EN 60691:2016

SLOVENSKI STANDARD
01-april-2017
1DGRPHãþD
SIST EN 60691:2004
SIST EN 60691:2004/A1:2007
SIST EN 60691:2004/A2:2010
7HUPLþQLWDOMLYLYORåNL=DKWHYHLQQDYRGLOR]DXSRUDER,(&SRSUDYHN
&25
Thermal-links - Requirements and application guide (IEC 60691:2015 + COR1:2016)
Temperatursicherungen - Anforderungen und Anwendungshinweise (IEC 60691:2015 +
COR1:2016)
Protecteurs thermiques - Exigences et guide d'application (IEC 60691:2015 +
COR1:2016)
Ta slovenski standard je istoveten z: EN 60691:2016
ICS:
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60691
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2016
ICS 29.120.50 Supersedes EN 60691:2003
English Version
Thermal-links -
Requirements and application guide
(IEC 60691:2015 + COR1:2016)
Protecteurs thermiques -  Temperatursicherungen -
Exigences et guide d'application Anforderungen und Anwendungshinweise
(IEC 60691:2015 + COR1:2016) (IEC 60691:2015 + COR1:2016)
This European Standard was approved by CENELEC on 2015-11-12. 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
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60691:2016 E
European foreword
The text of document 32C/512/FDIS, future edition 4 of IEC 60691, prepared by SC 32C "Miniature
fuses", of IEC/TC 32 "Fuses" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 60691:2016.
The following dates are fixed:
(dop) 2017-04-07
• latest date by which the document has to be implemented at
national level by publication of an identical national
standard or by endorsement
(dow) 2019-10-07
• latest date by which the national standards conflicting with
the document have to be withdrawn

This document supersedes EN 60691:2003.
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.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association.
Endorsement notice
The text of the International Standard IEC 60691:2015 + COR1:2016 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 60085:2007 NOTE Harmonized as EN 60085:2008 (not modified).
IEC 60695-10-3:2002 NOTE Harmonized as EN 60695-10-3:2002 (not modified).
IEC 60695-11-20:1999/A1:2003 NOTE Harmonized as EN 60695-11-20:1999/A1:2003
(not modified).
IEC 60127-1:2006/A1:2011 NOTE Harmonized as EN 60127-1:2006/A1:2011 (not modified).
IEC 60216-1:2013 NOTE Harmonized as EN 60216-1:2013 (not modified).
IEC 60695-2-11:2014 NOTE Harmonized as EN 60695-2-11:2014 (not modified).
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
IEC 60065 (mod) 2014 Audio, video and similar electronic EN 60065 2014
apparatus - Safety requirements
IEC 60112 2003 Method for the determination of the EN 60112 2003
proof and the comparative tracking
+ A1 2009 + A1 2009
indices of solid insulating materials
IEC 60127-2 2014 Miniature fuses - EN 60127-2 2014
Part 2: Cartridge fuse-links
IEC 60216-5 2008 Electrical insulating materials - Thermal EN 60216-5 2008
endurance properties -
Part 5: Determination of relative thermal
endurance index (RTE) of an insulating
material
IEC 60664-1 2007 Insulation coordination for equipment EN 60664-1 2007
within low-voltage systems -
Part 1: Principles, requirements and
tests
IEC 60695-2-12 2010 Fire hazard testing - EN 60695-2-12 2010
Part 2-12: Glowing/hot-wire based test
+ A1 2014 + A1 2014
methods - Glow-wire flammability index
(GWFI) test method for materials
IEC 60695-2-13 2010 Fire hazard testing - EN 60695-2-13 2010
Part 2-13: Glowing/hot-wire based test
+ A1 2014 + A1 2014
methods - Glow-wire ignition
temperature (GWIT) test method for
materials
IEC 60695-10-2 2014 Fire hazard testing - EN 60695-10-2 2014
Part 10-2: Abnormal heat - Ball pressure
test method
Publication Year Title EN/HD Year
IEC 60695-11-10 2013 Fire hazard testing - EN 60695-11-10 2013
Part 11-10: Test flames - 50 W
horizontal and vertical flame test
methods
IEC 60730-1 (mod) 2013 Automatic electrical controls - EN 60730-1 2016
Part 1: General requirements
IEC 61210 (mod) 2010 Connecting devices - Flat quick-connect EN 61210 2010
terminations for electrical copper
conductors - Safety requirements

