IEC PAS 62400:2005

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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.
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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch 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
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,
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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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.
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 of objects

Table 3 – Definitions and letter codes of subclasses related to main classes

Purpose or task of object:
a
A
two or more purposes or tasks
Class and
Task related to subclass Examples of components

subclass
AA
AB
Free for the subdivision of objects, tasks obtained

AC
on electrical energy
AD
AE
AF
AG
Free for the subdivision of objects, tasks obtained
AH
on information or signals
AJ
AK
AL
AM
AN
AP
AQ
AR
Free for the subdivision of objects, tasks obtained
on mechanical engineering, structural engineering
AS
(non-electrical engineering)
AT
AU
AV
AW
AX
AY
AZ Combined tasks
a
This class is only for objects for which no main purpose or no main task can be identified.

PAS 62400 © IEC:2005(E) – 9 –
Table 3 (continued) B
Purpose or task of object:
b
conversion of an input variable (physical property, condition or event) to a specific
B
signal for further processing.

Class and
Task related to subclass Examples of components

subclass
BA Reserved for future standardization

BB Conversion of input variables for protection Protection relay, overload relay

purposes (thermal), Buchholtz relay

BC Reserved for future standardization
BD Density
BE Electrical units Current transformer, measuring relay,
voltage transformer, measuring
transformer, measuring resistance
(shunt)
BF Flow, throughput Measuring orifice, pressure difference
transducer, flow meter, gas meter, water
meter
BG Distance, length, position, elongation, amplitude (Radar), motion sensor, position switch,
proximity switch, proximity sensor
BH Reserved for future standardization
BJ Output
BK Time Clock, time counter
BL Height, level Sonic depth finder, (sonar), sight glass
BM Moisture content Humidity meter
BN Open
BP Pressure, vacuum Pressure sensor, pressure gauge
BQ Material property, quality parameter, analysis X-ray device
(except D, M, V), pH, SO content
BR Radiation values, neutron flux measurement Photocell, flame detector, smoke
detector
BS Velocity, speed of rotation, frequency, vibration, Vibration pick-up, speedometer,
oscillation tachometer
BT Temperature Temperature sensor, thermometer
BU Combined units, multiple variables
c
BV Viscosity
BW Weight force, mass
BX Other units Video camera, microphone
BY Reserved for future standardization
BZ Number of events, amount Switching cycle detector, (radar device)
b
The letter codes in accordance with ISO 14617-6:2002, 7.3.1, were used for the subclasses. In
accordance with the specifications of ISO 14617-6, subclass Z in the main class B is not available for "combined
tasks".
c
In accordance with ISO 14617-6:2002, 7.3.1, the letter code "V" is "released for use". No letter code is
specified in this standard for measurements/measuring equipment for "viscosity". As it is necessary to designate
measurements/measuring equipment for viscosity, the letter "V" is assigned to viscosity here for the letter B.

– 10 – PAS 62400 © IEC:2005(E)

Table 3 (continued) C
Purpose or task of object:
C
storage of energy, information or material

Class and
Task related to subclass Examples of components
subclass
CA Capacitive storage of electric energy Capacitor

CB Inductive storage of electric energy Superconductor, coil

CC Chemical storage of electric energy Buffer battery, battery

CD
CE
CF Storage of information RAM, EPROM, CD-ROM, event recorder,
hard disc, magnetic tape recorder,
voltage recorder
CG
CH
CJ
CK
CL Storage, collection and housing of materials (fixed Pits, pools, bunkers, cisterns
location, open)
CM Storage, collection and housing of materials (fixed Containers, tanks, boilers, silos, gas
location, closed) holders, accumulators, buffers, flash
tanks
CN Storage, collection and housing of materials Containers, shipping containers, gas
(mobile) cylinder, drum
CP Storage of thermal energy (heat and cold energy, Ice tank, hybrid heat storage,
direct) underground thermal energy storage,
thermal energy storage, hot water
storage, steam storage
CQ Storage of mechanical energy Flywheel
CR
CS
CT
CU
CV
CW
CX
CY
CZ Combined tasks
NOTE Storage batteries are assigned to main group "G".

