IEC TR 60664-2-1:2011
(Main)Insulation coordination for equipment within low-voltage systems - Part 2-1: Application guide - Explanation of the application of the IEC 60664 series, dimensioning examples and dielectric testing
Insulation coordination for equipment within low-voltage systems - Part 2-1: Application guide - Explanation of the application of the IEC 60664 series, dimensioning examples and dielectric testing
IEC/TR 60664-2-1:2011, which is a technical report, serves as an application guide for technical committees and manufacturers specifying dimensioning requirements for products in accordance with the IEC 60664 series. The significant items for consideration are as follows:
a) nominal system voltage(s) or rated insulation voltage(s);
b) overvoltage category of the products (OV cat.);
c) any type of overvoltages;
d) frequency of the voltage;
e) characteristics of the solid insulating material;
f) pollution degree and humidity levels.
The main changes with respect to the previous edition are listed below:
- the previous edition was only an application guide for IEC 60664-1. This second edition takes into account not only IEC 60664-1 but also the other parts IEC 60664-3, IEC 60664-4, and IEC 60664-5 and their interrelation;
- principles of the IEC 60664 series for insulation dimensioning of LV equipment are explained and examples of practical application are provided together with some background information;
- Annex A provides an overview of clauses of IEC 60664-1 requiring decisions by technical committees, or specification of options, or requiring activities of the manufacturer;
- Annex B provides an overview of such clauses of IEC 60664-4;
- Annex C provides an overview of such clauses of IEC 60664-5;
- Annex D amends the tables of Annex F of IEC 60664-1:2007 with rated impulse voltages for voltages line to neutral derived from nominal d.c. voltages up to and including 1 500 V.
The contents of the corrigendum of October 2011 have been included in this copy.
Coordination de l'isolement des matériels dans les systèmes (réseaux) à basse tension - Partie 2-1: Guide d'application - Explication de l'application de la série CEI 60664, exemples de dimensionnement et d'essais diélectriques
La CEI/TR 60664-2-1:2011 qui est un rapport technique, sert comme guide d'application aux comités d'études et aux fabricants en spécifiant les exigences en matière de dimensionnement des produits conformes à la série CEI 60664. Les éléments significatifs à prendre en compte sont les suivants:
a) la/les tension(s) nominale(s) du réseau ou la/les tension(s) assignée(s) d'isolement;
b) la catégorie de surtension des produits (cat. OV);
c) tous les types de surtension;
d) la fréquence de la tension;
e) les caractéristiques du matériau isolant solide;
f) le degré de pollution et les niveaux d'humidité.
Les modifications principles par rapport à l'édition précédente sont les suivantes:
- l'édition précédente n'était qu'un guide d'application pour la CEI 60664-1. Cette deuxième édition prend en compte non seulement la CEI 60664-1 mais également les autres parties qui sont les CEI 60664-3, CEI 60664-4, et CEI 60664-5 et leurs relations mutuelles;
- les principes de la série 60664 concernant le dimensionnement de l'isolement des appareils basse tension sont expliqués et des exemples d'application pratiques sont fournis avec des informations de base;
- l'Annexe A fournit une vue d'ensemble des articles de la CEI 60664-1 nécessitant des décisions des comités techniques, ou des spécifications des options, ou nécessitant les activités du fabricant;
- l'Annexe B fournit une vue d'ensemble de tels articles de la CEI 60664-4;
- l'Annexe C fournit une vue d'ensemble de tels articles de la CEI 60664-5;
- l'Annexe D amende les tableaux de l'Annexe F de la CEI 60664-1:2007 avec des tensions d'impulsion assignées concernant les tensions phase-neutre dérivées des tensions nominales en courant continu allant jusqu'à 1 500 V inclus.
Le contenu du corrigendum d'octobre 2011 a été pris en considération dans cet exemplaire.
General Information
- Status
- Published
- Publication Date
- 30-Jan-2011
- Technical Committee
- TC 109 - Insulation co-ordination for low-voltage equipment
- Drafting Committee
- MT 1 - TC 109/MT 1
- Current Stage
- PPUB - Publication issued
- Start Date
- 31-Jan-2011
- Completion Date
- 30-Apr-2011
Relations
- Effective Date
- 05-Sep-2023
- Effective Date
- 05-Sep-2023
Overview
The IEC TR 60664-2-1:2011 is a comprehensive technical report published by the International Electrotechnical Commission (IEC) that serves as an application guide for insulation coordination within low-voltage (LV) electrical equipment. This report explains how the IEC 60664 series standards are applied, providing dimensioning examples and guidance on dielectric testing. It addresses key factors influencing insulation design such as nominal system voltages, overvoltage categories, pollution degrees, frequency, and characteristics of solid insulating materials.
The second edition expands beyond the initial focus on IEC 60664-1 to include interrelations with IEC 60664-3, IEC 60664-4, and IEC 60664-5, making it a vital document for technical committees and manufacturers who specify insulation requirements for safety and reliability in electrical products.
Key Topics
- Insulation Coordination Principles: Clarifies the foundational concepts involved in insulation dimensioning for LV equipment, emphasizing coordination of overvoltage categories inside devices.
- Dimensioning of Clearances and Creepage Distances: Guides practical calculation of spatial separations needed to prevent electrical breakdown considering pollution degrees and humidity.
- Solid Insulation Characteristics: Discusses selection and dimensioning of solid insulators based on material properties and voltage stress.
- Functional vs. Basic Insulation: Explains testing and design approaches for different insulation classes ensuring both operational safety and protection.
- Frequency Influence: Addresses how AC and DC voltage frequencies affect withstand capabilities of different insulation types.
- Practical Testing Guidance: Provides methodology for dielectric testing including substitution of impulse withstand tests with AC or DC voltage tests.
- Application Examples: Furnishes detailed dimensioning worksheets and real-world examples categorized by equipment types and insulation classes to illustrate proper insulation design.
- Technical Committee Guidance: Includes annexes summarizing relevant clauses from IEC 60664 series parts that require committee decisions or manufacturer specifications.
Applications
This IEC technical report is indispensable for:
- Electrical Equipment Manufacturers: Offering detailed instructions on designing and verifying insulation systems for LV products such as control gear, switchgear, and household appliances.
- Standards Development Bodies: Assisting technical committees in harmonizing requirements across different IEC 60664 series parts, ensuring safety and compatibility.
- Testing Laboratories: Providing frameworks to conduct reliable dielectric strength tests and evaluate insulation performance under operational conditions.
- Safety Engineers and Designers: Equipping professionals with practical methods to calculate clearances, creepage distances, and insulation thicknesses for optimal reliability in different environments and pollution categories.
- Quality Assurance Teams: Supporting compliance verification through standard-compliant dimensioning and testing approaches.
Related Standards
The IEC TR 60664-2-1:2011 builds upon and relates closely to the following standards from the IEC 60664 series:
- IEC 60664-1: General requirements for insulation coordination including definitions and fundamental principles.
- IEC 60664-3: Specific guidance on insulation coordination for printed board assemblies.
- IEC 60664-4: Instructions on insulation coordination linked to particular equipment or environmental conditions.
- IEC 60664-5: Provisions focusing on insulation coordination in power electronic equipment and converters.
Additionally, this guide complements other key IEC electrical safety standards by ensuring equipment insulation is designed to resist overvoltage stresses, thereby enhancing the safety and longevity of electrical installations.
For professionals involved in low-voltage electrical system design and testing, IEC TR 60664-2-1:2011 is a core reference that enables confident, standardized, and safe insulation coordination practices that comply with international norms.
