IEC 81346-2:2019

Industrial systems, installations and equipment and industrial products — Structuring principles and reference designations — Part 2: Classification of objects and codes for classes

IEC 81346-2:2019 establishes classification schemes with defined object classes and their associated letter codes, and is primarily intended for use in reference designations and for designation of generic types. The classification schemes are applicable for objects in all technical disciplines and all branches of industry. IEC 81346-2:2019 is a horizontal publication also intended for for use by technical committees in preparation of publications related to reference designations in accordance with the principles laid down in IEC Guide 108. IEC 81346-2:2019 cancels and replaces the first edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) The entry classes of the classification scheme have been defined to reflect the “inherent function” of the object classified; b) The classes are defined to align with the principles of ISO 22274 and ISO 704; c) A three-level classification scheme has been defined, which provides a greater flexibility for the designer in some technical fields; d) Classes are defined by their definition and provided with a preferred term. Examples are provided if needed; e) A separate classification scheme for spaces has been provided.

Systèmes industriels, installations et appareils, et produits industriels — Principes de structuration et désignations de référence — Partie 2: Classification des objets et codes pour les classes

IEC 81346-2:2019 établit des plans de classification et définit les classes d’objets ainsi que leurs lettres codes associées, et est principalement destinée à un usage dans les désignations de référence et pour la désignation des types génériques. Les plans de classification s’appliquent aux objets appartenant à toutes les disciplines techniques ainsi qu’à toutes les branches d'industrie. IEC 81346-2:2019 est une publication horizontale également destinée à être utilisée par les comités d’études pour l’établissement de publications liées aux désignations de référence conformément aux principes exposés dans le Guide IEC 108. IEC 81346-2:2019 annule et remplace la première édition parue en 2009. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente: a) Les classes d’entrée du plan de classification ont été définies afin de refléter la «fonction intrinsèque» de l’objet classé; b) Les classes sont définies de sorte à s’aligner sur les principes définis dans l’ISO 22274 et l’ISO 704; c) Un plan de classification à trois niveaux a été défini afin de garantir au concepteur une plus grande latitude dans certains domaines techniques; d) Les classes sont définies avec un terme préférentiel. Des exemples sont fournis, si nécessaire; e) Un plan de classification distinct a été fourni pour les espaces.

General Information

• Status: Published
• Publication Date: 20-Jun-2019
• ICS: 01.110 - Technical product documentation
• ICS: 25.040.01 - Industrial automation systems in general
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: ISO/TC 10 - Technical product documentation
• Drafting Committee: ISO/TC 10 - Technical product documentation

Relations

• Revises: IEC 81346-2:2009 - Industrial systems, installations and equipment and industrial products — Structuring principles and reference designations — Part 2: Classification of objects and codes for classes
• Effective Date: 20-Jan-2018

Standards Content (Sample)

IEC 81346-2
Edition 2.0 2019-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL STANDARD
NORME HORIZONTALE
Industrial systems, installations and equipment and industrial products –
Structuring principles and reference designations –
Part 2: Classification of objects and codes for classes

Systèmes industriels, installations et appareils, et produits industriels –
Principes de structuration et désignations de référence –
Partie 2: Classification des objets et codes pour les classes


IEC 81346-2:2019-06(en-fr)

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IEC 81346-2


Edition 2.0 2019-06




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside



HORIZONTAL STANDARD

NORME HORIZONTALE




Industrial systems, installations and equipment and industrial products –

Structuring principles and reference designations –

Part 2: Classification of objects and codes for classes




Systèmes industriels, installations et appareils, et produits industriels –

Principes de structuration et désignations de référence –


Partie 2: Classification des objets et codes pour les classes













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 01.110; 29.020 ISBN 978-2-8322-7001-1



Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

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– 2 – IEC 81346-2:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Classification principles . 7
4.1 General . 7
4.2 Relation between classification and composition . 8
4.3 Classification schemes of this document . 8
5 Classification scheme for the inherent function of objects . 9
5.1 General . 9
5.2 Entry classes . 9
5.3 Complete classification scheme . 10
6 Classification of spaces . 69
7 Classification of objects applicable for infrastructure . 79
Annex A (informative) Classification criteria for objects . 82
A.1 General . 82
A.2 Structure of classes and subclasses . 82
A.3 Definition of classes . 83
Annex B (informative) Object classes related to a generic process . 84
Annex C (informative) Object classes related to objects in a generic infrastructure . 85
Annex D (informative) Comparison between Tables 1, 2 and 3 of this document and
Tables 1 and 2 of IEC 81346-2:2009 . 87
Annex E (informative) Basic requirements for the development of IEC 81346-2 . 91
Bibliography . 92

Figure 1 – Illustration of a classification hierarchy and a composition hierarchy . 8
Figure A.1 – Illustration of class hierarchy . 83
Figure B.1 – Object classes related to a generic process . 84
Figure C.1 – Object classes related to objects in a generic infrastructure . 86

Table 1 – Entry classes . 10
Table 2 – First two levels of the classification scheme for inherent function of objects . 11
Table 3 – Complete classification scheme for inherent function of objects. 26
Table 4 – Classification scheme for spaces. 70
Table 5 – Classes of infrastructure objects . 80
Table 6 – Examples of branch-related classes B to U of Table 5 . 81
Table D.1 – Comparison between Table 1 of the current edition and Table 1 of IEC
81346-2:2009. 87
Table D.2 – Comparison between Table 2 and Table 3 of the current edition and Table
2 of IEC 81346-2:2009 . 87

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IEC 81346-2:2019 © IEC 2019 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

INDUSTRIAL SYSTEMS, INSTALLATIONS
AND EQUIPMENT AND INDUSTRIAL PRODUCTS –
STRUCTURING PRINCIPLES AND REFERENCE DESIGNATIONS –

Part 2: Classification of objects and codes for classes

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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International Standard IEC 81346-2 has been prepared by IEC technical committee 3:
Information structures and elements, identification and marking principles, documentation and
graphical symbols, in cooperation with ISO technical committee 10: Technical product
documentation.
It is published as a double logo standard.
It has the status of a horizontal standard in accordance with IEC Guide 108.
This second edition cancels and replaces the first edition published in 2009. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:

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a) The entry classes of the classification scheme have been defined to reflect the “inherent
function” of the object classified;
b) The classes are defined to align with the principles of ISO 22274 and ISO 704;
c) A three-level classification scheme has been defined, which provides a greater flexibility
for the designer in some technical fields;
d) Classes are defined by their definition and provided with a preferred term. Examples are
provided if needed;
e) A separate classification scheme for spaces has been provided.
The text of this International Standard is based on the following documents:
FDIS Report on voting
3/1393/FDIS 3/1402/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 81346 series, published under the general title Industrial systems,
installations and equipment and industrial products – Structuring principles and reference
designations, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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.

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IEC 81346-2:2019 © IEC 2019 – 5 –
INTRODUCTION
The aim of this document is to establish classification schemes for objects with assigned letter
codes for the defined classes, which can be applied throughout all technical areas,
e.g. electric, mechanical, process and civil engineering as well as all branches of industry,
e.g. energy, chemical, construction, automotive, shipbuilding and marine. The letter codes are
intended for use with the rules for the construction of reference designations in accordance
with IEC 81346-1 and other parts of the ISO/IEC 81346 series. The letter codes can also be
used ”stand-alone” as a generic type designation where a type of component is to be
indicated, for example in specifications.
The classification scheme in Clause 5 of this document is an enumerative and faceted
classification scheme with the inherent function as the entry class. It is made in accordance
with the rules in ISO 704 and the guidelines in ISO 22274.
At the entry level, as shown in Table 1, the inherent function is used to narrow down the areas
of applicability of the individual classes to a manageable size. For the sub-divisions of the
entry classes, faceted approaches are applied to specify the nature of the concepts contained
in the leaf classes.
By applying this method, this document provides stable class codes for objects (including
systems and system elements), which are independent of how the objects are used or applied
in any design during the entire lifecycle.
Any class is defined by its definition only. Users should select the appropriate class for their
object to be classified based on the definition, and not rely upon the class name or the
examples.

