IEC 61020-1:2019

IEC 61020-1 ®
Edition 3.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electromechanical switches for use in electrical and electronic equipment –
Part 1: Generic specification
Interrupteurs électromécaniques pour équipements électriques et électroniques –
Partie 1: Spécification générique

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IEC 61020-1 ®
Edition 3.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electromechanical switches for use in electrical and electronic equipment –

Part 1: Generic specification
Interrupteurs électromécaniques pour équipements électriques et électroniques –

Partie 1: Spécification générique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.220.20 ISBN 978-2-8322-6388-4

– 2 – IEC 61020-1:2019 © IEC 2019
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms, definitions, units and symbols . 11
3.1 Terms and definitions . 11
3.2 Units and symbols. 13
4 Test and measurement procedures . 14
4.1 General . 14
4.1.1 General requirements to tests and measuring procedures . 14
4.1.2 Tolerances . 14
4.1.3 Preconditioning . 14
4.1.4 Mounting . 14
4.2 Standard atmospheric conditions . 14
4.3 General examination . 15
4.3.1 Visual examination . 15
4.3.2 Dimensions . 15
4.3.3 Dimensions, gauging . 16
4.3.4 Mass . 16
4.3.5 Functional operation . 17
4.3.6 Operating characteristics . 17
4.3.7 Contact bounce . 21
4.4 Resistance measurements . 23
4.4.1 Contact resistance – Millivolt level . 23
4.4.2 Contact resistance – Specified current . 26
4.4.3 Resistance from actuator to mounting bushing (surface) . 27
4.4.4 Insulation resistance . 28
4.5 Withstand voltage . 29
4.5.1 Withstand voltage at standard atmospheric conditions . 29
4.5.2 Withstand voltage at low air pressure . 30
4.6 Heating . 31
4.6.1 Object . 31
4.6.2 Method . 31
4.6.3 Requirement . 31
4.6.4 Items to be specified in the detail specification . 31
4.7 Dynamic stress . 32
4.7.1 Shock . 32
4.7.2 Vibration . 32
4.7.3 Contact disturbance . 33
4.8 Mechanical strength . 34
4.8.1 Robustness of actuator . 34
4.8.2 Robustness of mounting bushing . 37
4.8.3 Robustness of screw mounting . 37
4.8.4 Robustness of terminations . 37
4.9 Mechanical endurance . 38
4.9.1 Mechanical endurance – Standard atmospheric conditions . 38
4.9.2 Mechanical endurance – Category temperature range . 39

4.10 Electrical endurance . 40
4.10.1 Electrical endurance – Standard atmospheric conditions . 40
4.10.2 Electrical endurance – Upper category temperature . 42
4.10.3 Electrical endurance – Category temperature range . 43
4.10.4 Electrical endurance – low air pressure . 43
4.10.5 Logic loads (TTL). 44
4.10.6 Low level endurance test . 45
4.11 Overload . 46
4.11.1 Electrical overload . 46
4.11.2 Capacitive load switching . 47
4.12 Environmental testing . 48
4.12.1 Climatic sequence . 48
4.12.2 Dry heat . 50
4.12.3 Cold. 51
4.12.4 Damp heat, steady state . 53
4.12.5 Damp heat, cyclic . 54
4.12.6 Rapid change of temperature . 56
4.12.7 Mould growth (resistance) . 57
4.12.8 Corrosion, industrial atmosphere . 58
4.12.9 Dust and sand . 62
4.12.10 Salt mist . 64
4.12.11 Contact resistance stability . 65
4.13 Soldering . 66
4.13.1 Solderability, wetting, solder bath method . 66
4.13.2 Solderability, wetting, soldering iron method . 67
4.13.3 Solderability, dewetting . 68
4.13.4 Resistance to soldering heat, solder bath method . 68
4.13.5 Resistance to soldering heat, soldering iron method . 69
4.14 Panel seal . 70
4.14.1 General . 70
4.14.2 Drip – Proof . 70
4.14.3 Splash – Proof . 70
4.14.4 Immersion. 71
4.14.5 Submersion . 72
4.15 Enclosure seal . 73
4.15.1 General . 73
4.15.2 Watertight immersion . 73
4.15.3 Resilient or hermetic seal . 74
4.16 Fluid resistance – Immersion in cleaning solvents (marking) . 74
4.16.1 Object . 74
4.16.2 Method . 74
4.16.3 Requirement . 75
4.16.4 Items to be specified in the detail specification . 75
4.17 Fire hazard . 75
4.18 Capacitance . 75
4.18.1 Object . 75
4.18.2 Method . 75
4.18.3 Requirement . 75
4.18.4 Items to be specified in the detail specification . 75