IEC TR 60664-2-1:2011 - Insulation coordination for equipment within low-voltage systems - Part 2-1: Application guide - Explanation of the application of the IEC 60664 series, dimensioning examples and dielectric testing
IEC TR 60664-2-1:2011 - Insulation coordination for equipment within low-voltage systems - Part 2-1: Application guide - Explanation of the application of the IEC 60664 series, dimensioning examples and dielectric testing Released:1/31/2011 Isbn:9782889123513
Frequently Asked Questions
IEC TR 60664-2-1:2011 is a technical report published by the International Electrotechnical Commission (IEC). Its full title is "Insulation coordination for equipment within low-voltage systems - Part 2-1: Application guide - Explanation of the application of the IEC 60664 series, dimensioning examples and dielectric testing". This standard covers: IEC/TR 60664-2-1:2011, which is a technical report, serves as an application guide for technical committees and manufacturers specifying dimensioning requirements for products in accordance with the IEC 60664 series. The significant items for consideration are as follows: a) nominal system voltage(s) or rated insulation voltage(s); b) overvoltage category of the products (OV cat.); c) any type of overvoltages; d) frequency of the voltage; e) characteristics of the solid insulating material; f) pollution degree and humidity levels. The main changes with respect to the previous edition are listed below: - the previous edition was only an application guide for IEC 60664-1. This second edition takes into account not only IEC 60664-1 but also the other parts IEC 60664-3, IEC 60664-4, and IEC 60664-5 and their interrelation; - principles of the IEC 60664 series for insulation dimensioning of LV equipment are explained and examples of practical application are provided together with some background information; - Annex A provides an overview of clauses of IEC 60664-1 requiring decisions by technical committees, or specification of options, or requiring activities of the manufacturer; - Annex B provides an overview of such clauses of IEC 60664-4; - Annex C provides an overview of such clauses of IEC 60664-5; - Annex D amends the tables of Annex F of IEC 60664-1:2007 with rated impulse voltages for voltages line to neutral derived from nominal d.c. voltages up to and including 1 500 V. The contents of the corrigendum of October 2011 have been included in this copy.
IEC/TR 60664-2-1:2011, which is a technical report, serves as an application guide for technical committees and manufacturers specifying dimensioning requirements for products in accordance with the IEC 60664 series. The significant items for consideration are as follows: a) nominal system voltage(s) or rated insulation voltage(s); b) overvoltage category of the products (OV cat.); c) any type of overvoltages; d) frequency of the voltage; e) characteristics of the solid insulating material; f) pollution degree and humidity levels. The main changes with respect to the previous edition are listed below: - the previous edition was only an application guide for IEC 60664-1. This second edition takes into account not only IEC 60664-1 but also the other parts IEC 60664-3, IEC 60664-4, and IEC 60664-5 and their interrelation; - principles of the IEC 60664 series for insulation dimensioning of LV equipment are explained and examples of practical application are provided together with some background information; - Annex A provides an overview of clauses of IEC 60664-1 requiring decisions by technical committees, or specification of options, or requiring activities of the manufacturer; - Annex B provides an overview of such clauses of IEC 60664-4; - Annex C provides an overview of such clauses of IEC 60664-5; - Annex D amends the tables of Annex F of IEC 60664-1:2007 with rated impulse voltages for voltages line to neutral derived from nominal d.c. voltages up to and including 1 500 V. The contents of the corrigendum of October 2011 have been included in this copy.
IEC TR 60664-2-1:2011 is classified under the following ICS (International Classification for Standards) categories: 29.080.30 - Insulation systems. The ICS classification helps identify the subject area and facilitates finding related standards.
IEC TR 60664-2-1:2011 has the following relationships with other standards: It is inter standard links to IEC TR 60664-2-1:2011/COR1:2011, IEC TR 60664-2-1:1997. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase IEC TR 60664-2-1:2011 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of IEC standards.
Standards Content (Sample)
IEC/TR 60664-2-1 ®
Edition 2.0 2011-01
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Insulation coordination for equipment within low-voltage systems –
Part 2-1: Application guide – Explanation of the application of
the IEC 60664 series, dimensioning examples and dielectric testing
Coordination de l'isolement des matériels dans les systèmes (réseaux) à basse
tension –
Partie 2-1: Guide d'application – Explication de l’application de la série
CEI 60664, exemples de dimensionnement et d’essais diélectriques
IEC/TR 60664-2-1:2011
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IEC/TR 60664-2-1 ®
Edition 2.0 2011-01
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Insulation coordination for equipment within low-voltage systems –
Part 2-1: Application guide – Explanation of the application of
the IEC 60664 series, dimensioning examples and dielectric testing
Coordination de l'isolement des matériels dans les systèmes (réseaux) à basse
tension –
Partie 2-1: Guide d'application – Explication de l’application de la série
CEI 60664, exemples de dimensionnement et d’essais diélectriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 29.080.30 ISBN 978-2-88912-351-3
– 2 – TR 60664-2-1 IEC:2011
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 Principles and practical application of the IEC 60664 series for insulation
dimensioning of LV equipment . 17
4.1 Basic principles . 17
4.2 Coordination of overvoltage categories inside equipment . 17
4.3 Practical use of the IEC 60664 series for the dimensioning of clearances . 18
4.3.1 General . 18
4.3.2 Practical use of Tables F.2 and F.7 of IEC 60664-1:2007 for the
dimensioning of clearances . 18
4.3.3 Practical use of Tables 2 and 3 of IEC 60664-5:2007 for the
dimensioning of clearances . 20
4.4 Practical use of the IEC 60664 series for the dimensioning of creepage
distances . 20
4.4.1 General . 20
4.4.2 Practical use of Table F.4 of IEC 60664-1:2007 and Table 4 of
IEC 60664-5:2007 for the dimensioning of creepage distances . 21
4.4.3 Practical use of Table 5 in IEC 60664-5:2007 for dimensioning of
creepage distances . 22
4.4.4 Practical use of IEC 60664-1:2007 for checking the dimensioning of
creepage distances with regard to time under voltage stress . 22
4.4.5 Practical use of IEC 60664-3:2003 for the reduction of micro-
environmental conditions for the dimensioning of creepage distances . 23
4.5 Practical use of the IEC 60664 series for the dimensioning of solid insulation . 23
4.5.1 General . 23
4.5.2 Coordination of clearances and solid insulation . 24
4.5.3 Practical information for checking the correct dimensioning of solid
insulation . 25
4.6 Practical use of the IEC 60664 series for designing functional insulation . 31
4.6.1 General . 31
4.6.2 Dimensioning and testing of functional isolation compared to basic
insulation . 31
4.7 Practical use of the IEC 60664 series for dimensioning with respect to the
influence of the frequency of the voltage . 32
4.7.1 General influence of the frequency on withstand characteristics . 32
4.7.2 Influence of the frequency on the withstand characteristics of
clearances . 32
4.7.3 Influence of frequency on the withstand characteristics of creepage
distances . 32
4.7.4 Influence of frequency on the withstand characteristics of solid
insulation . 33
5 Four examples showing appropriate dimensioning of insulation within equipment . 34
5.1 General . 34
5.2 Examples for the dimensioning of clearances for class I equipment according
to IEC 60664-1 . 36
TR 60664-2-1 IEC:2011 – 3 –
5.3 Examples for the dimensioning of clearances for class II equipment
according to IEC 60664-1 . 37
5.4 Examples for the dimensioning of clearances for class II equipment
according to IEC 60664-5 . 39
6 Practical application of the IEC 60664 series with regards to particular questions . 40
6.1 General . 40
6.2 Testing complete equipment in case of components bridging the basic
insulation. 40
6.3 Testing complete equipment in case of components bridging the functional
insulation. 41
6.3.1 General . 41
6.3.2 Verification of clearances and creepage distances . 41
6.3.3 Verification of components bridging the insulation . 42
6.4 Dimensioning of insulation distances for parts of equipment which can have
isolation capability . 42
6.4.1 General . 42
6.4.2 Dimensioning for device associated with an equipment declared
suitable for isolation . 42
6.4.3 Dimensioning for device associated with an equipment not declared
suitable for isolation . 42
6.5 Testing with respect to high-frequency voltage stress . 43
6.6 Practical information in case of substitution an impulse withstand test by an
AC or DC test . 43
6.6.1 General . 43
6.6.2 Characteristics of the a.c. voltage substituted to an impulse
withstand test for dielectric test . 43
6.6.3 Characteristics of the d.c. voltage substituted to an impulse
withstand test for dielectric test . 44
7 Examples of a dimensioning worksheet (based on case A as described in
IEC 60664-1:2007) . 44
7.1 Use of IEC 60664-1:2007, for circuits in equipment either directly or not
directly connected to the mains supply . 44
7.2 Use of IEC 60664-5:2007, for circuits in equipment either directly or not
directly connected to the mains supply . 45
7.3 Use of IEC 60664-4:2005, for circuits in equipment either directly or not
directly connected to the mains supply . 46
7.4 Examples comparing the dimensioning of clearances and creepage
distances according to IEC 60664-1 and IEC 60664-5 based on case A
condition (basic insulation, for equipment up to 2 000 m altitude) . 48
7.4.1 Circuits not directly connected to mains supply . 48
7.4.2 Circuits not directly connected to mains supply . 49
7.5 Examples of dimension comparison for clearances and creepage distances
according to IEC 60664-1 and IEC 60664-4 based on case A condition (basic
insulation, for equipment up to 2 000 m altitude) . 50
7.5.1 Circuits not directly connected to mains supply . 50
7.5.2 Circuits not directly connected to mains supply . 52
Annex A (informative) Overview of Clauses of IEC 60664-1 requiring decisions by
technical committees, specification of options or requiring activities by the
manufacturer . 54
Annex B (informative) Overview of Clauses of IEC 60664-4 requiring decisions by
technical committees . 58
– 4 – TR 60664-2-1 IEC:2011
Annex C (informative) Overview of Clauses of IEC 60664-5 requiring decisions by
technical committees, specification of options or requiring activities by the
manufacturer . 59
Annex D (informative) Dimensioning of clearances and creepage distances for d.c.
