IEC 60939-3:2015

IEC 60939-3 ®
Edition 1.0 2015-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Passive filter units for electromagnetic interference suppression –
Part 3: Passive filter units for which safety tests are appropriate

Filtres passifs d’antiparasitage –
Partie 3: Filtres passifs pour lesquels des essais de sécurité sont appropriés

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IEC 60939-3 ®
Edition 1.0 2015-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Passive filter units for electromagnetic interference suppression –

Part 3: Passive filter units for which safety tests are appropriate

Filtres passifs d’antiparasitage –

Partie 3: Filtres passifs pour lesquels des essais de sécurité sont appropriés

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.160 ISBN 978-2-8322-2807-4

– 2 – IEC 60939-3:2015 © IEC 2015
CONTENTS
FOREWORD . 7
1 General . 9
1.1 Scope . 9
1.2 Normative references . 9
1.3 Information to be given in a detail specification . 11
1.3.1 General . 11
1.3.2 Outline drawing and dimensions . 11
1.3.3 Mounting . 11
1.3.4 Ratings and characteristics . 12
1.3.5 Marking . 12
1.4 Terms and definitions . 12
1.5 Marking . 17
1.5.1 General . 17
1.5.2 Coding . 18
1.5.3 Marking details . 18
1.5.4 Marking of filters . 18
1.5.5 Marking of packaging . 18
1.5.6 Additional marking . 18
1.6 Components . 18
1.7 Overcurrent protective devices . 18
1.8 Wiring and Insulation . 19
1.8.1 General . 19
1.8.2 Sleeving, tubing and wire insulation . 19
1.8.3 Properties of insulation material . 19
1.9 Protective Bonding Conductors . 19
1.10 Corrosion . 20
2 Preferred ratings and characteristics . 20
2.1 Preferred characteristics . 20
2.1.1 General . 20
2.1.2 Preferred climatic categories . 20
2.2 Preferred values of ratings . 20
2.2.1 Rated voltage (U ) . 20
R
2.2.2 Rated temperature . 20
2.2.3 Passive flammability . 20
3 Test plan for safety tests . 21
3.1 Structurally similar filters . 21
3.2 Safety approval procedure . 21
3.2.1 General . 21
3.2.2 Sampling . 21
3.2.3 Tests . 22
3.3 Requalification tests . 22
4 Test and measurement procedures . 24
4.1 General . 24
4.1.1 General . 24
4.1.2 Standard atmospheric conditions . 24
4.1.3 Standard atmospheric conditions for testing . 24
4.1.4 Recovery conditions . 25

4.1.5 Referee conditions . 25
4.1.6 Reference conditions . 25
4.1.7 Drying . 26
4.2 Visual examination and check of dimensions . 26
4.2.1 Visual examination . 26
4.2.2 Dimensions (gauging) . 26
4.2.3 Dimensions (detail) . 26
4.2.4 Creepage distances and clearances . 26
4.3 Inductance measurement . 29
4.3.1 General . 29
4.3.2 Measuring conditions . 29
4.4 Earth inductors incorporated in filters. 29
4.5 Capacitance . 29
4.5.1 General . 29
4.5.2 Measuring conditions . 29
4.6 Insertion loss . 30
4.7 Insulation resistance . 30
4.7.1 General . 30
4.7.2 Measuring voltage . 30
4.7.3 Application of measuring voltage . 31
4.7.4 Mean time to measuring . 32
4.7.5 Temperature correction factor . 32
4.7.6 Information to be given in a detail specification . 32
4.7.7 Requirements . 34
4.8 Voltage proof . 35
4.8.1 General . 35
4.8.2 Test procedure . 35
4.8.3 Applied voltage . 35
4.8.4 Tests . 36
4.8.5 Requirements . 37
4.8.6 Repetition of the voltage proof test . 37
4.8.7 Information to be given in a detail specification . 37
4.8.8 Requirements . 37
4.9 DC line resistance or voltage drop at rated current . 37
4.9.1 General . 37
4.9.2 DC line resistance . 37
4.9.3 Voltage drop at rated current . 37
4.10 Discharge resistance . 38
4.10.1 General . 38
4.10.2 Resistor Test . 38
4.11 Robustness of terminations . 39
4.11.1 General . 39
4.11.2 Test Ua1 – Tensile . 39
4.11.3 Test Ub – Bending . 39
4.11.4 Test Uc – Torsion . 39
4.11.5 Test Ud – Torque . 39
4.11.6 Visual examination . 41
4.12 Resistance to soldering heat . 41
4.12.1 Applicability of the test . 41

