IEC 61810-7:2006

INTERNATIONAL IEC
STANDARD 61810-7
Second edition
2006-03
Electromechanical elementary relays –
Part 7:
Test and measurement procedures
Reference number
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INTERNATIONAL IEC
STANDARD 61810-7
Second edition
2006-03
Electromechanical elementary relays –
Part 7:
Test and measurement procedures

 IEC 2006  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
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For price, see current catalogue

– 2 – 61810-7  IEC:2006(E)
CONTENTS
FOREWORD.5

1 Scope.7
2 Normative references.7
3 Terms and definitions .9
4 Test and measurement procedures .18
4.1 General .18
4.2 Deviations .18
4.3 Precision of measurement .18
4.4 Power supplies .18
4.5 Reference conditions for testing.19
4.6 Visual inspection and check of dimensions.20
4.7 Mechanical tests and weighing.20
4.8 Relay coil properties .21
4.9 Dielectric strength test .25
4.10 Impulse voltage test.26
4.11 Insulation resistance.27
4.12 Contact-circuit resistance (or voltage drop) .28
4.13 Functional tests .29
4.14 Timing tests.35
4.15 Climatic tests/sequence.38
4.16 Damp heat, steady state .40
4.17 Thermal resistance of the coil .41
4.18 Heating.42
4.19 Rapid change of temperature.44
4.20 Enclosure .44
4.21 Internal moisture.46
4.22 Corrosive atmospheres.46
4.23 Mould growth.47
4.24 Robustness of terminals .48
4.25 Soldering.48
4.26 Shock.49
4.27 Bump .50
4.28 Vibration.51
4.29 Acceleration .52
4.30 Electrical endurance .53
4.31 Mechanical endurance .56
4.32 Thermal endurance.56
4.33 Limiting continuous current .57
4.34 Overload (contact circuit).57
4.35 Load transfer .58
4.36 Electromagnetic compatibility.59
4.37 Magnetic interference .60
4.38 Crosstalk and insertion loss .61
4.39 Electrical contact noise .61

61810-7  IEC:2006(E) – 3 –
4.40 Thermoelectric e.m.f.62
4.41 Capacitance .62
4.42 Contact sticking (delayed release) .63
4.43 Magnetic remanence .63
4.44 Acoustic noise .65
4.45 Continuity of protective earth connection.66
4.46 Fluid contamination .66
4.47 Resistance to cleaning solvents .67
4.48 Fire hazard .68
4.49 Temperature rise at rated load.68
4.50 Mechanical interlock .69
4.51 Insertion and withdrawal force (mating relay and socket).69

Annex A (normative) Heating test arrangement.71
Annex B (normative) Fire hazard testing .72
Annex C (normative) Test circuit for endurance tests.77
Annex D (informative) Inductive contact loads .84

Bibliography .86

Figure 1 – Typical circuit for the measurement of coil transient suppression.23
Figure 2 – Typical traces on an oscilloscope screen during transient voltage
measurement.24
Figure 3 – Monostable non-polarized relay.30
Figure 4 – Monostable relay polarized by diode.31
Figure 5 – Monostable polarized relay with magnetic biasing.32
Figure 6 – Bistable non-polarized relay (not applicable to remanence relays) .33
Figure 7 – Bistable polarized relay (example) .34
Figure 8 – Typical circuit for the measurement of time parameters.36
Figure 9 – Typical traces on an oscilloscope screen during time measurements.37
Figure 10 – Test circuit for load transfer .59
Figure 11 – Mounting array for adjacent similar relays .60
Figure 12 – Directions of the test current for magnetic interference test, method 3.61
Figure 13 – Sequential diagram for magnetic remanence test .64
Figure 14 – Installation for the test for acoustic noise emission.65
Figure A.1 – Test arrangement.71
Figure B.1 – Glow-wire and position of the thermocouple.73
Figure B.2 – Glow-wire test apparatus (example).74
Figure B.3 – Needle flame test details .76
Figure C.1 – Standard test circuit .77
Figure C.2 – Functional block diagram.78
Figure C.3 – Circuit for cable load .80
Figure C.4 – Test circuit for inrush current loads (for example capacitive loads and
simulated tungsten filament lamp loads) – a.c. circuits.81