voltages above 1000 V d.c. . 63
Bibliography . 64
Figure 1 – Breakdown voltage of solid insulation depending upon the time of voltage
stress . 24
Figure 2 – Series connection of clearance and solid insulation. 27
Figure 3 – Capacitive voltage divider . 27
Figure 4 – Permissible field strength for dimensioning of solid insulation according to
Equation (7) . 34
Figure 5a – Example 1 – Simple illustration of insulation system containing functional,
basic and reinforced/double insulation for a class I equipment . 35
Figure 5b – Example 2 – Dimensioning of clearances for class I equipment, based on
overvoltage category III . 36
Figure 5c – Example 3 – Dimensioning of clearances (class II equipment) . 37
Figure 5d – Example 4 – Dimensioning of clearances (class II equipment) . 39
Figure 6 – Arrangement for a.c. (or d.c.) voltage test . 41
Table 1 – Examples for rated voltage 100 V and 230 V and overvoltage category II . 26
Table 2 – Example 2 – Dimensioning of clearances according to Table F.2 of
IEC 60664-1:2007 (pollution degree 2) (see example 2 of Figure 5b) . 36
Table 3 – Example 2 – Dimensioning of clearances according to Tables F.2 and F.7a
of IEC 60664-1:2007, temporary overvoltages according to 5.3.3.2.3 of IEC 60664-
1:2007 (U +1200 V) (see example 2 of Figure 5b) . 37
n
Table 4 – Example 3 – Dimensioning of clearances according to Table F.2 of
IEC 60664-1:2007 (pollution degree 2) (see example 3 of Figure 5c) . 38
Table 5 – Example 3 – Dimensioning of clearances according to Tables F.2 and F.7a
of IEC 60664-1:2007, temporary overvoltages according to 5.3.3.2.3 of IEC 60664-
1:2007 (U +1200 V) (see example 3 of Figure 5c) . 38
n
Table 6 – Example 4 – Dimensioning of clearances according to Table 2 of
IEC 60664-5:2007 (see example 4 on Figure 5d) . 39
Table 7 – Example 4 – Dimensioning of clearances according to Tables 2 and 3 of
IEC 60664-5:2007, temporary overvoltages according to 5.3.3.2.3 of IEC 60664-1:2007
(U +1 200 V) (see example 4 on Figure 5d) . 40
n
Table 8 – Relationship between influencing parameters and normative references in
IEC 60664-1 . 44
Table 9 – Relationship between influencing parameters and normative references in
IEC 60664-1 or IEC 60664-5 . 45
Table 10 – Relationship between influencing parameters and normative references in
IEC 60664-1 or IEC 60664-4 . 46
Table 11 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 . 48
Table 12 – Example for dimensioning a clearance and creepage distance following
IEC 60664-5 . 49
Table 13 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 in circuits not directly connected to mains supply . 49
TR 60664-2-1 IEC:2011 – 5 –
Table 14 – Example for dimensioning a clearance and creepage distance following
IEC 60664-5 in circuits not directly connected to mains supply . 50
Table 15 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 in circuits not directly connected to mains supply . 51
Table 16 – Example for dimensioning a clearance and creepage distance following
IEC 60664-4 (approximately homogeneous field) . 51
Table 17 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 in circuits not directly connected to mains supply . 52
Table 18 – Example for dimensioning a clearance and creepage distance following
IEC 60664-4 (approximately homogeneous field) . 53
Table A.1 – Clauses and titles of IEC 60664-1 and items to be considered by technical
committees . 54
Table A.2 – Clauses and titles of IEC 60664-1 and optional specifications for
consideration by technical committees . 56
Table A.3 – Clauses and titles of IEC 60664-1 and required manufacturer activities . 57
Table B.1 – Clauses and titles of IEC 60664-4 and optional specifications for
consideration by technical committees . 58
Table C.1 – Clauses and titles of IEC 60664-5 and items to be considered by technical
committees . 59
Table C.2 – Clauses and titles of IEC 60664-5 and optional specifications for
consideration by technical committees . 61
Table C.3 – Clauses and titles of IEC 60664-5 and required manufacturer activities . 62
Table D.1 – Rated impulse voltage for equipment . 63
– 6 – TR 60664-2-1 IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATION COORDINATION FOR EQUIPMENT
WITHIN LOW-VOLTAGE SYSTEMS –
Part 2-1: Application guide –
Explanation of the application of the IEC 60664 series,
dimensioning examples and dielectric testing
FOREWORD
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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.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC/TR 60664-2-1, which is a technical report, serves as an application guide for the
IEC 60664 series and has been prepared by IEC technical committee 109: Insulation
coordination for low-voltage equipment.
This second edition cancels and replaces the first edition, published in 1997, and constitutes
a technical revision.
TR 60664-2-1 IEC:2011 – 7 –
The main changes with respect to the previous edition are listed below:
– the previous edition was only an application guide for IEC 60664-1. This second edition
takes into account not only IEC 60664-1 but also the other parts IEC 60664-3, IEC 60664-
4, and IEC 60664-5 and their interrelation;
– principles of the IEC 60664 series for insulation dimensioning of LV equipment are
explained and examples of practical application are provided together with some
background information;
– Annex A provides an overview of clauses of IEC 60664-1 requiring decisions by technical
committees, or specification of options, or requiring activities of the manufacturer;
– Annex B provides an overview of such clauses of IEC 60664-4;
– Annex C provides an overview of such clauses of IEC 60664-5;
– Annex D amends the tables of Annex F of IEC 60664-1:2007 with rated impulse voltages
for voltages line to neutral derived from nominal d.c. voltages up to and including 1 500 V.
The text of this application guide is based on the following documents:
Enquiry draft Report on voting
109/82/DTR 109/83/RVC
Full information on the voting for the approval of this application guide 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.
It has the status of a basic safety publication in accordance with IEC Guide 104.
A list of all the parts in the IEC 60664 series, published under the general title Insulation
coordination for equipment within low-voltage systems, can be found on the IEC website.
The committee has decided that the contents of this amendment and the base 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 corrigendum of October 2011 have been included in this copy.
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.
– 8 – TR 60664-2-1 IEC:2011
INTRODUCTION
This application guide provides information relating to insulation coordination, as described in
the IEC 60664 series, for the benefit of IEC technical committees and manufacturers. It
covers general information for the dimensioning of clearances, creepage distances and solid
insulation for equipment.
It aims to highlight the use and understanding of the IEC 60664 series when applied by
technical committees and manufacturers.
Insulation coordination for equipment implies the assessment of the minimum necessary
dimensioning for clearances, creepage distances and solid insulation in order to allow safe
use of the equipment during its lifetime, taking into consideration the foreseeable
environmental conditions.
