IEC 63261:2024

IEC 63261 ®
Edition 1.0 2024-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Representation of electrical and instrument objects in digital 3D plant models
during engineering
Représentation des objets électriques et d'instrumentation dans des modèles
d'installation numérique 3D pendant la phase d'ingénierie

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IEC 63261 ®
Edition 1.0 2024-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Representation of electrical and instrument objects in digital 3D plant models

during engineering
Représentation des objets électriques et d'instrumentation dans des modèles

d'installation numérique 3D pendant la phase d'ingénierie

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40  ISBN 978-2-8322-8359-2

– 2 – IEC 63261:2024 © IEC 2024
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 7
4 Requirements for E&I objects . 7
4.1 Properties . 7
4.2 Detail of design . 8
5 Content and timeline of the 3D plant model during engineering. 8
5.1 Content of the 3D plant model . 8
5.2 Timeline of the 3D plant model . 10
6 Model output . 10
7 Conformity . 11
Bibliography . 12

Table 1 – Content of 3D plant model . 8
Table 2 – Model output drawings . 10
Table 3 – Model output reports . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
REPRESENTATION OF ELECTRICAL AND INSTRUMENT OBJECTS
IN DIGITAL 3D PLANT MODELS DURING ENGINEERING

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,
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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
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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
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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
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
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the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 63261 has been prepared by subcommittee SC 65E Devices and integration in enterprise
systems, of IEC technical committee 65: Industrial-process measurement, control and
automation. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
65E/1083/FDIS 65E/1137/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

– 4 – IEC 63261:2024 © IEC 2024
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
INTRODUCTION
Engineering and construction in the process industries typically involve the cooperation of
multiple companies. Due to economic reasons, special knowledge, special license,
authorization or simply capacity utilization, the work is divided between partners. They will
arrange their cooperation for each individual project differently. This implies well defined
division of work and responsibilities across the different phases of project execution.
Efficient engineering of a digital 3D plant model is inextricably linked to highly sophisticated
tools for the different needs of the involved work processes and departments. By nature of the
plant model, all engineering disciplines meet in the model and imply clear definitions of the
content and interfaces.
Digital 3D plant models play an important part in electrical and instrumentation engineering to
create technical drawings and avoid clashes between the elements provided by different
engineering disciplines.
The first aim of this document is to define the level of details of electrical and instrumentation
equipment representations placed in the 3D plant model. It specifies minimum requirements at
the different maturity grades of the model for each equipment, its related metadata and reports
retrieved from the 3D plant model.
The second aim of this document is to define a timeline and project milestones with the
associated level of detail for the incorporation of electrical and instrumentation equipment into
the 3D plant model.
This document aims at avoiding misunderstandings and erroneous design work in order to
reduce additional corrective works and expenses for clarification.

– 6 – IEC 63261:2024 © IEC 2024
REPRESENTATION OF ELECTRICAL AND INSTRUMENT OBJECTS
IN DIGITAL 3D PLANT MODELS DURING ENGINEERING

1 Scope
This International Standard provides requirements for the E&I objects of a digital 3D plant
model, used in the engineering phase to design and construct a process plant and its
instrumentation. It provides guidance how to model plants and their electrical and
instrumentation equipment.
This document also specifies the content and the possible output of the 3D plant model at
project milestones.
This document can be used by the contractual partners to agree upon the content of the 3D
plant model to be delivered at specified milestones.
This document does not specify the transfer and format of digital 3D plant models.
This document does not specify definitions or instructions to equipment representations and
details of elements in the 3D plant model not belonging to electrical and instrumentation
domains.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1.1
plant
complete set of technical equipment and facilities for solving a defined technical task
Note 1 to entry: A plant includes apparatus, machines, instruments, devices, means of transportation, control
equipment and other operating equipment.
Note 2 to entry: This entry was numbered IEV 351-42-35 in IEC 60050-351:2013.
3.1.2
digital 3D plant model
representation that defines, characterizes and relates electrical and instrumentation equipment,
piping, structural elements as well as their building containment in a three-dimensional space

3.1.3
E&I object
electrical and instrumentation object
physical components, devices, or equipment used in the electrical and instrumentation systems
of process plants
Note 1 to entry: For details about E&I objects, see Table 1.
3.1.4
functional location
identifier that references technical objects of a plant according to functional, process-related or
spatial criteria
3.1.5
room number
number that identifies a physical or virtual space in a plant, normally with reference to the
building grid and level
3.1.6
30 % model review
design review of the 3D plant model with 30 % progress, including equipment arrangement, E&I
rooms and preliminary information of E&I objects with reservation of space
Note 1 to entry: Major plant buildings, structures, equipment outlines, pipe bridges are modelled. Major large bore
piping systems are planned.
3.1.7
60 % model review
design review of the 3D plant model with 60 % progress
3.1.8
90 % model review
design review of the 3D plant model with 90 % progress
Note 1 to entry: All equipment, piping, valves, electrical, structural items are modelled, before design freeze of
small-bore piping system.
3.2 Abbreviated terms
FAS Fire alarm system
E&I Electrical & instrumentation
HVAC Heating, Ventilation, Air conditioning
MTO Material take-off
P&ID Piping and instrumentation diagram
4 Requirements for E&I objects
4.1 Properties
The properties of the E&I objects shall at least include
• a unique designation as an identifier, related to functional location or to project
designation structure;
• the class or type of the E&I object;
• the process connection properties of the E&I object (nominal diameter; nominal
pressure) if applicable;
• the electrical, signal and pneumatic connection properties if applicable.