– 4 – IEC 60939-3:2015 © IEC 2015
4.12.2 Pre-measurement . 41
4.12.3 Test conditions . 41
4.12.4 Test severity . 41
4.12.5 Intermediate inspection, measurements and requirements . 41
4.13 Solderability (for performance only) . 41
4.13.1 General . 41
4.13.2 Test method . 42
4.13.3 Test conditions . 42
4.13.4 Requirements . 42
4.13.5 Final measurements and requirements . 42
4.14 Rapid change of temperature (for performance only) . 42
4.14.1 Pre-measurements . 42
4.14.2 Test method . 43
4.14.3 Final inspection . 43
4.15 Vibration (for performance only) . 43
4.15.1 Pre-measurements . 43
4.15.2 Test method . 43
4.15.3 Test conditions . 43
4.15.4 Intermediate inspection . 43
4.15.5 Final Inspection . 43
4.16 Shock (for performance only) . 43
4.16.1 Pre measurements . 43
4.16.2 Test method . 44
4.16.3 Test conditions . 44
4.16.4 Final Inspection . 44
4.17 Container sealing (for performance only) . 44
4.17.1 General . 44
4.17.2 Test conditions . 44
4.17.3 Requirements . 44
4.18 Climatic sequence . 44
4.18.1 General . 44
4.18.2 Initial measurements . 44
4.18.3 Dry heat . 45
4.18.4 Damp heat, cyclic . 45
4.18.5 Cold . 45
4.18.6 Low air pressure . 45
4.18.7 Damp heat, cyclic, remaining cycles . 46
4.18.8 Final inspection, measurements and requirements . 46
4.19 Damp heat, steady state . 46
4.19.1 Pre-measurements . 46
4.19.2 Test method . 46
4.19.3 Test conditions . 46
4.19.4 Final inspection, measurements and requirements . 47
4.20 Temperature rise . 47
4.20.1 General . 47
4.20.2 Test method . 47
4.20.3 Test description . 48
4.20.4 Requirements . 49
4.21 Current overload . 50

4.21.1 Pre-measurements . 50
4.21.2 Test method . 50
4.21.3 Final inspection, measurements and requirements . 50
4.22 Leakage current . 50
4.23 Protective conductor resistance . 50
4.24 Impulse voltage . 51
4.24.1 General . 51
4.24.2 Initial measurements . 51
4.24.3 Test conditions . 51
4.24.4 Requirements . 51
4.25 Endurance . 52
4.25.1 General . 52
4.25.2 General test conditions . 52
4.25.3 Test conditions – current test . 52
4.25.4 Test conditions – voltage test, terminations/case . 53
4.25.5 Test conditions – voltage test between terminations . 53
4.25.6 Test conditions – combined voltage/current tests . 54
4.25.7 Final inspection, measurements and requirements . 54
4.26 Charge and discharge (for performance only) . 54
4.26.1 General . 54
4.26.2 Test circuits and wave forms . 54
4.26.3 Information given in detail specification . 56
4.26.4 Initial measurements . 56
4.26.5 Test conditions . 57
4.26.6 Final measurements and requirements . 57
4.27 Passive flammability . 57
4.27.1 General . 57
4.27.2 Test method . 57
4.28 Active flammability . 58
4.29 Solvent resistance of the marking . 58
4.29.1 General . 58
4.29.2 Test description . 58
4.29.3 Requirements after test . 59
4.30 Component solvent resistance (for performance only) . 59
4.30.1 General . 59
4.30.2 Initial measurements . 59
4.30.3 Test description . 59
4.30.4 Final measurements . 59
Annex A (informative) Calculation of leakage current . 60
A.1 General . 60
A.2 Calculation of leakage current for 1-line filters . 60
A.3 Calculation of leakage current for 2-line filters . 61
A.4 Calculation of leakage current for 3-line filters . 61
A.5 Calculation of leakage current for 4-line filters . 63
Annex B (normative) Test schedule for safety requirements only . 64
Annex C (normative) Circuit for the impulse voltage test . 67
Annex D (normative) Circuit for the endurance test . 69
Annex E (normative) Declaration of design . 70

– 6 – IEC 60939-3:2015 © IEC 2015
Annex F (informative) Safety and performance tests qualification approval –
Assessment level DZ . 71
Annex P (informative) Additional components and material standards . 73
Bibliography . 74

Figure 1 – Asymmetrical and symmetrical test circuit . 17
Figure 2 – Examples for the application of Tests A and B of Table 9 . 33
Figure 3 – Examples for the application of Test C of Table 9 . 34
Figure 4 – Impulse wave form . 51
Figure 5 – Relay circuit . 55
Figure 6 – Thyristor circuit . 55
Figure 7 – Voltage and current waveforms . 56
Figure A.1 – Leakage current for 1-line filters . 60
Figure A.2 – Leakage current for 2-line filters . 61
Figure A.3 – Leakage current for 3-line filters . 62
Figure A.4 – Leakage current for 4-line filters . 63
Figure C.1 – Impulse voltage test circuit . 67
Figure D.1 – Endurance test circuit . 69