The main parameters to be taken into account for the understanding of the IEC 60664 series
include:
– the maximum voltage stress to be withstood in order to avoid flashover across clearances;
– the characteristics of the solid insulating material and the environmental conditions
regarding tracking. IEC 60664-3 provides methods for improving the micro-environment at the
creepage distance;
– the electrical field stress through solid insulation as it relates to the risk of partial
discharge and dielectric loss causing a risk of breakdown due to excessive heating. In
particular, technical committees and manufacturers should consider a partial discharge
test if the maximum peak voltage across the insulation material exceeds 700 V and the
peak value of the field strength exceeds 1 kV/mm. Due to the fact that both partial
discharge phenomena and dielectric losses increase in importance with voltage frequency,
a dedicated standard, IEC 60664-4, applies for frequencies higher than 30 kHz;
NOTE IEC 60664-4 provides information concerning clearances, creepage distances, solid insulation and testing
for frequencies above 30 kHz.
– the long-term maximum voltage stress to be withstood in order to avoid tracking over the
surface of the insulation material;
– flashover; besides tracking, this is increasingly important with reduction of creepage
distance in the presence of high humidity. IEC 60664-5 introduces humidity levels
classifying the effects of humidity on creepage distances equal to or less than 2 mm.
Other stresses such as heat, vibration, mechanical shocks, radiation, etc. may influence the
performance of solid insulating materials in service. Technical committees and manufacturers
should consider the risks related to these stresses when specifying conditions for testing
equipment to be used under particular situations.
TR 60664-2-1 IEC:2011 – 9 –
INSULATION COORDINATION FOR EQUIPMENT
WITHIN LOW-VOLTAGE SYSTEMS –
Part 2-1: Application guide –
Explanation of the application of the IEC 60664 series,
dimensioning examples and dielectric testing
1 Scope
This part of IEC 60664, which is a technical report, serves as an application guide for
technical committees and manufacturers specifying dimensioning requirements for products in
accordance with the IEC 60664 series.
The significant items for consideration are as follows:
a) nominal system voltage(s) or rated insulation voltage(s);
b) overvoltage category of the products (OV cat.);
c) any type of overvoltages;
d) frequency of the voltage;
e) characteristics of the solid insulating material;
f) pollution degree and humidity levels.
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 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60112:2003, Method for the determination of the proof and the comparative tracking
indices of solid insulating materials
Amendment 1 (2009)
IEC 60216 (all parts), Electrical insulating materials – Properties of thermal endurance
IEC 60364-4-44:2007, Low-voltage electrical installations – Part 4-44: Protection for safety –
Protection against voltage disturbances and electromagnetic disturbances
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-3:2003, Insulation coordination for equipment within low-voltage systems – Part 3:
Use of coating, potting or moulding for protection against pollution
IEC 60664-4:2005, Insulation coordination for equipment within low-voltage systems – Part 4:
Consideration of high-frequency voltage stress
IEC 60664-5:2007, Insulation coordination for equipment within low-voltage systems – Part 5:
Comprehensive method for determining clearances and creepage distances equal to or less
than 2 mm
IEC 61140:2001, Protection against electric shock – Common aspects for installation and
equipment
– 10 – TR 60664-2-1 IEC:2011
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE All definitions can be found in the various parts of the IEC 60664 series, as indicated below.
3.0
apparent charge
q
electric charge which can be measured at the terminals of the specimen under test
NOTE 1 The apparent charge is smaller than the partial discharge.
NOTE 2 The measurement of the apparent charge requires a short-circuit condition at the terminals of the
specimen under test.
[IEC 60664-1:2007, 3.18.1]
3.1
approximately homogeneous field
for frequencies exceeding 30 kHz the field is considered to be approximately homogeneous
when the radius of curvature of the conductive parts is equal or greater than 20 % of the
clearance
[IEC 60664-4:2005, 3.1]
3.2
base material
insulating material upon which a conductive pattern may be formed
NOTE The base material may be rigid or flexible, or both. It may be a dielectric or an insulated metal sheet.
(IEC 60194, definition 40.1334)
[IEC 60664-3:2003, 3.1]
3.3
basic insulation
insulation of hazardous-live-parts which provides basic protection
NOTE The concept does not apply to insulation used exclusively for functional purposes.
(IEV 826-12-14)
[IEC 60664-1:2007, 3.17.2]
3.4
clearance
shortest distance in air between two conductive parts
[IEC 60664-1:2007, 3.2]
3.5
coating
insulating material such as varnish or dry film laid on the surface of the assembly
NOTE Coating and base material of a printed board form an insulating system that may have properties similar to
solid insulation.
[IEC 60664-3:2003, 3.5]
3.6
conductor
single conductive path in a conductive pattern
(IEC 60194, definition 22.0251)
TR 60664-2-1 IEC:2011 – 11 –
[IEC 60664-3:2003, 3.3]
3.7
creepage distance
shortest distance along the surface of a solid insulating material between two conductive
parts
(IEV 151-15-50)
[IEC 60664-1:2007, 3.3]
3.8
double insulation
insulation comprising both basic insulation and supplementary insulation
(IEV 826-12-16)
[IEC 60664-1:2007, 3.17.4]
3.9
electrical breakdown
failure of insulation under electric stress when the discharge completely bridges the
insulation, thus reducing the voltage between the electrodes almost to zero
[IEC 60664-1:2007, 3.20]
3.10
electrical field strength
E
voltage gradient per unit length usually expressed in kV/mm
[IEC 60664-4:2005, 3.7]
3.11
environment
surrounding which may affect performance of a device or system
NOTE Examples are pressure, temperature, humidity, pollution, radiation, vibration.
(IEV 151-16-03, modified)
[IEC 60664-1:2007, 3.12]
3.12
flashover
electrical breakdown along a surface of solid insulation located in a gaseous or liquid medium
[IEC 60664-1:2007, 3.20.2]
3.13
functional insulation
insulation between conductive parts which is necessary only for the proper functioning of the
equipment
[IEC 60664-1:2007, 3.17.1]
3.14
homogeneous field
electric field which has an essentially constant voltage gradient between electrodes (uniform
field), such as that between two spheres where the radius of each sphere is greater than the
distance between them
NOTE The homogeneous field condition is referred to as case B.
[IEC 60664-1:2007, 3.14]
– 12 – TR 60664-2-1 IEC:2011
3.15
impulse withstand voltage
highest peak value of impulse voltage of prescribed form and polarity which does not cause
breakdown of insulation under specified conditions
[IEC 60664-1:2007, 3.8.1]
3.16
inhomogeneous field
electric field which does not have an essentially constant voltage gradient between electrodes
(non-uniform field)
NOTE 1 The inhomogeneous field condition of a point-plane electrode configuration is the worst case with regard
to voltage withstand capability and is referred to as case A. It is represented by a point electrode having a 30 µm
radius and a plane of 1 m × 1 m.
NOTE 2 For frequencies exceeding 30 kHz the field is considered to be inhomogeneous when the radius of
curvature of the conductive parts is less than 20 % of the clearance.
[IEC 60664-1:2007, 3.15, modified, and IEC 60664-4:2005, 3.2]
3.17
insulation
that part of an electrotechnical product which separates the conducting parts at different
electrical potentials
(IEV 212-01-05)
[IEC 60664-1:2007, 3.17]
3.18
insulation coordination
mutual correlation of insulation characteristics of electrical equipment taking into account the
expected micro-environment and other influencing stresses
[IEC 60664-1:2007, 3.1, modified]
3.19
macro-environment
environment of the room or other location in which the equipment is installed or used
[IEC 60664-1:2007, 3.12.1]
3.20
micro-environment
immediate environment of the insulation which particularly influences the dimensioning of the
creepage distances
[IEC 60664-1:2007, 3.12.2]
3.21
overvoltage
any voltage having a peak value exceeding the corresponding peak value of maximum
steady-state voltage at normal operating conditions
[IEC 60664-1:2007, 3.7]
3.22
overvoltage category
numeral defining a transient overvoltage condition
[IEC 60664-1:2007, 3.10, modified]
TR 60664-2-1 IEC:2011 – 13 –
3.23
partial discharge
PD
electric discharge that partially bridges the insulation
[IEC 60664-1:2007, 3.18]
3.24
partial discharge inception voltage
U
i
lowest peak value of the test voltage at which the apparent charge becomes greater than the
specified discharge magnitude when the test voltage is increased above a low value for which
no discharge occurs
NOTE For a.c. tests the r.m.s. value may be used.
