IEC 61810-1:2003

INTERNATIONAL IEC
STANDARD
61810-1
Second edition
2003-08
Electromechanical elementary relays –
Part 1:
General and safety requirements
Relais électromécaniques élémentaires –
Partie 1:
Exigences générales et de sécurité

Reference number
Publication numbering
As from 1 January 1997 all IEC publications are issued with a designation in the

60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

Consolidated editions
The IEC is now publishing consolidated versions of its publications. For example,

edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the

base publication incorporating amendment 1 and the base publication incorporating

amendments 1 and 2.
Further information on IEC publications
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology. Information relating to
this publication, including its validity, is available in the IEC Catalogue of
publications (see below) in addition to new editions, amendments and corrigenda.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is also available from the following:
• IEC Web Site (www.iec.ch)
• Catalogue of IEC publications
The on-line catalogue on the IEC web site (http://www.iec.ch/searchpub/cur_fut.htm)
enables you to search by a variety of criteria including text searches, technical
committees and date of publication. On-line information is also available on
recently issued publications, withdrawn and replaced publications, as well as
corrigenda.
• IEC Just Published
This summary of recently issued publications (http://www.iec.ch/online_news/
justpub/jp_entry.htm) is also available by email. Please contact the Customer
Service Centre (see below) for further information.
• Customer Service Centre
If you have any questions regarding this publication or need further assistance,
please contact the Customer Service Centre:
Email: custserv@iec.ch
Tel: +41 22 919 02 11
Fax: +41 22 919 03 00
INTERNATIONAL IEC
STANDARD
61810-1
Second edition
2003-08
Electromechanical elementary relays –
Part 1:
General and safety requirements
Relais électromécaniques élémentaires –
Partie 1:
Exigences générales et de sécurité

 IEC 2003  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: +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 – 61810-1  IEC:2003(E)
CONTENTS
FOREWORD . 4

1 Scope . 6

2 Normative references. 6

3 Terms and definitions . 8

3.1 Definitions related to general terms . 8

3.2 Definitions of relay types . 8

3.3 Definitions related to conditions and operations. 9
3.4 Definitions of operating values.12
3.5 Definitions related to contacts.13
3.6 Definitions related to accessories .15
3.7 Definitions related to insulation.16
4 Influence quantities.18
5 Rated values.18
5.1 Rated coil voltage/rated coil voltage range .19
5.2 Operative range.19
5.3 Release .19
5.4 Reset (bistable relays).19
5.5 Recommended number of cycles for electrical endurance.20
5.6 Recommended frequencies of operation .20
5.7 Contact loads .20
5.8 Ambient temperature .20
5.9 Categories of environmental protection.20
5.10 Duty factor.21
6 General provisions for testing .21
7 Documentation and marking .22
7.1 Data .22
7.2 Additional data.23
7.3 Marking .23
7.4 Symbols .24
8 Terminations.24
8.1 Screw terminals and screwless terminals.24

8.2 Flat quick-connect terminations .24
8.3 Solder terminals .25
8.3.1 Resistance to soldering heat.25
8.3.2 Solder pins .25
8.3.3 Terminals for surface mounting (SMD) .25
8.3.4 Other solder terminations (for example soldering lugs).25
8.4 Sockets .25
8.5 Alternative termination types.26
9 Sealing .26
10 Insulation resistance and dielectric strength.26
10.1 Preconditioning.26
10.2 Insulation resistance.26
10.3 Dielectric strength.27

61810-1  IEC:2003(E) – 3 –
11 Heating.29

11.1 Requirements .29

11.2 Test procedure .29

11.3 Terminals .30

11.3.1 General test conditions .30

11.3.2 Solder terminals.30

11.3.3 Flat quick-connect terminations.31

11.3.4 Screw and screwless type terminals.31

11.3.5 Alternative termination types.31

12 Basic operating function .32
12.1 General test conditions .32
12.2 Operate (monostable relays).32
12.3 Release (monostable relays) .32
12.4 Operate/reset (bistable relays).32
13 Heat and fire resistance.33
14 Electrical endurance .33
15 Mechanical endurance .35
16 Clearances, creepage distances and solid insulation .35
16.1 Clearances and creepage distances .35
16.2 Solid insulation .39
16.3 Accessible surfaces .40
Annex A (normative) Explanations regarding relays.41
Annex B (normative) Heating test arrangement .44
Annex C (informative) Schematic diagram of families of terminations .45
Annex D (normative) Glow-wire test .46
Annex E (normative) Proof tracking test .49
Annex F (normative) Ball pressure test.51
Annex G (informative) Needle flame test .52
Annex H (normative) Measurement of clearances and creepage distances.54
Annex I (normative) Relation between rated impulse withstand voltage, rated voltage
and overvoltage category .59
Annex J (normative) Pollution degrees .60

