SIST EN 60691:2004
(Main)Thermal-links - Requirements and application guide
Thermal-links - Requirements and application guide
Applies 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. May be applicable to thermal-links for use under other than indoor conditions, provided that the climatic and other circum- stances in the immediate surroundings of such thermal-links are comparable with those in this standard.
Temperatursicherungen - Anforderungen und Anwendungshinweise
Protecteurs thermiques - Prescriptions et guide d'application
Applies 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. May be applicable to thermal-links for use under other than indoor conditions, provided that the climatic and other circum- stances in the immediate surroundings of such thermal-links are comparable with those in this standard.
Termični taljivi vložki - Zahteve in navodilo za uporabo (IEC 60691:2002)
Velja za termične taljive vložke, namenjene vključitvi v električne naprave in elektronsko opremo ter njihove sestavne dele za uporabo v zaprtih prostorih za zaščito pred prekomernimi temperaturami pod neobičajnimi pogoji. Velja lahko tudi za termične taljive vložke, ki se uporabljajo pod drugimi zunanjimi pogoji, če so podnebne in druge okoliščine v neposredni bližini takega termičnega taljivega vložka primerljive z okoliščinami v tem standardu.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 60691:2004
01-marec-2004
1DGRPHãþD
SIST EN 60691:1998
7HUPLþQLWDOMLYLYORåNL=DKWHYHLQQDYRGLOR]DXSRUDER ,(&
Thermal-links - Requirements and application guide
Temperatursicherungen - Anforderungen und Anwendungshinweise
Protecteurs thermiques - Prescriptions et guide d'application
Ta slovenski standard je istoveten z: EN 60691:2003
ICS:
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
SIST EN 60691:2004 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 60691:2004
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SIST EN 60691:2004
NORME CEI
INTERNATIONALE IEC
60691
INTERNATIONAL
Troisième édition
STANDARD
Third edition
2002-12
Protecteurs thermiques –
Prescriptions et guide d'application
Thermal-links –
Requirements and application guide
IEC 2002 Droits de reproduction réservés Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
W
Commission Electrotechnique Internationale PRICE CODE
International Electrotechnical Commission
Международная Электротехническая Комиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue
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SIST EN 60691:2004
60691 IEC:2002 – 3 –
CONTENTS
FOREWORD . 5
INTRODUCTION .9
1 Scope .11
2 Normative references.13
3 Definitions .15
4 General requirements .17
5 General notes on tests.19
6 Classification .23
7 Marking .23
8 Documentation.25
9 Mechanical requirements .25
10 Electrical requirements .33
11 Temperature tests.47
12 Resistance to rusting .49
Annex A (normative) Application guide.53
Annex B (normative) Alternative ageing test for thermal-links with T
h
greater than 250 °C for use in electric irons .55
Annex C (normative) Conductive heat ageing test .57
Annex D (informative) Extended holding temperature evaluation .67
Annex E (normative) Seal ageing test .71
Annex F (normative) Identification requirements.75
Annex G (informative) Indelibility of markings .77
Figure 1 – Bending/twist test .31
Figure C.1 – Typical test fixture assembly .63
Figure C.2 – Typical thermal-link test oven.65
Figure D.1 – Typical terminal block support test fixture .69
Figure E.1 – Conditioning time versus oven temperature for proposed temperature index .73
Figure G.1 – Apparatus for testing durability of markings .77
Table 1 – Test schedule .21
Table 2 – Strength of terminals – Minimum required tensile and thrust test forces.33
Table 3 – Creepage distances and clearances (absolute minimum values).35
Table 4 – Test voltages for dielectric strength .37
Table 5 – Test current for interrupting test.41
Table 6 – Limited short-circuit test capacity.45
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THERMAL-LINKS –
REQUIREMENTS AND APPLICATION GUIDE
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The 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 third edition cancels and replaces the second edition published in 1993, its amendment 1
(1995) and its amendment 2 (2000). This third edition constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
32C/321/FDIS 32C/329/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 US national standard UL 1020 (fifth edition) which deals with thermal cutoffs/thermal-
links, has served as a basis for the elaboration of this new edition.