PAS 62400 © IEC:2005(E) – 11 –

Table 3 (continued) E
Purpose or task of object:
E
providing radiant or thermal energy

Class and
Task related to subclass Examples of components
subclass
EA Generation of electromagnetic radiation for Incandescent lamp, fluorescent tubes,

lighting purposes using electrical energy UV radiators

EB Generation of thermal energy (heat) by conversion Heating wire, heating rod, electrical

of electrical energy heating, electrical boiler, electrode steam

boiler, electric furnace, infrared heating
element, electric radiator
EC Generation of thermal energy (cold) by conversion Cooling unit, freezing unit, refrigerator,
of electrical energy freezer, compression chiller, turbine-
driven chiller
ED
EE
EF Generation of other electromagnetic radiation
EG
EH
EJ
EK
EL Generation of electromagnetic radiation for Gas light, gas lamp
lighting purposes by combustion of fossil fuels
EM Generation of thermal energy by conversion of Boiler, burner, furnace, combustion grate
chemical energy
EN Generation of cold energy by conversion of Refrigerator, cold pump
chemical energy
EP Generation of heat energy by energy transfer Condenser, heat exchanger, evaporator,
economizer, feed-water heater, steam
generator, heat-recovery steam
generator, radiator, boiler
EQ Generation of cold energy by energy transfer Refrigerator, freezer, cold pump
ER Generation of heat by conversion of mechanical
energy
ES Generation of cold by conversion of mechanical Mechanical refrigerator
energy
ET Generation of thermal energy by nuclear fission Nuclear reactor

EU Generation of particle radiation Neutron generator
EV
EW Heater, radiator, boiler, heating stove
EX
EY
EZ Combined tasks
– 12 – PAS 62400 © IEC:2005(E)

Table 3 (continued) F
Purpose or task of object:
direct (self-acting) protection of an energy or signal flow, of personnel or facilities from
F
dangerous or unwanted conditions, including systems and equipment for protective
purposes
Class and
Task related to subclass Examples of components
subclass
FA Free for subdivision of objects, tasks based on Fuse, arrester, Faraday cage, miniature
electrical energy circuit-breaker, surge arrester, thermal

FB
overload trip
FC
FD
FE
FF Free for subdivision of objects, tasks based on
information and signals
FG
FH
FJ
FK
FL Protection of mechanical and building objects Rupture disc, safety valve, also automatic
from hazardous pressure conditions directly loaded air inlet and vent valve),
automatic drains trap, vacuum breaker
FM Protection of mechanical and building objects Fire protection facilities (risk detection
from effects of fire and initiation of protective measures),
fire damper, fire protection door, locks
FN Protection of mechanical and building objects Protective shield, protection device,
from hazardous operating conditions or damage protective sleeve for thermocouple,
safety clutch, impact protection
FP Protection of the environment from emissions (for Reactor protection equipment
example, radiation, chemical emissions, noise)
FQ Protection of persons/animals Railings, barriers, gates, fence, contact
protection, vision protection, glare
protection, escape door, escape window,
airbag, safety belt
FR Protection of mechanical and building objects Protective anode (cathodic),
from wear (for example, corrosion)
FS Protection against environmental effects (for Weather, avalanche protection,
example, weather, geophysical effects) geophysical protection
FT
FU
FV
FW
FX
FY
FZ Combined tasks
PAS 62400 © IEC:2005(E) – 13 –

Table 3 (continued) G
Purpose or task of object:
d
initiation of an energy or material flow; generation of signals which are used as
G
information carrier or reference source