IEC 60691 ®
Edition 4.0 2015-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Thermal-links – Requirements and application guide

Protecteurs thermiques – Exigences et guide d'application

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.50 ISBN 978-2-8322-2921-7

– 2 – IEC 60691:2015 © IEC 2015
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 General requirements . 10
5 General notes on tests . 11
6 Classification . 13
6.1 Electrical conditions . 13
6.2 Thermal conditions. 14
6.3 Resistance to tracking . 14
7 Marking . 14
8 Documentation . 15
9 Constructional requirements . 15
9.1 General . 15
9.2 Lead secureness tests . 16
9.2.1 General . 16
9.2.2 Tensile test . 16
9.2.3 Thrust test . 17
9.2.4 Bending/twist test . 17
9.3 Contacts used for the current path . 18
9.4 Accessible mounting brackets or metal parts . 18
9.5 Insulating materials . 18
9.6 Resistance to tracking . 18
9.7 Creepage distances and clearances . 18
9.8 Temperature and humidity cycle conditioning . 19
9.9 Terminals and terminations . 19
10 Electrical requirements . 19
10.1 Dielectric strength . 19
10.2 Insulation resistance . 20
10.3 Interrupting current . 21
10.3.1 General . 21
10.3.2 Specific conditions . 21
10.4 Transient overload current . 22
10.5 Limited short-circuit test . 23
10.5.1 General . 23
10.5.2 Test method . 23
10.5.3 Fuse size (rating) . 23
10.5.4 Compliance . 24
11 Temperature tests . 24
11.1 General . 24
11.2 Holding temperature, T . 24
h
11.3 Rated functioning temperature, T . 25
f
11.4 Maximum temperature limit, T . 25
m
IEC 60691:2015 © IEC 2015 – 3 –
11.5 Ageing . 25
12 Resistance to rusting . 26
13 Manufacturer’s validation programme . 26
Annex A (normative) Application guide. 28
Annex B (normative) Alternative ageing test for thermal-links with T greater than
h
250 °C for use in electric irons . 29
Annex C (normative) Conductive heat ageing test . 30
C.1 Conductive heat ageing test . 30
C.2 Method . 30
C.3 Ageing . 31
C.4 Results . 32
C.5 Dielectric strength test . 32
C.6 Test oven . 32
Annex D (informative) Extended holding temperature evaluation . 34
D.1 Extended holding temperature conditioning test . 34
D.2 Load current interrupt test . 34
Annex E (normative) Seal ageing test . 36
Annex F (normative) Identification requirements . 38
Annex G (normative) Indelibility of markings . 39
Annex H (normative) Requirements for thermal-link packaged assemblies . 40
Bibliography . 43

Figure 1 – Bending/twist test . 17
Figure C.1 – Typical test fixture assembly . 32
Figure C.2 – Typical thermal-link test oven . 33
Figure D.1 – Typical terminal block support test fixture . 35
Figure E.1 – Conditioning time versus oven temperature for proposed temperature
index. 37
Figure G.1 – Apparatus for testing durability of markings . 39

Table 1 – Test schedule . 13
Table 2 – Strength of leads and terminal parts – Minimum required tensile and thrust
test forces . 17
Table 3 – Creepage distances and clearances (absolute minimum values) . 19
Table 4 – Test voltages for dielectric strength . 20
Table 5 – Test current for interrupting test . 21
Table 6 – Limited short-circuit test capacity . 23
Table H.1 – Push and pull force . 41
Table H.2 – Minimum nominal cross-sectional area of conductor . 42

– 4 – IEC 60691:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THERMAL-LINKS –
REQUIREMENTS AND APPLICATION GUIDE

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 60691 has been prepared by subcommittee 32C: Miniature fuses,
of IEC technical committee 32: Fuses.
This fourth edition cancels and replaces the third edition published in 2002, Amendment 1:
2006 and Amendment 2: 2010. This fourth edition constitutes a technical revision.
This fourth edition includes the following significant technical changes with respect to the
previous edition:
a) requirements for thermal-link packaged assemblies;
b) renew the requirements and definitions for T -test;
h
c) change starting temperature for interrupt current test;
d) clarify requirements for marking (packing label);
e) minimum Proof Tracking Index 175 instead 120.