– 8 – IEC 63261:2024 © IEC 2024
4.2 Detail of design
The type of the objects in the 3D plant model shall be visually recognizable. The dimensions of
the objects shall reflect the technical specification sheets of these objects.
The representation of E&I objects in the 3D plant model shall include necessary interference
volumes for regular operation and maintenance aspects.
5 Content and timeline of the 3D plant model during engineering
5.1 Content of the 3D plant model
Table 1 shows which E&I objects the 3D plant model shall contain, should contain, should not
contain or may contain.
Table 1 provides the minimum requirements and can possibly be extended.
Table 1 – Content of 3D plant model
E&I-Object Description Requirement,
recommendation
or permission
Instruments / Valves
Automated valves All control devices (installed in the piping) within the P&ID with their shall
maximum geometric dimension of their drives and description of the
mounting
In-line instruments All in-line devices within the P&ID (installed in piping) with their shall
maximum geometric dimension according to the installation drawing
Inlet and outlet Special inlet and outlet sections should
sections
Flange-mounted All flange-mounted devices within the P&ID with their maximum shall
instruments geometric dimension. The room for installation and removal shall be
considered.
Surface-mounted Clamp-on measurement devices shall
instruments
Externally- Process control devices with tubing measurement lines: At least one shall
mounted measurement connection including the tubing adapter shall be modelled
instruments
E&I-Object Description Requirement,
recommendation
or permission
Electrical / Cable trays
Transformers Transformers shall
Motors Electrical drive for motors with equipment shall
Cable trays and All horizontal and vertical cable routes (equal and larger than 200 mm shall
ladders width)
Cable trays smaller than 200 mm width may
Mesh cable trays are usually not depicted should not
Cable routing Configuration of the cable routes and cable run. All cables at a given should
cross section
Major electrical
supports
Cable tray Major electrical supports for cable routes shall be planned in the model. shall
supports
Cable ducts Mounting for cable trays only as required should
Trenches / Planned wall openings for cable trays or cable entries shall be depicted shall
culverts and
underground
conduits
Electrical Panels / All trenches and underground conduits should
Cabinets
Electrical panels
Cabinets Cabinets, local control boards (LCB) and control rooms in the field shall
Process analyzer Cabinets in the switch room (required for cable routing and collision shall
cabinets and avoidance with HVAC and FSA)
containers
Remote-IOs Analyzer cabinets, analyzer container; including room air measurement shall
Junction boxes Remote IOs shall

Electrical junction box shall
Grounding boxes Field bus and transition junction box should
Installation Grounding box and central grounding point should
Local control station
Power sockets Local control station including mounting should
Instrument air Power sockets and welding receptacles shall
distribution
Air distributors (minimum placeholder) should
Electrical heat
Air distributors in case it is connected to piping shall
tracing
Identification of electrical heat tracing by its thermal insulation shall
Lighting Reference measurement and distribution for electrical trace heating. should
Electrical trace heating shall only be depicted by its thermal insulation
Emergency Lighting row, lighting fixtures should
lighting
Communication Emergency lights should
systems
Fire alarm system
Public address Fire detectors and alarm annunciators (horn, lights) may
system
Video systems Speaker, intercom stations may
WLAN access Cameras may
points
Others Network components may

– 10 – IEC 63261:2024 © IEC 2024
E&I-Object Description Requirement,
recommendation
or permission
Hazardous areas
Depiction of explosion hazard zones may

5.2 Timeline of the 3D plant model
The degree of detail design in the 3D plant model shall be specified at project milestones like
30 % model review, 60 % model review, 90 % model review or equivalent project related
milestones.
6 Model output
All documents and models shall be delivered in a format that can be digitally interpreted and
ensures that all properties of E&I objects (Table 1) are contained.
The 3D digital plant model shall be capable to generate the output drawing. The contractual
partners of the 3D plant model agree upon the deliverables.
All drawings shall include the naming and dimensions of the E&I objects as specified in Table 2.
Table 2 is a guideline for model output and can be extended.
Table 2 – Model output drawings
Document type Requirement, Remarks
recommendation
or permission
Cable tray layout drawing shall Plan view
Cable tray routing plan should Isometric perspective drawing of cable
tray routes
Cable tray isometric drawing may Isometric perspective drawing of single
cable tray with dimensions and material
details
Location drawings for cabinets, panels, boxes shall
Location drawings for power sockets shall
Location plan of electrical consumers should Equipment with motors are included in
arrangement drawings.
Instrument locations plan may
Arrangement drawings of E&I rooms may
Lighting plans may
Instrument air distribution plans may
Location drawings for communication systems may

Table 3 specifies which reports are part of the model documentation.

Table 3 – Model output reports
Reports Requirement Remarks
recommendation
or permission
Cable tray MTO report shall On basis of E&I data base catalogue.
Location reports for cabinets, panels, boxes shall List with coordinates or room numbers.
Location report of electrical consumers shall List with coordinates or room numbers.
Instrument locations report shall List with coordinates or room numbers.
Cable schedule with route list shall If auto cable routing is used.
Cable tray cross section table should Table for ducts, trenches and conduits.

All coordinate lists or room numberings shall refer to an aligned building reference point.
7 Conformity
The author of a 3D model may declare that this 3D model conforms to this document if it fulfils
all mandatory requirements listed in Clause 4, 5.1 and Clause 6.
A contract between parties that includes provision for a 3D model should include project
milestones and deliverables according to 5.2.

– 12 – IEC 63261:2024 © IEC 2024
Bibliography
IEC 60050-351:2013, International electrotechnical vocabulary – Part 351: Control technology
IEC 61082-1, Preparation of documents used in electrotechnology – Part 1: Rules
IEC 61355-1, Classification and designation of documents for plants, systems a
...