Annex K (normative) Inductive contact loads .61

– 4 – 61810-1  IEC:2003(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
ELECTROMECHANICAL ELEMENTARY RELAYS –

Part 1: General and safety requirements

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, and Guides (hereafter referred to as “IEC Publication(s)”). Their 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
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
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) 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 61810-1 has been prepared by IEC technical committee 94: All-or-
nothing electrical relays.
This second edition cancels and replaces the first edition published in 1998 and IEC 61810-5,
published in 1998. This edition constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
94/182/FDIS 94/186/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A bilingual version of this document may be issued at a later date.

61810-1  IEC:2003(E) – 5 –
This new edition has been completely revised in order to

– establish a stand-alone standard for the type testing of electromechanical elementary

relays,
– incorporate and update the requirements and tests with regard to insulation coordination

as contained in former IEC 61810-5:1998,

– improve the structure of the standard to achieve better readability,

– update various requirements and tests.

The committee has decided that the contents of this publication will remain unchanged until

2005. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
The contents of the corrigendum of October 2004 have been included in this copy.

– 6 – 61810-1  IEC:2003(E)
ELECTROMECHANICAL ELEMENTARY RELAYS –

Part 1: General and safety requirements

1 Scope
This part of IEC 61810 applies to electromechanical elementary relays (non-specified time all-

or-nothing relays) for incorporation. It defines the basic safety-related and functional
requirements for applications in all areas of electrical engineering or electronics, such as:
• general industrial equipment,
• electrical facilities,
• electrical machines,
• electrical appliances for household and similar use,
• information technology and business equipment,
• building automation equipment,
• automation equipment,
• electrical installation equipment,
• medical equipment,
• control equipment,
• telecommunications,
• vehicles,
• transportation,
• etc.
Compliance with the requirements of this standard is verified by the type tests indicated.
In case the application of a relay determines additional requirements exceeding those
specified in this standard, the relay should be assessed in line with this application in
accordance with the relevant IEC standard(s) (for example IEC 60730-1, IEC 60335-1,
IEC 60950-1).
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 60038:1983, IEC standard voltages
Amendment 1 (1994)
Amendment 2 (1997)
IEC 60050: International Electrotechnical Vocabulary
IEC 60068-2-17:1994, Basic environmental testing procedures – Part 2: Tests – Test Q:
Sealing
61810-1  IEC:2003(E) – 7 –
IEC 60068-2-20:1979, Basic environmental testing procedures – Part 2: Tests – Test T:

Soldering
Amendment 2 (1987)
IEC 60085:1984, Thermal evaluation and classification of electrical insulation

IEC 60112:2003, Method for the determination of the proof and the comparative tracking

indices of solid insulating materials

IEC 60364-4-44:2001, Electrical installations of buildings – Part 4-44: Protection for safety –

Protection against voltage disturbances and electromagnetic disturbances

IEC 60417-DB:2002, Graphical symbols for use on equipment
IEC 60664-1:1992, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
Amendment 1 (2000)
Amendment 2 (2002)
IEC 60695-2-2:1991, Fire hazard testing – Part 2: Test methods – Section 2: Needle flame test
Amendment 1 (1994)
IEC 60695-2-10:2000, Fire hazard testing – Part 2-10: Glowing/hot-wire based test methods –
Glow-wire apparatus and common test procedure
IEC 60695-10-2:1995, Fire hazard testing – Part 10-2: Guidance and test methods for the
minimization of the effects of abnormal heat on electrotechnical products involved in fires –
Method for testing products made from non-metallic materials for resistance to heat using the
ball pressure test
Amendment 1 (2001)
IEC 60721-3-3:1994, Classification of environmental conditions – Part 3-3: Classification of
groups of environmental parameters and their severities – Stationary use at weatherprotected
locations
Amendment 1 (1995)
Amendment 2 (1996)
IEC 60730-1:1999, Automatic electrical controls for household and similar use – Part 1:
General requirements
IEC 60947-5-1:1997, Low-voltage switchgear and controlgear – Part 5-1: Control circuit

