Low-voltage switchgear and controlgear - Active arc-fault mitigation systems - Part 9-1: Arc quenching devices (IEC 60947-9-1:2019)

This part of IEC 60947 covers low-voltage arc quenching devices, hereinafter referred to as
AQDs, which are intended to eliminate arc-faults in low-voltage assemblies (typically lowvoltage
switchgear and controlgear assemblies in accordance with the IEC 61439 series), by
creating a lower impedance current path, to cause the arcing current to transfer to the new
current path. This new current path is maintained until a short-circuit protection device (SCPD)
interrupts the short-circuit current.
AQDs are installed in low-voltage assemblies, connected to the main circuit, preferably as
close as possible to all primary power sources.
Their rated voltage does not exceed 1 000 V AC or 1 500 V DC.
This document does not cover:
• sensors intended to detect arc-faults;
• devices intended to trigger the functioning of the arc quenching device;
• devices intended to interrupt arc-fault current;
• special requirements for AQDs for use in explosive atmospheres (e.g. ATEX).

Niederspannungsschaltgeräte - Aktive Systeme zur Verringerung von Lichtbogenfehlern - Teil 9-1: Lichtbogenlöschgeräte (IEC 60947-9-1:2019)

Appareillage à basse tension - Partie 9-1: Systèmes actifs de limitation des défauts d'arc - Dispositifs d'extinction d'arc (IEC 60947-9-1:2019)

L'IEC 60947-9-1:2019 couvre les dispositifs d’extinction d’arc à basse tension, ci-après appelés «AQD» (arc quenching devices). Ces appareils sont destinés à éliminer les défauts d’arc dans les ensembles à basse tension (en règle générale, des ensembles d'appareillage à basse tension conformes à la série IEC 61439) en créant un chemin de courant à impédance plus faible pour provoquer le transfert du courant d’arc vers ce nouveau chemin de courant. Ce nouveau chemin de courant est maintenu jusqu’à la coupure du courant de court-circuit par le DPCC.
Les AQD sont installés dans les ensembles à basse tension, raccordés au circuit principal, de préférence le plus près possible de toutes les sources primaires d’alimentation.
Leur tension assignée ne dépasse pas 1 000 V en courant alternatif ou 1 500 V en courant continu.

Nizkonapetostne stikalne in krmilne naprave - 9-1. del: Aktivni sistemi za blažitev učinkov okvarnega obloka - Naprave za gašenje obloka (IEC 60947-9-1:2019)

Ta del standarda IEC 60947 zajema nizkonapetostne naprave za gašenje obloka (AQD), ki so namenjene preprečevanju učinkov okvarnega obloka pri nizkonapetostnih sestavih (običajno pri sestavih nizkonapetostnih stikalnih in krmilnih naprav v skladu s skupino standardov IEC 61439), tako da se tvori zelo majhna impedanca, ki povzroči, da se obločni tok prenese na novo tokovno pot. Ta nova tokovna pot se ohranja, dokler naprava za zaščito pred kratkim stikom (SCPD) ne prekine kratkostičnega toka.
Naprave za gašenje obloka so nameščene v nizkonapetostnih sestavih in povezane na glavni tokokrog, po možnosti čim bližje vsem primarnim virom napajanja.
Njihova nazivna napetost ne presega 1000 V izmenične napetosti ali 1500 V enosmerne napetosti.
Ta dokument ne zajema:
• tipal, namenjenih odkrivanju učinkov okvarnega obloka;
• naprav, namenjenih proženju naprave za gašenje obloka;
• naprav, namenjenih prekinjanju učinkov okvarnega obloka;
• posebnih zahtev za naprave za gašenje obloka glede uporabe v eksplozivnih okoljih (npr. ATEX).

General Information

Status
Published
Publication Date
05-Jun-2019
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
30-May-2019
Due Date
04-Aug-2019
Completion Date
06-Jun-2019

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SLOVENSKI STANDARD
SIST EN IEC 60947-9-1:2019
01-julij-2019
Nizkonapetostne stikalne in krmilne naprave - 9-1. del: Aktivni sistemi za blažitev
učinkov okvarnega obloka - Naprave za gašenje obloka (IEC 60947-9-1:2019)
Low-voltage switchgear and controlgear - Active arc-fault mitigation systems - Part 9-1:
Arc quenching devices (IEC 60947-9-1:2019)
Niederspannungsschaltgeräte - Aktive Systeme zur Verringerung von Lichtbogenfehlern
- Teil 9-1: Lichtbogenlöschgeräte (IEC 60947-9-1:2019)
Appareillage à basse tension - Partie 9-1: Systèmes actifs de limitation des défauts d'arc
- Dispositifs d'extinction d'arc (IEC 60947-9-1:2019)
Ta slovenski standard je istoveten z: EN IEC 60947-9-1:2019
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
SIST EN IEC 60947-9-1:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60947-9-1:2019

