Fire hazard testing - Part 2-10: Glowing/hot-wire based test methods - Glow-wire apparatus and common test procedure

IEC 60695-2-10:2021 is available as IEC 60695-2-10:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 60695-2-10:2021 specifies the glow-wire apparatus and common test procedure to simulate the effects of thermal stresses which may be produced by heat sources such as glowing elements or overloaded resistors, for short periods, in order to assess the fire hazard by a simulation technique. The test procedure described in this document is a common test procedure intended for the small-scale tests in which a standardized electrically heated wire is used as a source of ignition. It is a common part of the test procedures applied to end products and to solid electrical insulating materials or other solid combustible materials. A detailed description of each particular test procedure is given in IEC 60695-2-11, IEC 60695-2-12 and IEC 60695-2-13. This basic safety publication focusing on safety test method(s) is primarily intended for use by technical committees in the preparation of safety publications in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51. One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications. This standard is to be used in conjunction with IEC 60695-2-11, IEC 60695-2-12, and IEC 60695-2-13. This third edition cancels and replaces the second edition published in 2013. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) New terms and definitions with regards to times and durations have been added to Clause 3.
b) Previous Annex A of Equipment manufacturers and suppliers has been deleted.
c) Annex A (previous Annex B) for ignition and flaming observations has been changed from informative to normative.
d) New Annex C has been added, which visualizes times and durations, and gives examples for the behaviour of specimens, and how to evaluate them.

Essais relatifs aux risques du feu - Partie 2-10: Essais au fil incandescent/chauffant - Appareillage et méthode commune d'essai

IEC 60695-2-10:2021 est disponible sous forme de IEC 60695-2-10:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 60695-2-10:2021 spécifie l’appareillage et la méthode commune d’essai au fil incandescent pour simuler l’effet de contraintes thermiques qui peuvent être produites par des sources de chaleur telles que des éléments incandescents ou des résistances surchargées, sur de courtes durées, afin d’évaluer de façon simulée les dangers d’incendie. La méthode d’essai décrite dans le présent document représente une méthode commune d’essai destinée aux essais à petite échelle qui utilisent un fil normalisé chauffé électriquement comme source d’allumage. Il s’agit d’une partie commune des méthodes d’essai appliquées aux produits finis et aux matériaux isolants électriques solides ou à d'autres matériaux combustibles. Une description détaillée de chaque méthode d’essai particulière est donnée dans l’IEC 60695 2 11, l’IEC 60695 2 12 et l’IEC 60695-2-13. La présente publication fondamentale de sécurité, fondée sur la ou les méthodes d’essai de sécurité, est essentiellement destinée à être utilisée par les comités d’études dans le cadre de l’élaboration de publications de sécurité conformément aux principes établis dans le Guide IEC 104 et le Guide ISO/IEC 51. L'une des responsabilités d'un comité d'études consiste, le cas échéant, à utiliser les publications fondamentales de sécurité dans le cadre de l'élaboration de ses publications. Cette norme doit être utilisée conjointement avec l’IEC 60695-2-11, l’IEC 60695-2-12 et l’IEC 60695-2-13. Cette troisième édition annule et remplace la deuxième édition parue en 2013. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) De nouveaux termes et définitions concernant les moments et les durées ont été ajoutés à l'Article 3.
b) L'ancienne Annexe A relative aux fabricants et fournisseurs d'appareillage a été supprimée.
c) L'Annexe A (ancienne Annexe B) relative aux observations sur l'allumage et l’inflammation qui était informative est devenue normative.
d) Une nouvelle Annexe C qui donne une représentation des moments et des durées, ainsi que des exemples du comportement des éprouvettes d’essai, et de la manière de les évaluer a été ajoutée.

