IEC 60127-1:2006
(Main)Miniature fuses - Part 1: Definitions for miniature fuses and general requirements for miniature fuse-links
Miniature fuses - Part 1: Definitions for miniature fuses and general requirements for miniature fuse-links
This part of IEC 60127 covers the general requirements and tests applicable to all types of miniature fuse-links (e.g. cartridge fuse-links, sub-miniature fuse-links and universal modular fuse-links) for the protection of electric appliances, electronic equipment and component parts thereof normally intended to be used indoors.
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INTERNATIONAL IEC
STANDARD 60127-1
Second edition
2006-06
Miniature fuses –
Part 1:
Definitions for miniature fuses and
general requirements for miniature fuse-links
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.
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INTERNATIONAL IEC
STANDARD 60127-1
Second edition
2006-06
Miniature fuses –
Part 1:
Definitions for miniature fuses and
general requirements for miniature fuse-links
IEC 2006 Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from 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
PRICE CODE
Commission Electrotechnique Internationale U
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
– 2 – 60127-1 IEC:2006(E)
CONTENTS
FOREWORD.3
1 Scope and object.5
2 Normative references .5
3 Terms and definitions .5
4 General requirements .9
5 Standard ratings .9
6 Marking .9
7 General notes on tests .10
7.1 Atmospheric conditions for testing.10
7.2 Type tests .11
7.3 Fuse-bases for tests.11
7.4 Nature of supply .11
8 Dimensions and construction.12
8.1 Dimensions .12
8.2 Construction.12
8.3 Terminations .12
8.4 Alignment and configuration of terminations .12
8.5 Soldered joints .12
9 Electrical requirements .12
9.1 Voltage drop.12
9.2 Time/current characteristic .13
9.3 Breaking capacity.14
9.4 Endurance tests .15
9.5 Maximum sustained dissipation .16
9.6 Pulse tests .16
9.7 Fuse-link temperature .16
Annex A (informative) Colour coding for miniature fuse-links .17
Annex B (informative) Example presentations of time/current characteristic
Annex C (informative) Audit testing and surveillance – Guidelines for the application of
the principles of IECEE 03 (CB-FCS) to miniature fuse-links.21
Bibliography.27
Figure A.1– Layout of colour bands.17
Figure B.1 – Example presentation of time/current characteristic, ratio 2:1 .19
Figure B.2 – Example presentation of time/current characteristic, ratio 3:1 .20
Figure C.1 – Example of a fuse-link description .22
Table A.1 – Colour coding for miniature fuse-links .18
Table C.1 – Audit testing for option 3 .25
Table C.2 – Audit testing for option 4 .26
60127-1 IEC:2006(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MINIATURE FUSES –
Part 1: Definitions for miniature fuses and
general requirements for miniature fuse-links
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,
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
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6) All users should ensure that they have the latest edition of this publication.
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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.
International Standard IEC 60127-1 has been prepared by subcommittee 32C: Miniature
fuses, of IEC technical committee 32: Fuses.
This second edition cancels and replaces the first edition (1988), together with amendment 1
(1999) and amendment 2 (2002), and constitutes a technical revision.
The major technical changes with regard to the first edition concern subclause 9.2.3 where
the nature of the current source has been clarified; in addition, IEC 60038: IEC standard
voltages, has been added to the list of normative references.
– 4 – 60127-1 IEC:2006(E)
The text of this standard is based on the following documents:
FDIS Report on voting
32C/387/FDIS 32C/390/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.
This Part 1 of the IEC 60127 series covers definitions, general requirements and tests
applicable to all types of miniature fuses (e.g. cartridge fuse-links, sub-miniature fuse-links
and universal modular fuse-links). All subsequent parts of the complete series should be read
in conjunction with this Part 1.
IEC 60127 consists of the following parts, under the general heading Mi ni ature fuses:
Part 1: Definitions for miniature fuses and general requirements for miniature fuse-links
Part 2: Cartridge fuse-links
Part 3: Sub-miniature fuse-links
Part 4: Universal modular fuse-links (UMF) – Through-hole and surface mount types
Part 5: Guidelines for quality assessment of miniature fuse-links
Part 6: Fuse-holders for miniature fuse-links
Part 7: (Free for further documents)
Part 8: (Free for further documents)
Part 9: (Free for further documents)
Part 10: User guide for miniature fuses
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
A bilingual version of this publication may be issued at a later date.
60127-1 IEC:2006(E) – 5 –
MINIATURE FUSES –
Part 1: Definitions for miniature fuses and
general requirements for miniature fuse-links
1 Scope and object
This part of IEC 60127 covers the general requirements and tests applicable to all types of
miniature fuse-links (e.g. cartridge fuse-links, sub-miniature fuse-links and universal modular
fuse-links) for the protection of electric appliances, electronic equipment and component parts
thereof normally intended to be used indoors.
Specific details covering each major subdivision are given in subsequent parts.
This standard does not apply to fuses for appliances intended to be used under special
conditions, such as in a corrosive or explosive atmosphere.
The object of this standard is
a) to establish uniform requirements for miniature fuses so as to protect appliances or parts
of appliances in the most suitable way,
b) to define the performance of the fuses, so as to give guidance to designers of electrical
appliances and electronic equipment and to ensure replacement of fuse-links by those of
similar dimensions and characteristics,
c) to define methods of testing,
d) to define maximum sustained dissipation of fuse-links to ensure good compatibility of
stated power acceptance when used with fuse-holders according to this standard (see
IEC 60127-6).
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 60038, IEC standard voltages
IEC 60127-6:1994, Miniature fuses – Part 6: Fuse-holders for miniature fuse-links
Amendment 1 (1996)
Amendment 2 (2003)
3 Terms and definitions
For the purposes of this document, the following definitions apply.