devices and switching elements – Electromechanical control circuit devices
Amendment 1 (1999)
Amendment 2 (1999)
IEC 60950-1:2001, Information technology equipment – Safety – Part 1: General requirements
IEC 60999-1:1999, Connecting devices – Electrical copper conductors – Safety requirements
for screw-type and screwless-type clamping units – Part 1: General requirements and
2 2
particular requirements for clamping units for conductors from 0,2 mm up to 35 mm
(included)
IEC 61210:1993, Connecting devices – Flat quick-connect terminations for electrical copper
conductors – Safety requirements
———————
"DB" refers to the IEC on-line database.

– 8 – 61810-1  IEC:2003(E)
IEC 61760-1:1998, Surface mounting technology – Part 1: Standard method for the specifica-

tion of surface mounting components (SMDs)

IEC 61984:2001, Connectors – Safety requirements and tests

3 Terms and definitions
For the purpose of this part of IEC 61810, the following terms and definitions apply.

NOTE 1 Definitions of terms not stipulated in this standard are given in IEC 60050, in particular in

IEC 60050(444).
NOTE 2 Some definitions taken from IEC 60050(444) have been modified for the application to this standard.
NOTE 3 In the text of this standard, the term relay is used instead of elementary relay to improve the readability.
3.1 Definitions related to general terms
3.1.1
marking
identification of a relay which, when completely given to the manufacturer of this relay, allows
the unambiguous indication of its electrical, mechanical, dimensional and functional
parameters
EXAMPLE Through the indication of the trade mark and the type designation on the relay, all relay-specific data
can be derived from the type code.
3.1.2
intended use
use of a relay for the purpose for which it was made, and in the manner intended by the
manufacturer
3.1.3
relay technology categories
categorization of relays, based upon environmental protection
[IEV 444-01-11, modified]
NOTE Six categories are in use (RT 0 to RT V).
3.2 Definitions of relay types
3.2.1
electrical relay
device designed to produce sudden and predetermined changes in one or more output circuits
when certain conditions are fulfilled in the electric input circuits controlling the device

[IEV 444-01-01]
NOTE 1 For the purpose of this standard, output circuits are contact circuits.
NOTE 2 For the purpose of this standard, the term “coil” is used to denote “input circuit”, although other types of
input circuits are possible.
3.2.2
all-or-nothing relay
electrical relay, which is intended to be energized by a quantity, the value of which is either
within its operative range or effectively zero
[IEV 444-01-02]
NOTE "All-or-nothing relays" include both "elementary relays" and "time relays".

61810-1  IEC:2003(E) – 9 –
3.2.3
elementary relay
all-or-nothing relay which operates and releases without any intentional time delay

[IEV 444-01-03]
3.2.4
electromechanical relay
electrical relay in which the intended response results mainly from the movement of

mechanical elements
[IEV 444-01-04]
3.2.5
electromagnetic relay
electromechanical relay in which the designed response is produced by means of electro-
magnetic forces
[IEV 444-01-05]
3.2.6
monostable relay
electrical relay which, having responded to an energizing quantity and having changed its
condition, returns to its previous condition when that quantity is removed
[IEV 444-01-07]
3.2.7
bistable relay
electrical relay which, having responded to an energizing quantity and having changed its
condition, remains in that condition after the quantity has been removed; a further appropriate
energization is required to make it change its condition
[IEV 444-01-08]
NOTE Bistable relays are also called latching relays.
3.2.8
polarized relay
electrical relay, the change of condition of which depends upon the polarity of its DC
energizing quantity
[IEV 444-01-09]
3.2.9
non-polarized relay
electrical relay, the change of condition of which does not depend upon the polarity of its
energizing quantity
[IEV 444-01-10]
3.3 Definitions related to conditions and operations
3.3.1
release condition
for a monostable relay, specified condition of the relay when it is not energized; for a bistable
relay, one of the specified conditions, as declared by the manufacturer
[IEV 444-02-01]
NOTE See Figure A.1.
– 10 – 61810-1  IEC:2003(E)
3.3.2
operate condition
for a monostable relay, specified condition of the relay when it is energized by the specified

energizing quantity and has responded to that quantity; for a bistable relay, the condition