General Information

Status
Published
Publication Date
27-Oct-2021
Technical Committee
Current Stage
PPUB - Publication issued
Completion Date
28-Oct-2021
Ref Project

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IEC 60695-2-10
Edition 3.0 2021-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL PUBLICATION
PUBLICATION HORIZONTALE
Fire hazard testing –
Part 2-10: Glowing/hot-wire based test methods – Glow-wire apparatus and
common test procedure
Essais relatifs aux risques du feu –
Partie 2-10: Essais au fil incandescent/chauffant – Appareillage et méthode
commune d’essai
IEC 60695-2-10:2021-10(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60695-2-10
Edition 3.0 2021-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL PUBLICATION
PUBLICATION HORIZONTALE
Fire hazard testing –
Part 2-10: Glowing/hot-wire based test methods – Glow-wire apparatus and
common test procedure
Essais relatifs aux risques du feu –
Partie 2-10: Essais au fil incandescent/chauffant – Appareillage et méthode
commune d’essai
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.220.40; 29.020 ISBN 978-2-8322-1010-9

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
---------------------- Page: 3 ----------------------
– 2 – IEC 60695-2-10:2021 © IEC 2021
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 8

4 Description of the test apparatus ................................................................................... 10

4.1 Glow-wire.............................................................................................................. 10

4.2 Electrical circuit of the glow-wire apparatus .......................................................... 11

4.3 Temperature measuring system ............................................................................ 12

4.4 Specified layer ...................................................................................................... 13

4.5 Test chamber ........................................................................................................ 14

4.6 Timing device ....................................................................................................... 14

5 Verification of the apparatus .......................................................................................... 15

5.1 Verification of the glow-wire tip ............................................................................. 15

5.2 Verification of the temperature measuring system ................................................. 15

6 Conditioning .................................................................................................................. 15

7 Common test procedure ................................................................................................ 15

7.1 Test specimen support .......................................................................................... 15

7.2 Glow-wire temperature .......................................................................................... 16

7.3 Application of the glow-wire .................................................................................. 16

8 General test observations and evaluations of test results .............................................. 16

Annex A (normative) Requirements for "ignition" and "flaming" observations ....................... 17

A.1 General ................................................................................................................. 17

A.2 Examples of ignition and non-ignition .................................................................... 17

Annex B (informative) Guidance on the verification procedure of the glow-wire

temperature measuring system by the heating current .......................................................... 19

B.1 Objective .............................................................................................................. 19

B.2 Preparation ........................................................................................................... 19

B.3 Verification procedure ........................................................................................... 19

B.3.1 Observation and measurement ...................................................................... 19

B.3.2 Correlation chart ............................................................................................ 19

B.3.3 Frequency of revising the correlation chart .................................................... 20

Annex C (informative) Supplement – Times and durations, and examples of

evaluations ........................................................................................................................... 21

C.1 Times and durations (in accordance with Clause 3) .............................................. 21

C.2 Examples of evaluations ....................................................................................... 21

Bibliography .......................................................................................................................... 23

Figure 1 – Glow-wire and position of thermocouple ............................................................... 11

Figure 2 – Electrical circuit of the glow-wire apparatus .......................................................... 12

Figure 3 – Test apparatus examples ..................................................................................... 14

Figure A.1 – Example of a brightly shining flame ................................................................... 17

Figure A.2 – Example of a blue corona at the glow-wire tip ................................................... 18

Figure A.3 – Example of ionized gases in the form of a tail near the glow wire tip ................. 18

---------------------- Page: 4 ----------------------
IEC 60695-2-10:2021 © IEC 2021 – 3 –
Figure B.1 – Correlation curve between the heating current and the glow-wire

temperature (example) .......................................................................................................... 20

Figure C.1 – Times and durations (Example: ignition occurs at 5 s and extinguishing

occurs at 50 s) ...................................................................................................................... 21

Figure C.2 – Evaluation scheme with examples .................................................................... 22

---------------------- Page: 5 ----------------------
– 4 – IEC 60695-2-10:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIRE HAZARD TESTING –
Part 2-10: Glowing/hot-wire based test methods –
Glow-wire apparatus and common test procedure
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

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any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

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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.