IEC 60691:2015 © IEC 2015 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
32C/512/FDIS 32C/515/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.
The basis for this standard is the harmonization of the USA national standard, UL 1020, fifth
edition (withdrawn 2003), and IEC 60691:1993, together with its Amendment 1:1995 and
Amendment 2:2000.
The following differing practices of a less permanent nature exist in the country indicated
below:
– Annex C is required to be declared in the USA;
– Annex E is required in the USA, if applicable;
– Annex F is required to be declared in the USA.
In this standard, the following type is used:
– compliance statements: in italic type.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website 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.
The contents of the corrigendum of August 2016 have been included in this copy.

– 6 – IEC 60691:2015 © IEC 2015
INTRODUCTION
Thermal-links, defined as non-resettable devices functioning once only without refunctioning,
are widely applied for the thermal protection of equipment in which, under fault (abnormal)
conditions, one or more parts may reach hazardous temperatures.
As these devices have several aspects in common with miniature fuse-links and are used for
obtaining a comparable degree of protection, this standard has endeavoured to lay down a
number of basic requirements for such devices.

IEC 60691:2015 © IEC 2015 – 7 –
THERMAL-LINKS –
REQUIREMENTS AND APPLICATION GUIDE

1 Scope
This International Standard is applicable to thermal-links intended for incorporation in
electrical appliances, electronic equipment and component parts thereof, normally intended
for use indoors, in order to protect them against excessive temperatures under abnormal
conditions.
NOTE 1 The equipment is not designed to generate heat.
NOTE 2 The effectiveness of the protection against excessive temperatures logically depends upon the position
and method of mounting of the thermal-link, as well as upon the current which it is carrying.
This standard may be applicable to thermal-links for use under conditions other than indoors,
provided that the climatic and other circumstances in the immediate surroundings of such
thermal-links are comparable with those in this standard.
This standard may be applicable to thermal-links in their simplest forms (e.g. melting strips or
wires), provided that molten materials expelled during function cannot adversely interfere with
the safe use of the equipment, especially in the case of hand-held or portable equipment,
irrespective of its position.
Annex H of this standard is applicable to thermal-link packaged assemblies where the
thermal-link(s) has already been approved to this standard but packaged in a metallic or non-
metallic housing and provided with terminals/wiring leads.
This standard is applicable to thermal-links with a rated voltage not exceeding 690 V a.c. or
d.c. and a rated current not exceeding 63 A.
The objectives of this standard are:
a) to establish uniform requirements for thermal-links,
b) to define methods of test,
c) to provide useful information for the application of thermal-links in equipment.
This standard is not applicable to thermal-links used under extreme conditions such as
corrosive or explosive atmospheres.
This standard is not applicable to thermal-links to be used in circuits on a.c. with a frequency
lower than 45 Hz or higher than 62 Hz.
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.
IEC 60065:2014, Audio, video and similar electronic apparatus – Safety requirements

– 8 – IEC 60691:2015 © IEC 2015
IEC 60112:2003, Method for the determination of the proof and the comparative tracking
indices of solid insulating materials
IEC 60112:2003/AMD1:2009
IEC 60127-2:2014, Miniature fuses – Part 2: Cartridge fuse-links
IEC 60216-5:2008, Electrical insulating materials – Thermal endurance properties – Part 5:
Determination of relative thermal endurance index (RTE) of an insulating material
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60695-2-12:2010, Fire hazard testing – Part 2-12: Glowing/hot-wire based test methods –
Glow-wire flammability index (GWFI) test method for materials
IEC 60695-2-12:2010/AMD1:2014
IEC 60695-2-13:2010, Fire hazard testing – Part 2-13: Glowing/hot-wire based test methods –
Glow-wire ignition temperature (GWIT) test method for materials
IEC 60695-2-13:2010/AMD1:2014
IEC 60695-10-2:2014, Fire hazard testing – Part 10-2: Abnormal heat – Ball pressure test
method
IEC 60695-11-10:2013, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and
vertical flame test methods
IEC 60730-1:2013, Automatic electrical controls – Part 1: General requirements
IEC 61210:2010, Connecting devices – Flat quick-connect terminations for electrical copper
conductors – Safety requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
clearance
shortest distance in air between two conductive parts
3.2
creepage distance
shortest distance along the surface of insulating material between two conductive parts
3.3
holding temperature
T
h
maximum temperature of the thermal-link at which it will not change its state of conductivity
during a specified time at the rated current
Note 1 to entry: The minimum permissible value of T is 35 °C.
h
3.4
homogeneous series
series of thermal-links having the same external dimensions and common overall construction,
deviating from each other only in such characteristics (including ratings) that, for a given test,