– 4 – IEC 61020-1:2019 © IEC 2019
4.19 Illumination . 76
4.19.1 Chromaticity . 76
4.19.2 Transmittancy . 76
4.19.3 Temperature of illuminated surface . 77
4.20 Soldering for surface mounting switches . 77
4.20.1 Solderability, solder bath method (surface mounting switches) . 77
4.20.2 Solderability, reflow method (surface mounting switches) . 78
4.20.3 Solderability, soldering iron method (surface mounting switches) . 79
4.20.4 Resistance to soldering heat, solder bath method (surface mounting
switches) . 80
4.20.5 Resistance to soldering heat, reflow method (surface mounting switches) . 80
4.20.6 Resistance to soldering heat, soldering iron method (surface mounting
switches) . 81
4.21 Mechanical strength (surface mounting switches) . 82
4.21.1 Substrate bending (surface mounting switches) . 82
4.21.2 Pull-off and push-off (surface mounting switches) . 82
4.21.3 Shear (surface mounting switches) . 83
4.21.4 Body strength (surface mounting switches) . 84
5 Preferred values . 84
5.1 General . 84
5.2 Clearance and creepage distances . 84
6 Marking . 85
6.1 Markings on switch body . 85
6.2 Markings on packaging . 85
Bibliography . 86

Figure 1 – Measuring direction of operating force and torque . 18
Figure 2 – Example of measuring points specified in detail specifications . 20
Figure 3 – Contact bounce test circuit . 22
Figure 4 – Typical trace of contact bounce . 22
Figure 5 – Low voltage and current method (by DC) . 25
Figure 6 – Low voltage and current method (by AC) . 25
Figure 7 – Specified current method (by DC) . 27
Figure 8 – Specified current method (by AC) . 27
Figure 9 – Application of forces and torques for 4.8.1 . 36
Figure 10 – Composition of one cycle . 56
Figure 11 – Composition of cycle of test procedure . 63
Figure 12 – Submersion seal enclosure . 73

Table 1 – Torque values for mounting screws . 37
Table 2 – Climatic sequence . 49
Table 3 – . 49
Remain cycles
Table 4 – Concentration of H S . 59
Table 5 – Test temperature . 59
Table 6 – Test duration . 59
Table 7 – Concentration of SO . 61
Table 8 – Test temperature . 61
Table 9 – Test duration . 61
Table 10 – Solderability, bath method: Test severities (duration and temperature) . 67

– 6 – IEC 61020-1:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMECHANICAL SWITCHES
FOR USE IN ELECTRICAL AND ELECTRONIC EQUIPMENT –

Part 1: Generic specification
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
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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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Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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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 61020-1 has been prepared by subcommittee 23J: Switches for
appliances, of IEC technical committee 23: Electrical accessories.
This third edition cancels and replaces the second edition published in 2009.
This edition includes the following significant technical changes with respect to the previous
edition:
a) In accordance with the ISO/IEC Directives, Part 2:2016, Clause 2 General has been
replaced by two new clauses: Clause 2 Normative references and Clause 3 Terms,
definitions, units and symbols.
2.4 Preferred values and 2.5 Marking have been moved to Clauses 5 and 6. In addition, 6.2
Markings on packaging has been added.
b) Clause 3 Quality assurance procedures and Annex A have been deleted.
c) 4.3.6.3 Returning force has been added.
d) 4.3.6.4 Travel (movement of the actuator) has been added.
e) 4.12 Environmental testing:

4.12.1.3 and 4.12.1.5 have been renumbered 4.12.2 and 4.12.3, respectively. 4.12.1.4 and
4.12.1.7 have been integrated in 4.12.5. 4.12.10 Salt mist has been added.
f) Following publication of IEC 61058-1-1:2016, some cross-references to IEC 61058-1 have
been updated.
g) The following items have been updated with respect to the second edition.
– Tables and figures:
Tables 1 and 3 have been deleted, Table 4 has been renumbered to Table 10. New
Tables 2, 3, 4, 5, 6, 7, 8 and 9 have been added.
Figure 1 has been renumbered to Figure 3, Figure 2 renumbered to Figure 4, Figure 3
renumbered to Figure 9 and Figure 4 renumbered to Figure 12. Added new Figures 1, 2,
5, 6, 7, 8, 10 and 11 have been added.
– Specific words and common names have been unified.
The text of this International Standard is based on the following documents:
CDV Report on voting
23J/443/CDV 23J/448/RVC
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61020 series, published under the general title Electromechanical
switches for use in electrical and electronic equipment, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 8 – IEC 61020-1:2019 © IEC 2019
INTRODUCTION
This document covers the general requirements and test methods for electromechanical
switches with optional quality assurance procedures. It provides the general requirements and
test methods for use in any detail specifications for pushbutton switches, rotary switches,
sensitive switches, toggle switches, and other electromechanical switches.
Where it is intended that an electromechanical switch comply with requirements related to
safety, the specific safety requirements will be specified in IEC 61058-1.

ELECTROMECHANICAL SWITCHES
FOR USE IN ELECTRICAL AND ELECTRONIC EQUIPMENT –

Part 1: Generic specification
1 Scope
This part of IEC 61020 specifies the terminology, symbols, test methods and other necessary
information to provide consistency in detail specifications for electromechanical switches.
This document relates to electromechanical switches intended for use in electrical and
electronic appliances. Switches covered by this document:
a) are devices which open, close, or change the connection of a circuit by the mechanical
motion of conducting parts (contacts);
b) have a maximum rated voltage of 480 V;
c) have a maximum rated current of 63 A.
This document does not include keyboards and keypads which are intended for use in
information-handling systems. Electromechanical key switches can be included under the scope
of this document.
Switch families will be described in any detail specifications that reference this document.
This document is a performance standard intended to describe evaluation methods to better
clarify the capabilities of a switch.
NOTE 1 Safety requirements for switches for household and similar fixed electrical installations are given in
IEC 60669 (all parts).
NOTE 2 Safety requirements for appliance switches are given in IEC 61058 (all parts).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60027 (all parts), Letter symbols to be used in electrical technology
IEC 60050-581, International Electrotechnical Vocabulary – Part 581: Electromechanical
components for electronic equipment
IEC 60068-1:2013, Environmental testing – Part 1: General and guidance
IEC 60068-2-1, Environmental testing – Part 2-1: Tests – Test A: Cold
IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Test B: Dry Heat
IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-10, Environmental testing – Part 2-10: Tests – Test J and guidance: Mould growth

– 10 – IEC 61020-1:2019 © IEC 2019
IEC 60068-2-11, Environmental testing – Part 2-11: Tests – Test Ka: Salt mist
IEC 60068-2-13, Environmental testing – Part 2-13: Tests – Test M: Low air pressure
IEC 60068-2-14, Environmental testing – Part 2-14: Tests – Test N: Change of temperature
IEC 60068-2-17, Environmental testing – Part 2-17: Tests – Test Q: Sealing
IEC 60068-2-20:2008, Environmental testing – Part 2-20: Tests – Test T: Test methods for
solderability and resistance to soldering heat of devices with leads
IEC 60068-2-21, Environmental testing – Part 2-21: Tests – Test U: Robustness of terminations
and integral mounting devices
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic
(12 h + 12 h cycle)
IEC 60068-2-38:2009, Environmental testing – Part 2-38: Tests – Test Z/AD: Composite
temperature/humidity cyclic test
IEC 60068-2-42, Environmental testing – Part 2-42: Tests – Test Kc: Sulphur dioxide test for
contacts and connections
IEC 60068-2-43, Environmental testing – Part 2-43: Tests – Test Kd: Hydrogen sulphide test
for contacts and connections
IEC 60068-2-45, Environmental testing – Part 2-45: Tests – Test XA and guidance: Immersion
in cleaning solvents
IEC 60068-2-46, Basic environmental testing procedures – Part 2-46: Tests – Guidance to
test Kd: Hydrogen sulphide test for contacts and connections
IEC 60068-2-49, Basic environmental testing procedures – Part 2-49: Tests – Guidance to
Test Kc: Sulphur dioxide test for contacts and connections
IEC 60068-2-58:2015, Environmental testing Part 2-58: Tests, Tests Td: Test methods for
solderability, resistance to dissolution of metallization and to soldering heat of surface mounting
devices (SMD)
IEC 60068-2-58:2015/AMD1:2017
IEC 60068-2-61:1991, Environmental testing – Part 2-61: Test methods; Test Z/ABDM: Climatic
sequence
IEC 60068-2-68:1994, Environmental testing – Part 2-68: Tests – Test L: Dust and sand
IEC 60068-2-77, Environmental testing – Part 2-77: Tests – Test 77: Body strength and impact
shock
IEC 60068-2-78, Environmental testing – Part 2-78: Tests, Test Cab: Damp heat, steady state
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60617, Graphical symbols for diagrams (available at: http://std.iec.ch/iec60617)