– 4 – 61810-7  IEC:2006(E)
Figure C.5 – Example for a tungsten filament lamp test for relays rated 10/100 A/250 V~/
2,5 ms .82
Figure C.6 – Test circuit for inrush current loads (for example capacitive loads and
simulated lamp loads) – d.c. circuits.82
Figure C.7 – Test circuit for inrush current loads (for example simulated fluorescent
lamp loads) with power-factor correction.83

Table 1 – Coil voltage values and corresponding functions .29
Table 2 – Cross-sectional areas and lengths of conductors dependent on the current
carried by the terminal.43
Table 3 – Schematics for contact loading .55
Table 4 – Test fluids and temperatures of tests .67
Table C.1 – Characteristics of power sources for contact loads.78
Table C.2 – Standard contact load characteristics .79
Table D.1 – Verification of the making and breaking capacity for AC-15/DC-13 (normal
conditions) .84
Table D.2 – Making and breaking capacity for electrical endurance test .85

61810-7  IEC:2006(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMECHANICAL ELEMENTARY RELAYS –

Part 7: Test and measurement procedures

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, Publicly Available Specifications (PAS) 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
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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 61810-7 has been prepared by IEC technical committee 94: All-or-
nothing electrical relays.
This second edition cancels and replaces the first edition published in 1997. This second
edition constitutes a technical revision.
This new edition has been revised in order to
– update all normative references,
– adapt its contents to the newest issues of the other parts of this series of basic relay
standards (IEC 61810-1 and IEC 61810-2),
– establish coherence with other IEC standards (for example of the IEC 60068-2 series),
– improve test and measurement procedures where appropriate,
– delete those tests no longer used in case of elementary relays for industrial application.

– 6 – 61810-7  IEC:2006(E)
The text of this standard is based on the following documents:
FDIS Report on voting
94/226/FDIS 94/231/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.
IEC 61810 consists of the following parts, under the general title Electromechanical elementary
relays:
Part 1: General and safety requirements
Part 2: Reliability
Part 7: Test and measurement procedures
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

61810-7  IEC:2006(E) – 7 –
ELECTROMECHANICAL ELEMENTARY RELAYS –

Part 7: Test and measurement procedures

1 Scope
This part of IEC 61810 states the test and measurement procedures for electromechanical
elementary relays. It covers basic considerations which are, in general, common to all types of
electromechanical elementary relays. Supplementary requirements may be necessitated by
specific designs or application.
The test and measurement procedures of this standard are described as individual provisions
covering a specific requirement. When combining them in a test programme, care must be
taken (for example by suitable grouping of tested relays) to ensure that preceding tests do not
devalue subsequent ones.
Where in this standard the term “specified” is used, this means a prescription in the
appropriate documentation for the relay, for example manufacturer’s data sheet, test
specification, customer detail specification. For application within the IECQ system such
prescriptions are contained in the detail specification as defined in Clause A.7 of QC 001001.
NOTE 1 To improve the readability of this standard, the term “relay” is generally used in place of
“electromechanical elementary relay”.
NOTE 2 Requirements and tests related to the type testing of electromechanical elementary relays are contained
in IEC 61810-1. For that purpose, the generally described test and measurement procedures of this standard have
been prescribed in a more restricted and stringent form in IEC 61810-1.
NOTE 3 Standards covering relays subjected to quality assessment in accordance with IECQ are compiled in the
IEC 61811 series of publications.
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 60068-2-1:1990, Environmental testing – Part 2: Tests – Tests A: Cold
Amendment 1 (1993)
Amendment 2 (1994)
IEC 60068-2-2:1974, Environmental testing – Part 2: Tests – Tests B: Dry heat
Amendment 1 (1993)
Amendment 2 (1994)
IEC 60068-2-6:1995, Environmental testing – Part 2: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-7:1983, Environmental testing – Part 2: Tests – Test Ga: Acceleration, steady state
Amendment 1 (1986)
IEC 60068-2-10:2005, Environmental testing – Part 2: Tests – Test J and guidance: Mould
growth
IEC 60068-2-11:1981, Environmental testing – Part 2: Tests – Test Ka: Salt mist