Class and
Task related to subclass Examples of components

subclass
GA Initiation of an electrical energy flow by use of Generator, dynamo, motor-generator set

mechanical energy
GB Initiation of an electrical energy flow by chemical Fuel cell, battery, dry cell battery

conversion
GC Initiation of an electrical energy flow using light Solar cell
GD
GE
GF Generation of signals as an information carrier Signal generator, transducer
GG
GH
GJ
GK
GL Initiation of a flow (conveyance) of solid materials Belt, chain conveyor, distributor
(continuous)
GM Initiation of a flow (conveyance) of solid materials Crane, elevators, lifting gear,
(discontinuous) manipulator, lifting device
GN Initiation of a flow (conveyance) of solid materials Forklift, mobile crane, truck, train
(mobile)
GP Initiation of a flow (conveyance) of liquid and Pump, screw conveyor
flowable substances (continuous)
GQ Initiation of a flow (conveyance) and compression Blower (ventilator, fan), compressor,
of gaseous substances (continuous) vacuum pump, aspirator
GR Initiation of a flow (conveyance) of gaseous Tank car
substances (mobile)
GS Initiation of a flow (conveyance) of liquid and Ejector, injector, jet
gaseous materials (driven by driving medium)
GT
GU
GV
GW
GX
GY
GZ Combined tasks
d
The motor- generator set is also assigned to subgroup GA.

– 14 – PAS 62400 © IEC:2005(E)

Table 3 (continued) H
Purpose or task of object:
H
production of a new type of material or products

Class and
Task related to subclass Examples of components
subclass
HA
HB
HC
HD
HE
HF
HG
HH
HJ
HK
HL Separation of mixtures of substances by Screen, rake, grate
classification
HM Separation of mixtures of substances by Cyclone device, centrifuge
centrifugal force
HN Separation of mixtures of substances by gravity Settling tank, dewatering
HP Separation of mixtures of substances by thermal Distillation column, extraction system,
processes dewatering, drying (Munters air dryer)
HQ Separation of mixtures of substances by filtering Fluid filter, gas filter
HR Separation of mixtures of substances by Magnetic separator, electrostatic
electrostatic or magnetic forces precipitator
HS Separation of mixtures of substances by physical Absorption washer, active charcoal
processes adsorber, ion exchanger wet scrubber
HT Generation of new gaseous substances Gasifier
HU Crushing to generate a new form of solid Mill, crusher
materials
HV Coarsening to generate a new form of solid Briquette maker, pellet maker, tablet
materials maker, sintering facility
HW Mixing to generate new solid, liquid, flowable and Mixer, mixing vessel, kneader, static
gaseous substances mixer, emulsifier, stirrer, (steam)
humidifier
HX Generation of new substances by chemical Reactor, reaction furnace
reaction
HY Generation of new substances by biological Fermenter, composter
reaction
HZ Combined tasks
PAS 62400 © IEC:2005(E) – 15 –

Table 3 (continued) K
Purpose or task of object:
processing (receipt, processing and providing) signals or information (excluding
K
objects for protection purposes, see class F)

Class and
Task related to subclass Examples of components

subclass
KA
KB
KC
KD
KE
KF Generation of electrical and electronic signals Relay, transistor, binary elements, delay
systems, controller, input/output module,
receiver, transmitter, optocoupler
KG Processing of optical and acoustical signals Mirror, controller, test unit
KH Processing of fluid and pneumatic signals Valve assembly, pilot valve, controller
(valve position controller)
KJ Processing of mechanical signals Linkages, controller
KK Processing of various input/output information Electro-hydraulic converter, controller,
carriers (for example, electrical/pneumatic) electric pilot valve
KL
KM
KN
KP
KQ
KR
KS
KT
KU
KV
W
KX
KY
KZ Combined tasks
– 16 – PAS 62400 © IEC:2005(E)