IEC 60721-3-3, Classification of environmental conditions – Part 3-3: Classification of groups
of environmental parameters and their severities – Stationary use at weatherprotected locations
IEC 61058-1:2016, Switches for appliances – Part 1: General requirements
IEC 61058-1-1:2016, Switches for appliances – Part 1-1: Requirements for mechanical switches
ISO 80000-1, Quantities and units – Part 1: General
3 Terms, definitions, units and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-581 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

Note 1 to entry: Terminology peculiar to a particular switch subfamily is defined in the applicable detail specification.
Terminology peculiar to a group of structurally similar switches is defined in the detail specification.
Note 2 to entry: The following terminology is common to all electromechanical switches. Where the definition is
compatible with an established IEC 60050 definition, the IEC 60050 reference for the related definition is given as
source information.
3.1.1
category temperature range
range of ambient temperature for which the switch has been designed to operate continuously
3.1.2
clearance
shortest distance in air between two conductive parts
3.1.3
contact bounce
intermittent and random opening of closed contacts and closing of open contacts which may
occur after contact transfer and which is caused by the switch mechanism
3.1.4
contact bounce time
time period measured from the moment of first closure of two mating contacts or first opening
of two closed contacts to the moment when all contact bounce ceases
3.1.5
contact disturbance
intermittent and random closing of open contacts and/or opening of closed contacts caused
by external influences such as shock and vibration
3.1.6
creepage distance
shortest distance along the surface of the insulation material between two conductive parts
[SOURCE: IEC 60050-151:2001, 151-15-50, modified – “a solid insulating material” has been
replaced by “the insulation material”.]

– 12 – IEC 61020-1:2019 © IEC 2019
3.1.7
detail specification
declarations of switch parameters including ratings, test conditions and performance criteria,
agreed upon by the manufacturer and/or all interested parties
3.1.8
duty cycle
ratio of conducting (ON) time to the total time for one cycle
EXAMPLE 30 % ON.
3.1.9
electrical load
element connected to a circuit to pass a certain current through a specimen switch
Note 1 to entry: Resistor, coil and capacitor are examples of elements.
3.1.10
electromechanical switch
switch which opens, closes, or changes the connection of an electrical circuit by the mechanical
motion of conducting parts (contacts)
3.1.11
latch
latching mechanism for holding the button at the position when the operating button of a switch
is pushed down
3.1.12
lever switch
switch where the actuating member is a lever which has to be moved (tilted) to one or more
indexed positions in order to achieve a change in contact state
3.1.13
lower category temperature
minimum ambient temperature for which a switch has been designed to operate continuously
3.1.14
mounting bushing
component of a switch by which the switch is mounted on an equipment and which also serves
as a bearing
3.1.15
operating cycle
succession of operations from one position to another and back to the first position through all
other positions, if any
[SOURCE: IEC 60050-441:2000, 441-16-02]
3.1.16
operation
movement of a contact from a position to an adjacent position
3.1.17
operation test
test in which a switch is operated with the electric load connected under the simulated state of
actual use
3.1.18
pole
part associated exclusively with one, electrically separated, conducting path of
the switch
Note 1 to entry: Those parts that provide a means for mounting and operating all poles together are excluded from
the definition of a pole.
Note 2 to entry: A switch is called "single-pole" if it has only one pole. If it has more than one pole, it may be called
"multi-pole" (two-pole, three-pole, etc.) provided that the poles are coupled in such a manner as to operate together.
3.1.19
push-button switch
switch where the actuating member is a button which has to be pushed in order to achieve a
change in contact state
3.1.20
rated current
current assigned by the manufacturer for a specified operating condition
3.1.21
rated voltage
voltage assigned by the manufacturer for a specified operating condition
3.1.22
returning force
force possessed by the automatic returning mechanism which returns the actuator to the
position before operation when the operating force is removed
3.1.23
rocker switch
switch where the actuating member is a low profile lever (rocker) which has to be tilted to one
or more indexed positions in order to achieve a change in contact state
3.1.24
rotary switch
switch where the actuating member is a shaft or a spindle which has to be rotated to one or
more indexed positions in order to achieve a change in contact state
Note 1 to entry: The rotation of the actuating member may be unlimited or restricted in either direction.
3.1.25
slide switch
switch, the actuating member of which is a button which has to be displaced laterally in order
to achieve a change in contact state
3.1.26
surface mounting switch
small-sized switch which is suitable for surface mounting on the printed wiring board, consisting
of terminals and framing parts
3.1.27
upper category temperature
maximum ambient temperature for which a switch has been designed to operate continuously
3.2 Units and symbols
Units, graphical symbols, and letter symbols shall be, whenever possible, in accordance with
ISO 80000-1, IEC 60617 and IEC 60027 (all parts), respectively.