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The committee has decided that the contents of this publication will remain unchanged until
2005. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
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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 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.
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THERMAL-LINKS –
REQUIREMENTS AND APPLICATION GUIDE
1 Scope and object
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 need not be 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.
NOTE 3 Attention is drawn to the fact that the external creepage distances and clearances specified in Table 3
may in some cases be smaller than those required by certain appliance or equipment standards. In such cases,
additional means should be provided when a thermal-link is mounted in the equipment in order to adjust the
creepage distances and clearances to the values required by the relevant equipment standard.
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.
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 object of this standard is
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.
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2 Normative references
The following referenced documents are indispensable for the application 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 60065:2001, Audio, video and similar electronic apparatus – Safety requirements
IEC 60085:1984, Thermal evaluation and classification of electrical insulation
IEC 60112, Method for determining the comparative and the proof tracking indices of solid
1
insulating materials under moist conditions
IEC 60216-1:2001, Electrical insulating materials – Properties of thermal endurance – Part 1:
Ageing procedures and evaluation of test results
IEC 60664-1:1992, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60695-2-11:2000, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end-products
IEC 60695-10-2:1995, Fire hazard testing – Part 10-2: Guidance and test methods for the
minimization of the effects of abnormal heat on electrotechnical products involved in fires –
Method for testing products made from non-metallic materials for resistance to heat using the
ball pressure test
IEC 60695-10-3:2002, Fire hazard testing – Part 10-3: Abnormal heat – Mould stress relief
distortion test
IEC 60695-11-10:1999, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and
vertical flame test methods
IEC 60695-11-20:1999, Fire hazard testing – Part 11-20: Test flames – 500 W flame test
methods
IEC 60730-1:1999, Automatic electrical controls for household and similar use – Part 1:
General requirements
IEC 61210:1993, Connecting devices – Flat quick-connect terminations for electrical copper
conductors – Safety requirements
UL 1020:1994, Thermal Cutoffs for Use in Electrical Appliances and Components
———————
1
A fourth edition of IEC 60112, due to be published in 2003, is being prepared.
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3 Definitions
For the purposes of this International Standard, the following 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 under specified conditions
3.4
homogeneous series (of thermal-links)
series of thermal-links having common overall construction, deviating from each other only in
such characteristics that, for a given test, 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, l
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
class of operation in which the ultimate electrical load is controlled by an auxiliary means
such as a 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
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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
3.14
transient overload current, l
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 (see
Annex D)
NOTE This is a rating for user consideration during the investigation of the end product.
3.17
conductive heat ageing test
CHAT
test to evaluate a thermal-link for use in an appliance (see Annex C)
NOTE 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.
4 General requirements
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.
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.
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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.
NOTE 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.
5 General notes on tests
Unless otherwise indicated, all tests described in this standard are type tests and shall be
carried out under room ambient conditions.
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.
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.
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 tem-
f
peratures need only be subjected to tests according to 10.6, 11.2, 11.3 and 11.4.
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 groups assigned an alphabetical letter from A to K. Each group consists of three
specimens. In general, 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 3 of Table 1.
No failures are permitted in the tests carried out in accordance with Clauses 10 and 11.
If, in any of the tests carried out in accordance with the other clauses, one failure is reported,
that test shall be repeated on twice the number of specimens and no further failures are
allowed.
The conductive heat ageing test is applicable when declared by the manufacturer. This test
shall be conducted on thermal-links with a functioning temperature (T ) rating of 175 °C or
f
above. The conductive heat ageing test is optional for thermal-links with a T rating less than
f
175 °C.
Exception: The conductive heat ageing test may be omitted if the thermal-link is of eutectic
type and is constructed without contacts.
NOTE In the USA the conductive heat ageing test is required to be declared.
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Manufacturer's inspection and factory test programme
The manufacturer shall provide regular production control, inspection and tests. Details of the
programme shall be agreed to between manufacturer and the testing house.