IEC 60691:2015 © IEC 2015 – 9 –
the testing of one or a reduced number of particular thermal-links of that series shall be taken
as representative for all the thermal-links of the series
3.5
interrupting current
I
b
value of the current that the thermal-link is capable of interrupting at rated voltage and under
specified circuit conditions
3.6
maximum temperature limit
T
m
temperature of the thermal-link stated by the manufacturer, up to which the mechanical and
electrical properties of the thermal-link, having changed its state of conductivity, will not be
impaired for a given time
3.7
pilot duty
rating assigned to a switching device that controls the coil of another electro-mechanical
device such as a solenoid, relay or contactor
3.8
portable equipment
equipment which is moved while in operation or which can easily be moved from one place to
another while connected to the supply
3.9
rated current
I
r
current used to classify a thermal-link
3.10
rated functioning temperature
T
f
temperature of the thermal-link which causes it to change its state of conductivity with a
detection current up to 10 mA as the only load
3.11
rated voltage
U
r
voltage used to classify a thermal-link
3.12
thermal element
metallic or non-metallic fusible material that is part of a thermal-link and is responsive to
temperature by a change of state such as from solid to liquid at the temperature for which it is
calibrated
3.13
thermal-link
non-resettable device incorporating a thermal element, which will open a circuit once only
when exposed for a sufficient length of time to a temperature in excess of that for which it has
been designed
– 10 – IEC 60691:2015 © IEC 2015
3.14
transient overload current
I
p
direct current pulse train which the thermal-link is able to withstand without impairing its
characteristics
3.15
type test
conformity testing on the basis of one or more specimens of a product representative of the
production
3.16
extended holding temperature
T
h-100
maximum temperature at which a thermal-link can be maintained while conducting the rated
load current at the rated voltage for a period of 100 weeks which will not cause the thermal-
link to open circuit in accordance with extended holding temperature evaluation
Note 1 to entry: This is a rating for user consideration during the investigation of the end product.
Note 2 to entry: Annex D specifies the extended holding temperature evaluation.
3.17
conductive heat ageing test
CHAT
test to evaluate a thermal-link for use in an appliance
Note 1 to entry: If it performs satisfactorily, the thermal-link will be assigned a CHAT rating. This rating is for end-
product user consideration during the investigation of the end-use product.
Note 2 to entry: Annex C specifies the conductive heat ageing test.
4 General requirements
4.1 Adequate protection of the equipment against excessive temperatures not only
depends upon the properties of the thermal-link but also to a large extent upon the mounting
of the thermal-link in the equipment. Therefore, in addition to good engineering practice, the
requirements of the application guide in Annex A shall be considered.
4.2 Thermal-links shall have adequate electrical and mechanical strength and shall be
constructed so as to withstand all conditions of handling likely to be encountered during
mounting and normal use, when used within the requirements of this standard.
4.3 When a thermal-link changes its state of conductivity, no arc or flame shall be
maintained, nor material expelled that might impair the surrounding area or otherwise create a
risk of electric shock or fire.
For thermal-links using melting strips or wires, care should be taken to prevent molten
material from short-circuiting or bridging creepage distances and clearances in air, so as to
reduce the risk of impairing the insulation system of the equipment.
After it has functioned, the thermal-link shall not be damaged when subjected to temperatures
not exceeding T , in such a way that the safety of the equipment with regard to risk of electric
m
shock hazard and electrical breakdown is impaired. The thermal-link shall not reclose after it has
operated.
IEC 60691:2015 © IEC 2015 – 11 –
4.4 For requirements for thermal-link packaged assemblies, see Annex H.
5 General notes on tests
5.1 The test conditions are as follows.
5.1.1 Unless otherwise specified, only tests that are not required to be performed inside an
environmental chamber and/or test oven shall be carried out under the following atmospheric
conditions:
– temperature: 15 °C to 35 °C,
– relative humidity: 25 % to 75 %,
4 5
– air pressure: 8,6 × 10 Pa to 1,06 × 10 Pa.
The required atmospheric conditions during testing can be controlled when carrying out the
tests and during the duration of the tests. The required atmospheric conditions do not have to
be maintained in a test laboratory when tests are not performed.
5.1.2 Where the conditions given in 5.1.1 have a significant influence, they shall be kept
substantially constant during the tests.
5.1.3 If the temperature limits given in 5.1.1 are too wide for certain tests, these shall be
repeated, in case of doubt, at a temperature of (23 ± 1) °C.
5.2 In every test report, the ambient temperature shall be stated. If the standard conditions
for relative humidity or pressure are not fulfilled during the tests, a note to this effect shall be
added to the report.
5.3 If the result of a test is influenced, to an appreciable extent, by the position and method
of mounting of the specimen, the most unfavourable condition shall be chosen for the relevant
tests and recorded.
5.4 If a thermal-link has been specifically designed for use in a special type of equipment
and cannot be tested separately, the tests of this standard shall be performed in that
equipment or in the relevant part of it, or similar.
5.5 When testing a homogeneous series of thermal-links, all the tests shall be applied to
thermal-links with the lowest and highest T . Thermal-links with intermediate rated functioning
f
temperatures need only be subjected to tests according to 10.3, 11.3, 11.4 and 11.5.
5.6 The number of specimens is as follows.
5.6.1 The total number of specimens required is 48. Out of a total of 48 specimens, 15 are
kept as spares in case some of the tests have to be repeated. Out of a total of 48 specimens,
33 are divided into 11 groups assigned by alphabetical letters from A to K. Each group
consists of three specimens. Tests shall be performed in the order indicated in Table 1 but, if
so required, tests may be repeated, for example the test on marking (see Clause 7).
Additional samples may be needed according to Note 2 of Table 1.
For optional tests, additional samples should be required as per the applicable annexes.

