SIST EN 61482-1-2:2015
(Main)Live working - Protective clothing against the thermal hazards of an electric arc - Part 1-2: Test methods - Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test)
Live working - Protective clothing against the thermal hazards of an electric arc - Part 1-2: Test methods - Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test)
IEC 61482-1-2:2014 specifies procedures to test material and garments intended for use in heat and flame-resistant clothing for workers if there is an electric arc hazard. A directed and constrained electric arc in a test circuit is used to classify material and clothing in two defined arc protection classes. This International Standard is not dedicated toward measuring the arc rating values (ATPV, ELIM, or EBT). Procedures determining these arc rating values are prescribed in IEC 61482-1-1, using an open arc for testing. Other effects than the thermal effects of an electric arc like noise, light emissions, pressure rise, hot oil, electric shock, the consequences of physical and mental shock or toxic influences are not covered by this standard. Protective clothing for work intentionally using an electric arc, e.g. arc welding, plasma torch, is not covered by this standard. This second edition cancels and replaces the first edition, published in 2007. This edition constitutes a technical revision which includes the following significant technical changes with regard to the previous edition:
- new mean values of main control parameters arc energy and incident energy based on an extended statistical database consisting of parameter values measured in four laboratories;
- reduction of validity check ranges of main control parameters;
- determination of the incident energy by averaging the two sensor values of a test (instead of considering each single sensor value);
- determination of the heat curves of transmitted incident energy and an amendment to the heat flux acceptance criterion;
- clarification of the scope;
- and selection of the arc protection classes (test classes) by the amount of the arc energy and incident energy instead of the short-circuit current.
Arbeiten unter Spannung - Schutzkleidung gegen die thermischen Gefahren eines elektrischen Lichtbogens - Teil 1-2: Prüfverfahren - Verfahren 2: Bestimmung der Lichtbogen-Schutzklasse des Materials und der Kleidung unter Verwendung eines gerichteten Prüflichtbogens (Box-Test)
Travaux sous tension - Vêtements de protection contre les dangers thermiques d'un arc électrique - Partie 1-2: Méthodes d’essai - Méthode 2: Détermination de la classe de protection contre l’arc de matériaux et de vêtements au moyen d’un arc dirigé et contraint (enceinte d’essai)
L'IEC 61482-1-2:2014 spécifie des procédures d'essai des matériaux et des articles d'habillement destinés à être utilisés dans les vêtements résistant à la chaleur et à la flamme pour les travailleurs, en cas de danger d'arc (de défaut) électrique. Dans un circuit d'essai, un arc électrique dirigé et contraint permet de classer les matériaux et les vêtements dans deux classes de protection contre les arcs définies. Cette Norme Internationale n'est pas destinée à mesurer les valeurs de performance de l'arc (ATPV, ELIM, ou EBT). Les procédures déterminant les valeurs de performance thermique de l'arc sont présentées dans l'IEC 61482-1-1. Elles utilisent un arc à l'air libre pour les essais. D'autres effets que les effets thermiques d'un arc électrique tel que le bruit, les émissions de lumière, la montée de pression, l'huile chaude, les chocs électriques, les conséquences des chocs physiques et mentaux ou les influences toxiques ne sont pas couvert par cette norme. Les vêtements de protection destinés au travail intentionnel avec un arc électrique, par exemple soudure l'arc, torche au plasma, ne sont pas couvert par cette norme. Cette deuxième édition annule et remplace la première édition parue en 2007. Cette édition constitue une révision technique qui inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- nouvelles valeurs moyennes des paramètres de commande énergie d'arc et énergie incidente selon une base de données statistique étendue des valeurs de paramètre mesurées dans quatre laboratoires;
- réduction des plages de contrôle de validité des principaux paramètres de commande;
- détermination de l'énergie incidente par calcul de la moyenne de deux valeurs de capteur d'un essai (au lieu de considérer chaque valeur unique de capteur);
- détermination des courbes thermiques de l'énergie incidente émise et un amendement au critère d'acceptation de flux thermique;
- clarification du domaine d'application;
- et sélection des classes de protection contre l'arc (classes d'essai) par la quantité d'énergie d'arc et d'énergie incidente à la place du courant de court-circuit.