other than the release condition as declared by the manufacturer

[IEV 444-02-02]
NOTE See Figure A.1.
3.3.3
operate (verb)
change from the release condition to the operate condition
[IEV 444-02-04]
NOTE See Figure A.1.
3.3.4
release (verb)
for a monostable relay, change from the operate condition to the release condition
[IEV 444-02-05]
NOTE See Figure A.1.
3.3.5
reset (verb)
for a bistable relay, change from the operate condition to the release condition
[IEV 444-02-06]
3.3.6
cycle
operation and subsequent release/reset
[IEV 444-02-11]
3.3.7
frequency of operation
number of cycles per unit of time
[IEV 444-02-12]
3.3.8
continuous duty
duty in which the relay remains energized for a period long enough to reach thermal
equilibrium
[IEV 444-02-13]
3.3.9
intermittent duty
duty in which the relay performs a series of identical cycles, the durations in the energized
and unenergized conditions being specified; the duration of energization of the relay is such
as will not permit the relay to reach thermal equilibrium
[IEV 444-02-14, modified]
61810-1  IEC:2003(E) – 11 –
3.3.10
temporary duty
duty in which the relay remains energized for insufficient duration to reach thermal

equilibrium, the time intervals of energization being separated by unenergized time intervals

of duration sufficient to restore equality of temperature between the relay and the surrounding

medium
[IEV 444-02-16]
3.3.11
duty factor
ratio of the duration of energization to the total period in which intermittent or continuous or
temporary duty takes place
[IEV 444-02-15]
NOTE The duty factor can be expressed as a percentage of the total period.
3.3.12
thermal resistance (of the coil)
quotient of the temperature rise of the relay coil by the input power, measured after a period
long enough to reach thermal equilibrium
[IEV 444-02-17]
NOTE The thermal resistance usually is given in K/W.
3.3.13
ambient temperature
temperature(s) prescribed for the air surrounding the relay under certain conditions, when the
relay is mounted as indicated by the manufacturer
3.3.14
limiting continuous thermal withstand power
highest steady state value of the applied electric power that a relay can withstand
continuously, and under specified conditions, while satisfying specified temperature rise
requirements
[IEV 444-03-18, modified]
NOTE Comprises both the applied power at the coil(s) and the contact(s).
3.3.15
thermal equilibrium
steady state condition of the relay when the temperature does not change by more than ± 2 K

within 10 minutes
3.3.16
rated value
value of a quantity used for specification purposes, established for a specific set of operating
conditions
[IEV 444-02-18, modified]
3.3.17
test value
value of a quantity for which the relay shall comply with a specified action during a test
[IEV 444-02-20]
– 12 – 61810-1  IEC:2003(E)
3.3.18
actual value
value of a quantity determined by measurement on a specific relay, during performance of a

specified function
[IEV 444-02-21]
3.3.19
mechanical endurance
number of cycles under specified conditions with unloaded contact(s)

[IEV 444-07-10, modified]
3.4 Definitions of operating values
3.4.1
energizing quantity
electrical quantity which, when applied to the coil(s) of a relay under specified conditions,
enables it to fulfill its purpose
[IEV 444-03-01, modified]
NOTE For relays, the energizing quantity is usually a voltage. Therefore, the input voltage as energizing quantity
is used in the definitions given in 3.4. Where a relay is energized by a given current instead, the respective terms
and definitions apply with "current" used instead of "voltage".
3.4.2
operate voltage
set voltage (for bistable relays only)
value of the coil voltage at which a relay operates
[IEV 444-03-06, modified]
3.4.3
operate voltage
U
value of the coil voltage at which a relay operates, having previously been energized at that
same voltage
NOTE Thermal equilibrium has to be achieved.
3.4.4
limiting voltage
U
value of the coil voltage, taking into account the effect of heating due to the power dissipated

by the coil(s), which when exceeded may result in a relay failure caused by thermal overload
NOTE Thermal equilibrium has to be achieved.
3.4.5
operative range
range of values of coil voltage for which a relay is able to perform its specified function
[IEV 444-03-05, modified]
3.4.6
release voltage
value of the coil voltage at which a monostable relay releases
[IEV 444-03-08, modified]
61810-1  IEC:2003(E) – 13 –
3.4.7
reset voltage
value of the coil voltage at which a bistable relay resets

[IEV 444-03-10, modified]
3.5 Definitions related to contacts

For AC, r.m.s. values for voltage and current are specified, unless otherwise indicated.