3.1
fuse
device that, by the fusing of one or more of its specially designed and proportioned
components, opens the circuit in which it is inserted by breaking the current when this
exceeds a given value for a sufficient time
NOTE The fuse comprises all the parts that form the complete device.
– 6 – 60127-1 IEC:2006(E)
3.2
miniature fuse
fuse in which the fuse-link is a miniature fuse-link
3.3
fuse-link
part of a fuse including the fuse-element(s) intended to be replaced after the fuse has
operated
3.4
enclosed fuse-link
fuse-link in which the fuse-element is totally enclosed, so that during operation within its
rating it cannot produce any harmful external effects, e.g. due to development of an arc, the
release of gas or the ejection of flame or metallic particles
3.5
miniature fuse-link
enclosed fuse-link of rated breaking capacity not exceeding 2 kA and which has at least one
of its principal dimensions not exceeding 10 mm
NOTE Principal dimensions are length, width, height and diameter.
3.6
sub-miniature fuse-link
miniature fuse-link of which the case (body) has no principal dimension exceeding 10 mm
NOTE Principal dimensions are length, width, height and diameter.
3.7
universal modular fuse-link
miniature fuse-link primarily adapted for direct electrical connection to printed circuit boards
or other conductive substrates, incorporating features designed to provide a degree of non-
interchangeability where necessary
3.8
fuse-link contact
conductive part of a fuse-link designed to engage with a fuse-base contact or with a fuse-
carrier contact
3.9
fuse-holder
combination of a fuse-base with its fuse-carrier
3.10
fuse-base
fuse-mount
fixed part of a fuse provided with contacts and terminals for connection to the system
3.11
fuse-base contact
fuse-mount contact
conductive part of a fuse-base, connected to a terminal designed to engage with a fuse-
carrier contact or with a fuse-link contact
3.12
fuse-carrier
movable part of a fuse designed to carry a fuse-link
60127-1 IEC:2006(E) – 7 –
3.13
fuse-carrier contact
conductive part of a fuse-carrier connected to a fuse-link contact and designed to engage with
a fuse-base contact
3.14
fuse-element
part of the fuse-link designed to melt when the fuse operates
3.15
homogeneous series (of fuse-links)
series of fuse-links, deviating from each other only in such characteristics that, for a given
test, the testing of one or a reduced number of particular fuse-links of the series may be taken
as representative of all the fuse-links of the series
NOTE Fuse-links are considered as forming a homogeneous series when the characteristics comply with the
following:
– the bodies have the same dimensions, material and method of manufacture;
– the caps or other end closures of the body have the same dimensions, materials and method of attachment and
sealing;
– the granular filler, if any, of the body is of the same material and completeness of filling. It should be of the
same size or any variation of the grain size with current rating should be monotonous;
– the fuse-elements are of the same material with the same principles of design and construction; any changes of
fuse-element dimensions with current rating should be monotonous;
– the rated voltage is the same;
– for low-breaking capacity fuse-links it is only necessary to test the highest rated breaking capacity in a
homogeneous series.
3.16
rating
general term employed to designate the characteristic values that together define the working
conditions upon which the tests are based and for which the fuse is designed
Examples of rated values usually stated for fuses:
− voltage (U );
N
− current (I );
N
− breaking capacity.
3.17
time/current characteristics (of a fuse-link)
a) For a.c.: curve giving, under stated conditions of operation, the value of time expressed as
virtual time as a function of the prospective symmetrical current, expressed as the r.m.s.
value
b) For d.c.: curve giving, under stated conditions of operation, the value of time expressed as
actual time as a function of the d.c. prospective current
NOTE Time/current characteristics usually stated for a fuse-link relate to the pre-arcing time and the operating
time.
3.18
conventional non-fusing current
value of current specified as that which the fuse-link is capable of carrying for a specified time
(conventional time) without melting
3.19
prospective current (of a circuit and with respect to a fuse)
current that would flow in a circuit, if a fuse situated therein were replaced by a link of
negligible impedance
– 8 – 60127-1 IEC:2006(E)
3.20
pre-arcing time (melting time)
interval of time between the beginning of a current large enough to cause a break in the fuse-
element and the instant when an arc is initiated
3.21
arcing time
interval of time between the instant of the initiation of the arc and the instant of final arc
extinction
3.22
operating time (total clearing time)
sum of the pre-arcing time and the arcing time
3.23
virtual time
value of I t divided by the value of the square of the value of the prospective current
NOTE The values of the virtual times, usually stated for a fuse-link, are the values of the pre-arcing time and of
the operating time.
3.24
I t (joule integral)
integral of the square of the current over a given time interval:
t
I²t = i dt
∫
t = 0
2 2
NOTE 1 The pre-arcing I t is the I t integral extended over the pre-arcing time of the fuse.
2 2
NOTE 2 The operating I t is the I t integral extended over the operating time of the fuse.
NOTE 3 The energy in joules released in 1 Ω of resistance in a circuit protected by a fuse is equal to the value of
2 2
the operating I t expressed in A s.
3.25
breaking capacity of a fuse-link
value (r.m.s. for a.c.) of prospective current that a fuse-link is capable of breaking at a stated
voltage under prescribed conditions of use and behaviour
3.26
recovery voltage
voltage which appears across the terminals of a fuse after breaking of the current
NOTE This voltage may be considered in two successive intervals of time, one during which a transient voltage
exists, followed by a second one during which the power frequency or the steady-state recovery voltage exists.
3.27
maximum sustained dissipation
power dissipation of a fuse-link measured under prescribed conditions of measurement at the
maximum current level that can be sustained for a minimum of 1 h
NOTE 1 The figure for maximum sustained dissipation is used in connection with the maximum power acceptance
of fuse-holders for miniature fuse-links in accordance with IEC 60127-6.
NOTE 2 These values are often exceeded for short periods of time immediately before the fuse-element melts.
Values as high as twice the maximum sustained dissipation have been recorded.
