IEC 81346-2:2019

IEC 81346-2
Edition 2.0 2019-06
INTERNATIONAL
STANDARD
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HORIZONTAL STANDARD
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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

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

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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

– 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

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
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
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6) All users should ensure that they have the latest edition of this publication.
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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.
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:
– 4 – IEC 81346-2:2019 © IEC 2019
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.
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.
– 6 – IEC 81346-2:2019 © IEC 2019
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.

[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.

– 8 – IEC 81346-2:2019 © IEC 2019
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:
• 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.

– 10 – IEC 81346-2:2019 © IEC 2019
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 composition structure, i.e. they do not describe a subdivision of
the object. Class and subclass refer to the same object.
Annex B illustrates how the classes in Table 1 relate to a generic process.
5.3 Complete classification scheme
Table 2 shows the first two levels of the classification scheme for inherent function of object,
while Table 3 shows all the three levels defined.
Numerals below class code in Table 2 and Table 3 show the level in the classification
structure, that is, level 1, 2 and 3 mean entry class, sub-class and sub-sub class respectively,
see Annex A.
Table 2 – First two levels of the classification scheme for inherent function of objects
Class code Criteria for
Class name
Class definition Examples of terms definition of
(preferred term)
1 2
subclasses
B object for picking up information and sensing object Kind of quantity
providing a representation
BA sensing object for electric potential electric potential sensing object coupling capacitor, measuring voltage relay, measuring Kind of output
voltage transformer, voltage relay, voltage transformer signal
electric resistivity detector, electric resistivity sensor, Kind of flow and
BB sensing object for resistivity or conductivity resistivity sensing object
thermal resistivity detector, thermal resistivity detector output signal
BC sensing object for electric current electric current sensing object electronic overload relay, measuring current relay, Kind of output
measuring current transformer, overload relay signal
BD sensing object for density density sensing object aerometer, density sensor, density switch, density Kind of output
transformer, hydrometer signal
BE sensing object for field field sensing object electric field detector, electric field sensor, magnetic field Kind of output
detector, magnetic field sensor, reed relay, reed switch signal
BF sensing object for flow flow sensing object flow sensor, flow switch, flow transmitter, gas flow sensor, Kind of output
gas flow switch, liquid flow sensor, matter flow sensor, signal
matter flow switch, water flow sensor
BG sensing object of spatial dimension and/or physical dimension sensing 2D-scanner, 3D-scanner, alignment sensor, alignment Kind being sensed
position object threshold detector, angle switch, angle transmitter, and kind of output
coordinates scanner, distance switch, distance signal
transmitter, end stop, laser distance sensing switch, laser
distance sensor, laser scanner, movement detector,
movement sensor (PIR), object scanner, position sensor,
position switch, position transmitter, presence indicator,
presence locator, radar, rotary encode, visibility sensor,
wind direction indicator, wind direction sensor
BH sensing object for energy energy sensing object condensate sensor, electric energy meter, energy cooling Kind of energy
meter, energy meter, energy sensor, flow energy meter,
gas energy meter, kWh sensor, thermal energy meter
BJ sensing object for power power sensing object kW meter, power limit switch, power meter Kind of output
signal
BK sensing object for time time sensing object Clock, time counter, time information device, time sensor, Kind of output
timer switch signal
BL sensing object for level level sensing object level sensor, level switch, level transmitter, liquid level Kind of output
sensor, liquid level switch signal