– 8 – 61810-7  IEC:2006(E)
IEC 60068-2-13:1983, Environmental testing – Part 2: Tests – Test M: Low air pressure
IEC 60068-2-14:1984, Environmental testing – Part 2: Tests – Test N: Change of temperature
Amendment 1 (1986)
IEC 60068-2-17:1994, Environmental testing – Part 2: Tests – Test Q: Sealing
IEC 60068-2-20:1979, Environmental testing – Part 2: Tests – Test T: Soldering
Amendment 2 (1987)
IEC 60068-2-21:1999, Environmental testing – Part 2-21: Tests – Test U: Robustness of
terminations and integral mounting devices
IEC 60068-2-27:1987, Environmental testing – Part 2: Tests – Test Ea and guidance: Shock
IEC 60068-2-29:1987, Environmental testing – Part 2: Tests – Test Eb and guidance: Bump
IEC 60068-2-30:2005, Environmental testing – Part 2: Tests – Test Db: Damp heat, cyclic (12 +
12-hour cycle)
IEC 60068-2-42:2003, Environmental testing – Part 2-42: Tests – Test Kc: Sulphur dioxide test
for contacts and connections
IEC 60068-2-43:2003, Environmental testing – Part 2-43: Tests – Test Kd: Hydrogen sulphide
test for contacts and connections
IEC 60068-2-45:1980, Environmental testing – Part 2: Tests – Test XA and guidance:
Immersion in cleaning solvents
Amendment 1 (1993)
IEC 60068-2-58:2004, Environmental testing – Part 2-58: Tests – Test Td – Test methods for
solderability, resistance to dissolution of metallization and to soldering heat of surface
mounting devices (SMD)
IEC 60068-2-64:1993, Environmental testing – Part 2: Test methods – Test Fh: Vibration,
broad-band random (digital control) and guidance
IEC 60068-2-68:1994, Environmental testing – Part 2: Tests – Test L: Dust and sand
IEC 60068-2-78:2001, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady
state
IEC 60512-7: 1993, Electromechanical components for electronic equipment; basic testing
procedures and measuring methods – Part 7: Mechanical operating tests and sealing tests
IEC 60695-2 (all parts), Fire hazard testing – Part 2: Test methods
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 60695-2-11:2000, Fire hazard testing – Part 2-11: Glowing/hot wire based test methods –
Glow-wire flammability test method for end-products
IEC 60695-2-12:2000, Fire hazard testing – Part 2-12: Glowing/hot wire based test methods –
Glow-wire flammability test method for materials

61810-7  IEC:2006(E) – 9 –
IEC 60695-2-13:2000, Fire hazard testing – Part 2-13: Glowing/hot wire based test methods –
Glow-wire ignitability test method for materials
IEC 60695-11-5:2004, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method
– Apparatus, confirmatory test arrangement and guidance
IEC 60999-1:1999, Connecting devices – Electrical copper conductors – Safety requirements
for screw-type and screwless-type clamping units – Part 1: General requirements and particular
2 2
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 electric copper
conductors – Safety requirements
IEC 61180-1:1992, High-voltage test techniques for low-voltage equipment – Part 1:
Definitions, test and procedure requirements
IEC 61180-2:1994, High-voltage test techniques for low-voltage equipment – Part 2: Test
equipment
IEC 61672-1:2002, Electroacoustics – Sound level meters – Part 1: Specifications
IEC 61810-1:2004, Electromechanical elementary relays – Part 1: General and safety
requirements
IECQ QC 001001:2000, IEC Quality Assessment System for Electronic Components (IECQ) –
Basic Rules
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Types of relays
3.1.1
electromechanical relay
electrical relay in which the intended response results mainly from the movement of
mechanical elements
[IEV 444-01-04]
3.1.2
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]
3.1.3
elementary relay
all-or-nothing relay which operates and releases without any intentional time delay
[IEV 444-01-03]
– 10 – 61810-7  IEC:2006(E)
3.1.4
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]
3.1.5
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]
3.1.6
polarized relay
electrical relay, the change of condition of which depends upon the polarity of its DC energizing
quantity
[IEV 444-01-09]
3.1.7
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]
3.2 Types of relays, based upon environmental protection (relay technology RT)
3.2.1
RT 0 unenclosed relay
relay not provided with a protective case
3.2.2
RT I dust protected relay
relay provided with a case which protects its mechanism from dust
3.2.3
RT II flux proof relay
relay capable of being automatically soldered without allowing the migration of solder fluxes
beyond the intended areas
NOTE Where an enclosed construction is used, venting to the outside atmosphere is permissible.
3.2.4
RT III wash tight relay
relay capable of being automatically soldered and subsequently undergoing a washing process
to remove flux residues without allowing the ingress of flux or washing solvents
NOTE In service, this type of relay is sometimes vented to the atmosphere after the soldering or washing process.
3.2.5
RT IV sealed relay
relay provided with a case which has no venting to the outside atmosphere, and having a time
constant better than 2 × 10 s (see IEC 60068-2-17)