Table 1 – Test schedule
Specimen groups
Clause or
Test
subclause
A B CDE F G H I J K
7* Marking (rub test) XX
9 Mechanical requirements
9.2* Tensile force X
9.3* Thrust force X
9.4* Bending/twist force X
12* Resistance to rusting (ferrous parts only) X
10 Electrical requirements
10.1* Creepage distances and clearances X X
10.2.1* Humidity test X X X X X
10.2.2* Temperature and humidity cycle conditioning XX X X X
(note 2)
10.3* Dielectric strength (if applicable) XX X X X
10.4* Insulation resistance (if applicable) X X X X X
10.5* Resistance to tracking X X
10.6 Interrupting current X X
10.7* Transient overload current X X X
11 Temperature tests
11.2 Check on T X X
f
11.3 Check on T followed by dielectric test X X
m
11.4 Ageing XXX XX 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 h
10.3 Dielectric strength XX XX XXX XX X X
10.4 Insulation resistance X X X X X X X X X X X
7* Marking (visual inspection only) X X
NOTE 1 For homogeneous series, tests marked with an asterisk may be omitted for intermediate ratings.
NOTE 2 At the manufacturer's request, the humidity test of 10.2.1 can be omitted if the third humidity cycle of the
temperature and humidity condition of 10.2.2 is conducted for 168 h.
NOTE 3 If the conditions of voltage, power and current in c), d) and e) of 10.6.2 are not covered by one test, a
minimum of three samples should be tested for each condition.
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6 Classification
6.1 Electrical conditions
With regard to electrical conditions, the following terms are used:
a) Voltage
1) AC
2) DC
b) Current
1) Resistive
2) Inductive
–Motor
– Pilot duty
– Electric discharge lamp
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 120 to 174;
b) Proof tracking index from 175 to 249;
c) 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
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.
NOTE 1 If there is only one factory, the factory location may be omitted.
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The rated functioning temperature T may be omitted if a different type or catalogue reference
f
is employed for each different functioning temperature.
Where size permits, additional markings such as rated voltage followed by V, rated current
followed by A, and other optional markings as needed, may be placed on the thermal-link.
Marking shall be indelible and legible.
Indelibility is checked by trying to remove the marking by rubbing lightly for 15 s with a piece
of cloth soaked with water. Legibility is checked by inspection. After the ageing tests of 11.4,
compliance is checked by inspection.
NOTE 2 Instead of “rubbing lightly” the apparatus shown in Figure G.1 may be used.
The marking in accordance with a), b), c) and d) above 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 his 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 l , l , l ;
r b p
3) rated voltage U ;
r
c) suitability for sealing in, or use with impregnating fluids or cleaning solvents;
NOTE 1 In order to avoid possible damage to the thermal-link, the manufacturer should be consulted when
the end-use application involves sealing in or the use of cleaning solvents.
d) information for mounting the thermal-link in the equipment.
NOTE 2 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.
NOTE 3 Catalogue or reference numbers should define those parameters such as temperature, current and
voltage which together classify a thermal-link.
9 Mechanical requirements
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.
Tab terminals shall be constructed in accordance with IEC 61210.
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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 IEC 60730-1.
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 spacings to less than those required elsewhere in this standard. The security of
contact assemblies shall be such that alignment of contacts is maintained.
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.
Exception: 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 9.4
and the rated functioning temperature test of 11.2.
2
Thermal-links with leads smaller than 0,21 mm shall be provided with application instructions
that instruct the user how to mount the device in equipment, taking into consideration the
device's temperature response. The instructions shall also include guidance on the effects
that movement and vibration in the equipment may have on the thermal-link's terminals,
connections and other mounting components.
A terminal for a soldered connection shall have provision, such as a hole, for holding the
conductor independently of solder.
When applicable, provision shall be made for securely mounting a thermal-link in position.
Exception: Types intended to be embedded in windings and the like need not have provision
for
...
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