Delo pod napetostjo - Oblačila za zaščito pred temperaturno nevarnostjo električnega obloka - 1-2. del: Preskusne metode - 2. metoda: Določanje zaščitnega razreda pri obloku za material in oblačila z uporabo omejenega in usmerjenega obloka (preskus v zaboju)(IEC 61482-1-2:2014)
Ta del standarda IEC 61482 določa postopke za preskušanje materiala in oblačil, namenjenih uporabi za zaščito pred vročino in ognjem za delavce v primeru nevarnosti zaradi električnega obloka. Za razvrstitev materiala in oblačil v dva zaščitna razreda pri obloku se uporablja omejen in usmerjen oblok v preskusnem tokokrogu.
Ta mednarodni standard ni namenjen merjenju vrednosti zaščitnega razreda pri obloku (ATPV1, ELIM2 ali EBT3). Postopki za določanje teh vrednosti zaščitnega razreda pri obloku so navedeni v standardu IEC 61482-1-1, v katerem se za preskušanje uporablja odprt oblok.
Drugi učinki razen toplotnih učinkov električnega hrupa, podobnega obločnemu, emisij svetlobe, dviga tlaka, vročega olja, električnega udara, posledic telesnega in duševnega šoka ali strupenih vplivov niso zajeti v tem standardu.
Zaščitna oblačila za opravljanje dela z načrtovano uporabo električnega obloka, npr. obločno varjenje in plazemski gorilniki, niso zajeta v tem standardu.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.QRVWMRRþDQMHLive working - Protective clothing against the thermal hazards of an electric arc - Part 1-2: Test methods - Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test)13.340.10Varovalna oblekaProtective clothing13.260Protection against electric shock. Live workingICS:Ta slovenski standard je istoveten z:EN 61482-1-2:2014SIST EN 61482-1-2:2015en01-april-2015SIST EN 61482-1-2:2015SLOVENSKI
STANDARDSIST EN 61482-1-2:20071DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 61482-1-2
December 2014 ICS 13.220.40; 29.260; 29.260.99
Supersedes
EN 61482-1-2:2007
English Version
Live working - Protective clothing against the thermal hazards of an electric arc - Part 1-2: Test methods - Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test) (IEC 61482-1-2:2014)
Travaux sous tension - Vêtements de protection contre les dangers thermiques d'un arc électrique - Partie 1-2: Méthodes d'essai - Méthode 2: Détermination de la classe de protection contre l'arc de matériaux et de vêtements au moyen d'un arc dirigé et contraint (enceinte d'essai) (CEI 61482-1-2:2014)
Arbeiten unter Spannung - Schutzkleidung gegen die thermischen Gefahren eines elektrischen Lichtbogens - Teil 1-2: Prüfverfahren - Verfahren 2: Bestimmung der Lichtbogen-Schutzklasse des Materials und der Kleidung unter Verwendung eines gerichteten Prüflichtbogens (Box-Test) (IEC 61482-1-2:2014) This European Standard was approved by CENELEC on 2014-11-13. 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 © 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61482-1-2:2014 E SIST EN 61482-1-2:2015
This document supersedes EN 61482-1-2:2007. 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. Endorsement notice The text of the International Standard IEC 61482-1-2:2014 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 61482-1-1 NOTE Harmonized as EN 61482-1-1. ISO 3175-2 NOTE Harmonized as EN ISO 3175-2. ISO 6330 NOTE Harmonized as EN ISO 6330. ISO 13688:2013 NOTE Harmonized as EN ISO 13688:2013 (not modified). ISO 15797 NOTE Harmonized as EN ISO 15797.