– 12 – IEC 60691:2015 © IEC 2015
5.6.2 If, in any of the tests carried out in accordance with any relevant test clause, a failure
is reported, the cause of the failure will be identified and corrective action taken. Based on the
failure analysis report and the corrective action, as a minimum, the test sequence shall be
repeated on twice the number of revised specimens, and no further failures are allowed.
If no corrective actions are necessary, the test should be repeated with double the same size
and no further deviation is allowed.
5.6.3 For requirements for thermal-link packaged assemblies, see Annex H
5.7 The conductive heat ageing test of Annex C is applicable when declared by the
manufacturer.
The conductive heat ageing test may be omitted if the thermal-link is constructed without
contacts.
NOTE In the USA the conductive heat ageing test is required to be declared.

IEC 60691:2015 © IEC 2015 – 13 –
Table 1 – Test schedule
Clause or Test Specimen groups
Sub-clause
A B C D E F G H I J K
a
7 Marking (Rub test) X X
a
7 Marking (visual inspection only) X X
9 Constructional requirements
a
9.2.2 Tensile forces X
a
9.2.3 Thrust force X
a
9.2.4 Bending/twist force  X
a
9.6 Resistance to tracking       X
a
X X
9.7 Creepage distances and clearances
X X X  X X
9.8 Temperature and humidity cycle
conditioning
10 Electrical requirements
10.1 Dielectric strength (if applicable) X X X  X X
10.2 Insulation resistance (if applicable) X X X  X X
10.3 Interrupting current   X X
10.4 Transient overload current X X   X
11 Temperature tests
11.2 Check on T      X
h
11.3 Check on T X X
f
11.4 Check on T followed by dielectric  X X
m
test and insulation resistance
11.5 Ageing X  X  X X X
step 1 (optional) 21 days
step 2 (mandatory) 21 days
step 3 (mandatory) 14 days
step 4 (mandatory) 7 days
step 5 (mandatory) 7 days
step 6 (mandatory) 24 hours
10.1 Dielectric strength X X  X X X X X X
10.2 Insulation resistance X X  X X X X X X
12     Resistance to rusting
a
X X X
12 Resistance to rusting (ferrous parts)
If the conditions of voltage, power and current in 10.3.2.3, 10.3.2.4 and 10.3.2.5 are not covered by one test,
a minimum of three samples should be tested for each condition.
a
For homogeneous series, these tests may be omitted for intermediate ratings.