– 12 – IEC 81346-2:2019 © IEC 2019

Class code Criteria for
Class name
Class definition Examples of terms definition of
(preferred term)
1 2
subclasses
BM sensing object for humidity humidity sensing object humidity sensor, humidity switch, humidity transmitter Kind of output
signal
BP sensing object for pressure pressure sensing object absolute pressure sensor, absolute pressure switch, Kind of output
absolute pressure transmitter, differential pressure signal
sensor, differential pressure switch, differential pressure
transmitter, manometer, pressure monitor, pressure
sensor, pressure switch, pressure transducer, relative
pressure detector, relative pressure sensor, relative
pressure switch
BQ sensing object for substance concentration concentration sensing object CO concentration sensor, CO concentration sensor, Kind of object and
concentration sensor, concentration detection switch, fog kind of output
detector, fog sensor, gas detector, gas sensor, liquid signal
detector, liquid sensor, NH concentration sensor, petrol
concentration sensor, smoke detector, smoke sensor,
smoke switch, solid matter detector, solid matter sensor,
turbidity detector, turbidity sensor, visibility detector,
visibility sensor
BR sensing object for radiation radiation sensing object electromagnetic wave detector, electromagnetic wave Kind of radiation
sensor, Geiger meter, gamma-radiation detector, IR- and kind of output
sensor, light curtain, light detector, light sensor, light signal
transmitter, line detector, low-light relays, lux sensor,
photocell, radar-sensor, radiation counter, radiation
detector, UV-sensor
BS sensing object for time-rate time-rating object accelerometer relay, accelerometer transmitter, cycle rate Kind of time object
detecting switch, cycle rate sensor, cycle rate transmitter, sensed and kind of
frequency transmitter, movement detector, movement output signal
transmitter, rotation speed relay, rotation speed sensor,
seismic sensor, seismic switch, shake switch, speed
detecting switch, speed sensing transmitter, speed
sensor, tachometer
BT sensing object for temperature temperature sensing object temperature detector, temperature sensor, temperature Kind of output
switch, temperature transmitter signal
BU sensing object for multiple quantities multi-quantity sensing object Buchholz relay, distance protection relay, impedance Kind of output
protection relay, multi-detector, multi- sensor, multi- signal
sensor switch, negative phase-sequence relay
BW sensing object for weight, force or torque force sensing object force detecting switch, force sensor, force value Kind of object
transmitter, load cell, torque sensor, torque switch, torque sensed and kind of
value transmitter, weight detecting switch, weight sensor, output signal
weight transmitter
Class code Criteria for
Class name
Class definition Examples of terms definition of
(preferred term)
1 2
subclasses
BX sensing object of sound and/or visual audio-visual sensing object alarm microphone, acoustic detector, acoustic sensor, Kind of output
appearance acoustic survey device, camera, CCTV, face recognition signal
device, finger-print reader, glass breakage detector,
image sensor, image detector, iris reader, microphone,
profile control, PTZ camera, scanner, video camera
BY sensing object of stored information information sensing object barcode reader, chip card reader, chip reader, Kind of method
electromagnetic reader, magnetic stripe reader, optical
disk reader, optical reader, RFC reader, RFID reader, QR-
reader, tape reader
BZ sensing object for incidents or amounts incident sensing object counter, matter detector, person detector, presence Kind of incidents or
detector, threshold counter amounts sensed
C object for storing for subsequent retrieval storing object Kind of object being
stored and the
method applied
CA storing object for electric energy within an capacitive storing object capacitor Kind of method
electrostatic field applied
CB storing object for electric energy within an inductive storing object inductor Kind of method
electromagnetic field applied
CC storing object for electric energy within an electrochemical storing object rechargeable battery Kind of method
electrochemical substance applied
CF storing object for information information storing object information storing media, seat Kind of method
applied
CL storing object for matters or persons within open stationary storing object bed, bunker, chair, cistern, couch, pit, pool, shelf Kind of method
a stationary open enclosure applied
CM storing object for matters within a enclosed stationary storing box, cabinet, cupboard, tank Kind of matters
stationary closed enclosure object stored
CN storing object for matters or persons within moveable storing object container, drum, elevator bucket, excavator bucket, gas Kind of matters
a moveable closed enclosure cylinder, lift car stored
CP storing object of thermal energy thermal energy storing object calorifier, crystalline tank, gas tank, liquid tank, matter Kind of thermal
tank energy
CQ storing object of mechanical energy mechanical energy storing counterweight, elevated mass, flywheel, rubber band, Kind of mechanical
object spring energy
– 14 – IEC 81346-2:2019 © IEC 2019