- 3 - EN 61482-1-2:2014 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 ISO 9151 1995
Protective clothing against heat and flame - Determination of heat transmission on exposure to flame - -
IEC 61482-1-2 Edition 2.0 2014-10 INTERNATIONAL STANDARD NORME INTERNATIONALE Live working – Protective clothing against the thermal hazards of an electric arc –
Part 1-2: Test methods – Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test)
Travaux sous tension – Vêtements de protection contre les dangers thermiques d'un arc électrique –
Partie 1-2: Méthodes d’essai – Méthode 2: Détermination de la classe de protection contre l’arc de matériaux et de vêtements au moyen d’un arc dirigé et contraint (enceinte d'essai) INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE U ICS 13.220.40, 29.260, 29.260.99
PRICE CODE CODE PRIX ISBN 978-2-8322-1881-5
– 2 – IEC 61482-1-2:2014 © IEC 2014
CONTENTS FOREWORD . 4 1 Scope . 6 2 Normative references . 6 3 Terms, definitions and symbols. 6 3.1 Terms and definitions . 6 3.2 Symbols and units used in this document . 11 4 Principle of the test method . 11 4.1 Material box test procedure . 11 4.2 Garment box test procedure . 11 5 Significance and use of the test method . 12 6 Test apparatus . 12 6.1 Test apparatus and test box . 12 6.2 Material box test procedure . 15 6.2.1 Arrangement of the material box test procedure . 15 6.2.2 Test plate (panel) construction . 16 6.2.3 Sensor construction . 17 6.2.4 Sensor response . 17 6.3 Garment box test procedure . 17 6.3.1 Arrangement of the garment box test procedure . 17 6.3.2 Mannequin construction . 17 6.4 Electric supply and electrodes . 18 6.4.1 Test circuit . 18 6.4.2 Test circuit control . 18 6.4.3 Electrodes . 18 6.4.4 Fuse wire . 18 6.5 Electric test arc characteristics . 19 6.6 Measurement and data acquisition system . 19 7 Operator safety . 19 8 Specimen preparation . 20 8.1 Description of the test specimens . 20 8.1.1 Test specimens for material box test procedure . 20 8.1.2 Test specimens for garment box test procedure . 20 8.2 Pre-treatment by cleaning . 20 8.3 Pre-conditioning of the test specimens . 20 9 Calibration . 20 9.1 Data acquisition system pre-calibration . 20 9.2 Calorimeter calibration check . 20 9.3 Arc exposure calibration . 21 9.4 Calibration of the electric test circuit and testing . 21 9.5 Confirmation of test apparatus setting . 22 9.6 Preparing and conditioning of the box . 22 10 Apparatus care and maintenance . 22 10.1 Surface reconditioning of the sensors . 22 10.2 Care of test plate and mannequin . 23 10.3 Care of electrodes . 23 SIST EN 61482-1-2:2015
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11 Test procedures . 23 11.1 Test parameters . 23 11.2 Number of tests . 23 11.3 Test conditions and initial temperature . 24 11.4 Specimen mounting . 24 11.4.1 Material box test procedure . 24 11.4.2 Garment box test procedure . 24 11.5 Specimen description . 24 12 Interpretation of results . 25 12.1 Heat transfer . 25 12.1.1 Determining time zero . 25 12.1.2 Plotting sensor response . 25 12.1.3 Incident energy Ei . 25 12.1.4 Sensor response versus Stoll curve . 25 12.2 Visual inspection . 25 12.3 Test result. 26 12.3.1 Acceptance criteria of material box test procedure . 26 12.3.2 Acceptance criteria of garment box test procedure . 26 13 Test report . 27 Annex A (informative)
Precision of the test method . 28 Bibliography . 29
Figure 1 – Test box . 14 Figure 2 – Test set-up . 15 Figure 3 – Test plate with sensors
(calorimeters in mounting boards) . 16
Table 1 – Test validity check range of direct exposure incident energy
(permissible direct exposure incident energy range) . 21 Table 2 – Test validity check range of arc energy
(permissible arc energy range) . 22 Table 3 – Test parameters for Classes 1 and 2 . 23 Table 4 – Acceptance criteria for tests on materials . 26 Table 5 – Acceptance criteria for tests on garments . 26 Table A.1 – Repeatability and reproducibility values of test procedure . 28
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INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
LIVE WORKING – PROTECTIVE CLOTHING AGAINST
THE THERMAL HAZARDS OF AN ELECTRIC ARC –
Part 1-2: Test methods –
Method 2: Determination of arc protection class of material
and clothing by using a constrained and directed arc (box test)
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 61482-1-2 has been prepared by IEC technical committee 78: Live working. This second edition cancels and replaces the first edition, published in 2007. This edition constitutes a technical revision. It includes the following significant technical changes with regard to the previous edition: • new mean values of main control parameters arc energy and incident energy based on an extended statistical database consisting of parameter values measured in four laboratories; • reduction of validity check ranges of main control parameters; SIST EN 61482-1-2:2015
IEC 61482-1-2:2014 © IEC 2014 – 5 –