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INDUSTRIAL SYSTEMS, INSTALLATIONS
AND EQUIPMENT AND INDUSTRIAL PRODUCTS –
STRUCTURING PRINCIPLES AND REFERENCE DESIGNATIONS –

Part 2: Classification of objects and codes for classes



1 Scope
This part of IEC 81346 establishes classification schemes with defined object classes and
their associated letter codes, and is primarily intended for use in reference designations and
for designation of generic types.
The classification schemes are applicable for objects in all technical disciplines and all
branches of industry.
This document is a horizontal publication also intended for use by technical committees in
preparation of publications related to reference designations in accordance with the principles
laid down in IEC Guide 108.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 81346-1:2009, Industrial systems, installations and equipment and industrial products –
Structuring principles and reference designations – Part 1: Basic rules
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 81346-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
inherent function
function of an object, independent of any application of the object
Note 1 to entry: Inherent is regarded as existing in something as a permanent, essential, or characteristic
attribute.
3.2
classification scheme
descriptive information for an arrangement or division of objects into groups based on criteria
such as characteristics, which the objects have in common
Note 1 to entry: A classification scheme is a concept system used for classifying some objects.

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IEC 81346-2:2019 © IEC 2019 – 7 –
[SOURCE: ISO/IEC 11179-1:2015, 3.3.4, modified – examples deleted.]
3.3
class of object
set of objects characterized by the same inherent function
3.4
space
limited three-dimensional extent defined physically or notionally
[SOURCE: ISO 12006-2:2015, 3.1.8]
3.5
type-of relation
relation between two classes where the characteristics defining one of the classes includes
that of the other class and at least one additional delimiting characteristic
Note 1 to entry: This term corresponds to the term "generic relation" defined in ISO 1087-1:2000, 3.2.21.
3.6
part-of relation
relation between two classes where one of the classes constitutes the whole and the other
class a part of that whole
Note 1 to entry: This term corresponds to the term "partitive relation" defined in ISO 1087-1:2000, 3.2.22.
Note 2 to entry: Part-of relation is also known as partitive relation, part-whole relation or whole-part relation.
Note 3 to entry: See also IEC 81346-1.
3.7
activity space
space defined by the spatial extension of an activity
Note 1 to entry: A spatial extension of an activity, for example, a table or a bed, and the activity space around
them.
[SOURCE: ISO 12006-2:2015, 3.1.9]
3.8
built space
space defined by built or natural environment or both, intended for user activity or equipment
Note 1 to entry: A built space is, for example, a room defined by floor, ceiling, and wall, or a footpath, or power-
line corridor defined by a natural forest.
Note 2 to entry: Spaces occupied by construction elements are known as construction spaces, and are handled
as properties of construction elements themselves.
[SOURCE: ISO 12006-2:2015, 3.4.4]
4 Classification principles
4.1 General
The purpose of classifying is to distinguish among objects in a collection based on
differentiation of characteristics of interest. Classes are organized in type-of relations and are
defined by different values of a specific characteristic of interest.

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The classification in this document is made with an entry class based on function in a broad
sense. This is in accordance with ISO 22274:2013, 5.4.4 which recommends an enumerative
and faceted classification system with an entry class.
When a class code is applied in a reference designation, the purpose is to classify the
occurrence of the object, not the individual, as described in IEC 81346-1:2009, 4.8 and
Table 1 (general rules). In such a situation, the object is generally specified and assigned its
inherent function in the design stage of the project. Classes can also be used by
manufacturers to show multiple potential use of a product. In this way, the classification can
enhance searchability.
The class name (preferred term) assigned to the classes and the examples of terms provided
in this document are based on the inherent function of an object, i.e. independent of any
application.
This classification scheme ensures a life cycle stable class code, as the stable object
occurrence is classified by the stable inherent function of the object occurrence: A stake is a
stake, a door is a door and so on, no matter what individual is used to realize the occurrence.
Objects related to a class may be considered as a discrete collection of objects, and may
therefore be further classified into sub-classes based on the differentiation of a specific
characteristic. In this document, this has resulted in a classification scheme starting with
st
classes representing general types based on function in a broad sense (1 letter code),
continuing into classes representing types that are more specialized in two steps, represented
nd rd
by 2 and 3 class code.
All examples and terms in the classification scheme of this document are recognized as being
used to name a member of their class. As different branches have different usage of
terminology, the same example or term might occur in different classes.
4.2 Relation between classification and composition
IEC 81346-1 defines rules on how an object may be structured into its constituent objects
resulting in a composition hierarchy. For the purpose of classifying objects, this document
defines classes and codes that results in a classification hierarchy, see Figure 1, which is a
copy of Figure 2 in 4.2 of ISO 12006-2:2015.
IEC