61810-7  IEC:2006(E) – 11 –
3.2.6
RT V hermetically sealed relay
sealed relay having an enhanced level of sealing, assuring a time constant better than
2 × 10 s (see IEC 60068-2-17)
3.3 Functions of a relay
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 conditions, as declared by the manufacturer
[IEV 444-02-01]
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]
3.3.3
operate (verb)
change from the release condition to the operate condition
[IEV 444-02-04]
3.3.4
release (verb)
for a monostable relay, change from the operate condition to the release condition
[IEV 444-02-05]
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
change over (verb)
for a monostable relay, operate or release; for a bistable relay, operate or reset
[IEV 444-02-07]
3.3.7
cycle (verb)
for a monostable relay, operate and then release or vice versa; for a bistable relay, operate and
then reset or vice-versa
[IEV 444-02-08]
3.3.8
revert (verb)
for a specific type of polarized relay, release/reset again, or remain in the release condition,
when supplied with a coil voltage in excess of that required for operation and of the same
polarity as required for operation
[IEV 444-02-09, modified]
– 12 – 61810-7  IEC:2006(E)
3.3.9
revert reverse (verb)
for a specific type of polarized bistable relay, operate again, or remain in the operate condition,
when supplied with a coil voltage in excess of that required for resetting and of the same
polarity as required for resetting
[IEV 444-02-10, modified]
3.4 Types of contacts
3.4.1
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]
3.4.2
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]
3.4.3
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]
3.4.4
change-over make-before-break contact
change-over contact in which the make contact circuit closes before the break contact circuit
opens
[IEV 444-04-20]
3.4.5
change-over break-before-make contact
change-over contact in which the break contact circuit opens before the make contact circuit
closes
[IEV 444-04-21]
3.5 Prefixes for the values applicable to relays
Values may be defined as rated, actual (“just”), test (“must”) or characteristic value and
identified as such by using one of these words as a prefix. The prefixes are also applicable to
timing values.
3.5.1
rated value
value of a quantity used for specification purposes, established for a specified set of operating
conditions of a relay
[IEV 444-02-18, modified]
61810-7  IEC:2006(E) – 13 –
3.5.2
actual (“just”) value
value of a quantity determined by measurement on a specific relay, during performance of a
specified function
[IEV 444-02-21]
3.5.3
test (“must”) value
value of a quantity for which the relay shall comply with a specified action during a test
[IEV 444-02-20]
3.5.4
characteristic value
value of a quantity with which, in the initial condition of a relay or for a specified number of
cycles as specified, the relay shall comply with a specified requirement
[IEV 444-02-19, modified]
3.6 Energization values
3.6.1
energizing quantity
electrical quantity which, when applied to the coil(s) of a relay under specified conditions,
enables it to fulfil its purpose
[IEV 444-03-01, modified]
NOTE 1 For elementary relays, the energizing quantity is usually a voltage. Therefore, the input voltage as
energizing quantity is used in the definitions given below. When a relay is energized by a given current instead, the
respective terms and definitions apply with “current” used instead of “voltage”.
NOTE 2 The general term “input voltage” used in IEV Chapter 444 applies to all types of elementary relays (e.g.
including solid-state relays). For electromechanical elementary relays the more specific term “coil voltage” has been
chosen for the terms of 3.6, as in IEC 61810-1.
3.6.2
coil voltage
voltage applied as an energizing quantity
[IEV 444-03-03]
3.6.3
operative range
range of values of coil voltage for which a relay is able to perform its specified function
[IEV 444-03-05, modified]
NOTE For the following terms, refer also to Figures 3 to 7 which show the sequential functions of relays covered
by the definitions.
3.6.4
magnetic preconditioning value
value of the coil voltage at which the relay attains a defined magnetic condition
[IEV 444-03-19]
NOTE 1 For polarized relays, distinction is made between preconditioning in forward (operate) direction, and
preconditioning in reverse direction.
NOTE 2 For bistable relays, preconditioning may also be used to set the relay to a defined position.