[IEC 60664-1:2007, 3.18.4]
3.25
pollution
any addition of foreign matter, solid, liquid, or gaseous that can result in a reduction of
electric strength or surface resistivity of the insulation
[IEC 60664-1:2007, 3.11]
3.26
pollution degree
numeral characterizing the expected pollution of the micro-environment
[IEC 60664-1:2007, 3.13]
3.27
printed board
general term for completely processed printed circuit and printed wiring configurations
NOTE This includes single-sided, double-sided and multilayer boards with rigid, flexible, and rigid-flex base
materials.
(IEC 60194, definition 60.1485)
[IEC 60664-3:2003, 3.2]
3.28
protection
any kind of measure which reduces the influence of the environment
[IEC 60664-3:2003, 3.4]
3.29
r.m.s. withstand voltage
highest r.m.s. value of a voltage which does not cause breakdown of insulation under
specified conditions
[IEC 60664-1:2007, 3.8.2]
3.30
rated impulse voltage
impulse withstand voltage value assigned by the manufacturer to the equipment or to a part of
it, characterizing the specified withstand capability of its insulation against transient overvoltages
[IEC 60664-1:2007, 3.9.2]
– 14 – TR 60664-2-1 IEC:2011
3.31
rated insulation voltage
r.m.s. withstand voltage value assigned by the manufacturer to the equipment or to a part of
it, characterizing the specified (long-term) withstand capability of its insulation
NOTE The rated insulation voltage is not necessarily equal to the rated voltage of equipment which is primarily
related to functional performance.
[IEC 60664-1:2007, 3.9.1]
3.32
rated recurring peak voltage
recurring peak withstand voltage value assigned by the manufacturer to the equipment or to a
part of it, characterizing the specified withstand capability of its insulation against recurring
peak voltages
[IEC 60664-1:2007, 3.9.3]
3.33
rated temporary overvoltage
temporary withstand overvoltage value assigned by the manufacturer to the equipment, or to
a part of it, characterizing the specified short-term withstand capability of its insulation against
a.c. voltages
[IEC 60664-1:2007, 3.9.4]
3.34
rated voltage
value of voltage assigned by the manufacturer, to a component, device or equipment and to
which operation and performance characteristics are referred
NOTE Equipment may have more than one rated voltage value or may have a rated voltage range.
[IEC 60664-1:2007, 3.9]
3.35
recurring peak voltage
U
rp
maximum peak value of periodic excursions of the voltage waveform resulting from distortions
of an a.c. voltage or from a.c. components superimposed on a d.c. voltage
NOTE Random overvoltages, for example due to occasional switching, are not considered to be recurring peak
voltages.
[IEC 60664-1:2007, 3.6]
3.36
recurring peak withstand voltage
highest peak value of a recurring voltage which does not cause breakdown of insulation under
specified conditions
[IEC 60664-1:2007, 3.8.3]
3.37
reinforced insulation
insulation of hazardous-live-parts which provides a degree of protection against electric shock
equivalent to double insulation
NOTE Reinforced insulation may comprise several layers which cannot be tested singly as basic insulation or
supplementary insulation.
(IEV 826-12-17)
TR 60664-2-1 IEC:2011 – 15 –
[IEC 60664-1:2007, 3.17.5]
3.38
routine test
test to which each individual device is subjected during or after manufacture to ascertain
whether it complies with certain criteria
[IEC 60664-1:2007, 3.19.2]
3.39
sampling test
test on a number of devices taken at random from a batch
[IEC 60664-1:2007, 3.19.3]
3.40
solid insulation
solid insulating material interposed between two conductive parts
NOTE In the case of a printed board with a coating, solid insulation co
...
IEC/TR 60664-2-1 ®
Edition 2.0 2011-01
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Insulation coordination for equipment within low-voltage systems –
Part 2-1: Application guide – Explanation of the application of
the IEC 60664 series, dimensioning examples and dielectric testing
Coordination de l'isolement des matériels dans les systèmes (réseaux) à basse
tension –
Partie 2-1: Guide d'application – Explication de l’application de la série
CEI 60664, exemples de dimensionnement et d’essais diélectriques
IEC/TR 60664-2-1:2011
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IEC/TR 60664-2-1 ®
Edition 2.0 2011-01
TECHNICAL
REPORT
RAPPORT
TECHNIQUE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Insulation coordination for equipment within low-voltage systems –
Part 2-1: Application guide – Explanation of the application of
the IEC 60664 series, dimensioning examples and dielectric testing
Coordination de l'isolement des matériels dans les systèmes (réseaux) à basse
tension –
Partie 2-1: Guide d'application – Explication de l’application de la série
CEI 60664, exemples de dimensionnement et d’essais diélectriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 29.080.30 ISBN 978-2-88912-351-3
– 2 – TR 60664-2-1 IEC:2011
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 Principles and practical application of the IEC 60664 series for insulation
dimensioning of LV equipment . 17
4.1 Basic principles . 17
4.2 Coordination of overvoltage categories inside equipment . 17
4.3 Practical use of the IEC 60664 series for the dimensioning of clearances . 18
4.3.1 General . 18
4.3.2 Practical use of Tables F.2 and F.7 of IEC 60664-1:2007 for the
dimensioning of clearances . 18
4.3.3 Practical use of Tables 2 and 3 of IEC 60664-5:2007 for the
dimensioning of clearances . 20
4.4 Practical use of the IEC 60664 series for the dimensioning of creepage
distances . 20
4.4.1 General . 20
4.4.2 Practical use of Table F.4 of IEC 60664-1:2007 and Table 4 of
IEC 60664-5:2007 for the dimensioning of creepage distances . 21
4.4.3 Practical use of Table 5 in IEC 60664-5:2007 for dimensioning of
creepage distances . 22
4.4.4 Practical use of IEC 60664-1:2007 for checking the dimensioning of
creepage distances with regard to time under voltage stress . 22
4.4.5 Practical use of IEC 60664-3:2003 for the reduction of micro-
environmental conditions for the dimensioning of creepage distances . 23
4.5 Practical use of the IEC 60664 series for the dimensioning of solid insulation . 23
4.5.1 General . 23
4.5.2 Coordination of clearances and solid insulation . 24
4.5.3 Practical information for checking the correct dimensioning of solid
insulation . 25
4.6 Practical use of the IEC 60664 series for designing functional insulation . 31
4.6.1 General . 31
4.6.2 Dimensioning and testing of functional isolation compared to basic
insulation . 31
4.7 Practical use of the IEC 60664 series for dimensioning with respect to the
influence of the frequency of the voltage . 32
4.7.1 General influence of the frequency on withstand characteristics . 32
4.7.2 Influence of the frequency on the withstand characteristics of
clearances . 32
4.7.3 Influence of frequency on the withstand characteristics of creepage
distances . 32
4.7.4 Influence of frequency on the withstand characteristics of solid
insulation . 33
5 Four examples showing appropriate dimensioning of insulation within equipment . 34
5.1 General . 34
5.2 Examples for the dimensioning of clearances for class I equipment according
to IEC 60664-1 . 36
TR 60664-2-1 IEC:2011 – 3 –
5.3 Examples for the dimensioning of clearances for class II equipment
according to IEC 60664-1 . 37
5.4 Examples for the dimensioning of clearances for class II equipment
according to IEC 60664-5 . 39
6 Practical application of the IEC 60664 series with regards to particular questions . 40
6.1 General . 40
6.2 Testing complete equipment in case of components bridging the basic
insulation. 40
6.3 Testing complete equipment in case of components bridging the functional
insulation. 41
6.3.1 General . 41
6.3.2 Verification of clearances and creepage distances . 41
6.3.3 Verification of components bridging the insulation . 42
6.4 Dimensioning of insulation distances for parts of equipment which can have
isolation capability . 42
6.4.1 General . 42
6.4.2 Dimensioning for device associated with an equipment declared
suitable for isolation . 42
6.4.3 Dimensioning for device associated with an equipment not declared
suitable for isolation . 42
6.5 Testing with respect to high-frequency voltage stress . 43
6.6 Practical information in case of substitution an impulse withstand test by an
AC or DC test . 43
6.6.1 General . 43
6.6.2 Characteristics of the a.c. voltage substituted to an impulse
withstand test for dielectric test . 43
6.6.3 Characteristics of the d.c. voltage substituted to an impulse
withstand test for dielectric test . 44
7 Examples of a dimensioning worksheet (based on case A as described in
IEC 60664-1:2007) . 44
7.1 Use of IEC 60664-1:2007, for circuits in equipment either directly or not
directly connected to the mains supply . 44
7.2 Use of IEC 60664-5:2007, for circuits in equipment either directly or not
directly connected to the mains supply . 45
7.3 Use of IEC 60664-4:2005, for circuits in equipment either directly or not
directly connected to the mains supply . 46
7.4 Examples comparing the dimensioning of clearances and creepage
distances according to IEC 60664-1 and IEC 60664-5 based on case A
condition (basic insulation, for equipment up to 2 000 m altitude) . 48
7.4.1 Circuits not directly connected to mains supply . 48
7.4.2 Circuits not directly connected to mains supply . 49
7.5 Examples of dimension comparison for clearances and creepage distances
according to IEC 60664-1 and IEC 60664-4 based on case A condition (basic
insulation, for equipment up to 2 000 m altitude) . 50
7.5.1 Circuits not directly connected to mains supply . 50
7.5.2 Circuits not directly connected to mains supply . 52
Annex A (informative) Overview of Clauses of IEC 60664-1 requiring decisions by
technical committees, specification of options or requiring activities by the
manufacturer . 54
Annex B (informative) Overview of Clauses of IEC 60664-4 requiring decisions by
technical committees . 58
– 4 – TR 60664-2-1 IEC:2011
Annex C (informative) Overview of Clauses of IEC 60664-5 requiring decisions by
technical committees, specification of options or requiring activities by the
manufacturer . 59
Annex D (informative) Dimensioning of clearances and creepage distances for d.c.