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SIST EN IEC 60947-9-1:2019


EUROPEAN STANDARD EN IEC 60947-9-1

NORME EUROPÉENNE

EUROPÄISCHE NORM
May 2019
ICS 29.120.40; 29.130.20

English Version
Low-voltage switchgear and controlgear - Part 9-1: Active arc-
fault mitigation systems - Arc quenching devices
(IEC 60947-9-1:2019)
Appareillage à basse tension - Partie 9-1: Systèmes actifs Niederspannungsschaltgeräte - Aktive Systeme zur
de limitation des défauts d'arc - Dispositifs d'extinction d'arc Verringerung von Lichtbogenfehlern - Teil 9-1:
(IEC 60947-9-1:2019) Lichtbogenlöschgeräte
(IEC 60947-9-1:2019)
This European Standard was approved by CENELEC on 2019-02-20. 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, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 60947-9-1:2019 E

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SIST EN IEC 60947-9-1:2019
EN IEC 60947-9-1:2019 (E)
European foreword
The text of document 121A/254/FDIS, future edition 1 of IEC 60947-9-1, prepared by SC 121A "Low-
voltage switchgear and controlgear" of IEC/TC 121 "Switchgear and controlgear and their assemblies
for low voltage" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN IEC 60947-9-1:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2019-11-24
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-05-24
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directives and the standardization requests see informative Annex ZZA
and Annex ZZB, which are integral parts of this document.
Endorsement notice
The text of the International Standard IEC 60947-9-1:2019 was approved by CENELEC as a
European Standard without any modification.


2

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SIST EN IEC 60947-9-1:2019
EN IEC 60947-9-1:2019 (E)
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 1  Where 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 60068-2-30 2005 Environmental testing -- Part 2-30: Tests - EN 60068-2-30 2005
Test Db: Damp heat, cyclic (12 h + 12 h
cycle)
IEC 60417 Data- Graphical symbols for use on equipment - -
base
IEC 60947-1 2007 Low-voltage switchgear and controlgear -- EN 60947-1 2007
Part 1: General rules
+ A1 2010  + A1 2011
+ A2 2014  + A2 2014
IEC 61439 series Low-voltage switchgear and controlgear EN 61439 series
assemblies
CISPR 11 (mod) 2015 Industrial, scientific and medical equipment EN 55011 2016
- Radio-frequency disturbance
characteristics - Limits and methods of
measurement
+ A1 2016 + A1 2017
3

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SIST EN IEC 60947-9-1:2019
EN IEC 60947-9-1:2019 (E)
Annex ZZA
(informative)
Relationship between this European standard and the essential requirements
of Directive 2014/30/EU [2014 OJ L96] aimed to be covered
This European standard has been prepared under the European Commission standardisation request
1
C(2016) 7641 final of 30.11.2016 , ('M/552'), as regards harmonised standards in support of Directive
2014/30/EU relating to electromagnetic compatibility, to provide one voluntary means of conforming to
essential requirements of Directive 2014/30/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 electromagnetic
compatibility [2014 OJ L96].
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZZA.1 confers, within the limits
of the scope of this standard, a presumption of conformity with the corresponding essential
requirements of that Directive, and associated EFTA regulations.
Table ZZA.1 – Correspondence between this European standard and Annex I of Directive
2014/30/EU [2014 OJ L96]
Clause(s) / sub-clause(s)
Essential requirements of
Remarks / Notes
Directive 2014/30/EU
of this EN
Annex I. 1(a) (electromagnetic 8.3, 9.3.2.2
disturbances)
Annex I. 1(b) (electromagnetic 8.3, 9.3.2.1
immunity)
WARNING 1: Presumption of conformity stays valid only as long as a reference to this European
standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2: Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.

1
COMMISSION IMPLEMENTING DECISION C(2016) 7641 final of 30.11.2016 on a standardisation request to the European
Committee for Standardisation, to the European Committee for Electrotechnical Standardisation and to the European
Telecommunications Standards Institute as regards harmonised standards in support of Directive 2014/30/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
electromagnetic compatibility.
4

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SIST EN IEC 60947-9-1:2019
EN IEC 60947-9-1:2019 (E)
Annex ZZB
(informative)
Relationship between this European standard and the safety objectives of
Directive 2014/35/EU [2014 OJ L96] aimed to be covered
This European standard has been prepared under a Commission’s standardisation request relating to
harmonised standards in the field of the Low Voltage Directive, M/511, to provide one voluntary means
of conforming to safety objectives of 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
[2014 OJ L96].
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZZB.1 confers, within the limits
of the scope of this standard, a presumption of conformity with the corresponding safety objectives of
that Directive, and associated EFTA regulations.
Table ZZB.1 – Correspondence between this European standard and Annex I of Directive
2014/35/EU [2014 OJ L96]
Safety objectives of Clause(s) / sub-clause(s) of this EN Remarks/Notes
Directive 2014/35/EU
1 a) 6
1 b) 6
1 c) 1, 3, 4, 5, and 6.3
2 a) 8.1, 8.2, 9.3
2 b) 8.1, 9.3
2 c) 6.2, 6.3, 8.1, 9.3, 9.4
2 d) 8.1, 8.2, 9.3
3 a) 6.3, 8.1, 9.3, 9.4
3 b) 8.1, 9.3
3 c) - No hazard identified for products
falling under the scope of this
standard.
WARNING 1: Presumption of conformity stays valid only as long as a reference to this European
standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2: Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.

