be met under the specified system conditions, at a
total symmetrical system leakage capacitance of 1 μF upstream the evaluating current sensor
(C = 1 μF, C = 0 μF according to Figure C.2).
Lu Ld
Information on the influence of the system leakage capacitances higher than 1 μF on the
response sensitivity as well as possible interference from the distribution system on the
insulation fault location process shall be stated by the manufacturer.
NOTE The total leakage capacitance is the sum of the leakage capacitances of all phase conductors, including the
neutral conductor to PE.
4.3 Warning device
Insulation fault location systems shall contain a visual warning device, which indicates if an
insulation fault is detected or allow connection to such a device for the indication of a fault. If
externally connectable audible signalling devices are provided, they may be fitted with a
resetting facility. In this case, after clearing a fault or resetting the device, the audible signal
shall sound if a new fault occurs.
4.4 Locating current I
L
The maximum locating current I shall be limited to 500 mA, r.m.s., to ensure that the locating
L
current does not produce touch voltages above the conventional voltage limit (50 V a.c., 120 V

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SIST EN 61557-9:2009
61557-9 © IEC:2009 – 9 –
d.c.) under the first fault in the distribution system. The locating current shall not increase above
500 mA, r.m.s., under foreseeable component failures in the
...