voltages above 1000 V d.c. . 63
Bibliography . 64
Figure 1 – Breakdown voltage of solid insulation depending upon the time of voltage
stress . 24
Figure 2 – Series connection of clearance and solid insulation. 27
Figure 3 – Capacitive voltage divider . 27
Figure 4 – Permissible field strength for dimensioning of solid insulation according to
Equation (7) . 34
Figure 5a – Example 1 – Simple illustration of insulation system containing functional,
basic and reinforced/double insulation for a class I equipment . 35
Figure 5b – Example 2 – Dimensioning of clearances for class I equipment, based on
overvoltage category III . 36
Figure 5c – Example 3 – Dimensioning of clearances (class II equipment) . 37
Figure 5d – Example 4 – Dimensioning of clearances (class II equipment) . 39
Figure 6 – Arrangement for a.c. (or d.c.) voltage test . 41
Table 1 – Examples for rated voltage 100 V and 230 V and overvoltage category II . 26
Table 2 – Example 2 – Dimensioning of clearances according to Table F.2 of
IEC 60664-1:2007 (pollution degree 2) (see example 2 of Figure 5b) . 36
Table 3 – Example 2 – Dimensioning of clearances according to Tables F.2 and F.7a
of IEC 60664-1:2007, temporary overvoltages according to 5.3.3.2.3 of IEC 60664-
1:2007 (U +1200 V) (see example 2 of Figure 5b) . 37
n
Table 4 – Example 3 – Dimensioning of clearances according to Table F.2 of
IEC 60664-1:2007 (pollution degree 2) (see example 3 of Figure 5c) . 38
Table 5 – Example 3 – Dimensioning of clearances according to Tables F.2 and F.7a
of IEC 60664-1:2007, temporary overvoltages according to 5.3.3.2.3 of IEC 60664-
1:2007 (U +1200 V) (see example 3 of Figure 5c) . 38
n
Table 6 – Example 4 – Dimensioning of clearances according to Table 2 of
IEC 60664-5:2007 (see example 4 on Figure 5d) . 39
Table 7 – Example 4 – Dimensioning of clearances according to Tables 2 and 3 of
IEC 60664-5:2007, temporary overvoltages according to 5.3.3.2.3 of IEC 60664-1:2007
(U +1 200 V) (see example 4 on Figure 5d) . 40
n
Table 8 – Relationship between influencing parameters and normative references in
IEC 60664-1 . 44
Table 9 – Relationship between influencing parameters and normative references in
IEC 60664-1 or IEC 60664-5 . 45
Table 10 – Relationship between influencing parameters and normative references in
IEC 60664-1 or IEC 60664-4 . 46
Table 11 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 . 48
Table 12 – Example for dimensioning a clearance and creepage distance following
IEC 60664-5 . 49
Table 13 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 in circuits not directly connected to mains supply . 49
TR 60664-2-1 IEC:2011 – 5 –
Table 14 – Example for dimensioning a clearance and creepage distance following
IEC 60664-5 in circuits not directly connected to mains supply . 50
Table 15 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 in circuits not directly connected to mains supply . 51
Table 16 – Example for dimensioning a clearance and creepage distance following
IEC 60664-4 (approximately homogeneous field) . 51
Table 17 – Example for dimensioning a clearance and creepage distance following
IEC 60664-1 in circuits not directly connected to mains supply . 52
Table 18 – Example for dimensioning a clearance and creepage distance following
IEC 60664-4 (approximately homogeneous field) . 53
Table A.1 – Clauses and titles of IEC 60664-1 and items to be considered by technical
committees . 54
Table A.2 – Clauses and titles of IEC 60664-1 and optional specifications for
consideration by technical committees . 56
Table A.3 – Clauses and titles of IEC 60664-1 and required manufacturer activities . 57
Table B.1 – Clauses and titles of IEC 60664-4 and optional specifications for
consideration by technical committees . 58
Table C.1 – Clauses and titles of IEC 60664-5 and items to be considered by technical
committees . 59
Table C.2 – Clauses and titles of IEC 60664-5 and optional specifications for
consideration by technical committees . 61
Table C.3 – Clauses and titles of IEC 60664-5 and required manufacturer activities . 62
Table D.1 – Rated impulse voltage for equipment . 63
– 6 – TR 60664-2-1 IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATION COORDINATION FOR EQUIPMENT
WITHIN LOW-VOLTAGE SYSTEMS –
Part 2-1: Application guide –
Explanation of the application of the IEC 60664 series,
dimensioning examples and dielectric testing
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.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC/TR 60664-2-1, which is a technical report, serves as an application guide for the
IEC 60664 series and has been prepared by IEC technical committee 109: Insulation
coordination for low-voltage equipment.
This second edition cancels and replaces the first edition, published in 1997, and constitutes
a technical revision.
TR 60664-2-1 IEC:2011 – 7 –
The main changes with respect to the previous edition are listed below:
– the previous edition was only an application guide for IEC 60664-1. This second edition
takes into account not only IEC 60664-1 but also the other parts IEC 60664-3, IEC 60664-
4, and IEC 60664-5 and their interrelation;
– principles of the IEC 60664 series for insulation dimensioning of LV equipment are
explained and examples of practical application are provided together with some
background information;
– Annex A provides an overview of clauses of IEC 60664-1 requiring decisions by technical
committees, or specification of options, or requiring activities of the manufacturer;
– Annex B provides an overview of such clauses of IEC 60664-4;
– Annex C provides an overview of such clauses of IEC 60664-5;
– Annex D amends the tables of Annex F of IEC 60664-1:2007 with rated impulse voltages
for voltages line to neutral derived from nominal d.c. voltages up to and including 1 500 V.
The text of this application guide is based on the following documents:
Enquiry draft Report on voting
109/82/DTR 109/83/RVC
Full information on the voting for the approval of this application guide 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.
It has the status of a basic safety publication in accordance with IEC Guide 104.
A list of all the parts in the IEC 60664 series, published under the general title Insulation
coordination for equipment within low-voltage systems, can be found on the IEC website.
The committee has decided that the contents of this amendment and the base 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 corrigendum of October 2011 have been included in this copy.
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.
– 8 – TR 60664-2-1 IEC:2011
INTRODUCTION
This application guide provides information relating to insulation coordination, as described in
the IEC 60664 series, for the benefit of IEC technical committees and manufacturers. It
covers general information for the dimensioning of clearances, creepage distances and solid
insulation for equipment.
It aims to highlight the use and understanding of the IEC 60664 series when applied by
technical committees and manufacturers.