• determination of the incident energy by averaging the two sensor values of a test (instead of considering each single sensor value); • determination of the heat curves of transmitted incident energy and an amendment to the heat flux acceptance criterion; • information on precision (repeatability and reproducibility) of the test method; • clarification of the scope; • selection of the arc protection classes (test classes) by the amount of the arc energy and incident energy instead of the short-circuit current; • permitting electrode design without bores; • recommendations of the heat resistance materials to be used for the box and for the test plate; • clarification of the conditions for cleaning and replacing the box; • requirement for including in the test report the differences ∆Ei of the transmitted energy values to the Stoll limit value at tmax and the information if the heat curves of transmitted incident energy exceed the Stoll curve during the exposure time; • preconditioning of the samples according to manufacturer’s instruction. The text of this standard is based on the following documents: FDIS Report on voting 78/1053/FDIS 78/1089/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. In this standard terms defined in Clause 3 appear in italics. A list of all parts in the IEC 61482 series, published under the general title Live working – Protective clothing against the thermal hazards of an electric arc, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the stability 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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LIVE WORKING – PROTECTIVE CLOTHING AGAINST
THE THERMAL HAZARDS OF AN ELECTRIC ARC –
Part 1-2: Test methods –
Method 2: Determination of arc protection class of material
and clothing by using a constrained and directed arc (box test)
1 Scope This part of IEC 61482 specifies procedures to test material and garments intended for use in heat and flame-resistant clothing for workers if there is an electric arc hazard. A directed and constrained electric arc in a test circuit is used to classify material and clothing in two defined arc protection classes. This International Standard is not dedicated toward measuring the arc rating values (ATPV1, ELIM2 or EBT3). Procedures determining these arc rating values are prescribed in IEC 61482-1-1, using an open arc for testing. Other effects than the thermal effects of an electric arc like noise, light emissions, pressure rise, hot oil, electric shock, the consequences of physical and mental shock or toxic influences are not covered by this standard. Protective clothing for work intentionally using an electric arc, e.g. arc welding, plasma torch, is not covered by this standard.
2 Normative references 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. ISO 9151:1995, Protective clothing against heat and flame – Determination of heat transmission on exposure to flame 3 Terms, definitions and symbols For the purposes of this document, the following terms, definitions and symbols apply. 3.1 Terms and definitions 3.1.1
arc current
Iarc current actually flowing in the electric test circuit during arc duration (through the arc)
___________ 1
ATPV = arc thermal performance value. 2
ELIM= incident energy limit
EBT= breakopen energy threshold
IEC 61482-1-2:2014 © IEC 2014 – 7 –
Note 1 to entry: Arc current is expressed in kA rms. Note 2 to entry: The arc current flowing during arc duration fluctuates due to the non-linear arc impedance stochastically varying with time. 3.1.2
arc duration time duration of the arc Note 1 to entry: Arc duration is expressed in ms. 3.1.3
arc energy Warc electrical energy supplied to the arc and converted in the arc Note 1 to entry: Arc energy is the sum of the instantaneous arc voltage values multiplied by the instantaneous arc current values multiplied by the incremental time values during the arc duration.
Note 2 to entry: Arc energy is expressed in kJ or kW·s. 3.1.4
arc gap distance between the arc electrodes Note 1 to entry: Arc gap is expressed in mm. 3.1.5
arc protection class category of arc thermal protection of material and protective clothing tested in the box test (class 1 or class 2)
Note 1 to entry: The arc protection class is characterized by the test energy level of arc exposure (arc energy and incident energy). Note 2 to entry: Tested material and protective clothing show arc thermal protection at minimum up to the class energy level. In general the actual exposure energy limit up to which the material and protective clothing provide protection is higher. 3.1.6
arc thermal protection degree of thermal protection offered against electric arc under specific arc testing conditions Note 1 to entry: For materials, the arc thermal performance is obtained from the measurement of the transmitted energy and by evaluation of other thermal parameters (burning time, hole formation, melting). Note 2 to entry: For garments, the arc thermal performance is obtained by evaluation of thermal parameters (burning time, hole formation, melting) and of the functioning of fasteners and accessories. 3.1.7
arc voltage voltage across the arc Note 1 to entry: Arc voltage is expressed in V. 3.1.8
burning time
after flame time time for which a flaming of the test specimen is visible after the end of the electric arc duration Note 1 to entry: Burning time is expressed in s. SIST EN 61482-1-2:2015
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3.1.9
calorimeter
assembly of a copper disc with attached thermocouple used for measuring the heat flux and incident energy 3.1.10
charring formation of carbonaceous residue as the result of pyrolysis or incomplete combustion 3.1.11
clothing assembly of garments worn by workers 3.1.12
delta peak temperature
∆Tp
difference between the maximum temperature and the initial temperature of the sensor during the test exposure time Note 1 to entry: Delta peak temperature is expressed in °C. Note 2 to entry: The symbol ∆Tp is used without index when testing with material; an additional index “0” is used when testing without material for calibration (∆Tp0).