– 14 – 61810-7  IEC:2006(E)
3.6.5
non-operate voltage
value of the coil voltage at which a relay does not operate
[IEV 444-03-07, modified]
3.6.6
operate voltage, set voltage (for bistable relays only)
value of the coil voltage at which a relay operates
[IEV 444-03-06, modified]
3.6.7
non-release voltage
value of the coil voltage at which a monostable relay does not release
[IEV 444-03-09, modified]
3.6.8
release voltage
value of the coil voltage at which a monostable relay releases
[IEV 444-03-08, modified]
3.6.9
non-reset voltage
value of the coil voltage at which a bistable relay does not reset
[IEV 444-03-11, modified]
3.6.10
reset voltage
value of the coil voltage at which a bistable relay resets
[IEV 444-03-10, modified]
3.6.11
revert voltage
for a specific type of polarized relay, value of the coil voltage greater than and with the same
polarity as the operate voltage, at which the relay reverts
[IEV 444-03-12, modified]
3.6.12
non-revert voltage
for a specific type of polarized relay, value of the coil voltage greater than and with the same
polarity as the operate voltage, at which the relay does not revert
[IEV 444-03-13, modified]
3.6.13
revert reverse voltage
for a specific type of polarized bistable relay, value of the coil voltage greater than and with the
same polarity as the reset voltage, at which the relay reverts reverse
[IEV 444-03-14, modified]
61810-7  IEC:2006(E) – 15 –
3.6.14
non-revert reverse voltage
for a specific type of polarized bistable relay, value of the coil voltage greater than and with the
same polarity as the reset voltage, at which the relay does not revert reverse
[IEV 444-03-15, modified]
3.6.15
reverse polarity voltage
for a polarized monostable relay, value of the coil voltage of reverse polarity at which the relay
does not operate
[IEV 444-03-16, modified]
3.6.16
active power
under periodic conditions, mean value, taken over one period T, of the instantaneous power p:
T
P = 1 T p dt
∫
NOTE 1 Under sinusoidal conditions, the active power is the real part of the complex power.
NOTE 2 The SI unit for active power is the watt.
[IEV 131-11-42]
3.6.17
apparent power
product of the r.m.s. voltage U between the terminals of a two-terminal element or two-terminal
circuit and the r.m.s. electric current I in the element or circuit:
S = UI
NOTE 1 Under sinusoidal conditions, the apparent power is the modulus of the complex power.
NOTE 2 The SI unit for apparent power is the voltampere.
[IEV 131-11-41]
3.7 Electrical properties of contacts
3.7.1
contact current
electric current which a relay contact carries before opening or after closing
[IEV 444-04-26]
3.7.2
switching current
electric current which a relay contact makes and/or breaks
[IEV 444-04-27]
3.7.3
switching voltage
voltage between the contact members before closing or after opening of a relay contact
[IEV 444-04-25, modified]
– 16 – 61810-7  IEC:2006(E)
3.7.4
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]
3.7.5
contact noise
spurious voltage which appears across the terminals of a closed contact
[IEV 444-04-33]
3.8 Contact load categories
3.8.1
contact load category 0
CC 0
load characterized by a maximum switching voltage of 30 mV and a maximum switching
current of 10 mA
3.8.2
contact load category 1
CC 1
low load without contact arcing
NOTE Arcing with a duration of up to 1 ms is disregarded.
3.8.3
contact load category 2
CC 2
high load where contact arcing can occur
3.9 Mechanical properties of contacts
3.9.1
contact tip
contact point
part of a contact member at which the contact circuit opens or closes
[IEV 444-04-06]
3.9.2
contact gap
gap between the contact tips (points) when the contact circuit is open
[IEV 444-04-09, modified]
3.9.3
contact force
force which two contact members exert against each other at their contact tips (points) in the
closed position
[IEV 444-04-10, modified]
3.9.4
contact member
conductive part designed to co-act with another to close or open the contact
[IEV 444-04-05, modified]
61810-7  IEC:2006(E) – 17 –
3.10 Terms relating to times
3.10.1
operate time
time interval between the application of the specified coil voltage to a relay in the release
condition and the change of state of the last contact circuit, bounce time not included
[IEV 444-05-01, modified]
NOTE The operate time covers the closing time of a make contact, and the opening time of a break contact.
3.10.2
release time
time interval between the removal of the specified coil voltage from a monostable relay in the
operate condition and the change of state of the last contact circuit, bounce time not included
[IEV 444-05-02, modified]
NOTE The release time covers the opening time of a make contact and the closing time of a break contact.
3.10.3
reset time
time interval between the application of the specified coil voltage to a bistable relay in the
operate condition and the change of state of the last contact circuit, bounce time not included
[IEV 444-05-03, modified]
NOTE The reset time covers the opening time of a make contact and the closing time of a break contact.
3.10.4
bounce time
for a contact which is closing/opening its circuit, time interval between the instant when the
contact circuit first closes/opens and the instant when the circuit is finally closed/opened
[IEV 444-05-04]
3.10.5
transfer time; transit time
for a change-over break-before-make contact, time interval during which both contact circuits
are open
[IEV 444-05-06]
3.10.6
bridging time
for a change-over make-before-break contact, the time interval during which both contact
circuits are closed
[IEV 444-05-05]
3.10.7
stabilization time
time interval between the instant when a specified coil voltage is applied and the instant when
the last contact circuit is closed/opened and fulfils the specified requirements, bounce time
included
[IEV 444-05-07, modified]
3.10.8
minimum time of energization
minimum duration of application of the coil voltage to ensure that the relay operates or resets