Insulation coordination for equipment implies the assessment of the minimum necessary
dimensioning for clearances, creepage distances and solid insulation in order to allow safe
use of the equipment during its lifetime, taking into consideration the foreseeable
environmental conditions.
The main parameters to be taken into account for the understanding of the IEC 60664 series
include:
– the maximum voltage stress to be withstood in order to avoid flashover across clearances;
– the characteristics of the solid insulating material and the environmental conditions
regarding tracking. IEC 60664-3 provides methods for improving the micro-environment at the
creepage distance;
– the electrical field stress through solid insulation as it relates to the risk of partial
discharge and dielectric loss causing a risk of breakdown due to excessive heating. In
particular, technical committees and manufacturers should consider a partial discharge
test if the maximum peak voltage across the insulation material exceeds 700 V and the
peak value of the field strength exceeds 1 kV/mm. Due to the fact that both partial
discharge phenomena and dielectric losses increase in importance with voltage frequency,
a dedicated standard, IEC 60664-4, applies for frequencies higher than 30 kHz;
NOTE IEC 60664-4 provides information concerning clearances, creepage distances, solid insulation and testing
for frequencies above 30 kHz.
– the long-term maximum voltage stress to be withstood in order to avoid tracking over the
surface of the insulation material;
– flashover; besides tracking, this is increasingly important with reduction of creepage
distance in the presence of high humidity. IEC 60664-5 introduces humidity levels
classifying the effects of humidity on creepage distances equal to or less than 2 mm.
Other stresses such as heat, vibration, mechanical shocks, radiation, etc. may influence the
performance of solid insulating materials in service. Technical committees and manufacturers
should consider the risks related to these stresses when specifying conditions for testing
equipment to be used under particular situations.
TR 60664-2-1 IEC:2011 – 9 –
INSULATION COORDINATION FOR EQUIPMENT
WITHIN LOW-VOLTAGE SYSTEMS –
Part 2-1: Application guide –
Explanation of the application of the IEC 60664 series,
dimensioning examples and dielectric testing
1 Scope
This part of IEC 60664, which is a technical report, serves as an application guide for
technical committees and manufacturers specifying dimensioning requirements for products in
accordance with the IEC 60664 series.
The significant items for consideration are as follows:
a) nominal system voltage(s) or rated insulation voltage(s);
b) overvoltage category of the products (OV cat.);
c) any type of overvoltages;
d) frequency of the voltage;
e) characteristics of the solid insulating material;
f) pollution degree and humidity levels.
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 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60112:2003, Method for the determination of the proof and the comparative tracking
indices of solid insulating materials
Amendment 1 (2009)
IEC 60216 (all parts), Electrical insulating materials – Properties of thermal endurance
IEC 60364-4-44:2007, Low-voltage electrical installations – Part 4-44: Protection for safety –
Protection against voltage disturbances and electromagnetic disturbances
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-3:2003, Insulation coordination for equipment within low-voltage systems – Part 3:
Use of coating, potting or moulding for protection against pollution
IEC 60664-4:2005, Insulation coordination for equipment within low-voltage systems – Part 4:
Consideration of high-frequency voltage stress
IEC 60664-5:2007, Insulation coordination for equipment within low-voltage systems – Part 5:
Comprehensive method for determining clearances and creepage distances equal to or less
than 2 mm
IEC 61140:2001, Protection against electric shock – Common aspects for installation and
equipment
– 10 – TR 60664-2-1 IEC:2011
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE All definitions can be found in the various parts of the IEC 60664 series, as indicated below.
3.0
apparent charge
q
electric charge which can be measured at the terminals of the specimen under test
NOTE 1 The apparent charge is smaller than the partial discharge.
NOTE 2 The measurement of the apparent charge requires a short-circuit condition at the terminals of the
specimen under test.
[IEC 60664-1:2007, 3.18.1]
3.1
approximately homogeneous field
for frequencies exceeding 30 kHz the field is considered to be approximately homogeneous
when the radius of curvature of the conductive parts is equal or greater than 20 % of the
clearance
[IEC 60664-4:2005, 3.1]
3.2
base material
insulating material upon which a conductive pattern may be formed
NOTE The base material may be rigid or flexible, or both. It may be a dielectric or an insulated metal sheet.
(IEC 60194, definition 40.1334)
[IEC 60664-3:2003, 3.1]
3.3
basic insulation
insulation of hazardous-live-parts which provides basic protection
NOTE The concept does not apply to insulation used exclusively for functional purposes.
(IEV 826-12-14)
[IEC 60664-1:2007, 3.17.2]
3.4
clearance
shortest distance in air between two conductive parts
[IEC 60664-1:2007, 3.2]
3.5
coating
insulating material such as varnish or dry film laid on the surface of the assembly
NOTE Coating and base material of a printed board form an insulating system that may have properties similar to
solid insulation.
[IEC 60664-3:2003, 3.5]
3.6
conductor
single conductive path in a conductive pattern
(IEC 60194, definition 22.0251)
TR 60664-2-1 IEC:2011 – 11 –
[IEC 60664-3:2003, 3.3]
3.7
creepage distance
shortest distance along the surface of a solid insulating material between two conductive
parts
(IEV 151-15-50)
[IEC 60664-1:2007, 3.3]
3.8
double insulation
insulation comprising both basic insulation and supplementary insulation
(IEV 826-12-16)
[IEC 60664-1:2007, 3.17.4]
3.9
electrical breakdown
failure of insulation under electric stress when the discharge completely bridges the
insulation, thus reducing the voltage between the electrodes almost to zero
[IEC 60664-1:2007, 3.20]
3.10
electrical field strength
E
voltage gradient per unit length usually expressed in kV/mm
[IEC 60664-4:2005, 3.7]
3.11
environment
surrounding which may affect performance of a device or system
NOTE Examples are pressure, temperature, humidity, pollution, radiation, vibration.
(IEV 151-16-03, modified)
[IEC 60664-1:2007, 3.12]
3.12
flashover
electrical breakdown along a surface of solid insulation located in a gaseous or liquid medium
[IEC 60664-1:2007, 3.20.2]
3.13
functional insulation
insulation between conductive parts which is necessary only for the proper functioning of the
equipment
[IEC 60664-1:2007, 3.17.1]
3.14
homogeneous field
electric field which has an essentially constant voltage gradient between electrodes (uniform
field), such as that between two spheres where the radius of each sphere is greater than the
distance between them
NOTE The homogeneous field condition is referred to as case B.
[IEC 60664-1:2007, 3.14]
– 12 – TR 60664-2-1 IEC:2011
3.15
impulse withstand voltage
highest peak value of impulse voltage of prescribed form and polarity which does not cause
breakdown of insulation under specified conditions
[IEC 60664-1:2007, 3.8.1]
3.16
inhomogeneous field
electric field which does not have an essentially constant voltage gradient between electrodes
(non-uniform field)
NOTE 1 The inhomogeneous field condition of a point-plane electrode configuration is the worst case with regard
to voltage withstand capability and is referred to as case A. It is represented by a point electrode having a 30 µm
radius and a plane of 1 m × 1 m.
NOTE 2 For frequencies exceeding 30 kHz the field is considered to be inhomogeneous when the radius of
curvature of the conductive parts is less than 20 % of the clearance.
[IEC 60664-1:2007, 3.15, modified, and IEC 60664-4:2005, 3.2]
3.17
insulation
that part of an electrotechnical product which separates the conducting parts at different
electrical potentials
(IEV 212-01-05)
[IEC 60664-1:2007, 3.17]
3.18
insulation coordination
mutual correlation of insulation characteristics of electrical equipment taking into account the
expected micro-environment and other influencing stresses
[IEC 60664-1:2007, 3.1, modified]
3.19
macro-environment
environment of the room or other location in which the equipment is installed or used
[IEC 60664-1:2007, 3.12.1]
3.20
micro-environment
immediate environment of the insulation which particularly influences the dimensioning of the
creepage distances
[IEC 60664-1:2007, 3.12.2]
3.21
overvoltage
any voltage having a peak value exceeding the corresponding peak value of maximum
steady-state voltage at normal operating conditions
[IEC 60664-1:2007, 3.7]
3.22
overvoltage category
numeral defining a transient overvoltage condition
[IEC 60664-1:2007, 3.10, modified]
TR 60664-2-1 IEC:2011 – 13 –
3.23
partial discharge
PD
electric discharge that partially bridges the insulation
[IEC 60664-1:2007, 3.18]
3.24
partial discharge inception voltage
U
i
lowest peak value of the test voltage at which the apparent charge becomes greater than the
specified discharge magnitude when the test voltage is increased above a low value for which
no discharge occurs
NOTE For a.c. tests the r.m.s. value may be used.