5

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SIST EN IEC 60947-9-1:2019

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SIST EN IEC 60947-9-1:2019



IEC 60947-9-1

®


Edition 1.0 2019-01




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Low-voltage switchgear and controlgear –

Part 9-1: Active arc-fault mitigation systems – Arc quenching devices




Appareillage à basse tension –

Partie 9-1: Systèmes actifs de limitation des défauts d'arc – Dispositifs

d'extinction d'arc















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.120.40; 29.130.20 ISBN 978-2-8322-6404-1




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN IEC 60947-9-1:2019
– 2 – IEC 60947-9-1:2019 © IEC 2019
CONTENTS

FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Classification . 8
4.1 According to the number of operations . 8
4.1.1 Single shot AQD . 8
4.1.2 Resettable AQD . 9
4.2 According to the mounting characteristics . 9
4.2.1 Fixed AQD . 9
4.2.2 Withdrawable or plug-in AQD . 9
5 Characteristics . 9
5.1 Rated operational voltage (U ) . 9
e
5.2 Rated insulation voltage (U ) . 9
i
5.3 Rated impulse withstand voltage (U ) . 9
imp
5.4 Rated short-time withstand current (I ) . 9
cw
5.5 Maximum voltage drop in low-impedance state . 9
5.6 Maximum operating time . 10
5.7 Number of operating cycles (of a resettable AQD) . 10
5.8 Maximum permissible temperature of the AQD main circuit terminals . 10
6 Product information . 10
6.1 Nature of information . 10
6.2 Marking . 10
6.3 Instructions for installation, operation, maintenance, decommissioning and
dismantling . 11
7 Normal service, mounting and transport conditions . 11
8 Constructional and performance requirements . 11
8.1 Constructional requirements . 11
8.2 Performance requirements . 12
8.3 Electromagnetic compatibility (EMC) . 12
9 Tests . 13
9.1 Kind of tests . 13
9.2 Compliance with constructional requirements . 13
9.3 Type tests . 13
9.3.1 Performance tests . 13
9.3.2 Electromagnetic compatibility tests . 15
9.4 Routine tests. 16
9.4.1 Closing operation. 16
9.4.2 Dielectric test . 16

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IEC 60947-9-1:2019 © IEC 2019 – 3 –
Annex A (informative) Rationale for defining the maximum voltage drop value in low-
impedance state . 17
A.1 Condition for arc extinction . 17
A.2 Determination of minimum distance and corresponding voltage drop . 18
Bibliography . 19

Table 1 – Product information . 11

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– 4 – IEC 60947-9-1:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 9-1: Active arc-fault mitigation systems –
Arc quenching devices

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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 60947-9-1 has been prepared by subcommittee SC121A: Low-
voltage switchgear and controlgear, of IEC technical committee 121: Switchgear and
controlgear and their assemblies for low voltage.
The text of this International Standard is based on the following documents:
FDIS Report on voting
121A/254/FDIS 121A/266/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

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IEC 60947-9-1:2019 © IEC 2019 – 5 –
A list of all parts in the IEC 60947 series, published under the general title Low-voltage
switchgear and controlgear, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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– 6 – IEC 60947-9-1:2019 © IEC 2019
INTRODUCTION
The effects of arc-faults inside an enclosure are more and more taken into consideration, both
from user safety and time-to-repair points of view. Protection against the effects of internal
arc-faults can be achieved through passive components (containment) or through active
components, also known as "active arc-fault mitigation systems".
Active arc-fault mitigation systems generally use internal arc-fault control devices (IACDs),
based on the effects of the arc (light, pressure, current or voltage harmonics, etc.), and an
actuator to eliminate the arc-fault.
This actuator can be an upstream circuit-breaker, which is tripped to interrupt the fault current,
or an arc quenching device that will transfer the fault to a dedicated low-impedance circuit,
before the short-circuit current is interrupted by the upstream short-circuit protective device
(SCPD).
The purpose of this document is to set the requirements for arc quenching devices, so that
the necessary safety is ensured and their performance can be fairly assessed.
Special requirements for environmental withstand (e.g. ambient temperature, damp heat,
shock, vibrations) are included, considering the high impact of a malfunction, either unwanted
operation (creation of a short-circuit) or failure to operate.
Requirements for internal arc-fault control devices are under development and will be
1
published as IEC 60947-9-2 .
Requirements for integration of internal arc-fault mitigation systems in power switchgear and
2
controlgear assemblies are under development and will be published as IEC TS 63107 .


