IEC PAS 62400:2005

Structuring principles for technical products and technical product documentation - Letter codes - Main classes and subclasses of objects according to their purpose and task

Extends the letter codes of the main classes for purposes or tasks of objects in accordance with IEC 61346-2. Applies to all disciplines, such as construction, process and electrical engineering, power generation and distribution, process engineering facilities, naval architecture and ocean engineering.

General Information

• Status: Replaced
• Publication Date: 27-Jun-2005
• ICS: 01.110 - Technical product documentation
• Technical Committee: TC 3 - Documentation, graphical symbols and representations of technical information
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 30-Jul-2009

Relations

• Replaced By: 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: 05-Sep-2023

Standards Content (Sample)

PUBLICLY
IEC
AVAILABLE
PAS 62400
SPECIFICATION
First edition
2005-06
Structuring principles for technical products
and technical product documentation –

Letter codes – Main classes and subclasses
of objects according to their purpose
and task
Reference number
IEC/PAS 62400:2005(E)
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PUBLICLY
IEC
AVAILABLE
PAS 62400
SPECIFICATION
First edition
2005-06
Structuring principles for technical products
and technical product documentation –

Letter codes – Main classes and subclasses
of objects according to their purpose
and task
 IEC 2005  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
XB
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – PAS 62400 © IEC:2005(E)
CONTENTS
FOREWORD.3

1 Scope .5

2 Normative references .5

3 Specification of letter codes .5

4 Letter codes for objects based on their purpose or task .6

4.1 Overview of main classes of objects with associated letter codes.6
4.2 Rules for generating subclasses .6
4.3 Definition of subclasses of objects .8
Annex A (informative) List of terms.26

Table 1 – Letter codes for objects in accordance with IEC 61346–2 (main classes) .6
Table 2 – General assignment of groups of letter codes for subclasses to application
areas.7
Table 3 – Definitions and letter codes of subclasses related to main classes.8
Table A.1 – List of terms for objects, alphabetically ordered by object.26
Table A.2 – List of terms for objects, alphabetically ordered by letter code .45

PAS 62400 © IEC:2005(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
STRUCTURING PRINCIPLES FOR TECHNICAL PRODUCTS AND

TECHNICAL PRODUCT DOCUMENTATION –

LETTER CODES – MAIN CLASSES AND SUBCLASSES OF OBJECTS

ACCORDING TO THEIR PURPOSE AND TASK

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
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
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A PAS is a technical specification not fulfilling the requirements for a standard but made
available to the public.
IEC-PAS 62400 has been processed by IEC technical committee 3: Information structures,
documentation and graphical symbols.
The text of this PAS is This PAS was approved
based on the following for publication by the
document: members of the
committee concerned as
indicated in the following
document:
Draft PAS Report on voting
3/746/NP 3/761/RVN
– 4 – PAS 62400 © IEC:2005(E)
Following publication of this PAS, the technical committee will investigate the possibility of

incorporating the contents of it into a part of IEC 61346, in the context of the maintenance of

this standard.
This PAS shall remain valid for an initial maximum period of three years starting from

2005-06. The validity may be extended for a single three-year period, following which it shall

be revised to become another type of normative document, or shall be withdrawn.

PAS 62400 © IEC:2005(E) – 5 –
STRUCTURING PRINCIPLES FOR TECHNICAL PRODUCTS AND

TECHNICAL PRODUCT DOCUMENTATION –

LETTER CODES – MAIN CLASSES AND SUBCLASSES OF OBJECTS

ACCORDING TO THEIR PURPOSE AND TASK

1 Scope
This PAS extends the letter codes of the main classes for purposes or tasks of objects in
accordance with IEC 61346-2, Table 1, with a second-letter code for subclasses. These
specifications are generally applicable. They apply equally for all disciplines, such as
construction, process and electrical engineering, and for standards, for example, for power
generation, power distribution, process engineering facilities, naval architecture and ocean
engineering. Additional letter codes may be specified for further subdivision of the classes.
Specification of letter codes for the main and subclasses for infrastructure objects in
accordance with IEC 61346-2, Table 2, are not part of this document.
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 61346-2, Industrial systems, installations and equipment and industrial products –
Structuring principles and reference designations – Part 2: Classification of objects and codes
for classes
ISO 3511-1, Process measurement, control functions and instrumentation – Symbolic
representation – Part 1: Basic requirements
ISO 14617-6:2002, Graphical symbols for diagrams – Part 6: Measurement and control
functions
3 Specification of letter codes
Letter codes are specified and are generally applicable for objects fulfilling the following
purposes or tasks.
- Control functions, functional allocation  = = Functional allocation
- Functional equipment unit, equipment unit = Function, system
- Product, components  – Product, component

– 6 – PAS 62400 © IEC:2005(E)
4 Letter codes for objects based on their purpose or task

4.1 Overview of main classes of objects with associated letter codes

Table 1 – Letter codes for objects in accordance with IEC 61346-2 (main classes)

Letter code Purpose or task of object

A Two or more purposes or tasks

B Conversion of an input variable (physical property, condition or event) to a specific signal for

further processing
C Storage of energy, information or material
D Reserved for future standardization
E Providing radiant or thermal energy
F Direct (self-acting) protection of an energy or signal flow, of personnel or facilities from
dangerous or unwanted conditions including systems and equipment for protective purposes
G Initiation of an energy or material flow; generation of signals which are used as an information
carrier or reference source
H Production of a new type of material or products
J Reserved for future standardization
K Processing (receipt, processing and providing) signals or information (with the exception of
objects for protection purposes; see class F)
L Reserved for future standardization
M Providing mechanical energy (rotational or linear mechanical motion) for driving purposes
N Reserved for future standardization
P Presentation of information
Q Controlled switching or variation of a flow of energy, signal or material (see classes K and S for
signals in closed/open feedback control loops)
R Restricting or stabilization of movement or flow of energy, information or material
S Conversion of a manual operation to a specific signal for further processing
T Conversion of energy while maintaining the kind of energy, conversion of an established signal
while maintaining the content of information, conversion of the form or shape of a material
U Keeping objects in a defined position
V Processing (handling) of material or products (including pre-treatment and post-treatment)
W Conducting or routing energy, signals, materials or products from one location to another

X Connecting objects
Y Reserved for future standardization
Z Reserved for future standardization

4.2 Rules for generating subclasses
The following rules have been observed for determining the letter codes for the subclasses
(2nd data character).
- The main classes as defined in Table 1 are subdivided into subclasses as shown in Table
2, with the exception of the main class with the letter code B.
- The letter codes for subclasses of the main class with the letter code B are specified
according to ISO 3511-1.
PAS 62400 © IEC:2005(E) – 7 –
Table 2 – General assignment of groups of letter codes for subclasses

to application areas
Letter code for subclasses Object, task based on

A
B
C Electrical energy
D
E
F
G
H Information or signals
J
K
L
M
N
P
Q
R Mechanical engineering
S Structural engineering
T (Non-electrical engineering)
U
V
W
X
Y
Z Combined tasks
– 8 – PAS 62400 © IEC:2005(E)
4.3 Definition of subclasses
...