3.5.1
contact
arrangement of contact members, with their insulation, which close or open their contact
circuit by their relative movement (see Figure A.2)
[IEV 444-04-03]
3.5.2
contact set
combination of contacts within a relay, separated by their insulation (see Figure A.2)
[IEV 444-04-04]
3.5.3
contact gap
gap between the contact points when the contact circuit is open
[IEV 444-04-09]
3.5.4
make contact
contact which is closed when the relay is in its operate condition and which is open when the
relay is in its release condition
[IEV 444-04-17]
3.5.5
break contact
contact which is open when the relay is in its operate condition and which is closed when the
relay is in its release condition
[IEV 444-04-18]
3.5.6
change-over contact
combination of two contact circuits with three contact members, one of which is common to
the two contact circuits; such that when one of these contact circuits is open, the other is
closed
[IEV 444-04-19]
3.5.7
switching power
power which a relay contact makes and/or breaks
[IEV 444-04-24]
NOTE The switching power is usually specified in W for DC and in VA for AC.

– 14 – 61810-1  IEC:2003(E)
3.5.8
switching voltage
voltage between the contact members before closing or after opening of a relay contact

NOTE The term “contact voltage” (see IEV 444-04-25) has been replaced by “switching voltage”. The definition

remains unchanged, however.
3.5.9
contact current
electric current which a relay contact carries before opening or after closing

[IEV 444-04-26]
3.5.10
switching current
electric current which a relay contact makes and/or breaks
[IEV 444-04-27]
3.5.11
limiting continuous current
greatest value of electric current which a closed contact is capable of carrying continuously
under specified conditions
[IEV 444-04-28, modified]
3.5.12
limiting short-time current
greatest value of electric current which a closed contact is capable of carrying for a specified
short period under specified conditions
[IEV 444-04-29, modified]
3.5.13
limiting making capacity
greatest value of electric current which a contact is capable of making under specified
conditions such as switching voltage, number of makes, power factor, time constant
[IEV 444-04-30, modified]
3.5.14
limiting breaking capacity
greatest value of electric current which a contact is capable of breaking under specified
conditions such as switching voltage, number of breaks, power factor, time constant

[IEV 444-04-31, modified]
3.5.15
limiting cycling capacity
greatest value of electric current which a contact is capable of making and breaking
successively under specified conditions such as switching voltage, number of breaks, power
factor, time constant
[IEV 444-04-32, modified]
61810-1  IEC:2003(E) – 15 –
3.5.16
micro-interruption
interruption of a circuit by contact separation which does not provide full-disconnection or

micro-disconnection
[IEC 60730-1, 2.4.4, modified]

NOTE There are no dielectric strength or dimensional requirements for the contact gap.

3.5.17
micro-disconnection
adequate contact separation in at least one contact so as to provide functional security

[IEC 60730-1, 2.4.3, modified]
NOTE There is a requirement for the dielectric strength of the contact gap but no dimensional requirement.
3.5.18
full-disconnection
contact separation for the disconnection of conductors so as to provide the equivalent of basic
insulation between those parts intended to be disconnected
[IEC 60730-1, 2.4.2, modified]
NOTE There are dielectric strength and dimensional requirements.
3.5.19
all-pole disconnection
full-disconnection of all conductors by a single switching action
3.5.20
failure
termination of the ability of an item to perform a required function
[IEV 191-04-01]
NOTE For the purpose of this standard, items are elementary relays.
3.5.21
malfunction
single event when an item does not perform a required function
3.5.22
contact failure
occurrence of break and/or make malfunctions of a contact under test, exceeding a specified

number
3.5.23
electrical endurance
number of cycles without contact failure under specified conditions, with loaded contacts
3.6 Definitions related to accessories
3.6.1
manual operation
manual movement of the actuating member of the relay
3.6.2
actuating member
part which is pulled, pushed, turned or otherwise operated in order to initiate a function

– 16 – 61810-1  IEC:2003(E)
3.6.3
switching position indicator
device of a relay for visual indication of the switching position

3.7 Definitions related to insulation

3.7.1
functional insulation
insulation between conductive parts which is necessary only for the proper functioning of the
relay
[IEC 60664-1, 1.3.17.1, modified]