3.1.13
direct exposure incident energy
Ei0 heat energy or incident energy emitted by the electric arc and received at a calorimeter directly exposed to the arc without material influence
Note 1 to entry: Direct exposure incident energy is used for calibration. Note 2 to entry: Direct exposure incident energy is expressed in kJ/m2 or kW·s/m2 (cal/cm2)4. 3.1.14
dripping material response evidenced by flowing of the fibre polymer 3.1.15
electric arc
self-maintained gas conduction for which most of the charge carriers are electrons supplied by primary-electron emission Note 1 to entry: During live working, the electric arc is generated by gas ionisation arising from an unintentional electrical conducting connection or breakdown between live parts or a live part and the earth path of an electrical installation or an electrical device. During testing, the electric arc is initiated by the blowing of a fuse wire. [SOURCE: IEC 60050-121:1998, 121-13-12, modified – the Note 1 to entry has been added to refer specifically to live working and arc testing.] 3.1.16
embrittlement formation of a brittle residue as the result of pyrolysis or incomplete combustion 3.1.17
exposure time total test time interval of observation and measurement ___________ 4 Correlation: 1 cal/cm2 = 41,868 kJ/m2; 1 kJ/m2 = 0,023 885 cal/cm2. SIST EN 61482-1-2:2015
IEC 61482-1-2:2014 © IEC 2014 – 9 –
Note 1 to entry: Exposure time is expressed in s. 3.1.18
garment single item of clothing which may consist of single or multiple layers 3.1.19
heat flux thermal intensity of an electric arc indicated by the amount of energy transmitted per unit area and time Note 1 to entry: Heat flux is expressed in kW/m2. 3.1.20
hole formation existence of openings in the test specimen material with minimum 5 mm in any direction 3.1.21
ignition initiation of flaming and combustion
3.1.22
incident energy Ei heat energy (total heat) received at a unit surface area as a result of an electric arc
Note 1 to entry: Incident energy is measured as a proportional peak temperature rise ∆Tp of a calorimeter sensor. Note 2 to entry: Incident energy is expressed in kJ/m2 or kW·s/m2 (cal/cm2). 3.1.23
material
fabric or other substances of which the garment is made Note 1 to entry: The material may consist of single or multiple layers.