IEC 60695-2-10 has been prepared by IEC technical committee 89: Fire hazard testing. It is an

International Standard.

This third edition cancels and replaces the second edition published in 2013. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) New terms and definitions with regards to times and durations have been added to Clause 3.

b) Previous Annex A of Equipment manufacturers and suppliers has been deleted.

c) Annex A (previous Annex B) for ignition and flaming observations has been changed from

informative to normative.

d) New Annex C has been added, which visualizes times and durations, and gives examples

for the behaviour of specimens, and how to evaluate them.
---------------------- Page: 6 ----------------------
IEC 60695-2-10:2021 © IEC 2021 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
89/1535/FDIS 89/1547/RVD

Full information on the voting for its approval can be found in the report on voting indicated in

the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in

accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available

at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are

described in greater detail at www.iec.ch/standardsdev/publications.

It has the status of a basic safety publication in accordance with IEC Guide 104.

This standard is to be used in conjunction with IEC 60695-2-11, IEC 60695-2-12, and

IEC 60695-2-13.

A list of all parts in the IEC 60695 series, published under the general title Fire hazard testing,

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 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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct understanding

of its contents. Users should therefore print this document using a colour printer.

---------------------- Page: 7 ----------------------
– 6 – IEC 60695-2-10:2021 © IEC 2021
INTRODUCTION

In the design of any electrotechnical product, the risk of fire and the potential hazards

associated with fire need to be considered. In this respect the objective of component, circuit,

and product design, as well as the choice of materials, is to reduce to acceptable levels the

potential risks of fire during normal operating conditions, reasonably foreseeable abnormal use,

malfunction, and/or failure. IEC 60695-1-10 [1] was developed, together with its companion,

IEC 60695-1-11 [2], to provide guidance on how this is to be accomplished.

The primary aims of IEC 60695-1-10 and IEC 60695-1-11 are to provide guidance on how:

a) to prevent ignition caused by an electrically energized component part; and

b) to confine any resulting fire within the bounds of the enclosure of the electrotechnical

product in the event of ignition.

Secondary aims of these documents include the minimization of any flame spread beyond the

product’s enclosure and the minimization of harmful effects of fire effluents such as heat,

smoke, toxicity and/or corrosivity.

Fires involving electrotechnical products can also be initiated from external non-electrical

sources. Considerations of this nature should be dealt with in the overall fire risk assessment.

In electrotechnical equipment, overheated metal parts can act as ignition sources. In glow-wire

tests, a glowing wire is used to simulate such an ignition source.

This part of IEC 60695 gives recommendations with regard to the glow-wire test apparatus and

describes a common test procedure for tests applicable to end products and materials to be

used with IEC 60695-2-11 which describes a glow-wire flammability test for end products

(GWEPT), IEC 60695-2-12 which describes a glow-wire flammability index test for materials

(GWFI), and IEC 60695-2-13 which describes a glow-wire ignition temperature test method for

materials (GWIT).
__________
Numbers in square brackets refer to the Bibliography.
---------------------- Page: 8 ----------------------
IEC 60695-2-10:2021 © IEC 2021 – 7 –
FIRE HAZARD TESTING –
Part 2-10: Glowing/hot-wire based test methods –
Glow-wire apparatus and common test procedure
1 Scope

This part of IEC 60695 specifies the glow-wire apparatus and common test procedure to

simulate the effects of thermal stresses which may be produced by heat sources such as

glowing elements or overloaded resistors, for short periods, in order to assess the fire hazard

by a simulation technique.

The test procedure described in this document is a common test procedure intended for the

small-scale tests in which a standardized electrically heated wire is used as a source of ignition.

It is a common part of the test procedures applied to end products and to solid electrical

insulating materials or other solid combustible materials.