Table 3 (continued) M
Purpose or task of object:
providing mechanical energy (rotational or linear mechanical motion) for driving
M
purposes
Class and
Task related to subclass Examples of components

subclass
MA Driving by electric motor Electric motor, linear motor

MB Electromagnetic driving Magnetic drive

MC
MD
ME
MF
MG
MH
MJ
MK
ML Mechanical driving Weight, spring force, actuator
(mechanical), stored-energy spring
actuator, friction wheel drive
MM Fluid and pneumatic driving Actuator, servomotor (fluid drive, fluid
motor, fluid cylinder, hydraulic cylinder)
MN Driving by steam flow Steam turbine
MP Driving by gas flow Gas turbine
MQ Driving by wind force Wind turbine
MR Driving by fluid flow Hydraulic turbine
MS Driving by chemical conversion Combustion motor
MT Driving and control of ships by conversion of Propeller system, jet system (jet vane),
driven machine output paddle-wheel system
MU
MV
MW
MX
MY
MZ Combined tasks
PAS 62400 © IEC:2005(E) – 17 –

Table 3 (continued) P
Purpose or task of object:
P
presentation of information
Class and
Task related to subclass Examples of components
subclass
PA
PB
PC
PD
PE
PF Presentation of information (permanent) Printer, recorder, plotter
PG Presentation of information (non-permanent) Detector, monitor, voltmeter, alarm lamp
PH
PJ
PK
PL
PM
PN
PP
PQ
PR
PS
PT
PU
PV
PW
PX
PY
PZ Combined tasks
– 18 – PAS 62400 © IEC:2005(E)

Table 3 (continued) Q
Purpose or task of object:
controlled switching or variation of a flow of energy, signal or material
Q
(see classes K and S for signals in closed/open feedback control loops)

Class and
Task related to subclass Examples of components

subclass
QA Switching and variation of electrical energy Circuit-breaker, contactor, thyristor,

circuits motor starter
QB Isolation of electrical energy circuits Isolating switch, load-break switch

QC Earthing (grounding) of electrical energy circuits Earthing (grounding) switch
QD By-passing of electrical energy circuits By-pass circuit-breaker
QE
QF
QG
QH
QJ
QK
QL Braking in mechanical power transmission Brakes
systems
QM Limiting of flow in closed enclosures for variable Shut-off valves (also drain valves),
flows of gaseous, liquid and flowable substances blanking plate, blank, dampers
QN Setting and control of flow in closed enclosures Control valve, gas control path, control
for variable flows of gaseous, liquid or flowable dampers
substances
QP Limiting of flow in open enclosures for liquid Lock gate, weirs, dam plates
substances
QQ Opening, closing of inlets or access (persons, Door, gate, window, cover, turnstile, bar
material, light, air) to bounded areas (lock)
QR Shutoff open/closed of flows of liquid and flowable Isolation device, rotary locks for
substances (no valves) open/closed
QS
QT
QU
QV
QW
QX
QY
QZ Combined tasks
PAS 62400 © IEC:2005(E) – 19 –

Table 3 (continued) R
Purpose or task of object:
R
restricting or stabilization of movement or flow of energy, information or material

Class and
Task related to subclass Examples of components
subclass
RA Limiting flow of electrical energy Resistance, reactance coil, diode

RB
RC
RD
RE
RF Stabilization of signals Low-pass, equalizer, filter
RG
RH
RJ
RK
RL Prevention of unauthorized operation and/or Blocking device, stop, latch, lock
movements (mechanical)
RM Prevention of return flow of gaseous, liquid and Check valve
flowable substances
RN Limiting flow of liquid and gaseous substances Venturi nozzle, flow restrictor
RP Shielding and insulation of noise Noise protection, sound absorber
RQ Shielding and insulation of heat or cold Thermal insulation louver damper,
insulation, jacket, lagging, lining
RR Shielding and insulation of mechanical effects Brick lining, compensator, vibration
absorption,
RS Shielding and insulation of chemical effects Brick lining, explosion protection, gas
penetration protection, splash protection
RT Shielding and insulation of light Shutter, blind, screen
RU Limiting and stabilizing movement in areas/in site Fence
RV
RW
RX
RY
RZ Combined tasks
– 20 – PAS 62400 © IEC:2005(E)

Table 3 (continued) S
Purpose or task of object:
S
conversion of a manual operation to a specific signal for further processing