3.1.24
material response reaction of the material to an electric arc characterized by burning time (after flame), ignition, hole formation, melting, dripping, charring, embrittlement, shrinkage and transmitted energy
3.1.25
melting material response evidenced by softening and deformation
Note 1 to entry: Materials which melt are normally polymer(s). 3.1.26
prospective short-circuit current
predicted current flowing when the arc electrodes are connected by a conductor of negligible impedance (short-circuit of supply) Note 1 to entry: Prospective short-circuit current is expressed in kA rms. Note 2 to entry: There is in general a difference between the actual arc current Iarc and the test current Iclass as defined. The actual arc current flowing during the arc duration is smaller and fluctuates due to the non-linear arc impedance stochastically varying with time. Reproducible test conditions may only be defined by means of the prospective short-circuit current to be expected in case of impedance-less connected arc electrodes. This prospective short-circuit current is, by the way, also a parameter which describes the practically interesting points in the electrical systems or installations where arc exposure has to be considered. SIST EN 61482-1-2:2015
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3.1.27
protective clothing clothing which covers or replaces personal clothing, and which is designed to provide protection against one or more hazards [SOURCE: ISO 13688:2013, 3.5, modified – the definition has been modified to clarify it by removing the unclear term “protector”] 3.1.28
sensor assembly with a calorimeter and a non-conductive heat-resistant material in which the calorimeter is mounted 3.1.29
shrinkage material response evidenced by the reduction in specimen size 3.1.30
Stoll curve an empirical predicted second-degree skin burn injury model defining a relationship between the amount of thermal energy transferred to human tissue and the time of exposure
3.1.31
test current
Iclass
prospective short-circuit current of the electric test circuit (predicted current) Note 1 to entry: Test current is expressed in kA rms (symmetrical a.c. component). 3.1.32
test voltage no-load a.c. voltage of the test circuit source at 50 Hz or 60 Hz Note 1 to entry: Test voltage is expressed in V rms. 3.1.33
time to delta peak temperature
tmax time from beginning of the initiation of the arc to the time the delta peak temperature is reached Note 1 to entry: Time to delta peak temperature is expressed in s. 3.1.34
transmitted energy
Eit
incident energy received at a calorimeter when testing material or clothing Note 1 to entry: Transmitted energy is the fraction of the emitted incident energy which is transmitted through the specimen. Note 2 to entry: Transmitted energy is expressed in kJ/m2 or kW·s/m2 (cal/cm2). 3.1.35
X/R ratio ratio of system inductive reactance to resistance Note 1 to entry: The X/R ratio is proportional to the L/R ratio of time constant, and is, therefore, indicative of the rate of decay of any d.c. offset. A large X/R ratio corresponds to a large time constant and a slow rate of decay. SIST EN 61482-1-2:2015
IEC 61482-1-2:2014 © IEC 2014 – 11 –
3.2 Symbols and units used in this document Ei incident energy
kJ/m2 or kW·s/m2 (cal/cm2) 1 cal/cm2 = 41,868 kJ/m2;
1 kJ/m2 = 0,023885 cal/cm2 Ei0 direct exposure incident energy
kJ/m2 or kW·s/m2 (cal/cm2) Eit transmitted energy
kJ/m2 or kW·s/m2 (cal/cm2) Iarc arc current kA Iclass test current (prospective short-circuit current) kA tmax time to delta peak temperature
s Ta ambient temperature °C T0 initial sensor temperature
°C Warc
arc energy
kJ, kW·s ∆Tp delta peak temperature
°C ∆Tp0 delta peak temperature by calibration °C 4 Principle of the test method
4.1 Material box test procedure The box test method comprises two procedures: the material box test procedure and the garment box test procedure. The material box test procedure covered by this standard determines the behaviour of materials when exposed to heat energy from electric arcs with specific characteristics. With the material box test procedure the amount of heat energy transferred by the flat material(s) is measured during and after exposure to a specified electric arc.
Material performance for this procedure is determined from the amount of heat transmitted through the specimen(s) and other thermal parameters.
The heat flux of the exposure during the calibration shot and the heat flux transferred by the test specimen(s) during a test shot are measured with copper calorimeters. The degree to which the temperature of the calorimeters increases is a direct measure of the heat energy received. Heat transfer data is used to assess the occurrence of a second-degree burn using the Stoll curve. Material response shall be further described by recording the observed effects of the electric arc exposure on the specimens. 4.2 Garment box test procedure The garment box test procedure covered by this standard determines the behaviour of garments when exposed to heat energy from electric arcs with specific characteristics. Garment performance for this procedure is determined by evaluating the function of the protective clothing after exposure to a specified electric arc, including all the garment findings, sewing thread, fastenings and other accessories. With the garment box test procedure, no heat flux will be measured. SIST EN 61482-1-2:2015
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5 Significance and use of the test method
This test method is for testing material and garments of protective clothing used for electrotechnical work if there is an electrical arc risk. The test method permits to assess the arc thermal performance of materials (material box test procedure) and garments (garment box test procedure) in terms of the energy level of the selected protection class. The protection class energy level is represented by the level of the arc energy and the corresponding level of the direct exposure incident energy according to the test conditions.
NOTE 1 There are two protection classes: Class 1 represents a basic protection level, class 2 an increased protection. NOTE 2 In practice there can be situations with higher arc energy levels. Performing an electrical arc risk assessment, the potential arc energy of an arc flash is determined for the specific equipment and network conditions.