A detailed description of each particular test procedure is given in IEC 60695-2-11,

IEC 60695-2-12 and IEC 60695-2-13.

This basic safety publication focusing on safety test method(s) is primarily intended for use by

technical committees in the preparation of safety publications in accordance with the principles

laid down in IEC Guide 104 and ISO/IEC Guide 51.

One of the responsibilities of a technical committee is, wherever applicable, to make use of

basic safety publications in the preparation of its publications.
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 60584-1, Thermocouples – Part 1: EMF specifications and tolerances

IEC 60695-2-11, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –

Glow-wire flammability test method for end-products (GWEPT)

IEC 60695-2-12, Fire hazard testing – Part 2-12: Glowing/hot-wire based test methods –

Glow-wire flammability index (GWFI) test method for materials

IEC 60695-2-13, Fire hazard testing – Part 2-13: Glowing/hot-wire based test methods –

Glow-wire ignition temperature (GWIT) test method for materials

ISO 4046-4:2016, Paper, board, pulps and related terms – Vocabulary – Part 4: Paper and

board grades and converted products
ISO 13943:2017, Fire safety – Vocabulary
---------------------- Page: 9 ----------------------
– 8 – IEC 60695-2-10:2021 © IEC 2021
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 13943:2017, some of

which are reproduced below for the user's convenience, and 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
combustible, adjective
capable of being ignited and burned
[SOURCE: ISO 13943:2017, 3.52]
3.2
draught-free environment

space in which the results of experiments are not significantly affected by the local air speed

Note 1 to entry: A qualitative example is a space in which a wax candle flame remains essentially undisturbed.

−1 −1

Quantitative examples are small-scale fire tests in which a maximum air speed of 0,1 m·s or 0,2 m·s is sometimes

specified.
[SOURCE: ISO 13943:2017, 3.83]
3.3
fire hazard
potential for harm associated with fire

Note 1 to entry: Alternatively, fire hazard can be a physical object or condition with a potential for an undesirable

consequence from fire.
[SOURCE: ISO 13943:2017, 3.131]
3.4
fire test
test that measures fire behaviour or exposes an item to the effects of a fire

Note 1 to entry: The results of a fire test can be used to quantify fire severity or determine the fire resistance or

reaction to fire of the test specimen.
[SOURCE: ISO 13943:2017, 3.157]
3.5
flame, noun

rapid, self-sustaining, sub-sonic propagation of combustion in a gaseous medium, usually with

emission of light
[SOURCE: ISO 13943:2017, 3.159]
3.6
flame event
sustained flaming and/or glowing combustion
---------------------- Page: 10 ----------------------
IEC 60695-2-10:2021 © IEC 2021 – 9 –
3.7
flammability
ability of a material or product to burn with a flame under specified conditions
[SOURCE: ISO 13943:2017, 3.178]
3.8
ignition
DEPRECATED: sustained ignition
initiation of combustion
[SOURCE: ISO 13943:2017, 3.217]
3.9
test temperature

temperature to which the tip of the glow-wire is heated and stabilized prior to any contact with

the test specimen
3.10
time of application
APP
application time of the glow-wire
Note 1 to entry: Time of application constitutes the first 30 s of the test.

Note 2 to entry: t was originally designated as t in Editions 1 and 2 of IEC 60695-2.

APP A
Note 3 to entry: See Annex C.
3.11
time of observation
OBS

observation time of the specimen and/or specified layer, starting immediately after t