Class and
Task related to subclass Examples of components
subclass
SA
SB
SC
SD
SE
SF Conversion of a manual operation to electrical Switch, light pen, keyboard, control
signals switch, discrepancy switch, push-button
switch, selector switch, set-point adjuster
SG Conversion of a manual operation to Cordless mouse
electromagnetic, optical and acoustical signals
SH Conversion of a manual operation to mechanical Hand wheel, selector switch
signals
SJ Conversion of a manual operation to fluid or
pneumatic signals
SK
SL
SM
SN
SP
SQ
SR
SS
ST
SU
SV
SW
SX
SY
SZ Combined tasks
PAS 62400 © IEC:2005(E) – 21 –

Table 3 (continued) T
Purpose or task of object:
conversion of energy while maintaining the kind of energy, conversion of an
T
established signal while maintaining the content of information, conversion of the form
or shape of a material
Class and
Task related to subclass Examples of components
subclass
TA Conversion of electrical energy while retaining the Transformer, d.c./d.c. converter,
energy type and energy form frequency converter

TB Conversion of electrical energy while retaining the Rectifier, inverter
energy type and changing the energy form
TC
TD
TE
TF Conversion of signals (retention of information Amplifier, isolating converter, electrical
content) transducer, impulse amplifier, aerial
TG
TH
TJ
TK
TL Conversion of speed of rotation, torque, force Speed, torque converter, control coupling
with primary task of changing speed,
indexing and automatic gears, pressure
amplifier
TM Forming, machining Machine tool, shear, saw
TN Handling and processing, chipless (cold) Balancing machine, burnisher (surface
treatment without machining)
TP Deforming, chipless (cold ) Deep drawing equipment, cold rolling
equipment, cold drawing equipment
TQ Deforming, chipless (hot) Casting, forging, extrusion, hot rolling,
hot drawing equipment,
TR Conversion of radiation energy while retaining Magnifying glass, parabolic mirror
energy form
TS
TT
TU
TV
TW
TX
TY
TZ Combined tasks
– 22 – PAS 62400 © IEC:2005(E)

Table 3 (continued) U
Purpose or task of object:
U
keeping objects in a defined position

Class and
Task related to subclass Examples of components
subclass
UA Holding and supporting electrical energy Post-insulator, supporting structure

equipment
UB Holding and supporting electrical energy cables Portal, mast, insulator, cable rack, cable

and conductors trough, cable duct, cable tray, post

insulator
UC Enclosure of electrical energy equipment Housing, encapsulation
UD
UE
UF Holding, supporting, enclosing I&C and Transducer rack, sub-rack, printed circuit
communications objects board
UG Holding and supporting I&C and communications Cable rack, cable duct
cables and conductors (to be used only if
separate from UB)
UH Enclosing I&C equipment Cabinet
UJ
UK
UL Holding and supporting machinery objects Machine foundation
UM Holding and supporting structural objects Building foundation, structural elements
(for example, lintel, joist, suspender
beam, column), shaft, duct (not cable
duct, see UG)
UN Holding and supporting piping objects Bracket for pipes, pipe bridge
UP Holding and routing shafts and rotors Roller bearing, ball bearing, sliding
bearing
UQ Holding and routing objects for fabrication and Clamping, centring device
erection
UR Fastening and anchoring machinery objects Bracket, carrier, erection plate, erection
frame, anchor plate
US
UT
UU
UV
UW
UX
UY
UZ Combined tasks
PAS 62400 © IEC:2005(E) – 23 –

Table 3 (continued) V
Purpose or task of object:
processing (handling) of materials or products (including pre-treatment and post-
V
treatment)
Class and
Task related to subclass Examples of components

subclass
VA
VB
VC
VD
VE
VF
VG
VH
VJ
VK
VL Filling of materials Sack, drum, tank car filling equipment
VM Packaging of products Wrapping machines, palletizer,
packaging machines
VN Treatment of surfaces Grinding, polishing machine, painting
machine
VP Handling of materials or products using thermal Annealing furnace, blast furnace, melting
energy furnace
VQ Cleaning of materials, products or facilities Vacuum cleaner, washing machine,
building cleaning equipment
VR
VS
VT
VU
VV
VW
VX
VY
VZ Combined tasks
– 24 – PAS 62400 © IEC:2005(E)