– 18 – 61810-7  IEC:2006(E)
[IEV 444-05-08, modified]
3.10.9
contact time difference
for a relay having several contacts of the same type, difference between the maximum value of
the operate (release/reset) time and the minimum value of the operate (release/reset) time
3.11 Miscellaneous terms
3.11.1
coil transient suppression device
device connected to the relay coil to limit its back electromotive force (e.m.f.) to a prescribed
value
3.11.2
thermal equilibrium
variation of less than 1 K between any two out of three consecutive measurements made at an
interval of 5 min
4 Test and measurement procedures
4.1 General
The test and measurement procedures specified in this part of IEC 61810 are recommended to
be used for the testing of parameters given for a relay.
4.2 Deviations
Any test and measurement procedures deviating from those given in this standard may be
applied but shall be indicated in the documentation of the relay.
4.3 Precision of measurement
Measurement inaccuracies shall be taken into account when evaluating the results. If not
otherwise specified, all measurements shall be taken with an accuracy of ±2 % for electrical, of
±5 % for mechanical parameters and with ±2 K for temperatures.
4.4 Power supplies
Unless otherwise specified, the following shall apply to power supplies and their connections:
Voltage or current shall be maintained within a tolerance range of ±5 % of the specified value.
The alternating component (ripple content) of the output of a d.c. supply shall not exceed 6 %.
NOTE 1 The alternating component in d.c., expressed as a percentage, is defined as:
(maximum value – minimum value) × 10/(d.c. component)
The frequency of an a.c. supply shall be maintained within a tolerance range of ±2 % of the
specified value, and the distortion factor shall not exceed 5 %.
NOTE 2 The distortion factor is defined as the 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.
The following shall be earthed as applicable: one side of the d.c. power supply, one side of the
single-phase a.c. power supply, or the neutral of the three-phase a.c. power supply. The
earthed side of the power supply shall be connected to: one terminal of each of one or more

61810-7  IEC:2006(E) – 19 –
coils of the relay under test and one terminal of each of the loads connected to the relay under
test.
4.5 Reference conditions for testing
4.5.1 General conditions
Unless otherwise specified, all tests shall be carried out under the standard atmospheric
conditions for testing as follows:
• temperature 23 °C ± 5 °C
• relative humidity 25 % to 75 %
• air pressure 86 kPa to 106 kPa (860 mbar to 1 060 mbar)
Before testing, the relays shall be subjected to the standard atmospheric conditions for a time
sufficient to allow them to reach thermal equilibrium.
Unless otherwise specified, the terms a.c. voltage and current indicate r.m.s. values throughout
this standard.
4.5.2 Use of sockets
4.5.2.1 General considerations
Relays with the option of connection via an appropriate socket may be tested using a specified
socket or via direct electrical connections. In either case, the wiri
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