60127-1 IEC:2006(E) – 9 –
4 General requirements
Fuse-links shall be so constructed that they are reliable and safe in operation and consistent
in performance at any current up to and including the breaking capacity rating and at any
voltage up to the rated voltage, when used within the limits of this standard.
During normal use of the fuse-link and within the conditions given in this standard, no
permanent arc, no external arcing, nor any flame that can endanger the surroundings, shall
be produced. During the test for establishing the maximum sustained dissipation and after
operation, the fuse-link shall not have suffered damage hindering its replacement and the
marking shall still be legible.
In general, compliance is checked by carrying out all the tests specified.
5 Standard ratings
In the relevant standard sheets, values are given for
– rated voltage,
– rated current,
– rated breaking capacity.
6 Marking
Unless otherwise stated in subsequent parts, the requirements for marking are as follows:
6.1 Each fuse-link shall be marked with:
a) Rated current in milliamperes for rated currents below 1 A, and in amperes for rated
currents of 1 A or more. The marking of the rated current shall precede and be adjacent to
the marking of the rated voltage.
To accommodate existing practice in some countries, for the time being, the current may
also be indicated in fractions of ampere.
b) Rated voltage in volts (V).
c) Maker's name or trade mark.
d) A symbol denoting the relative pre-arcing time/current characteristic as given in the
relevant standard sheet. This symbol shall be placed before and adjacent to the rated
current.
These symbols read as follows:
FF: denoting very quick acting
F: denoting quick acting
M: denoting medium time-lag
T: denoting time-lag
TT: denoting long time-lag.
– 10 – 60127-1 IEC:2006(E)
6.2 Marking shall be indelible and easily legible.
Compliance is checked by inspection and by rubbing the marking by hand for 15 s with a
piece of cloth soaked in water and again for 15 s with a piece of cloth soaked in petroleum
spirit.
NOTE 1 For petroleum spirit the use of an aliphatic solvent hexane, with an aromatics content of maximum 0,1 %
volume, a kauri-butanol value of 29, initial boiling point approximately 65 °C, dry-point approximately 69 °C and
specific gravity of approximately 0,68 is recommended.
NOTE 2 In the case of colour coding, the test for indelibility need not be applied.
6.3 The marking according to 6.1 shall be printed on the packing together with a reference to
this standard and an indication of the appropriate standard sheet. The marking on the packing
shall include the abbreviation A and mA.
Compliance is checked by inspection.
6.4 Further identification of the current rating and the time/current characteristics by means
of colour bands may be used.
Such an additional marking shall be in accordance with Annex A.
7 General notes on tests
Tests according to this standard are type tests.
It is recommended that where acceptance tests are required, they are chosen from the type
tests in this standard.
7.1 Atmospheric conditions for testing
7.1.1 Unless otherwise specified in subsequent parts, all tests shall be carried out under the
following atmospheric conditions:
– temperature between 15 °C and 35 °C;
– relative humidity between 45 % and 75 %;
4 5
– air pressure between 8,6 × 10 Pa and 1,06 × 10 Pa.
Where the above-mentioned conditions have a significant influence, they shall be kept
substantially constant during the tests.
Fuse-links shall be tested in the specified bases in free air, and be protected from draughts
and direct heat radiation. The position of the fuse-holder shall be horizontal.
If temperature has a marked effect on the results of the tests, these shall be performed at a
temperature of 23 °C ± 1 °C.
7.1.2 In every test report, the ambient temperature shall be stated. If the standard conditions
for relative humidity or pressure are not fulfilled during tests, a note to this effect shall be
added to the report.
Where tests are required at elevated temperatures, these tests shall be carried out at an
ambient temperature of 70 °C ± 2 °C, unless otherwise specified.
60127-1 IEC:2006(E) – 11 –
7.2 Type tests
7.2.1 The number of fuse-links required shall be specified in subsequent parts.
Fuse-links shall be tested or inspected in accordance with the following subclauses:
a) Marking (see 6.1)
b) Dimensions (see 8.1)
c) Construction (see 8.2)
d) Voltage drop (see 9.1)
with such additional tests as are specified in subsequent parts.
7.2.2 Based on the results of the test in item d) above, the fuse-links shall be sorted in
descending order of voltage drop, and numbered consecutively, lower numbers being
allocated to the fuse-links having the highest voltage drop. Tests from these fuse-links shall
then be made in accordance with the relevant testing schedule.
If a test is to be repeated, spare fuse-links having approximately the same voltage drop as the
original fuse-links shall be used for the repeat test.
7.2.3
a) No failure is allowed in any of the tests covered by Clauses 6 and 8, nor those described
in 9.1, 9.2.2 and 9.7 and such additional clauses and subclauses as shall be specified in
subsequent parts.
b) If in the tests covered by 9.2.1 and 9.3, two failures occur at any one current, the fuse-
links are deemed not to comply with this standard. If, however, one failure occurs, the test
shall be repeated on twice the number of fuse-links, at the same current and a second
failure shall be a cause for rejection.
If two failures occur, but not both in the same test, the fuse-link shall be deemed to comply
provided that there are no further failures in repeat tests with twice the number of fuse-
links.
If more than two failures occur, the fuse-link shall be deemed not to comply with this
standard.
c) In each of the tests according to 9.4, 9.5 and 9.6, one failure is allowed. If two or more
fuse-links fail in any one test, the fuse-links are deemed not to comply with this standard,
unless otherwise specified in subsequent parts.
7.3 Fuse-bases for tests
For tests that require a fuse-base for mounting the fuse-links, a base according to the
requirements specified in subsequent parts shall be used.
7.4 Nature of supply
The nature of the supply for the electrical tests is specified in the relevant clauses or in the
relevant standard sheets in subsequent parts.
For a.c., the test voltage is of substantially sinewave form with a frequency between 45 Hz
and 62 Hz.