Table 3 (continued) W
Purpose or task of object:
conducting or routing energy, signals, materials or products from one location to
W
another
Class and
Task related to subclass Examples of components

subclass
WA Distribution of electrical energy ≥ 1 kV Bus bar ≥ 1 kV

WB
Transporting electrical energy ≥ 1 kV Cable, conductor ≥ 1 kV

Bushing ≥ 1 kV
WC Distributing electrical energy < 1 kV Bus bar < 1 kV
WD Transporting electrical energy < 1 kV Cable, conductor < 1 kV
Bushing < 1 kV
WE Conducting ground potential or reference potential
WF Distribution of electrical or electronic signals Data bus
WG Transporting electrical or electronic signals Control cables, measuring cables, data
line
WH Transporting and routing optical signals  Glass fibre cable, optical wave guide
WJ
WK
WL Transporting materials and products (not driven) Inclined plane, roller table, conductor
WM Conducting and routing flows of liquid and Channel, trough
flowable substances (open enclosures)
WN Conducting and routing flows of liquid, flowable Hose
and gaseous substances (closed, flexible
enclosures)
WP Conducting and routing flows of liquid, flowable Pipe, air duct, stack
and gaseous substances (closed, rigid
enclosures)
WQ Transfer of mechanical energy Shaft, rotor, V-belt, chain, linkage
WR Conducting and routing rail transport equipment Rails, points
WS Conducting and routing persons (access Platform, stair, catwalk
equipment)
WT Conducting and routing mobile transport Path, road, shipping routes, railways
equipment (transport routes)
WU
WV
WW
WX
WY
WZ Combined tasks
PAS 62400 © IEC:2005(E) – 25 –

Table 3 (continued) X
Purpose or task of object:
X
connecting objects
Class and
Task related to subclass Examples of components
subclass
XA
XB Terminal, cable sealing end, junction box
Connections ≥ 1 kV
XC
XD Connections < 1 kV Terminal, cable sealing end, junction
box, socket
XE Connecting to ground potential or reference Grounding terminal, shield connection
potential terminal
XF
XG Connecting signals (electrical) Signal distributor, plug connector,
connection element
XH Connecting signals (optical) Optical connection
XJ
XK
XL Connecting rigid enclosures for flows of gaseous, Piping parts, for example, flange, fittings,
liquid and flowable substances couplings
XM Connecting flexible enclosures for flows of Hose connection, hose coupling
gaseous, liquid and flowable substances
XN Connecting objects for transfer of mechanical Coupling, rigid
energy (rigid)
XP Connecting objects for transfer of mechanical Disengaging coupling, control coupling
energy (switchable / variable)
XQ Connecting objects (permanent) Welded, soldered connection, bonded
connection
XR Connecting objects (temporary) Hook, lug
XS
XT
XU
XV
XW
XX
XY
XZ Combined tasks
– 26 – PAS 62400 © IEC:2005(E)

Annex A
(informative)
List of terms
Table A.1 lists the terms contained in Table 3 (designations for objects, purposes, tasks and
derived terms) in alphabetical order. Depending on purpose and task, the objects, purposes
or tasks may be assigned to the function aspect (=) and/or the product aspect (-).

Table A.2 lists the terms contained in Table 3 in alphabetical order of the letter codes.

