IEC TR 62246-3:2018

IEC TR 62246-3 ®
Edition 1.0 2018-06
TECHNICAL
REPORT
colour
inside
Reed switches –
Part 3: Reliability data for reed switch-devices in typical safety applications

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IEC TR 62246-3 ®
Edition 1.0 2018-06
TECHNICAL
REPORT
colour
inside
Reed switches –
Part 3: Reliability data for reed switch-devices in typical safety applications

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.70 ISBN 978-2-8322-5811-8

– 2 – IEC TR 62246-3:2018 © IEC 2018
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
3.1 Failure of systems . 9
3.2 Confirmation of safety measures for reed switch-devices . 9
3.3 Reliability data of reed switch-devices . 10
3.4 Functional safety of reed switch-devices . 11
4 Approach adopted for this document. 12
4.1 General . 12
4.2 Application of reed switches in accordance with IEC 62246 (all parts) . 12
4.3 Application in accordance with ISO 13849 (all parts), IEC 62061 and
IEC 61508 (all parts) . 13
4.4 Application of the design of the E/E/PE safety-related system . 13
4.5 Application of SIL capability to function units . 14
4.5.1 General . 14
4.5.2 Procedures . 14
4.5.3 Random hardware failures . 14
4.5.4 Systematic faults . 15
4.5.5 Safety manual . 15
4.5.6 Application of SIL capability for the allocation of SIL to systems . 15
5 Examples of reliability data for reed switch-devices . 16
6 Examples of classification of involved groups for responsibility . 16
Annex A (informative) Hydraulic and pneumatic fluid power . 17
A.1 Example of electric actuator in hydraulic fluid power . 17
A.2 Examples of group safety standards . 17
A.3 Example of safety requirements . 17
A.4 Example of safety measures for the reed switch-device . 17
A.4.1 Usage conditions of end-user . 17
A.4.2 Usage conditions of the reed switch-device . 18
A.5 Example of calculation of failure rates for the reed switch-device . 19
A.5.1 Dangerous failure rate of the reed switch-device . 19
A.5.2 Estimates for diagnostic coverage (DC) . 20
A.5.3 Estimates for common cause failure (CCF) . 20
A.6 Example of classification of involved groups for responsibility . 20
Annex B (informative) Safety of machinery. 21
B.1 Example of guard interlocking device . 21
B.2 Example of group safety standards . 21
B.3 Example of safety requirements for the system . 21
B.3.1 Description of Type 3 interlocking device – example . 21
B.3.2 Typical characteristics . 22
B.3.3 Remarks . 22
B.3.4 Description of Type 4 interlocking device – example . 23
B.3.5 Typical characteristics . 23
B.3.6 Remarks . 23

B.4 Example of safety measures for the reed switch-device . 23
B.4.1 Usage conditions of end-user . 23
B.4.2 Usage conditions of the reed switch-device . 24
B.5 Example of calculation of failure rates for the reed switch-device . 24
B.5.1 General . 24
B.5.2 Dangerous failure rate of reed switch-device . 24
B.5.3 Estimation for diagnostic coverage (DC) . 24
B.5.4 Estimates for common cause failure (CCF) . 24
B.6 Example of classification of involved groups for responsibility . 25
Annex C (informative) Automatic electrical controls for household and similar use . 26
C.1 Example of automatic electrical burner control system . 26
C.2 Examples of group safety standards . 26
C.3 Example of safety requirements for the system . 26
C.4 Example of safety measures for the reed switch-device . 27
C.4.1 Usage conditions of end-user . 27
C.4.2 Usage conditions of reed switch-device . 28
C.5 Example of calculation of failure rates for the reed switch-device . 28
C.5.1 Dangerous failure rate of reed switch-device . 28
C.5.2 Estimates for diagnostic coverage (DC) . 29
C.5.3 Estimates for common cause failure (CCF) . 29
C.5.4 Accident damage reduction . 29
C.6 Example of classification of involved groups for responsibility . 29
Annex D (informative) Household and similar electric appliances . 31
D.1 Example of automatic electric washing machine . 31
D.2 Examples of group safety standards . 31
D.3 Example of safety requirements for the system . 31
D.4 Example of safety measures for the reed switch-device . 31
D.4.1 Usage conditions of end-user . 31
D.4.2 Usage conditions of reed switch-device . 32
D.5 Example of calculation of failure rates for the reed switch-device . 33
D.5.1 Dangerous failure rate of reed switch-device . 33
D.5.2 Estimates for diagnostic coverage (DC) . 33
D.5.3 Estimation for common cause failure (CCF) . 33
D.6 Example of classification of involved groups for responsibility . 33
Annex E (informative) Electric power systems . 35
E.1 Example of measuring and protection relay system . 35
E.2 Industrial standards . 35
E.3 Safety requirements for the system – example . 35
E.4 Safety measures for the reed switch device – example . 35
E.4.1 Usage conditions of end-user . 35
E.4.2 Usage conditions of the reed switch-device . 36
E.5 Example of the calculation of failure rates for the reed switch-device . 37
E.6 Example of classification of involved groups for responsibility . 37
Annex F (informative) Railway application . 39
F.1 Example of automatic train control (ATC) system . 39
F.2 Examples of group safety standards . 39
F.3 Example of safety requirements for the system . 39
F.4 Example of safety measures for the reed switch-device . 39

– 4 – IEC TR 62246-3:2018 © IEC 2018
F.4.1 Usage conditions of end-user . 39
F.4.2 Usage conditions of the reed switch-device . 40
F.5 Example of calculation of failure rates for the reed switch-device . 41
F.6 Example of classification of involved groups for responsibility . 42
Bibliography . 43

Figure A.1 – Architecture of an electric actuator in hydraulic fluid power . 18
Figure A.2 – Control c
...