___________
1
 Under preparation. Stage at the time of publication: IEC/ACD 60947-9-2:2018.
2
 Under preparation. Stage at the time of publication: IEC/PCC 63107:2018.

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IEC 60947-9-1:2019 © IEC 2019 – 7 –
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 9-1: Active arc-fault mitigation systems –
Arc quenching devices



1 Scope
This part of IEC 60947 covers low-voltage arc quenching devices, hereinafter referred to as
AQDs, which are intended to eliminate arc-faults in low-voltage assemblies (typically low-
voltage switchgear and controlgear assemblies in accordance with the IEC 61439 series), by
creating a lower impedance current path, to cause the arcing current to transfer to the new
current path. This new current path is maintained until a short-circuit protection device (SCPD)
interrupts the short-circuit current.
AQDs are installed in low-voltage assemblies, connected to the main circuit, preferably as
close as possible to all primary power sources.
Their rated voltage does not exceed 1 000 V AC or 1 500 V DC.
This document does not cover:
• sensors intended to detect arc-faults;
• devices intended to trigger the functioning of the arc quenching device;
• devices intended to interrupt arc-fault current;
• special requirements for AQDs for use in explosive atmospheres (e.g. ATEX).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic
(12 h + 12 h cycle)
IEC 60417, Graphical symbols for use on equipment (available at http://www.graphical-
symbols.info/equipment)
IEC 60947-1:2007, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-1:2007/AMD1:2010
IEC 60947-1:2007/AMD2:2014
IEC 61439 (all parts), Low-voltage switchgear and controlgear assemblies
CISPR 11:2015, Industrial, scientific and medical equipment – Radio-frequency disturbance
characteristics – Limits and methods of measurement
CISPR 11:2015/AMD1:2016

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3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60947-1:2007,
IEC 60947-1:2007/AMD1:2010 and IEC 60947-1:2007/AMD2:2014, as well as the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
arc quenching device
AQD
device intended to eliminate arc-faults by creating a lower impedance current path in order to
cause the arcing current to transfer to the new current path
Note 1 to entry: This note applies to the French language only.
3.2
low impedance state
closed state
state where the voltage drop across the AQD is below a defined limit
Note 1 to entry: The limit value is defined in 5.5.
3.3
open state
state of the AQD, before operation or after resetting or re-opening (see Clause 4), in which
the predetermined dielectric withstand voltage requirements of the main circuit are satisfied
Note 1 to entry: This definition also covers devices without mechanical contacts, for example semi-conductor
devices.
4 Classification
4.1 According to the number of operations
4.1.1 Single shot AQD
4.1.1.1 Not able to be reopened after operating
AQD that:
• is designed and intended to operate only once, and needs to be replaced or refurbished
after operation;
• cannot be reopened after operation, and therefore needs to be removed or disconnected
from the equipment before the main circuit can be re-energized.
4.1.1.2 Able to be reopened after operating
AQD that:
• is designed and intended to operate only once, and needs to be replaced or refurbished
after operation;
• can be reopened after operation, to allow re-energization of the main circuit before
replacement.

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IEC 60947-9-1:2019 © IEC 2019 – 9 –
NOTE Re-opening after operation does not provide protection against internal arcs anymore. This function is
restored only after the device has been replaced.
4.1.2 Resettable AQD
AQD that is designed and intended to operate a number of times, as specified by the
manufacturer.
4.2 According to the mounting characteristics
4.2.1 Fixed AQD
AQD directly mounted and connected in the assembly, so that it is necessary for the operator
to come into contact with the main circuit conductors to replace it.
4.2.2 Withdrawable or plug-in AQD
AQD mounted in a draw-out cradle, or plugged on a fixed base, so that it can be easily
replaced after operation, or maintained, without the operator coming into contact with the
main circuit conductors.
5 Characteristics
5.1 Rated operational voltage (U )
e
Subclause 4.3.1.1 of IEC 60947-1:2007 applies.
5.2 Rated insulation voltage (U )
i
Subclause 4.3.1.2 of IEC 60947-1:2007 applies.
5.3 Rated impulse withstand voltage (U )
imp
Subclause 4.3.1.3 of IEC 60947-1:2007 applies.
5.4 Rated short-time withstand current (I )
cw
The rated short-time withstand current of an AQD is the RMS value of current that the device
is able to make and carry without damage for a given duration, under the test conditions
specified in Clause 9.
There may be different values of current associated with different durations.
The duration associated with the rated short-time withstand current shall be at leas
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