IEC 62912-2:2019

Railway applications - Direct current signalling monostable relays - Part 2: Spring type relays

IEC 62912-2:2019 gives requirements for direct current relays intended for safety-related applications in railway signalling installations.
This document is applicable to non-proved signalling monostable relays of the spring type, whose return force is generated by elasticity of spring.
The return force can be provided either from a separate spring and/or from the contact springs themselves.

General Information

• Status: Published
• Publication Date: 15-Aug-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 45.060.01 - Railway rolling stock in general
• Technical Committee: TC 9 - Electrical equipment and systems for railways
• Drafting Committee: PT 62912-2 - TC 9/PT 62912-2
• Current Stage: PPUB - Publication issued
• Start Date: 23-Aug-2019
• Completion Date: 16-Aug-2019

Standards Content (Sample)

IEC 62912-2 ®
Edition 1.0 2019-08
INTERNATIONAL
STANDARD
Railway applications – Direct current signalling monostable relays –
Part 2: Spring type relays
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IEC 62912-2 ®
Edition 1.0 2019-08
INTERNATIONAL
STANDARD
Railway applications – Direct current signalling monostable relays –

Part 2: Spring type relays
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 45.060.01 ISBN 978-2-8322-7202-2

– 2 – IEC 62912-2:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Essential requirements of the relays and their construction. 11
4.1 Generic requirements. 11
4.1.1 Generic requirements for spring type signalling relays . 11
4.1.2 Forcibly guided contacts . 11
4.1.3 Forcibly guided operation . 11
4.1.4 Degradation during service . 11
4.2 Specific requirements . 11
4.2.1 Non-welding characteristics . 11
4.2.2 Opening of make contacts . 11
4.2.3 Mounting orientation . 12
4.3 Mechanical construction . 12
4.3.1 Connecting device . 12
4.3.2 Materials and arrangement . 12
4.3.3 Prevention of spring breakage . 12
4.3.4 Prevention of screw loosening . 12
4.4 Environmental conditions . 13
4.4.1 General . 13
4.4.2 Vibrations and shocks . 13
4.5 Magnetic system . 13
4.5.1 Anti-residual magnetism design . 13
4.5.2 Function . 13
4.6 Design of insulation . 13
4.6.1 General . 13
4.6.2 Overvoltage . 14
4.6.3 Test voltage . 14
4.6.4 Pollution . 14
4.7 Contacts . 14
4.7.1 Spacing (contact gap) . 14
4.7.2 Break contact . 14
4.7.3 Contact heating . 15
4.7.4 Service life . 15
4.7.5 Minimum distance apart of the relay contact elements . 15
4.7.6 Contact force . 15
4.7.7 Opening force of contacts . 15
4.7.8 Self-cleaning . 16
4.7.9 Bounce . 16
4.7.10 Contact resistance . 16
5 Application conditions . 16
6 Measurement and test methods . 16

Annex A (normative) Modified Goodman diagram. 18
A.1 Modified Goodman diagram . 18
A.2 Calculation method for maximum stress of return spring . 18
A.3 Stress calculation example of return spring . 20
Annex B (informative) Example of service life agreement (lifetime expectation) . 22
Annex C (informative) Method of measuring the opening force of contacts . 23
Bibliography . 24

Figure A.1 – Modified Goodman diagram . 18
Figure A.2 – Example of railway direct current signalling monostable relay . 19
Figure A.3 – Stress calculation model of return spring . 19
Figure A.4 – Plot for an example stress of return spring at Modified Goodman Diagram . 21
Figure C.1 – Method of measuring the opening force of contacts . 23

Table 1 – Contact resistance . 16
Table 2 – List of measurement and test items . 17
Table B.1 – Example of service life agreement (minimum number of movements) . 22

– 4 – IEC 62912-2:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RAILWAY APPLICATIONS – DIRECT CURRENT
SIGNALLING MONOSTABLE RELAYS –

Part 2: Spring type relays
FOREWORD
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International Standard IEC 62912-2 has been prepared by IEC technical committee 9:
Electrical equipment and systems for railways.
The text of this International Standard is based on the following documents:
FDIS Report on voting
9/2513/FDIS 9/2532/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

The existing IEC 62912 will be renumbered as IEC 62912-1 on the occasion of its next
revision.
A list of all parts in the IEC 62912 series, published under the general title Railway
applications – Direct current signalling monostabe relays, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
...