– 12 – 60127-1 IEC:2006(E)
8 Dimensions and construction
8.1 Dimensions
The dimensions of the fuse-links shall comply with the relevant standard sheet, given in
subsequent parts.
Compliance is checked by measurement.
8.2 Construction
The fuse-element shall be completely enclosed. Further details of the construction are given,
as appropriate, in subsequent parts.
8.3 Terminations
Fuse-link contacts shall be made of non-corroding material or of material suitably protected
against corrosion, and shall be effectively free from flux or other non-conducting substance on
their outer surfaces.
Nickel or silver plating is deemed to be adequate protection for brass end caps.
Tests for firm attachment are given, where appropriate, in subsequent parts.
8.4 Alignment and configuration of terminations
Appropriate tests for alignment or position of pins, etc., as applicable, are given in subsequent
parts.
8.5 Soldered joints
Externally visible soldered joints (e.g., on end caps) shall not melt during normal use and
operation.
Compliance is checked by inspection of the soldered joints after the tests described in 9.2.1,
9.2.2, 9.4, 9.5 and 9.6.
9 Electrical requirements
9.1 Voltage drop
The voltage drop across the fuse-links at the
...
IEC 60127-1 ®
Edition 2.2 2015-02
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Miniature fuses –
Part 1: Definitions for miniature fuses and general requirements for miniature
fuse-links
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IEC 60127-1 ®
Edition 2.2 2015-02
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Miniature fuses –
Part 1: Definitions for miniature fuses and general requirements for miniature
fuse-links
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.50 ISBN 978-2-8322-2293-5
IEC 60127-1 ®
Edition 2.2 2015-02
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Miniature fuses –
Part 1: Definitions for miniature fuses and general requirements for miniature
fuse-links
– 2 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
CONTENTS
FOREWORD . 3
1 Scope and object . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General requirements . 9
5 Standard ratings . 9
6 Marking . 9
7 General notes on tests . 10
7.1 Atmospheric conditions for testing . 10
7.2 Type tests . 11
7.3 Fuse-bases for tests . 11
7.4 Nature of supply . 11
8 Dimensions and construction . 12
8.1 Dimensions . 12
8.2 Construction . 12
8.3 Terminations . 12
8.4 Alignment and configuration of terminations . 12
8.5 Soldered joints . 12
9 Electrical requirements . 12
9.1 Voltage drop . 12
9.2 Time/current characteristic . 13
9.3 Breaking capacity . 14
9.4 Endurance tests . 15
9.5 Maximum sustained dissipation . 16
9.6 Pulse tests . 16
9.7 Fuse-link temperature . 16
Annex A (informative) Colour coding for miniature fuse-links . 17
Annex B (informative) Example presentations of time/current characteristic . 19
Annex C (informative) Audit testing and surveillance – Guidelines for the application of
the principles of IECEE 03 (CB-FCS) to miniature fuse-links . 21
Bibliography . 27
Figure A.1– Layout of colour bands. 17
Figure B.1 – Example presentation of time/current characteristic, ratio 2:1 . 19
Figure B.2 – Example presentation of time/current characteristic, ratio 3:1 . 20
Figure C.1 – Example of a fuse-link description . 22
Table A.1 – Colour coding for miniature fuse-links . 18
Table C.1 – Audit testing for option 3 . 25
Table C.2 – Audit testing for option 4 . 26
+AMD1:2011+AMD2:2015 IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MINIATURE FUSES –
Part 1: Definitions for miniature fuses and
general requirements for miniature fuse-links
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.
This consolidated version of the official IEC Standard and its amendments has been prepared
for user convenience.
IEC 60127-1 edition 2.2 contains the second edition (2006-06) [documents 32C/387/FDIS and
32C/390/RVD], its amendment 1 (2011-04) [documents 32C/436/CDV and 32C/438/RVC] and its
amendment 2 (2015-02) [documents 32C/490/CDV and 32C/505/RVC].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendments 1 and 2. Additions and deletions are displayed in red, with deletions
being struck through. A separate Final version with all changes accepted is available in this
publication.
– 4 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
International Standard IEC 60127-1 has been prepared by subcommittee 32C: Miniature
fuses, of IEC technical committee 32: Fuses.
The major technical changes with regard to the first edition concern subclause 9.2.3 where
the nature of the current source has been clarified; in addition, IEC 60038: IEC standard
voltages, has been added to the list of normative references.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 1 of the IEC 60127 series covers definitions, general requirements and tests
applicable to all types of miniature fuses (e.g. cartridge fuse-links, sub-miniature fuse-links
and universal modular fuse-links). All subsequent parts of the complete series should be read
in conjunction with this Part 1.
IEC 60127 consists of the following parts, under the general heading Mi ni ature fuses:
Part 1: Definitions for miniature fuses and general requirements for miniature fuse-links
Part 2: Cartridge fuse-links
Part 3: Sub-miniature fuse-links
Part 4: Universal modular fuse-links (UMF) – Through-hole and surface mount types
Part 5: Guidelines for quality assessment of miniature fuse-links
Part 6: Fuse-holders for miniature fuse-links
Part 7: (Free for further documents)
Part 8: (Free for further documents)
Part 9: (Free for further documents)
Part 10: User guide for miniature fuses
The committee has decided that the contents of the base publication and its amendments 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.
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.
+AMD1:2011+AMD2:2015 IEC 2015
MINIATURE FUSES –
Part 1: Definitions for miniature fuses and
general requirements for miniature fuse-links
1 Scope and object
This part of IEC 60127 covers the general requirements and tests applicable to all types of
miniature fuse-links (e.g. cartridge fuse-links, sub-miniature fuse-links and universal modular
fuse-links) for the protection of electric appliances, electronic equipment and component parts
thereof normally intended to be used indoors.
This standard does not apply to fuses intended for the protection of low-voltage electrical
installations. These are covered by IEC 60269, Low Voltage Fuses.