Figure 1 – Illustration of a classification hierarchy and a composition hierarchy
4.3 Classification schemes of this document
This document provides different classification schemes of objects primarily intended for use
in reference designations, based on the basic requirements given in Annex E. The provided
classification schemes are:

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IEC 81346-2:2019 © IEC 2019 – 9 –
• inherent function of objects, see Clause 5;
• spaces, see Clause 6;
• infrastructure objects, see Clause 7.
The content of any class is determined by the definition of the class only. A preferred term
determines the class in daily use and forms part of the definition of subclasses. The
classification tables of this document are considered to be complete, and therefore no
“miscellaneous” or “other” classes are present. If no appropriate class for an object-of-interest
can be found on a sub or sub-sub level, objects shall be classified to the higher level i.e. to
the sub-class or entry class.
This document provides classification schemes with multiple classification levels. The user
may choose to apply letter codes using
• a single letter, representing the entry class; or
• two letter code, representing a sub-class in the scheme; or
• three letter code, representing a sub-sub-class in the scheme.
5 Classification scheme for the inherent function of objects
5.1 General
The classification scheme defined in this clause is based on the inherent function of objects.
The classification scheme has a hierarchical classification structure that constitute three
levels from top to lower.
The entry classes and their respective subclasses are defined considering the inherent
function of objects, based on the knowledge of the use of objects in existing designs, and the
classification schemes defined in IEC 81346-2:2009.
NOTE 1 When the classification scheme shown in Table 1 and Table 2 refer to high voltage (HV) or low voltage
(LV), high voltage is considered to be any voltage > 1 000 V AC or > 1 500 V DC. Low voltage is considered to be
any voltage ≤ 1 000 V AC or ≤ 1 500 V DC. These voltage limits are in accordance with IEC 61140.
NOTE 2 In Annex D the difference between the classification scheme and classes in IEC 81346-2:2009 and the
classification scheme and classes of this publication is given.
5.2 Entry classes
Table 1 defines the entry classes for the classification scheme for inherent function of objects.

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Table 1 – Entry classes
Class code Class definition Class name
B object for picking up information and providing a sensing object
representation
C object for storing for subsequent retrieval storing object
E object for emitting emitting object
F object for protecting against the effects of protecting object
dangerous or undesirable conditions
G object for providing a controllable flow generating object
H object for treating matter matter processing object
K object for treating input signals and providing an information processing object
appropriate output
M object for providing mechanical movement or force driving object
N object for enclosing partly or fully another object covering object
P object for providing perceptible information presenting object
Q object for controlling access or flow controlling object
R object for restricting or stabilising restricting object
S object for detecting a human action and providing an human interaction object
appropriate response
T object for transforming transforming object
U object for localising of other objects holding object
W object for leading from one place to another guiding object
X object for interfacing an object interfacing object
The letters A, I and O shall not be used as a class code.
The letters D, J, L, V, Y and Z are reserved for future standardization.

Each class defined in Table 1 is in this document associated with a set of predefined
subclasses allowing a more detailed characterization of an object, if required. The definitions
of subclasses of objects (sub-class and sub-sub-class) are presented in Table 2 and Table 3
together with their associated letter codes.
NOTE Subclasses do not define a new level in a c
...