EN IEC 61800-5-3:2023

Adjustable speed electrical power drive systems - Part 5-3: Safety requirements - Functional, electrical and environmental requirements for encoders

IEC 61800-5-3:2021, which is a product standard, specifies requirements and makes recommendations for the design and development, integration and validation of safety-related encoder (Encoder(SR)) in terms of their functional safety considerations, electrical safety and environmental conditions. It applies to Encoder(SR), being sensors as part of a PDS(SR). This document can also be referred to and used for Encoder(SR) in any other safety-related application, for example safety-related position monitoring. This document is applicable where functional safety of an encoder is claimed and the Encoder(SR) is operating mainly in the high demand or continuous mode. The requirements of IEC 61800-5-2:2016 for PDS(SR) apply to Encoder(SR) as applicable. This document includes additional or different requirements for Encoder(SR). It sets out safety-related considerations of Encoder(SR) in terms of the framework of IEC 61508 (all parts), and introduces requirements for Encoder(SR) as subsystems of a safety-related system. It is intended to facilitate the realisation of the electrical/electronic/programmable electronic (E/E/PE) and mechanical parts of an Encoder(SR) in relation to the safety performance of safety sub-function(s) of an Encoder(SR).

Elektrische Leistungsantriebssysteme mit einstellbarer Drehzahl - Teil 5-3: Anforderungen an die Sicherheit von Encodern (Gebern) - Funktional, elektrisch und umwelttechnisch

Entraînements électriques de puissance à vitesse variable - Partie 5-3: Exigences de sécurité - Exigences fonctionnelle, électrique et environnementale pour codeurs

L'IEC 61800-5-3:2021, qui est une norme de produit, spécifie des exigences et donne des recommandations pour la conception et le développement, l'intégration et la validation des codeurs relatifs à la sécurité (codeurs(SR)), au regard de leur sécurité fonctionnelle, de leur sécurité électrique et des conditions d'environnement. Elle s'applique aux codeurs(SR) qui sont des capteurs qui font partie d'un PDS(SR). Le présent document peut également servir de référence et être utilisé pour les codeurs(SR) dans le cadre de toute autre application relative à la sécurité, par exemple la surveillance de position relative à la sécurité. Le présent document est applicable lorsque la sécurité fonctionnelle d'un codeur est revendiquée et que le codeur(SR) fonctionne principalement en mode à sollicitation élevée ou en mode continu. Les exigences de l'IEC 61800-5-2:2016 concernant les PDS(SR) s'appliquent aux codeurs(SR), selon le cas. Le présent document comprend des exigences supplémentaires ou différentes pour les codeurs(SR). Il expose des considérations relatives à la sécurité des codeurs(SR), prises dans le cadre de l'IEC 61508 (toutes les parties), et présente des exigences pour les codeurs(SR) en tant que sous-systèmes d'un système relatif à la sécurité. Il est destiné à faciliter la réalisation des parties électriques/électroniques/électroniques programmables (E/E/PE) d'un codeur(SR) en liaison avec la performance de sécurité d'une ou de plusieurs sous-fonctions de sécurité d'un codeurs(SR)

Električni pogonski sistemi z nastavljivo hitrostjo - 5-3. del: Varnostne zahteve - Funkcionalne, električne in okoljske zahteve za kodirnike (IEC 61800-5-3:2021)