– 14 – IEC 61020-1:2019 © IEC 2019
Graphical symbols and letter symbols peculiar to a particular switch subfamily shall be defined
in the applicable detail specification. Graphical symbols and letter symbols peculiar to a group
of structurally similar switches shall be defined in the detail specification. When additional units
or symbols are required, they shall be derived in accordance with the principles of the
documents listed above whenever possible.
4 Test and measurement procedures
4.1 General
4.1.1 General requirements to tests and measuring procedures
Any detail specification shall contain tables showing the tests to be conducted, the
measurements to be made before and after each test or group of tests, and the sequence in
which they shall be carried out. The measuring conditions shall be the same for initial and final
measurements. When tests are performed in a sequence, the final measurements of one test
may be taken as the initial measurements for the succeeding test.
If national specifications within any quality assessment system include test methods other than
those specified in the above documents, the test methods shall be fully described.
Not all the test methods specified in this document are applicable to all types of switches.
The detail specification shall specify the test methods which are applicable for that type of
switch.
When necessary, additional test methods and/or details of the test methods shall be specified
by the detail specification.
Unless otherwise specified by the detail specification, the test sequence shall be as specified
in this document.
4.1.2 Tolerances
Unless otherwise specified, the actual value of the parameters, for example test voltage, test
current, test force or test torque, shall be within 5 % of the specified values of the switch.
4.1.3 Preconditioning
Unless specified by the test methods, the switches shall not be subjected to any special
preparations, such as cleaning, prior to or during the tests.
4.1.4 Mounting
When mounting is specified by the test methods, the switch shall be rigidly mounted by its
normal mounting means and connected as specified in the detail specification. The methods
of mounting and the materials used for mounting shall not adversely affect the electrical or
mechanical performance of the switch.
4.2 Standard atmospheric conditions
The standard atmospheric conditions shall be in accordance with Clause 4 of
IEC 60068- 1:2013.
4.3 General examination
4.3.1 Visual examination
4.3.1.1 Method
The visual examination shall be carried out by one of the following methods:
a) with the naked eye (normal strength of vision, normal colour perception, at the most
favourable viewing distance and with suitable illumination);
b) with magnifiers, if specified.
For the purpose of this document, special methods, for example using polarized light (for
observing internal tensions in materials) or other indicators (for observing internal material
cracks or pores), are not permitted unless explicitly required by the detail specification.
4.3.1.2 Features
The following features shall be examined without magnification:
a) markings according to Clause 6;
b) general appearance;
c) workmanship.
4.3.1.3 Requirement
The markings shall be correct and legible. The switch shall be manufactured in a careful and
workmanlike manner.
4.3.1.4 Items to be specified in the detail specification
When this test is required by the detail specification, the following details shall be specified:
a) details
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