3.7.2
basic insulation
insulation applied to live parts to provide basic protection against electric shock
[IEC 60664-1, 1.3.17.2]
NOTE Basic insulation does not necessarily include insulation used exclusively for functional purposes.
3.7.3
supplementary insulation
independent insulation applied in addition to basic insulation, in order to provide protection
against electric shock in the event of a failure of basic insulation
[IEC 60664-1, 1.3.17.3]
3.7.4
double insulation
insulation comprising both basic insulation and supplementary insulation
[IEC 60664-1, 1.3.17.4]
3.7.5
reinforced insulation
a single insulation system applied to live parts, which provides a degree of protection against
electric shock equivalent to double insulation
[IEC 60664-1, 1.3.17.5, modified]
3.7.6
conductive part
part suitable to conduct electric current, which is, however, not necessarily used for this

purpose
3.7.7
live part
conductor or conductive part intended to be energized in normal operation, including a neutral
conductor, but by convention not a PEN conductor
[IEV 195-02-19, modified]
NOTE A PEN conductor combines the functions of both a protective earthing conductor and a neutral conductor.

61810-1  IEC:2003(E) – 17 –
3.7.8
clearance
shortest distance in air between two conductive parts, or between a conductive part and the

accessible surface of a relay
[IEC 60664-1, 1.3.2, modified]

NOTE An example for an accessible surface is the actuating member of a relay used for manual operation.

3.7.9
solid insulation
solid insulating material interposed between two conductive parts

[IEC 60664-1, 1.3.4]
3.7.10
supporting material
solid insulating material keeping live parts in their position
3.7.11
creepage distance
shortest distance along the surface of the insulating material between two conductive parts
[IEC 60664-1, 1.3.3]
3.7.12
tracking
progressive degradation of a solid insulating material by local discharges to form conducting
or partially conducting paths
[IEV 212-01-42, modified]
NOTE Tracking usually occurs due to surface contamination.
3.7.13
proof tracking index
PTI
numerical value of the proof voltage expressed in volts which a material can withstand without
tracking under specified test conditions
[IEV 212-01-45, modified]
3.7.14
comparative tracking index
CTI
numerical value of the maximum voltage expressed in volts which a material can withstand
without tracking under specified test conditions
[IEV 212-01-44]
3.7.15
pollution
any addition of foreign matter, solid, liquid, or gaseous that can result in a reduction of
electric strength or surface resistivity of the insulation
[IEC 60664-1, 1.3.11]
3.7.16
pollution degree
number characterizing the expected pollution of the micro-environment

– 18 – 61810-1  IEC:2003(E)
[IEC 60664-1, 1.3.13, modified]

NOTE Pollution degrees 1, 2 and 3 are used, see Annex J.

3.7.17
micro-environment
the immediate environment of the insulation which particularly influences the dimensioning of

the creepage distances
[IEC 60664-1, 1.3.12.2]
4 Influence quantities
The specified performance of a relay shall be given with respect to the reference conditions,
i.e. the set of reference values of all influence quantities.
Unless otherwise explicitly stated by the manufacturer, the reference values and tolerance
ranges listed in Table 1 apply.
Table 1 – Reference values of influence quantities
Tolerance range and conditions
Influence quantity Reference value
1)
for testing
Ambient temperature 23 °C +5 K
Atmospheric pressure 96 kPa 86 kPa to 106 kPa
Relative humidity 50 % 25 % to 75 %
–4
External magnetic induction 0 0 ± 5 x 10 T in any direction
Position As indicated by the manufacturer According to 11.2 a)
Voltage/current (for coil and load) As indicated by the manufacturer ±5 % for steady-state conditions
Frequency 16 / Hz or Same as reference value with tolerance
50 Hz or 60 Hz or 400 Hz ±2 %
2)
Waveform Sinusoidal Sinusoidal; max. Distortion factor 5 %
3)
Alternating component in d.c. (ripple) 0 Max. 6 %
Direct component in a.c. 0 Max. 2 % of peak value
Shock and vibration 0 Max. 1 m/s²
Industrial and other atmospheres Clean air Clean air (pollution not exceeding class
3C2 of IEC 60721-3-3)
1) The test may be carried out with other values of the influence quantities, provided the quantitative relationship
between one or more influence quantities and the value of the considered characteristic is known.