6 Classification
6.1 Electrical conditions
With regard to electrical conditions, the following terms are used:
a) voltage
1) AC
– 14 – IEC 60691:2015 © IEC 2015
2) DC
b) current
1) resistive
2) inductive
c) motor
d) pilot duty
e) electric discharge lamp
f) special
6.2 Thermal conditions
With regard to thermal conditions, the following symbols and abbreviations are used:
a) T
f
b) T
h
c) T
m
d) CHAT
e) T
h-100
6.3 Resistance to tracking
With regard to resistance to tracking, the following ranges are used:
a) proof tracking index from 175 to 249;
b) proof tracking index greater than or equal to 250.
NOTE These ranges are based on test methods for surface tracking laid down in IEC 60112.
7 Marking
7.1 Each thermal-link shall be marked with the following:
a) type or catalogue reference;
b) manufacturer’s name or trade mark;
c) rated functioning temperature T with or without the symbol T followed by the number of
f f
degrees Celsius (marked with °C or C);
d) date code which identifies the date of manufacture and which does not repeat for at least
10 years, and a factory location or code, stamped on the thermal-link or the smallest
packaging.
If there is only one factory, the factory location may be omitted.
Catalogue or reference numbers should define those parameters such as temperature, current
and voltage, which together classify a thermal-link.
7.2 The rated functioning temperature T may be omitted if a different type or catalogue
f
reference is employed for each different functioning temperature.
7.3 Marking shall be indelible and legible.
Compliance with the requirements for Indelibility of markings is checked by the test in
Annex G using the apparatus shown in Figure G.1. Legibility is checked by inspection. After
the ageing tests of 11.4, compliance is checked by inspection.

IEC 60691:2015 © IEC 2015 – 15 –
7.4 The marking in accordance with a), b), c) and d) in 7.1 shall be printed additionally on
the packing, together with a reference to this standard.
7.5 If the thermal-link is small in size, and not intended to be replaced, the markings in
accordance with b) to d) in 7.1 shall be printed on the packaging, together with a reference to
this standard.
Compliance is checked by inspection.
8 Documentation
The manufacturer shall provide in the technical documentation, catalogues or instructional
leaflets the following information, in addition to that required in Clause 7:
a) classification in accordance with Clause 6;
b) for each of the classifications;
1) characteristic temperatures T , T , T ;
f h m
2) characteristic currents I , I , I ;
r b p
3) rated voltage U ;
r
c) suitability for sealing in, or use with impregnating fluids or cleaning solvents;
d) information for mounting the thermal-link in the equipment.
e) thermal-links small in size and not intended to be replaced.
For reasons of safety, it should be made clear in the documentation that a thermal-link is a
non-repairable item and that, in case of replacement, an equivalent thermal-link from the
same manufacturer and having the same catalogue reference should be used, mounted in
exactly the same way.
f) the position of the metal screen, if it is located at a distance other than 12,7 mm away
from the live parts in the case of a thermal-link having an exposed element.
9 Constructional requirements
9.1 General
9.1.1 Thermal-links shall have adequate mechanical strength and stability so as to
withstand the stresses likely to be encountered during handling, normal use and fault
conditions of the relevant end-use equipment.
9.1.2 Tab terminals shall be constructed in accordance with IEC 61210 and the maximum
permissible temperature of the used Tab materials shall be in accordance with Table A.1 of
IEC 61210:2010 (Tabs / Integrated).
9.1.3 Current-carrying parts shall be constructed in such a way that contact pressure is not
transmitted through non-metallic material other than ceramic, or any material considered as
having sufficient dimensional stability over the range of temperatures to be expected, unless
there is sufficient resilience in the corresponding metal parts to compensate for any shrinkage
or distortion of the non-metallic material.
Current-carrying parts shall have the necessary mechanical strength, be capable of carrying
the rated current and shall be of a material that is acceptable for the particular application.
For current-carrying parts, temperature limits should be considered according to Table 13 of
IEC 60730-1:2013.
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9.1.4 Friction shall not be used to secure uninsulated live parts (including terminals) to
supporting surfaces if there is a risk of such parts turning or shifting their position, resulting in
the reduction of creepage distances and clearances to less than those required elsewhere in
this standard. The security of contact assemblies shall be such that alignment of contacts is
maintained.
9.1.5 Leads and terminal parts shall be secured so that stress on them during installation
and normal use does not impair operation of the thermal-link. Thermal-links using seals with
formed leads for use in appliances or components shall not be bent less than 3 mm from the
thermal-link seal.
Leads may be bent less than 3 mm from the seal if:
a) the thermal-link manufacturer's bending fixture and procedure does not transmit stress to
the thermal-link operating mechanism, and if;
b) formed test samples shall be subjected to the bending/twist lead secureness test of 9.2.4
and the rated functioning temperature test of 11.3.
9.1.6 Thermal-links with leads smaller than 0,21 mm shall be provided with application
instructions that instruct
...