Table A.1 – List of terms for objects, alphabetically ordered by object
Object (fulfilling purpose or task) Letter code
Absorption washer HS
Access system WS
Accumulator CM
Accumulator, pressure CM
Acidity measurement BQ
Acoustic signal (electrical) PG
Acoustic signalling device (mechanical) PG
Activated carbon adsorber HS
Actuator MM
Actuator (fluid) MM
Actuator (mechanical) ML
Aerial TF
Air conditioner ER
Air conditioning system ER
Air conditioning with combustion of fossil fuels (mechanical energy) by generation of EP
thermal energy
Air duct WP
Airbag FN
Ammeter PG
Amount, measurement BZ
Amplifier TF
Amplitude measurement BG
Analysis measurement BQ
Anchor plate UR
Anchoring UR
Annealing furnace VP
Arrester FA … FE
Aspirator GQ
Audio transmission BX
Automatic drains trap FL
Automatic gear TL
Auxiliary contactor KF
Auxiliary equipment for fabrication and erection UQ

PAS 62400 © IEC:2005(E) – 27 –

Object (fulfilling purpose or task) Letter code

Avalanche protection FS
Baffle (flow restriction in open enclosures) QP

Balance PG
Balancing machine TN
Ball bearing UP
Barrier FQ
Battery GB
Battery (buffer, storage) CC
Battery (dry cell) GB
Bell (electrical) PG
Bell (mechanical) PG
Bellows expansion joint RS
Belt conveyor GL
Binary elements KF
Binary module KF
Blank QM
Blanking plate QM
Blast furnace VP
Blind RT
Blocking device RL
Blow-down (settling) HN
Blower GQ
Boiler (combustion of fossil fuels) EP
Boiler (generation of heat energy by energy transfer) EP
Boiler (generation of thermal energy by conversion of chemical energy) EM
Boiler (steam) CM
Boiler, electrical EB
Boiler, heat recovery steam generator EN
Bonded connection XQ
Bracket UR
Bracket for piping UN
Brake QL
Breaker (power, safety) QB
Brick lining (against chemical effects) RS
Brick lining (against mechanical effects) RR
Briquette maker HV
Buchholtz relay BB
Buffer battery CC
Building cleaning equipment VQ
Building foundation UM
Bunker CL
Burette PG
Burner EM
– 28 – PAS 62400 © IEC:2005(E)

Object (fulfilling purpose or task) Letter code

Burnisher (chipless surface treatment) TN

Bus bar (conducting electrical energy) WA

Bus bar < 1kV (distribution of electrical energy) WC

Bus bar ≥ 1 kV (distribution of electrical energy) WA

Bushing < 1 kV (transporting electrical energy) WD

Bushing ≥ 1 kV (transporting electrical energy) WB

By-pass circuit-breaker QD
Cabinet (enclosure of electrical I&C equipment) UH
Cabinet (for I&C objects) UF
Cable duct (for I&C cables, conductors; to be used only if separate from UB) UG
Cable rack UB
Cable rack (for I&C cables, conductors; to be used only if separate from UB) UG
Cable sealing end < 1kv XD
Cable sealing end ≥ 1 kv XB
Cable tray UB
Cable trough UB
Cable, conductor <1 kv WD
Cable, conductor ≥1 kv WB
Capacitor CA
Carrier UR
Casting equipment TQ
Catwalk WS
CD-ROM CF
Centring device UQ
Central processing unit (cpu) KF
Centrifuge HM
Chain WQ
Chain conveyor GL
Channel (open enclosure for conveying and conducting liquid and flowable liquids) WM
Check valve RM
Chillers (compression, turbine-driven) EC

Chipless (cold) deformation TP
Chipless (cold) handling and processing TN
Chipless (hot) deformation TQ
Circuit-breaker QA
Cistern CL
Clamp (<1 kV) XB
Cleaning VQ
Clock (electrical) PG
Clock (mechanical) PG
Coil CB
Cold drawing equipment TP
Cold energy generation by conversion of electrical energy EC

PAS 62400 © IEC:2005(E) – 29 –

Object (fulfilling purpose or task) Letter code

Cold energy storage CP
Cold energy to heat energy, conversion ER

Cold pump (generation of cold energy by conversion of chemical energy) EN

Cold pump (generation of cold energy by energy transfer) EQ

Cold pump (generation of heat by
...