IEC TR 61641:2014

Enclosed low-voltage switchgear and controlgear assemblies - Guide for testing under conditions of arcing due to internal fault

IEC TR 61641:2014 gives guidance on the method of testing of ASSEMBLIES under conditions of arcing in air due to an internal fault. The purpose of this test is to assess the ability of the ASSEMBLY to limit the risk of personal injury, damage of ASSEMBLIES and its suitability for further service as a result of an internal arcing fault. This third edition cancels and replaces the second edition published in 2008. It constitutes a technical revision. This third edition includes the following significant technical changes with respect to the previous edition:
- arcing classes to define the different forms of protection provided against arcing faults; (i) personnel protection, (ii) damage restricted to part of the ASSEMBLY, and (iii) ASSEMBLY suitable for limited further service.;
- two levels of personnel protection afforded by ASSEMBLIES under arcing fault conditions; (i) for ASSEMBLIES installed in areas where access to the ASSEMBLY is restricted to skilled persons, and (ii) for ASSEMBLIES installed in areas where the area is accessible to ordinary persons;
- option of individually insulating all live conductors to make the complete ASSEMBLY an arc ignition protected zone (referred to as an 'arc free zone' in previous editions of the Technical report);
- arc fault protection front, back and sides of an ASSEMBLY as the normal requirement;
- minimum performance requirements for arc ignition protected zone.

Ensembles d'appareillage à basse tension sous enveloppe - Guide pour l'essai en conditions d'arc dues à un défaut interne

L'IEC TR 61641:2014 donne des lignes directrices sur les méthodes d'essai des ENSEMBLES d'appareillage en conditions d'arc dus à un défaut interne se développant dans l'air. Le but de cet essai est d'évaluer l'aptitude de l'ENSEMBLE à limiter le risque de blessure corporelle et les dommages aux ENSEMBLES, ainsi que l'adaptabilité au service consécutif et postérieur à un arc dû à un défaut interne. Cette troisième édition annule et remplace la deuxième édition publiée en 2008. Cette édition constitue une révision technique. Cette troisième édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- les classes d'arc pour définir les différentes formes de protection fournies contre les défauts d'arc; (i) protection individuelle, (ii) dommage limité à une partie de l'ENSEMBLE et (iii) ENSEMBLE adapté à un service postérieur au défaut limité;
- deux niveaux de protection individuelle offerts par les ENSEMBLES dans des conditions de défaut d'arc; (i) pour les ENSEMBLES installés dans des zones où l'accès à l'ENSEMBLE est limité aux personnes formées et (ii) pour les ENSEMBLES installés dans des zones où l'accès est possible pour les personnes ordinaires;
- l'option d'isolation individuelle de tous les conducteurs sous tension afin de faire de l'ENSEMBLE complet une zone protégée à la création d'arc de défaut (désignée comme une "zone exempte d'arc" dans les éditions précédentes du rapport technique);
- la protection contre le défaut d'arc à l'avant, à l'arrière et sur les côtés d'un ENSEMBLE comme exigence normale;
- les exigences de performances minimales pour la zone à probabilité marginale de création d'arc.

General Information

• Status: Published
• Publication Date: 08-Sep-2014
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.130.20 - Low voltage switchgear and controlgear
• Technical Committee: SC 121B - Low-voltage switchgear and controlgear assemblies
• Drafting Committee: MT 2 - TC 121/SC 121B/MT 2
• Current Stage: PPUB - Publication issued
• Start Date: 15-Dec-2014
• Completion Date: 09-Sep-2014

Relations

• Revises: IEC TR 61641:2008 - Enclosed low-voltage switchgear and controlgear assemblies - Guide for testing under conditions of arcing due to internal fault
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TR 61641 ®
Edition 3.0 2014-09
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
Enclosed low-voltage switchgear and controlgear assemblies – Guide for
testing under conditions of arcing due to internal fault

Ensembles d'appareillage à basse tension sous enveloppe – Guide pour l'essai
en conditions d'arc dues à un défaut interne
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IEC TR 61641 ®
Edition 3.0 2014-09
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
Enclosed low-voltage switchgear and controlgear assemblies – Guide for

testing under conditions of arcing due to internal fault

Ensembles d'appareillage à basse tension sous enveloppe – Guide pour l'essai

en conditions d'arc dues à un défaut interne

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX T
ICS 29.130.20 ISBN 978-2-8322-1855-6

– 2 – IEC TR 61641:2014 © IEC 2014
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Classification of low-voltage switchgear and controlgear assemblies . 9
4.1 Classification with regard to the protection characteristic . 9
4.2 Classification with regard to persons who have access . 9
5 ASSEMBLY characteristics . 10
6 Requirements and tests for an arc ignition protected zone . 10
6.1 Constructional requirements of an arc ignition protected zone . 10
6.2 Dielectric test of arc ignition protected zones . 11
6.3 IP test of arc ignition protected zones . 11
7 Selection of test specimen and validity of tests for similar designs (possibilities for
derivation) . 11
8 Testing – Arc fault tests . 12
8.1 General . 12
8.2 Voltage . 12
8.3 Current . 13
8.4 Frequency . 13
8.5 Duration of the test . 13
8.6 Test procedure . 13
8.6.1 Supply circuit . 13
8.6.2 Arc initiation . 13
8.6.3 Repetition of the test . 15
8.6.4 Indicators (for observing the thermal effects of gases) . 15
8.7 Assessment of the test . 16
9 Test report . 16
Annex A (informative) User guide to arc fault mitigation . 19
A.1 General . 19
A.2 Arc ignition protected zones . 20
A.3 Items for classification . 20
A.4 Use of this technical report . 21
Annex B (informative) List of notes concerning certain countries . 22
Bibliography . 23

Figure 1 – Mounting frame for indicators . 18
Figure 2 – Examples of installation positions of the indicators . 18

Table 1 – Sizes of the copper ignition wire without current-limiting protection device . 14
Table 2 – Sizes of the copper ignition wire with current-limiting protection device . 14
Table A.1 – Options for classification . 20

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENCLOSED LOW-VOLTAGE SWITCHGEAR
AND CONTROLGEAR ASSEMBLIES –
GUIDE FOR TESTING UNDER CONDITIONS
OF ARCING DUE TO INTERNAL FAULT

FOREWORD
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