[IEC 60664-1:2007, 3.18.4]
3.25
pollution
any addition of foreign matter, solid, liquid, or gaseous that can result in a reduction of
electric strength or surface resistivity of the insulation
[IEC 60664-1:2007, 3.11]
3.26
pollution degree
numeral characterizing the expected pollution of the micro-environment
[IEC 60664-1:2007, 3.13]
3.27
printed board
general term for completely processed printed circuit and printed wiring configurations
NOTE This includes single-sided, double-sided and multilayer boards with rigid, flexible, and rigid-flex base
materials.
(IEC 60194, definition 60.1485)
[IEC 60664-3:2003, 3.2]
3.28
protection
any kind of measure which reduces the influence of the environment
[IEC 60664-3:2003, 3.4]
3.29
r.m.s. withstand voltage
highest r.m.s. value of a voltage which does not cause breakdown of insulation under
specified conditions
[IEC 60664-1:2007, 3.8.2]
3.30
rated impulse voltage
impulse withstand voltage value assigned by the manufacturer to the equipment or to a part of
it, characterizing the specified withstand capability of its insulation against transient overvoltages
[IEC 60664-1:2007, 3.9.2]
– 14 – TR 60664-2-1 IEC:2011
3.31
rated insulation voltage
r.m.s. withstand voltage value assigned by the manufacturer to the equipment or to a part of
it, characterizing the specified (long-term) withstand capability of its insulation
NOTE The rated insulation voltage is not necessarily equal to the rated voltage of equipment which is primarily
related to functional performance.
[IEC 60664-1:2007, 3.9.1]
3.32
rated recurring peak voltage
recurring peak withstand voltage value assigned by the manufacturer to the equipment or to a
part of it, characterizing the specified withstand capability of its insulation against recurring
peak voltages
[IEC 60664-1:2007, 3.9.3]
3.33
rated temporary overvoltage
temporary withstand overvoltage value assigned by the manufacturer to the equipment, or to
a part of it, characterizing the specified short-term withstand capability of its insulation against
a.c. voltages
[IEC 60664-1:2007, 3.9.4]
3.34
rated voltage
value of voltage assigned by the manufacturer, to a component, device or equipment and to
which operation and performance characteristics are referred
NOTE Equipment may have more than one rated voltage value or may have a rated voltage range.
[IEC 60664-1:2007, 3.9]
3.35
recurring peak voltage
U
rp
maximum peak value of periodic excursions of the voltage waveform resulting from distortions
of an a.c. voltage or from a.c. components superimposed on a d.c. voltage
NOTE Random overvoltages, for example due to occasional switching, are not considered to be recurring peak
voltages.
[IEC 60664-1:2007, 3.6]
3.36
recurring peak withstand voltage
highest peak value of a recurring voltage which does not cause breakdown of insulation under
specified conditions
[IEC 60664-1:2007, 3.8.3]
3.37
reinforced insulation
insulation of hazardous-live-parts which provides a degree of protection against electric shock
equivalent to double insulation
NOTE Reinforced insulation may comprise several layers which cannot be tested singly as basic insulation or
supplementary insulation.
(IEV 826-12-17)
TR 60664-2-1 IEC:2011 – 15 –
[IEC 60664-1:2007, 3.17.5]
3.38
routine test
test to which each individual device is subjected during or after manufacture to ascertain
whether it complies with certain criteria
[IEC 60664-1:2007, 3.19.2]
3.39
sampling test
test on a number of devices taken at random from a batch
[IEC 60664-1:2007, 3.19.3]
3.40
solid insulation
solid insulating material interposed between two conductive parts
NOTE In the case of a printed board with a coating, solid insulation co
...
IEC TR 60664-2-1:2011 is a technical report that serves as a guide for specifying dimensioning requirements for products in accordance with the IEC 60664 series. It covers factors such as system voltage, overvoltage category, frequency, insulation material characteristics, pollution degree, and humidity levels. This second edition includes information from IEC 60664-1, IEC 60664-3, IEC 60664-4, and IEC 60664-5. The report explains the principles of insulation dimensioning for low-voltage equipment and provides practical application examples. Annexes A, B, C, and D provide additional information and amendments. The copy includes the contents of the October 2011 corrigendum.
제목: IEC TR 60664-2-1:2011 - 저전압 시스템 내 장비에 대한 절연 코디네이션 - 제 2-1 부 : 적용 가이드 - IEC 60664 시리즈의 적용 설명, 치수 결정 예시 및 유전체 시험 IEC/TR 60664-2-1:2011은 기술 보고서로, IEC 60664 시리즈와 관련하여 제품의 치수 결정 요구 사항을 지정하는 기술 위원회와 제조업체를 위한 적용 가이드로 사용됩니다. 고려해야 할 중요한 항목은 다음과 같습니다: a) 명목 시스템 전압 또는 등급 절연 전압; b) 제품의 과전압 범주 (OV cat.); c) 과전압 유형; d) 전압의 주파수; e) 고체 절연 재료의 특성; f) 오염 정도 및 습도 수준. 이전 판과의 주요 변경 사항은 아래에 나열되어 있습니다: - 이전 판은 IEC 60664-1에 대한 요구 사항에 대한 적용 가이드만이었습니다. 이번 제 2판은 IEC 60664-1뿐만 아니라 IEC 60664-3, IEC 60664-4 및 IEC 60664-5 및 그들의 관계도를 고려합니다. - LV 장비의 절연 치수 결정을 위한 IEC 60664 시리즈의 원칙과 실제 적용 예시와 함께 일부 배경 정보가 제공됩니다. - 부록 A는 기술 위원회의 결정이 필요하거나 옵션의 사양이 필요하거나 제조업체의 활동이 요구되는 IEC 60664-1 조항에 대한 개요를 제공합니다. - 부록 B는 IEC 60664-4의 해당 조항에 대한 개요를 제공합니다. - 부록 C는 IEC 60664-5의 해당 조항에 대한 개요를 제공합니다. - 부록 D는 IEC 60664-1:2007의 부록 F 테이블을 보정하여 명목 직류 전압이 1,500 V까지의 선-중성 유도 평가 파형 전압을 추가합니다. 2011년 10월의 오정보의 내용이 이 복사본에 포함되어 있습니다.
記事タイトル：IEC TR 60664-2-1:2011 - 低電圧システム内の機器の絶縁協調 - 第2-1部：適用ガイド - IEC 60664シリーズの適用の説明、寸法決定の例、および誘電体試験 IEC/TR 60664-2-1:2011は、技術レポートであり、IEC 60664シリーズに準拠する製品に対する寸法決定要件を指定する技術委員会や製造業者向けの適用ガイドとして機能します。考慮すべき重要な項目は以下のとおりです： a）名目システム電圧もしくは定格絶縁電圧； b）製品の過電圧カテゴリ（OVカテゴリ）； c）任意の過電圧の種類； d）電圧の周波数； e）固体絶縁材料の特性； f）汚染度と湿度レベル。 前版と比較しての主な変更点は以下の通りです： - 前版はIEC 60664-1の適用ガイドのみでしたが、第2版ではIEC 60664-1だけでなく、IEC 60664-3、IEC 60664-4、およびIEC 60664-5の内容も考慮されています。 - 低電圧機器の絶縁寸法のIEC 60664シリーズの原則が説明され、実際の適用例と背景情報が提供されています。 - 付録Aは、技術委員会の決定、オプションの仕様の指定、または製造業者の活動が必要なIEC 60664-1の節に関する概要を提供しています。 - 付録Bは、IEC 60664-4の関連節の概要を提供しています。 - 付録Cは、IEC 60664-5の関連節の概要を提供しています。 - 付録Dは、IEC 60664-1:2007の付録F表を修正し、名目直流電圧が1,500V以下の線対中性からの定格脈波電圧を追加しています。 このコピーには2011年10月の訂正内容が含まれています。
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