IEC PAS 61810-2-1:2008

Electromechanical elementary relays - Part 2-1: Reliability - Procedure for the verification of <i>B</i>₁₀ values

IEC/PAS 61810-2-1:2008(E) specifies reliability test procedures for electromechanical elementary relays when enhanced requirements for the verification of reliability apply. Particular provisions are given for relays incorporated in safety-related control systems of machinery in accordance with IEC 62061 and ISO 13849-1. For such relays B10 values for dangerous failures (B10d values) are derived from the tests specified in this PAS.

General Information

• Status: Replaced
• Publication Date: 08-Jul-2008
• ICS: 11.040.50 - Radiographic equipment
• ICS: 29.120.70 - Relays
• Technical Committee: TC 94 - Electrical relays
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 25-Feb-2011

Relations

• Replaced By: IEC 61810-2-1:2011 - Electromechanical elementary relays - Part 2-1: Reliability - Procedure for the verification of B₁₀ values
• Effective Date: 05-Sep-2023
• Revised: IEC 61810-2-1:2017 - Electromechanical elementary relays - Part 2-1: Reliability - Procedure for the verification of B₁₀ values
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC/PAS 61810-2-1
Edition 1.0 2008-07
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
Electromechanical elementary relays –
Part 2-1: Reliability – Procedure for the verification of B values
IEC/PAS 61810-2-1:2008(E)
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IEC/PAS 61810-2-1
Edition 1.0 2008-07
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
Electromechanical elementary relays –
Part 2-1: Reliability – Procedure for the verification of B values
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
M
ICS 29.120.70 ISBN 2-8318-9842-0
– 2 – PAS 61810-2-1 © IEC:2008(E)

CONTENTS
FOREWORD.3
INTRODUCTION.5
1 Scope.6
2 Normative references .6
3 Terms and definitions .6
4 Verification of B .7
4.1 General .7
4.2 Requirements.7
4.2.1 Test specimens .7
4.2.2 Test circuit .7
4.2.3 Contact loads .7
4.2.4 Environmental conditions.7
4.2.5 Operating conditions.8
4.2.6 Failure criteria .8
4.3 Performance of the tests .8
4.3.1 Conformity test .8
4.3.2 Periodic test .8
5 Evaluation and verification of B .9
10d
5.1 General .9
5.2 Requirements.9
5.2.1 Test specimens .9
5.2.2 Test circuit .9
5.2.3 Contact loads .10
5.2.4 Environmental conditions.10
5.2.5 Operating conditions.10
5.2.6 Failure criteria .10
5.3 Performance of the tests .10
5.3.1 Conformity test .10
5.3.2 Periodic test .11

Figure 1 – Schematic flowchart .12
Figure 2 – Schematic flowchart for relays where dangerous failures have to be
assessed .13

PAS 61810-2-1 © IEC:2008(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMECHANICAL ELEMENTARY RELAYS –

Part 2-1: Reliability – Procedure for the verification of B values
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
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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.
This specification is only intended to be used in conjunction with IEC 61810-2.
IEC-PAS 61810-2-1 has been processed by IEC technical committee 94: All-or-nothing
electrical relays.
The text of this PAS is based on the following documents:
Draft PAS Report on voting
94/272/PAS 94/274/RVD
Full information on the voting for the approval of this PAS can be found in the report on voting
indicated in the above table.
– 4 – PAS 61810-2-1 © IEC:2008(E)

Following publication of this PAS, which is a pre-standard publication, the technical committee
concerned may transform it into an International Standard.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This PAS shall remain valid for an initial maximum period of three years starting from the
publication date. 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 61810-2-1 © IEC:2008(E) – 5 –
INTRODUCTION
This Publicly Available Specification (PAS) is published as an interim IEC document. Its
content is intended to be incorporated in the next edition of IEC 61810-2 during the upcoming
maintenance cycle of that standard.
Based on the general provisions of IEC 61810-2 this PAS specifies reliability test procedures
for electromechanical elementary relays where enhanced requirements for the verification of
reliability apply. An initial conformity test has to be passed and then confirmed by periodic
(the mean number of cycles
tests at least once a year. This PAS describes how figures for B
until 10 % of the relays have failed) are derived from these life tests performed with
representative relay samples.
In particular, when electromechanical elementary relays are intended to be incorporated in
safety-related control systems of machinery in accordance with IEC 62061 and ISO 13849-1,
the mean time to dangerous failure (MTTF ) is a measure that can be taken into account
d
when assessing the probability of dangerous failure of the safety function concerned.
Although a component failure cannot be defined as “dangerous” unless the detailed
application is known, it is common to consider a failure mode that is likely to result in danger
in a typical application of the component, and to refer to this failure mode as a “dangerous
failure”. The MTTF then becomes the expectation of the mean time to failure in this
d
“dangerous“ mode. For the calculation of MTTF for electromechanical relays, the data
d
can be used (see Clause C.4 of ISO 13849-1).
provided by the manufacturer for B
10d
Electromechanical elementary relays with forcibly guided (mechanically linked) contacts offer
the possibility of a high diagnostic coverage (DC) according to 4.5.3 of ISO 13849-1.
NOTE Requirements for such relays are given in EN 50205.

– 6 – PAS 61810-2-1 © IEC:2008(E)

ELECTROMECHANICAL ELEMENTARY RELAYS –

Part 2-1: Reliability – Procedure for the verification of B values
1 Scope
This PAS specifies reliability test procedures for electromechanical elementary relays when
enhanced requirements for the verification of reliability apply.
Particular provisions are given for relays incorporated in safety-related control systems of
machinery in accordance with IEC 62061 and ISO 13849-1. For such relays B values for
dangerous failures (B values) are derived from the tests specified in this PAS.
10d
This specification is only intended to be used in conjunction with IEC 61810-2.
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 61810-1:2003, Electromechanical elementary relays – Part 1: General and safety
requirements
IEC 61810-2:2005, Electromechanical elementary relays – Part 2: Reliability
IEC 62061:2005, Safety of machinery – Functional safety of safety-related electrical,
electronic and programmable electronic control systems
ISO 13849-1, Safety of machinery – Safety-related parts of machinery – Part 1: General
principles for design
3 Terms and definitions
For the purposes of this document, the terms and definitions of IEC 61810-2 apply.
3.1
dangerous failure
failure which has the potential to
...