Specific details covering each major subdivision are given in subsequent parts.
This standard does not apply to fuses for appliances intended to be used under special
conditions, such as in a corrosive or explosive atmosphere.
The object of this standard is
a) to establish uniform requirements for miniature fuses so as to protect appliances or parts
of appliances in the most suitable way,
b) to define the performance of the fuses, so as to give guidance to designers of electrical
appliances and electronic equipment and to ensure replacement of fuse-links by those of
similar dimensions and characteristics,
c) to define methods of testing,
d) to define maximum sustained dissipation of fuse-links to ensure good compatibility of
stated power acceptance when used with fuse-holders according to this standard (see
IEC 60127-6).
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 60038, IEC standard voltages
IEC 60127-6:1994, Miniature fuses – Part 6: Fuse-holders for miniature fuse-links
Amendment 1 (1996)
Amendment 2 (2003)
3 Terms and definitions
For the purposes of this document, the following definitions apply.
– 6 – IEC 60127-1:2006
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3.1
fuse
device that, by the fusing of one or more of its specially designed and proportioned
components, opens the circuit in which it is inserted by breaking the current when this
exceeds a given value for a sufficient time
NOTE The fuse comprises all the parts that form the complete device.
3.2
miniature fuse
fuse in which the fuse-link is a miniature fuse-link
3.3
fuse-link
part of a fuse including the fuse-element(s) intended to be replaced after the fuse has
operated
3.4
enclosed fuse-link
fuse-link in which the fuse-element is totally enclosed, so that during operation within its
rating it cannot produce any harmful external effects, e.g. due to development of an arc, the
release of gas or the ejection of flame or metallic particles
3.5
miniature fuse-link
enclosed fuse-link of rated breaking capacity not exceeding 2 kA and which has at least one
of its principal dimensions not exceeding 10 mm for the protection of electric appliances,
electronic equipment and component parts thereof normally intended to be used indoors
NOTE Principal dimensions are length, width, height and diameter.
3.5.1
cartridge fuse-link
enclosed miniature fuse-link of rated breaking capacity not exceeding 2 kA and which has at
least one of its principle dimensions not exceeding 10 mm
NOTE Principle dimensions are length, width, height and diameter.
3.5.2
miniature fuse-link for special applications
enclosed miniature fuse-link which is not covered in IEC 60127-2, IEC 60127-3 or IEC 60127-4 and of rated
breaking capacity not exceeding 50 kA and having a width and height not exceeding 12 mm and a length not
exceeding 50 mm
3.6
sub-miniature fuse-link
miniature fuse-link of which the case (body) has no principal dimension exceeding 10 mm
NOTE Principal dimensions are length, width, height and diameter.
3.7
universal modular fuse-link
miniature fuse-link primarily adapted for direct electrical connection to printed circuit boards
or other conductive substrates, incorporating features designed to provide a degree of non-
interchangeability where necessary
3.8
fuse-link contact
conductive part of a fuse-link designed to engage with a fuse-base contact or with a fuse-
carrier contact
+AMD1:2011+AMD2:2015 IEC 2015
3.9
fuse-holder
combination of a fuse-base with its fuse-carrier
3.10
fuse-base
fuse-mount
fixed part of a fuse provided with contacts and terminals for connection to the system
3.11
fuse-base contact
fuse-mount contact
conductive part of a fuse-base, connected to a terminal designed to engage with a fuse-
carrier contact or with a fuse-link contact
3.12
fuse-carrier
movable part of a fuse designed to carry a fuse-link
3.13
fuse-carrier contact
conductive part of a fuse-carrier connected to a fuse-link contact and designed to engage with
a fuse-base contact
3.14
fuse-element
part of the fuse-link designed to melt when the fuse operates
3.15
homogeneous series (of fuse-links)
series of fuse-links, deviating from each other only in such characteristics that, for a given
test, the testing of one or a reduced number of particular fuse-links of the series may be taken
as representative of all the fuse-links of the series
NOTE Fuse-links are considered as forming a homogeneous series when the characteristics comply with the
following:
– the bodies have the same dimensions, material and method of manufacture;
– the caps or other end closures of the body have the same dimensions, materials and method of attachment and
sealing;
– the granular filler, if any, of the body is of the same material and completeness of filling. It should be of the
same size or any variation of the grain size with current rating should be monotonous;
– the fuse-elements are of the same material with the same principles of design and construction; any changes of
fuse-element dimensions with current rating should be monotonous;
– the rated voltage is the same;
– for low-breaking capacity fuse-links it is only necessary to test the highest rated breaking capacity in a
homogeneous series.
3.16
rating
general term employed to designate the characteristic values that together define the working
conditions upon which the tests are based and for which the fuse is designed
Examples of rated values usually stated for fuses:
− voltage (U );
N
− current (I );
N
− breaking capacity.
– 8 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
3.17
time/current characteristics (of a fuse-link)
a) For a.c.: curve giving, under stated conditions of operation, the value of time expressed as
virtual time as a function of the prospective symmetrical current, expressed as the r.m.s.
value
b) For d.c.: curve giving, under stated conditions of operation, the value of time expressed as
actual time as a function of the d.c. prospective current
NOTE Time/current characteristics usually stated for a fuse-link relate to the pre-arcing time and the operating
time.
3.18
conventional non-fusing current
value of current specified as that which the fuse-link is capable of carrying for a specified time
(conventional time) without melting
3.19
prospective current (of a circuit and with respect to a fuse)
current that would flow in a circuit, if a fuse situated therein were replaced by a link of
negligible impedance
3.20
pre-arcing time (melting time)
interval of time between the beginning of a current large enough to cause a break in the fuse-
element and the instant when an arc is initiated
3.21
arcing time
interval of time between the instant of the initiation of the arc and the instant of final arc
extinction
3.22
operating time (total clearing time)
sum of the pre-arcing time and the arcing time
3.23
virtual time
value of I t divided by the value of the square of the value of the prospective current
NOTE The values of the virtual times, usually stated for a fuse-link, are the values of the pre-arcing time and of
the operating time.
