EN 61666:2010

SLOVENSKI STANDARD
01-november-2010
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SIST EN 61666:1997
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Industrial systems, installations and equipment and industrial products - Identification of
terminals within a system (IEC 61666:2010)
Industrielle Systeme, Anlagen und Ausrüstungen und Industrieprodukte - Identifikation
von Anschlüssen in Systemen (IEC 61666:2010)
Systèmes industriels, installations et appareils, et produits industriels - Indentification des
bornes dans le cadre d'un système (CEI 61666:2010)
Ta slovenski standard je istoveten z: EN 61666:2010
ICS:
01.080.40 *UDILþQLVLPEROL]DXSRUDERY Graphical symbols for use on
ULVEDKGLDJUDPLKQDþUWLKY electrical and electronics
HOHNWURWHKQLNLLQHOHNWURQLNL engineering drawings,
WHUYXVWUH]QLWHKQLþQL diagrams, charts and in
SURL]YRGQLGRNXPHQWDFLML relevant technical product
documentation
29.020 Elektrotehnika na splošno Electrical engineering in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61666
NORME EUROPÉENNE
September 2010
EUROPÄISCHE NORM
ICS 01.080.30 Supersedes EN 61666:1997

English version
Industrial systems, installations and equipment and industrial products -
Identification of terminals within a system
(IEC 61666:2010)
Systèmes industriels, installations  Industrielle Systeme, Anlagen
et appareils, et produits industriels - und Ausrüstungen und Industrieprodukte -
Identification des bornes dans le cadre Identifikation von Anschlüssen
d'un système in Systemen
(CEI 61666:2010) (IEC 61666:2010)

This European Standard was approved by CENELEC on 2010-09-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61666:2010 E
Foreword
The text of document 3/1001/FDIS, future edition 2 of IEC 61666, prepared by IEC TC 3, Information
structures, documentation and graphical symbols, was submitted to the IEC-CENELEC parallel vote and
was approved by CENELEC as EN 61666 on 2010-09-01.
This European Standard supersedes EN 61666:1997.
This European Standard includes the following substantial changes with respect to EN 61666:1997:
– the terminology used in the publication has been adapted to the one used in EN 81346-1;
– a more comprehensive description of the designation principles is provided;
– additional examples illustrating terminal designations related to the function aspect and location
aspect are provided;
– an additional example illustrating the use of terminal designation sets is provided;
– the former informative Annex A has been turned into a clause in the standard.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2011-06-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2013-09-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61666:2010 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60034-8:2007 NOTE  Harmonized as EN 60034-8:2007 (not modified).
IEC 60191-3:1999 NOTE  Harmonized as EN 60191-3:1999 (not modified).
__________
- 3 - EN 61666:2010
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60417 - Graphical symbols for use on equipment - -

IEC 60445 - Basic and safety principles for man-machine EN 60445 -
interface, marking and identification -
Identification of equipment terminals,
conductor terminations and conductors

IEC 60757 - Code for designation of colours HD 457 -

IEC 61082-1 2006 Preparation of documents used in EN 61082-1 2006
electrotechnology -
Part 1: Basic rules
IEC 81346-1 - Industrial systems, installations and EN 81346-1 -
equipment and industrial products -
Structuring principles and reference
designations -
Part 1: Rules
IEC 81714-3 - Design of graphical symbols for use in the - -
technical documentation of products -
Part 3: Classification of connect nodes,
networks and their encoding
IEC 61666 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial systems, installations and equipment and industrial products –
Identification of terminals within a system

Systèmes industriels, installations et appareils, et produits industriels –
Identification des bornes dans le cadre d’un système

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
P
CODE PRIX
ICS 01.080.30 ISBN 978-2-88912-148-9
– 2 – 61666 © IEC:2010
CONTENTS
FOREWORD.3
1 Scope.5
2 Normative references .5
3 Terms and definitions .5
4 Terminal designation .7
4.1 General .7
4.2 Designation of terminals with respect to the product aspect.8
4.3 Designation of terminals with respect to the function aspect .9
4.4 Designation of terminals with respect to the location aspect .10
4.5 Terminal designation set .11
5 Classification of terminals.13
Annex A (informative) Examples of terminal designations not specified by a
manufacturer .14
Bibliography.16

Figure 1 – Principle of terminal designation .7
Figure 2 – Example of designation of terminals for a 3-phase squirrel-cage motor .9
Figure 3 – A device shown with function labels on which the terminal designations
related to the function aspect are based, as well as terminal designations (pins) related
to the product aspect .10
Figure 4 – Example of a symbol for a motor starter provided with terminal designations
related to the function aspect.10
Figure 5 – Example of a terminal board for cross-connection where the terminals are
designated related to their location aspect .11
Figure 6 – Example of a terminal designation set.12
Figure 7 – Example of a design with terminal designations related to the function
aspect.12
Figure 8 – Example of an implemented design based on Figure 7 with terminal
designations related to the product aspect.13
Figure 9 – Example of an implemented design based on Figure 7 with terminal
designation sets related to the function and product aspects .13
Figure A.1 – Four terminal blocks composing one terminal assembly (each terminal
block is considered as an object) .
Figure A.2 – One terminal block with eight terminals (the complete unit is an object) .15
Figure A.3 – One terminal block with eight terminals with two entry points each .15

61666 © IEC:2010 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL SYSTEMS, INSTALLATIONS
AND EQUIPMENT AND INDUSTRIAL PRODUCTS –
IDENTIFICATION OF TERMINALS WITHIN A SYSTEM

FOREWORD
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patent rights. IEC shall not be held responsi
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