NOTE 3 This standard is for testing purposes. Guidance for the selection of the right protective clothing can be found in IEC 61482-2 and in an ISSA Guideline [1]5. Furthermore, there is a preliminary work of TC78 on a technical report for correlating the results of arc test methods to electrotechnical applications in order to select the proper electric arc protective equipment. NOTE 4 Work continues to evaluate higher energy exposures. With the box test set-up it is possible to evaluate materials and garments based on the use of a directed and constrained electric arc under defined laboratory conditions. A practical scenario concerning test set-up and test conditions, electrical and constructional parameters is selected. The heat energy transfer and impact of the test arc are due to radiation, convection by the hot plasma and gas cloud, direct contact with the plasma cloud or parts of it, and hot molten metal particles and splash. The test box set-up is introduced to meet typical arc fault conditions and particularly to cover actual arc exposure conditions in electrical equipment and switchgear, mainly in opened compact equipment, e.g. service entrance boxes, cable distribution cabinets, distribution substations or comparable installations where the electric arc is directed to the front of a worker at the height of his breastbone. NOTE 5 The test set-up configuration of this standard leads to high heat transmission. Other exposure conditions such as vertical electrodes open-arc conditions are also covered by the test set-up. The test set-ups maintain the specimen in a static vertical position and do not involve movement except that resulting from the exposure. The test method specifies a standard set of exposure conditions. Different exposure conditions may produce more or less severe results. In addition to the standard set of exposure conditions, other conditions representative of the expected hazard may be used. 6 Test apparatus 6.1 Test apparatus and test box
The test apparatus shall consist of the following elements: – test box for both procedures; ___________ 5
Numbers in square brackets refer to the Bibliography. SIST EN 61482-1-2:2015
IEC 61482-1-2:2014 © IEC 2014 – 13 –
– two-sensor test plate for material box test procedure; – mannequin for garment box test procedure; – electric supply and electrode configuration; – recorder; – data acquisition system. The test box arrangement (identical for both procedures) is shown in Figure 1. The test box shall be of electrically and thermally non-conductive, heat resistant material. If plaster is used, then plaster material which gives a smooth and solid surface shall be used. NOTE Besides others, the use of KeraquickTM6 moulding compound, a ceramic powder for relief casting, has shown suitable results. ___________ 6
KeraquickTM is the trade name of a product supplied by KnorrPrandell GmbH, 96215 Lichtenfels, Germany. This information is given for the convenience of users of this standard and does not constitute an endorsement by IEC of the product named. Equivalent products may be used if they can be shown to lead to the same results. SIST EN 61482-1-2:2015
– 14 – IEC 61482-1-2:2014 © IEC 2014
Dimensions in millimetres
Cut A profile Key
1 box, non-conductive heat resistant material (e.g. plaster) 2 insulating plate, thickness [ 15 3 electrode ∅ 25 ± 0,1 (aluminum) 4 electrode ∅ 25 ± 0,1 (copper) Figure 1 – Test box IEC Front view SIST EN 61482-1-2:2015
IEC 61482-1-2:2014 © IEC 2014 – 15 –
6.2 Material box test procedure 6.2.1 Arrangement of the material box test procedure
The material box test procedure is used to measure and find material response to an arc exposure when tested in a flat configuration. A quantitative measurement of the arc thermal performance by means of the heat flux or energy transmitted through the material is made. The arrangement is shown in Figure 2. The distance from electrode (centre line) to test plate (surface) shall be 300 mm ± 5 mm. The gap between electrodes shall be 30 mm ± 1 mm (arc gap). Dimensions in millimetres
Key
1 test plate with specimen (400 × 400, thickness [10 ) or test mannequin (torso) 2 cable connector 3 test box 4 connecting cable (R [ 1 000) 5 horizontal centre line Figure 2 – Test set-up
IEC R SIST EN 61482-1-2:2015
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6.2.2 Test plate (panel) construction The test plate construction is shown in Figure 3. The test plate shall be of non-conductive heat resistant material (e.g. Marinite A, Monolux 500, asbestosfree transite board, oven insulation, phenolic resin PF CP 201TM 7).