3.24
I t (joule integral)
integral of the square of the current over a given time interval:
t
I²t= i dt
∫
t= 0
2 2
NOTE 1 The pre-arcing I t is the I t integral extended over the pre-arcing time of the fuse.
2 2
NOTE 2 The operating I t is the I t integral extended over the operating time of the fuse.
NOTE 3 The energy in joules released in 1 Ω of resistance in a circuit protected by a fuse is equal to the value of
2 2
the operating I t expressed in A s.
3.25
breaking capacity of a fuse-link
value (r.m.s. for a.c.) of prospective current that a fuse-link is capable of breaking at a stated
voltage under prescribed conditions of use and behaviour
+AMD1:2011+AMD2:2015 IEC 2015
3.26
recovery voltage
voltage which appears across the terminals of a fuse after breaking of the current
NOTE This voltage may be considered in two successive intervals of time, one during which a transient voltage
exists, followed by a second one during which the power frequency or the steady-state recovery voltage exists.
3.27
maximum sustained dissipation
power dissipation of a fuse-link measured under prescribed conditions of measurement at the
maximum current level that can be sustained for a minimum of 1 h or, as specified in the
standard sheet for ratings above 6,3 A
NOTE 1 The figure for maximum sustained dissipation is used in connection with the maximum power acceptance
of fuse-holders for miniature fuse-links in accordance with IEC 60127-6.
NOTE 2 These values are often exceeded for short periods of time immediately before the fuse-element melts.
Values as high as twice the maximum sustained dissipation have been recorded.
4 General requirements
Fuse-links shall be so constructed that they are reliable and safe in operation and consistent
in performance at any current up to and including the breaking capacity rating and at any
voltage up to the rated voltage, when used within the limits of this standard.
During normal use of the fuse-link and within the conditions given in this standard, no
permanent arc, no external arcing, nor any flame that can endanger the surroundings, shall
be produced. During the test for establishing the maximum sustained dissipation and after
operation, the fuse-link shall not have suffered damage hindering its replacement and the
marking shall still be legible.
In general, compliance is checked by carrying out all the tests specified.
5 Standard ratings
In the relevant standard sheets, values are given for
– rated voltage,
– rated current,
– rated breaking capacity.
6 Marking
Unless otherwise stated in subsequent parts, the requirements for marking are as follows:
6.1 Each fuse-link shall be marked with:
a) Rated current in milliamperes for rated currents below 1 A, and in amperes for rated
currents of 1 A or more. The marking of the rated current shall precede and be adjacent to
the marking of the rated voltage.
To accommodate existing practice in some countries, for the time being, the current may
also be indicated in fractions of ampere.
b) Rated voltage in volts (V).
c) Maker's name or trade mark.
d) A symbol denoting the relative pre-arcing time/current characteristic as given in the
relevant standard sheet. This symbol shall be placed before and adjacent to the rated
current.
– 10 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
These symbols read as follows:
FF: denoting very quick acting
F: denoting quick acting
M: denoting medium time-lag
T: denoting time-lag
TT: denoting long time-lag.
6.2 Marking shall be indelible and easily legible.
Compliance is checked by inspection and by rubbing the marking by hand for 15 s with a
piece of cloth soaked in water and again for 15 s with a piece of cloth soaked in petroleum
spirit.
NOTE 1 For petroleum spirit the use of an aliphatic solvent hexane, with an aromatics content of maximum 0,1 %
volume, a kauri-butanol value of 29, initial boiling point approximately 65 °C, dry-point approximately 69 °C and
specific gravity of approximately 0,68 is recommended.
NOTE 2 In the case of colour coding, the test for indelibility need not be applied.
6.3 The marking according to 6.1 shall be printed on the packing together with a reference to
this standard and an indication of the appropriate standard sheet. The marking on the packing
shall include the abbreviation A and mA.
Compliance is checked by inspection.
6.4 Further identification of the current rating and the time/current characteristics by means
of colour bands may be used.
Such an additional marking shall be in accordance with Annex A.
7 General notes on tests
Tests according to this standard are type tests.
It is recommended that where acceptance tests are required, they are chosen from the type
tests in this standard.
7.1 Atmospheric conditions for testing
7.1.1 Unless otherwise specified in subsequent parts, all tests shall be carried out under the
following atmospheric conditions:
– temperature between 15 °C and 35 °C;
– relative humidity between 45 % and 75 %;
4 5
– air pressure between 8,6 × 10 Pa and 1,06 × 10 Pa.
Where the above-mentioned conditions have a significant influence, they shall be kept
substantially constant during the tests.
Fuse-links shall be tested in the specified bases in free air, and be protected from draughts
and direct heat radiation. The position of the fuse-holder shall be horizontal.
If temperature has a marked effect on the results of the tests, these shall be performed at a
temperature of 23 °C ± 1 °C.
+AMD1:2011+AMD2:2015 IEC 2015
7.1.2 In every test report, the ambient temperature shall be stated. If the standard conditions
for relative humidity or pressure are not fulfilled during tests, a note to this effect shall be
added to the report.
Where tests are required at elevated temperatures, these tests shall be carried out at an
ambient temperature of 70 °C ± 2 °C, unless otherwise specified.
7.2 Type tests
7.2.1 The number of fuse-links required shall be specified in subsequent parts.
Fuse-links shall be tested or inspected in accordance with the following subclauses:
a) Marking (see 6.1)
b) Dimensions (see 8.1)
c) Construction (see 8.2)
d) Voltage drop (see 9.1)
with such additional tests as are specified in subsequent parts.