APP
Note 1 to entry: Time of observation constitutes the second 30 s of the test.
Note 2 to entry: See Annex C.
3.12
time of ignition

time (to the nearest 0,5 s), from the start of test, at which the longest persisting flame event

starts
Note 1 to entry: This is a measured value.
Note 2 to entry: See Annex C.
3.13
time of extinguishing

time (to the nearest 0,5 s), from the start of the test, at which the longest persisting flame event

ends
Note 1 to entry: This is a measured value.
Note 2 to entry: See Annex C.
---------------------- Page: 11 ----------------------
– 10 – IEC 60695-2-10:2021 © IEC 2021
3.14
total flame event time
duration of the longest persisting flame event
t = t − t
T E I
Note 1 to entry: This is a calculated value.
Note 2 to entry: See Annex C.
3.15
flame time after removal

time elapsed after the removal of the glow-wire tip from the test specimen to the end of the

longest persisting flame event
t = t − 30 s
R E
Note 1 to entry: If t is less than 30 s then t is zero.
E R
Note 2 to entry: This is a calculated value.
Note 3 to entry: See Annex C.
3.16
flame time during application

duration of the longest persisting flame event whilst the glow-wire tip is in contact with the test

specimen
t = t − t
B T R
Note 1 to entry: This is a calculated value.
Note 2 to entry: See Annex C.
4 Description of the test apparatus
4.1 Glow-wire

The glow-wire is formed from nickel/chromium (> 77 % Ni/20 ± 1 % Cr) wire, having an overall

diameter of 4,00 mm ± 0,07 mm (before bending). The dimensions of the glow-wire loop are as

detailed in Figure 1. When forming the glow-wire, ensure that fine cracking at the tip is avoided.

NOTE Annealing is a suitable process for prevention of fine cracking at the tip.
---------------------- Page: 12 ----------------------
IEC 60695-2-10:2021 © IEC 2021 – 11 –
Dimensions in millimetres
Key
1 Glow-wire
2 Thermocouple
3 Stud
Dimension A (after bending): see 5.1.
Figure 1 – Glow-wire and position of thermocouple

A new glow-wire shall be annealed for a total of at least 10 h by being subjected to a current of

at least 120 A before being used for a test run. The total annealing time may be achieved

cumulatively. To avoid damage, the thermocouple shall not be installed during annealing. At

the end of annealing, the depth of the thermocouple pocket hole shall be verified.

NOTE 1 The temperature of a new glow-wire which has not been annealed gradually lowers during the first few

hours when subjected to a flow of current. After a period of time the temperature then reaches equilibrium.

The test apparatus shall be designed so that the glow-wire is kept in a horizontal plane and

applies a force of 0,95 N ± 0,10 N to the test specimen during the application of the glow-wire.

The force shall be maintained at this value when the glow-wire or the test specimen is moved

horizontally one towards the other. The penetration of the tip of the glow-wire into and through

the test specimen shall be limited to 7 mm ± 0,5 mm.

The test apparatus shall be designed in such a way that burning or glowing particles falling from

the test specimen are able to fall without obstruction onto the layer as specified in 4.4.

Two typical examples of the test apparatus are shown in Figure 3a) and Figure 3b).

NOTE 2 The apparatus shown in Figure 3b) has been found useful when testing heavy and/or awkwardly shaped

test specimens.
4.2 Electrical circuit of the glow-wire apparatus

The glow-wire shall be heated by an electric circuit as shown in Figure 2. There shall be no

feedback mechanism or circuit to maintain the temperature. The input voltage supplying the

glow-wire test apparatus shall be stable (±2 %) during the test.

NOTE 1 The stable voltage can be supplied using an appropriate stabilized voltage source. As an alternative, it has

been found useful to monitor the input voltage supplied to the glow-wire test apparatus during the test.

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– 12 – IEC 60695-2-10:2021 © IEC 2021

The circuit shall contain a current measuring device which indicates a true RMS value having

an accuracy of ±2,5 % or more accurate.

Due to the high currents involved, it is essential that all electrical connections for the glow-wire

are capable of carrying the current without affecting the performance or long-term stability of

the circuit. For the glow-wire to stud connection, a sufficient contact area (typically at least

at each end) is necessary for the stable and loss-less current necessary for the test.

60 mm
The glow-wire to stud connection shall be tightly screwed, soldered
...

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