Class code Criteria for
Class name
Class definition Examples of terms definition of
(preferred term)
1 2
subclasses
E object for emitting emitting object Kind of object being
emitted and kind of
energy source
EA emitting object of light light object argon lamp, electro luminescent devices, electric lamp, Kind of energy
fluorescent lamp, fluorescent tube, gas lamp, lamp, lamp
source
bulb, laser, liquid lamp, neon lamp, paraffin lamp
EB emitting object of heat provided by electric electric heating object arc heating object, electric arc furnace, electric boiler, Kind of delivery
electric heating surface, electric hot air blower, electric
energy method
oven, frying plate, heating cable, heat mat, induction
heater, induction oven, infrared heater, sauna
EC emitting object of coldness provided by electric cooling object compression chiller, electric cold air blower, electric Kind of method
electric energy cooling surface
EE emitting object of wireless power wireless power object capacitive coupler, gamma ray source, inductive power Kind of method
antenna, magnetron, maser, microwave oven, X-ray
source
EG emitting object of heat and coldness thermal energy transfer object freezer, fridge, heat exchanger, heat pump, Peltier Kind of method
provided by transfer of thermal energy element, refrigerated container, refrigerator, reversible
heat pump
EM emitting object of heat provided by combustion heating object burner, combustion boiler, stove Kind of object
combustion heated
EP emitting object of heat provided by thermal thermal heating object condenser, heating coil, heating panel, heating pipe, Kind of method
energy heating surface, heating tube, hot air blower, radiator
emitting object of coldness provided by chiller, condenser, cooler, cooling coil, cooling panel,
EQ thermal cooling object Kind of method
thermal energy cooling pipe, cooling surface, cooling tower, cooling tube,
evaporator
ET emitting object of heat provided by nuclear nuclear powered heating object boiling water reactor, high-temperature gas-cooled Kind of output
fission reactor, pebble bed reactor, pressurized water reactor
EU emitting object of sub-atomic particles particle emitting object alpha-ray device, beta-ray device, neutron-ray device, Kind of method
particle generator, plasma generator
EV emitting object of acoustic waves acoustic wave emitting object anti-noise loudspeaker, sonar Kind of method
F object for protecting against the effects of protecting object Kind of source
dangerous or undesirable conditions
FA protecting object related to overvoltages overvoltage protecting object limiter, spark gap surge arrester, surge absorber, varistor Kind of method
surge arrester, zener diode applied

Class code Criteria for
Class name
Class definition Examples of terms definition of
(preferred term)
1 2
subclasses
FB protecting object related to earth fault earth fault current protecting appliance leakage current interrupter (ALCI), earth fault Kind of method
currents object leakage breaker, earth-leakage circuit-breaker (ELCB), applied
ground fault circuit interrupter (GFCI), ground fault
interrupter (GFI), neutral earthing impedance, neutral
earthing limiter, neutral earthing reactor, Petersen coil,
residual current circuit breaker (RCCB), residual current
device
FC protecting object related to overcurrents overcurrent protecting object bimetal, bimetal circuit, fuse, miniature circuit-breaker, Kind of method
overload thermal release, thermal overload relay applied
FE protecting object related to electric and/or field protecting object concrete wall, electric field shield, electromagnetic field Kind of method
magnetic fields shield, Faraday cage, lead block, metal sheets, magnetic applied
field shield, Mu-metal shielding
FL protecting object related to pressure pressure protecting object expansion tank, expansion vessel, rupture disc, safety Kind of pressure
damper, safety valve, vacuum breaker
FM protecting object related to fire fire protecting object fire and flue damper, fire blind, fire damper, fire Kind of method
extinguisher, flue damper, fire impregnation, fire applied and cause
insulation, fire protecting coating, fire retardant coating, for activation
smoke closure, smoke curtain
FN protecting object related to mechanical mechanical force protecting cable protection, impact protection, safety clutch Kind of method
force object applied
FQ protecting object by barrier or obstacle preventive protecting object break protection, glare protection, glide protection, guard Kind of purpose of
rail, handrail, lock hatch cover, protective fabric, the prevention
protective grid, protective mesh, protective rail, protective
rod, protective roof, snow guard, splatter protection,
suspension guard
FR protecting object related to material erosion wear protecting object lubrication object, lubricating oil, wear pad Kind of method
applied
FS protecting object related to the local environment protecting object avalanche shed, cathodic protection, corrosion protection, Kind of method
environment cement, house, impregnation, impregnation sheet, applied
material separating layer, paint, mortar, plaster, protective
seal, seismic vibration control device, sacrificial anode,
shed, shelter, snow guard
G object for providing a controllable flow generating object Kind of object
flowing and kind of
source
GA generating object of electric energy mechanical to electrical energy AC generator, DC generator, dynamo, generator Kind of voltage and
powered by mechanical energy generating object current form

– 16 – IEC 81346-2:2019 © IEC 2019

Class code Criteria for
Class name
Class definition Examples of terms definition of
(preferred term)
1 2
subclasses
GB generatin
...