Size: (400 ± 10) mm × (400 ± 10) mm Thickness: minimum 10 mm Sensors: sensor with calorimeters according to 5.2 of ISO 9151:1995 with thermocouples type T
number: 2
configuration: in the test plate, see Figure 3. Dimensions in millimetres
Key
1 test plate (see also Figure 2) 2 horizontal centre line 3 centre line parallel to the arc axis
4 sensor (calorimeter in mounting board) Figure 3 – Test plate with sensors
(calorimeters in mounting boards)
___________ 7 Marinite A, Monolux 500 and phenolic resin PF CP 201TM
are examples of suitable products available commercially. This information is given for the convenience of users of this standard and does not constitute an endorsement by IEC of the product named. Equivalent products may be used if they can be shown to lead to the same results. IEC SIST EN 61482-1-2:2015
IEC 61482-1-2:2014 © IEC 2014 – 17 –
6.2.3 Sensor construction
The sensor consists of a calorimeter embedded in an insulating board. The sensor diameter is 90 mm ± 5 mm (see Figure 3). The calorimeter consists of a 18 g ± 1 g copper disc of 40 mm ± 0,1 mm in diameter, thickness of 1,6 mm ± 0,1 mm, a purity of at least 99 % and of a copper-constantan thermocouple T type. The disc shall be accurately weighted before assembly. The calorimeter shall be constructed from grade copper.
The copper-constantan wire thermocouple (type T) shall be mounted with the constantan wire in the copper disc centre and the copper wire at any distance outside the disc centre. The disc of the calorimeter shall be embedded in an insulating board. It shall be mounted flush with the surface of this mounting board. The surface area of the copper disc intended for heat receiving shall be covered by a thin layer of optical-black high temperature paint with an emissivity [ 0,9. 6.2.4 Sensor response The conversion of the sensor response in the form of the temperature rise in °C to heat energy (incident energy) in units of kJ/m2 is to be done by multiplying the delta temperature values by the constant factor 5,52 kJ/m2 °C.
NOTE 1 The constant factor (sensor constant) is based on an average value for the copper thermal capacity Cp equal to 0,385 J/g°C (80°C) in the tested temperature range, multiplied by the calorimeter copper plate mass of 18 g (resulting from a diameter of 40 mm and a thickness of 1,6 mm) and divided by the plate cross sectional area of 12,56 cm2. NOTE 2 Another way to consider the temperature dependency of copper thermal capacity Cp is to use the correction described in IEC 61482-1-1. 6.3 Garment box test procedure 6.3.1 Arrangement of the garment box test procedure
Instead of flat panels, a mannequin shall be employed for the garment box test procedure. The procedure is used to test the function of the protective clothing after an arc exposure including all the garment findings, sewing thread, fastenings and other accessories. The arrangement is shown in Figure 2. Instead of the flat test plate a mannequin shall be installed. The upper torso test mannequin shall be positioned such that the midpoint of the sternum area is horizontally and vertically aligned with the electrode gap.
The distance from electrode (centre line) to mannequin (surface) shall be 300 mm ± 5 mm. 6.3.2 Mannequin construction A test mannequin made of non flammable, non metallic material shall be used for the garment test. Suitable are upper torso mannequins with a chest circumference of 1 000 mm ± 100 mm. For the test of garments dedicated for the lower part of the body a mannequin consisting of hips with legs could be used. Position the centre of the electrodes gap at the height of the crotch. Portions of garments that are of interest can also be tested on the test plate in a flat position.
The test mannequin shall be supported in such a way, that it remains in position for the duration of the electric arc. SIST EN 61482-1-2:2015
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6.4 Electric supply and electrodes 6.4.1 Test circuit The electric supply shall be able to provide an almost constant a.c. source voltage and short-circuit current (symmetrical a.c. component) during a time interval according to the arc duration. Both 50 Hz and 60 Hz a.c. are allowed. The test circuit shall be set so that a voltage according to the test voltage appears under open-circuit conditions, and a current according to the test current would flow if the electrodes were connected impedance-less (short-circuit). The arc tests shall be carried out for this setting. 6.4.2 Test circuit control Test voltage and test current shall be verified by measurement. The test current (prospective short-circuit current) shall be recorded in form of an oscillogram of the instantaneous values. A graph shall be plotted. NOTE 1 Frequent verification measurements carried out before and/or after a series of arc tests are purposeful. An electrode shorting link sufficiently dimensioned is necessary for short-circuit tests. The closure and interruption of the electrical test circuit shall be done by circuit breakers which have to be controlled according to the
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