7.2.2 Based on the results of the test in item d) above, the fuse-links shall be sorted in
descending order of voltage drop, and numbered consecutively, lower numbers being
allocated to the fuse-links having the highest voltage drop. Tests from these fuse-links shall
then be made in accordance with the relevant testing schedule.
If a test is to be repeated, spare fuse-links having approximately the same voltage drop as the
original fuse-links shall be used for the repeat test.
7.2.3
a) No failure is allowed in any of the tests covered by Clauses 6 and 8, nor those described
in 9.1, 9.2.2 and 9.7 and such additional clauses and subclauses as shall be specified in
subsequent parts.
b) If in the tests covered by 9.2.1 and 9.3, two failures occur at any one current, the fuse-
links are deemed not to comply with this standard. If, however, one failure occurs, the test
shall be repeated on twice the number of fuse-links, at the same current and a second
failure shall be a cause for rejection.
If two failures occur, but not both in the same test, the fuse-link shall be deemed to comply
provided that there are no further failures in repeat tests with twice the number of fuse-
links.
If more than two failures occur, but not both in the same current, the fuse-link shall be
deemed not to comply with this standard provided that there are no further failures in
repeat tests with twice the number of fuse-links.
c) In each of the tests according to 9.4, 9.5 and 9.6, one failure is allowed. If two or more
fuse-links fail in any one test, the fuse-links are deemed not to comply with this standard,
unless otherwise specified in subsequent parts.
7.3 Fuse-bases for tests
For tests that require a fuse-base for mounting the fuse-links, a base according to the
requirements specified in subsequent parts shall be used.
7.4 Nature of supply
The nature of the supply for the electrical tests is specified in the relevant clauses or in the
relevant standard sheets in subsequent parts.
– 12 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
For a.c., the test voltage is of substantially sinewave form with a frequency between 45 Hz
and 62 Hz.
8 Dimensions and construction
8.1 Dimensions
The dimensions of the fuse-links shall comply with the relevant standard sheet, given in
subsequent parts.
Compliance is checked by measurement.
8.2 Construction
The fuse-element shall be completely enclosed. Further details of the construction are given,
as appropriate, in subsequent parts.
8.3 Terminations
Fuse-link contacts shall be made of non-corroding material or of material suitably protected
against corrosion, and shall be effectively free from flux or other non-conducting substance on
their outer surfaces.
Nickel or silver plating is deemed to be adequate protection for brass end caps.
Tests for firm attachment are given, where appropriate, in subsequent parts.
8.4 Alignment and configuration of terminations
Appropriate tests for alignment or position of pins, etc., as applicable, are given in subsequent
parts.
8.5 Soldered joints
Externally visible soldered joints (e.g., on end caps) shall not melt during normal use and
operation.
Compliance is checked by inspection of the soldered joints after the tests described in 9.2.1,
9.2.2, 9.4, 9.5 and 9.6.
9 Electrical requirements
9.1 Voltage drop
The voltage drop across the fuse-links at their rated current shall not exceed the maximum
values given on the relevant standard sheet.
Individual values shall not deviate from the mean value determined for the model under test
during type tests by more than 15 %.
NOTE 1 Attention is drawn to the fact that the second paragraph is based on the assumption that the fuse-links,
which are submitted to a type test, belong to the same manufacturing batch. Where samples are drawn at random,
the condition for the permitted deviation from the mean value need not be fulfilled. If, due to the Peltier effect,
different voltage drops are measured when the current through the fuse-link is reversed, the highest value shall be
taken.
Compliance is checked by measuring the voltage drop when the fuse-link has carried its rated
current for a time sufficient to reach temperature stability.
+AMD1:2011+AMD2:2015 IEC 2015
Direct current shall be used for this test; equipment shall be used which does not influence
the result of the test significantly.
Temperature stability is considered to be reached when the voltage drop changes by less
than 2 % of the previously observed value per minute. During this test, the current through the
fuse-link shall not deviate by more than ±1 % from the rated current and the accuracy of the
voltage drop measurement shall be within a tolerance of ±1 %.
NOTE 2 Problems can arise when fuse-links are used at voltages considerably lower than their rated voltage,
mainly for low ratings. Due to the increase of the voltage drop when the element of a fuse-link approaches its
melting point, care should be taken to ensure that there is sufficient circuit voltage available to cause the fuse-link
to interrupt the current when an electrical fault occurs. Furthermore, fuse-links of the same type and rating may,
due to difference in design or element material, have different voltage drops and may therefore not be
interchangeable in practice when used in applications with low circuit voltages, especially in combination with fuse-
links of lower rated currents.
9.2 Time/current characteristic
9.2.1 Time/current characteristic at normal ambient temperature
The time/current characteristic shall be within the limits specified in the relevant standard
sheets.
Compliance is checked by measuring the pre-arcing time under the atmospheric conditions
mentioned in 7.1.
The current through the fuse-link shall be adjusted to within ±1 % of the required value.
The current stability during the test shall be maintained within ±1 % of the adjusted value. The
voltage of the source shall not exceed the rated voltage of the fuse-link under test.
The accuracy of the measurement of time shall be within a tolerance of ±5 % for times of less
than 10 s and ±2 % for times of 10 s or more.
In the case of very short pre-arcing times at high levels of the current where constant current
no longer can be maintained, the I t value should be measured and the virtual time be
calculated.
9.2.2 Test at elevated temperature
When specified on the standard sheet, fuse-links shall also be tested for 1 h at an ambient
temperature and with the multiple of the rated current as specified on the relevant standard
sheet.
The current stability during the test shall be maintained within ±2,5 % of the adjusted value.
The fuse-link shall not operate.
9.2.3 Test procedure
Direct current shall be used for these tests.
NOTE 1 Direct current is used because it is easier to control and eliminates the variation inherent with alternating
current caused by the point on the voltage wave that switching occurs.