Table 1 – Classification of Class X capacitors . 13
Table 2 – Classification of Class Y capacitors . 14
Table 3 – Tests concerning safety requirements only . 23
Table 4 – Lot-by-lot test – Safety tests only approval . 24
Table 5 – Standard atmospheric conditions . 25
Table 6 – Creepage distances . 28
Table 7 – Clearance. 29
Table 8 – DC voltage for insulation resistance . 31
Table 9 – Measuring points . 33
Table 10 – Insulation resistance – Safety tests only . 34
Table 11 – Insulation resistance – Safety and performance tests . 35
Table 12 – Voltage proof (filter connected to mains) . 36
Table 13 – Voltage proof (filter not connected to mains; e.g. d.c. filters) . 36
Table 14 – Force for wire terminations . 39
Table 15 – Torque . 40
Table 16 – Preferred severity . 44
Table 17 – Number of cycles . 46
Table 18 – Maximum temperatures . 49
Table 19 – Measurements and requirements after charge and discharge . 57
Table 20 – Categories of flammability . 58
Table B.1 – Test schedule for safety requirements only (1 of 3) . 64
Table C.1 – Values of C , C , R , R , C . 67
X T P S P
Table C.2 – Values and tolerances of Cx, tr, td . 68
Table F.1 – Sampling plan – Assessment level DZ (1 of 2) . 71

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PASSIVE FILTER UNITS FOR ELECTROMAGNETIC
INTERFERENCE SUPPRESSION –
Part 3: Passive filter units for which safety tests are appropriate

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
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in the subject dealt with may participate in this preparatory work. International, governmental and non-
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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
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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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
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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 60939-3 has been prepared by IEC technical committee 40:
Capacitors and resistors for electronic equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
40/2387/FDIS 40/2398A/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.

– 8 – IEC 60939-3:2015 © IEC 2015
A list of all parts in the IEC 60939 series, published under the general title Passive filter units
for electromagnetic interference suppression, can be found on the IEC website.
The committee has decided that the contents of this publication 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.
The contents of the corrigenda of April 2016 and May 2018 have been included in this copy.

PASSIVE FILTER UNITS FOR ELECTROMAGNETIC
INTERFERENCE SUPPRESSION –
Part 3: Passive filter units for which safety tests are appropriate

1 General
1.1 Scope
This specification covers passive filters used to attenuate unwanted radio-frequency signals
(such as noise or interference) generated from electromagnetic sources.
Both single and multi-channel filters within one enclosure or which are built on a printed
circuit board forming a compact entity are included within the scope of this specification.
Filters constructed of capacitive elements where the inductance is inherent in the construction
of the filter are within the scope of this specification. Similarly, filters constructed of inductive
elements where the capacitance is inherent in the construction of the filter are also within the
scope of this specification. It is up to the manufacturer to state whether a given component is
to be designed as a capacitor, an inductor or a filter. Filters can include also other
components like resistors and/or varistors or similar components
This specification applies to passive filter units for electromagnetic interference suppression
for which safety tests are appropriate. This implies that filters specified according to this
specification will either be connected to mains supplies, when compliance with the mandatory
tests of Table 3 is necessary, or used in other circuit positions where the equipment
specification prescribes that some or all of these safety tests are required.
This specification applies to passive filter units, which will be connected to an a.c. mains or
other supply (d.c. or a.c.) with a nominal voltage not exceeding 1 000 V a.c., with a nominal
frequency not exceeding 400 Hz, or 1 500 V d.c.
NOTE For a.c. use, IEC 60384-14 applies to capacitors which will be connected to a.c. mains with a nominal
frequency not exceeding 100 Hz.
This specification covers appliance filters (US) but does not cover facility filters, cord-
connected filters or direct plug-in filters. These other filters will be covered by another
sectional specification.
1.2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
NOTE 1 These documents are referenced, in whole, in part or as alternative requirements to the requirements
contained in this standard. Their use is specified, where necessary, for the application of the requirements of this
standard.
NOTE 2 The list below is a summary of all standards that are referred to within this standard. Appearance of a
standard in the list does not mean that the standard or parts of it are applicable. Only those parts that are
specifically referenced in this standard are applicable.
IEC 60027-1, Letters symbols to be used in electrical technology – Part 1: General

– 10 – IEC 60939-3:2015 © IEC 2015
IEC 60050 (all parts), International electrotechnical vocabulary
IEC 60060-1:2010, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60062, Marking codes for resistors and capacitors
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 60068-2-14, Environmental testing – Part 2-14: Tests – Test N: Change of temperature
IEC 60068-2-17, Basic environmental testing procedures – 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 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic
(12 h + 12 h cycle)
IEC 60068-2-45:1980, Basic environmental testing procedures – Part 2-45: Tests – Test XA
and guidance: Immersion in cleaning solvents
IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady
state
IEC 60294, Measurement of the dimensions of a cylindrical component with axial terminations
IEC 60384-14:2013, Fixed capacitors for use in electronic equipment – Part 14: Sectional
specification – Fixed capacitors for electromagnetic interference suppression and connection
to the supply mains
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage system – Part 1:
Principles, requirements and tests
IEC 60695-11-5, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method –
Apparatus, confirmatory test arrangement and guidance
IEC 60695-11-10, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical
flame test methods
2006, Fixed inductors for electromagnetic interference s
...