2) Distortion factor: ratio of the harmonic content obtained by subtracting the fundamental wave from a non-
sinusoidal harmonic quantity and the r.m.s. value of the non-sinusoidal quantity. It is usually expressed as a
percentage.
3) The alternating component (ripple content) of a d.c. supply, expressed as a percentage, is defined as follows:
maximum value – minimum value
x 100
d.c. component
5 Rated values
The recommended values listed below do not comprise all technical possibilities and other
values may be adopted according to conditions of operation and use.

61810-1  IEC:2003(E) – 19 –
5.1 Rated coil voltage/rated coil voltage range

a) AC voltage, recommended r.m.s. values:

6 V; 12 V; 24 V; 48 V; 100 3 V; 110 3 V; 120 3 V; 100 V; 110 V; 115 V; 120 V;

127 V; 200 V; 230 V; 277 V; 400 V; 480 V; 500 V.

b) DC voltage, recommended values:

1,5 V; 3 V; 4,5 V; 5 V; 9 V; 12 V; 24 V; 28 V; 48 V; 60 V; 110 V; 125 V; 220 V; 250 V;

440 V; 500 V.
c) Rated voltage range (for example 220 V to 240 V) and corresponding frequencies (for

example 50 Hz/60 Hz) shall be specified by the manufacturer.

5.2 Operative range
The operative range of a relay coil can be specified either according to 5.2.1 or 5.2.2.
5.2.1 The recommended operative range is to be specified according to one of two classes:
• Class 1: 80 % to 110 % of the rated coil voltage (or range).
• Class 2: 85 % to 110 % of the rated coil voltage (or range).
NOTE Where a rated coil voltage range applies, the operative range is from 80 % (or 85 %) of the lower limit to
110 % of the upper limit of the rated coil voltage range.
The above values apply over the full ambient temperature range as declared by the
manufacturer.
Where the manufacturer deviates from the recommended classes, he shall specify both the
rated coil voltage (or range) and the corresponding operative range, see Figure A.3.
5.2.2 As an alternative to the operative range specified in 5.2.1, the manufacturer may
graphically represent the operative range against ambient temperature. This is achieved by
describing the upper limit (U = limiting coil voltage) and the lower limit (U = operate voltage)
2 1
of the operative range, as illustrated by Figure A.3.
5.3 Release
The release values indicated below apply over the full ambient temperature range as declared
by the manufacturer.
a) DC relay
Where the operative range is specified according to 5.2.1, the release voltage of
monostable relays shall be not lower than 5 % of the rated coil voltage (or the upper limit
of the rated coil voltage range), see Figure A.3.
Where the operative range is specified according to 5.2.2, the release voltage of
monostable relays shall be not lower than 10 % of the lower limit U of the operative range,
see Figure A.3.
b) AC relay
The same conditions as for DC relays apply, except that a value of 15 % shall be used in
place of 5 % or 10 %, respectively.
5.4 Reset (bistable relays)
The recommended values shall be the same as those specified in 5.2, unless otherwise
specified by the manufacturer.

– 20 – 61810-1  IEC:2003(E)
5.5 Recommended number of cycles for electrical endurance

5 000; 10 000; 20 000; 30 000; 50 000; 100 000; 200 000; 300 000; 500 000; etc.

5.6 Recommended frequencies of operation

360/h; 720/h; 900/h and multiples thereof.

0,1 Hz; 0,2 Hz; 0,5 Hz and multiples thereof.

5.7 Contact loads
a) Resistive loads, recommended values
Current: 0,1 A; 0,5 A; 1 A; 2 A; 3 A; 5 A; 6 A; 8 A; 10 A; 12 A; 16 A; 25 A; 35 A; 60 A;
100 A.
Voltage: 4,5 V; 5 V; 12 V; 24 V; 36 V; 42 V; 48 V; 110 V; 125 V; 230 V; 250 V; 400 V
(AC/DC).
b) Recommended inductive loads, for example AC-15, DC-13 in accordance with
IEC 60947-5-1: see Annex K of this standard.
5.8 Ambient temperature
Unless otherwise stated, the preferred ambient temperature range is –10 °C to +55 °C for the
operation of relays.
Other recommended values for the upper limit are:
+200 °C +175 °C +155 °C +125 °C +100 °C +85 °C
+70 °C +40 °C +30 °C
Other recommended values for the lower limit are:
–65 °C –55 °C –40 °C –25 °C –5 °C +5 °C
5.9 Categories of environmental protection
The relay technology categories describing the degree of sealing of the relay case or its
contact unit are given in Table 2 below.
Table 2 – Categor
...