NOTE 2 Care should be taken that the arcing time is not included in the total time measured
The output voltage of the current source shall be sufficient to limit the variation of current
during the pre-arcing time. Additionally, the output voltage shall not exceed a value declared
by the manufacturer and chosen from the list of d.c. voltages in Table 6 of IEC 60038.
The time constant of the circuit shall not exceed 3 % of the pre-arcing time.
Where there is a possible influence of the Peltier effect, care should be taken to reverse the
direction of the current passing through the fuse-link for each successive sample.
– 14 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
NOTE 3 Where the influence of the Peltier effect is essentially due to the construction, the time/current
characteristic should be tested with twice the number of fuse-links at 2,0 I or 2,1 I . The additional samples may
N N
be taken from the spare fuse-links.
Attention is drawn to the fact that, for certain types of fuse-links, the time/current
characteristic with a.c. can be significantly different from the characteristic determined with
d.c. and particularly with currents just exceeding the conventional non-fusing current.
Furthermore, it should be noted that due to the small thermal inertia of the fuse-elements for
low currents, the characteristic of the fuse-links may change considerably at very low
frequencies.
9.2.4 Presentation of results
If the time/current characteristics with the current as independent variable are plotted, it is
preferred that they are presented with logarithmic scales on both co-ordinate axes. The basis
of the logarithmic scales shall be in the ratio 2:1 with the longer dimension on the abscissa.
If the multiple of the rated current is used as the independent variable, the ratio shall be 3:1.
NOTE Examples of such formats are given in Annex B.
9.3 Breaking capacity
9.3.1 Operating conditions
Fuse-links shall operate satisfactorily without endangering the surroundings when breaking
prospective currents between the conventional non-fusing current and rated breaking capacity
in accordance with the relevant standard sheets in subsequent parts.
The recovery voltage shall be between 1,02 and 1,05 times the rated voltage of the fuse-
links and shall be maintained for 30 s after the fuse has operated.
Typical test circuits are given in subsequent parts.
For the breaking capacity test, the current shall be adjusted by changing the series
resistance.
The impedance of the a.c. source shall be less than 10 % of the adjusted value of the total
impedance of the applicable circuit.
Compliance is checked by either method A or method B.
1) Method A (individual ratings)
a) rated breaking capacity;
b) prospective currents of approximately 5, 10, 50 and 250 times the rated current, but
not exceeding the rated breaking capacity as specified in the relevant standard sheet.
The circuit shall be closed at (30 ± 5)° after the passage of voltage through zero.
2) Method B (homogeneous series)
a) rated breaking capacity with random closing angle;
b) fuse-links shall be tested at rated breaking capacity.
NOTE 1 The breaking capacity may be lower with d.c. than with a.c. It is influenced by the circuit inductance and,
with a.c., additionally by the instant of closing the circuit.
NOTE 2 The d.c. value, if required by the purchaser or user, should be specified by the manufacturer.
———————
This tolerance may be exceeded with the manufacturer’s consent.
+AMD1:2011+AMD2:2015 IEC 2015
More details of appropriate tests for the breaking capacity of each type of miniature fuse may
be found in the subsequent parts.
9.3.2 Criteria for satisfactory performance
In each of the tests, the fuse-link shall operate satisfactorily without any of the following
phenomena:
– permanent arcing;
– ignition;
– bursting of the fuse-link.
Additional criteria for satisfactory performance of individual types of miniature fuse-links are
given, where appropriate, in subsequent parts.
NOTE Changes in colour are not considered as a failure.
Criteria concerning switching overvoltages are under consideration.
9.3.3 Insulation resistance
After the breaking capacity test, the insulation resistance between the fuse-link terminations
shall be measured with a d.c. voltage equal to twice the rated voltage of the fuse-link, but not
less than 250 V. The resistance shall be not less than 0,1 MΩ.
9.3.4 Type test for fuse-links of homogeneous series
Fuse-links having the largest rated current shall be tested completely according to the
relevant testing schedule for the maximum ampere rating of a homogeneous series given in
the subsequent parts.
Fuse-links having the smallest rated current shall be tested according to the relevant testing
schedule for the minimum ampere rating of a homogeneous series given in the subsequent
parts.
9.4 Endurance tests
Fuse-links shall be so constructed as to prevent in extended normal use any electrical or
mechanical failure impairing their compliance with this standard.
Compliance is checked by the following test:
Direct current shall be used for this test, unless otherwise specified in subsequent parts.
a) A current specified in the relevant standard sheet is passed through the fuse-link for a
period of 1 h. The current is then switched off for a period of 15 min. This cycle is
repeated 100 times.
The current stability during the test shall be maintained within ±1 % of the adjusted value.
The test should be run continuously, but where unavoidable, a single interruption is
permitted.
b) A current specified in the relevant standard sheets is then passed through the fuse-link for
1 h, or, as specified in the standard sheet for ratings above 6,3 A. At the end of this test
the voltage drop across the fuse-link is measured and used for the calculation of the
maximum sustained power dissipation, where this is specified in subsequent parts.
c) Finally, the voltage drop across the fuse-link is measured again according to 9.1. The
voltage drop across the fuse-link after the test shall not have increased by more than 10 %
of the value measured before the test and shall not exceed the maximum value specified
in the relevant standard sheet.
– 16 – IEC 60127-1:2006
+AMD1:2011+AMD2:2015 IEC 2015
d) After the test, the marking shall still be legible and soldered joints on end caps, for
example, shall not show any appreciable deterioration.
NOTE Changes in colour are not considered as a failure.
9.5 Maximum sustained dissipation
The values calculated from the measurement taken in accordance with 9.4 b) shall be within
the limits specified in the relevant standard sheet.
9.6 Pulse tests
Where pulse tests are required in subsequent parts, they shall be performed as follows:
Pulse tests at normal ambient temperature
Fuse-links shall be so constructed as to prevent, when subjected to current surges normally
experienced in service, any electrical or mechanical failure impairing their complianc
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