Ta del standarda IEC 61800, ki je standard za izdelek, določa zahteve in podaja priporočila za načrtovanje in izdelavo, vgradnjo in potrjevanje z varnostjo povezanega kodirnika (Encoder(SR)) v smislu funkcionalne varnosti, električne varnosti in okoljskih pogojev. Uporablja se za kodirnik Encoder(SR) kot senzor v električnem pogonskem sistemu z nastavljivo hitrostjo (PDS(SR)).
OPOMBA 1: izraz »vgradnja« se nanaša na sam kodirnik Encoder(SR) in ne na njegovo vključitev v z varnostjo povezano aplikacijo.
Ta dokument se lahko nanaša in uporablja tudi za kodirnik Encoder(SR) v kateri koli drugi z varnostjo povezani aplikaciji, na primer v z varnostjo povezani kopirni napravi.
OPOMBA 2: Ta dokument določa samo zahteve za dopolnilno funkcionalno varnost, električno varnost in okoljske pogoje, ki niso jasno podani v drugih delih skupine standardov IEC 61800.
Ta dokument se uporablja, kjer se zahteva funkcionalna varnost kodirnika in kodirnik Encoder(SR) deluje predvsem v načinu z visokimi zahtevami ali neprekinjenem načinu.
OPOMBA 3: Čeprav je za kodirnik Encoder(SR) mogoče tudi delovanje v načinu z nizkimi zahtevami, se ta dokument osredotoča na delovanje v načinu z visokimi zahtevami in neprekinjenem načinu. Varnostne podfunkcije, ki so vpeljane za način z visokimi zahtevami ali neprekinjeni način, je mogoče uporabiti tudi v načinu z nizkimi zahtevami. Zahteve za način z nizkimi zahtevami so podane v standardu IEC 61508 (vsi deli) [2]. Nekaj navodil za ocenjevanje povprečne vrednosti verjetnosti nevarnih okvar na zahtevo (PFDavg) je podanih v dodatku F standarda IEC 61800-5-2:2016.
Zahteve standarda IEC 61800-5-2:2016 za električni pogonski sistem z nastavljivo hitrostjo se uporabljajo za kodirnik Encoder(SR), kjer je to ustrezno. Ta dokument vključuje dodatne ali različne zahteve za kodirnik Encoder(SR). Določa varnostne vidike za kodirnik Encoder(SR) v smislu okvira standarda IEC 61508 (vsi deli) in uvaja zahteve za kodirnik Encoder(SR) kot podsisteme varnostnega sistema. Namenjen je za lažjo realizacijo električnih/elektronskih/programirljivih elektronskih (E/E/PE) in mehanskih delov kodirnika Encoder(SR) v povezavi z varnostno zmogljivostjo varnostnih podfunkcij kodirnika Encoder(SR).
Proizvajalci in dobavitelji kodirnika Encoder(SR) bodo z uporabo normativnih zahtev tega dokumenta uporabnikom (integrator sistema, proizvajalec originalne opreme) navedli varnostno zmogljivost kodirnika Encoder(SR). To bo poenostavilo vključitev kodirnika Encoder(SR) v z varnostjo povezane nadzorne sisteme z uporabo načel iz standarda IEC 61508 (vsi deli) in po možnosti njegovih uvajanj za ustrezen sektor (npr. standard IEC 61511 (vsi deli) [3], IEC 61513 [4],
IEC 62061 [5] ali ISO 13849-1 in ISO 13849-2 (glej točko 2).
Z uporabo zahtev iz tega dokumenta se izpolnijo ustrezne zahteve standarda IEC 61508 (vsi deli), ki so potrebne za kodirnik Encoder(SR).
Ta dokument ne določa zahtev za:
• funkcionalne lastnosti kodirnika Encoder(SR) brez varnostnega vidika;
• analizo nevarnosti in tveganja za določeno uporabo;
• prepoznavanje varnostnih podfunkcij za to uporabo;
• začetno dodelitev stopenj varnostne celovitosti (SIL) tem varnostnim podfunkcijam;
• pogonsko opremo, razen za priprave vmesnika;
• sekundarne nevarnosti (npr. zaradi okvare pri postopku proizvodnje);
• postopek proizvodnje kodirnika Encoder(SR);
• veljavnost signalov in ukazov za kodirnik Encoder(SR); in
• varnostne vidike (npr. kibernetska varnost ali varnost dostopa do kodirnika Encoder(SR)).
OPOMBA 4: Zahteve za funkcionalno varnost kodirnika Encoder(SR) so odvisne od uporabe in jih je mogoče upoštevati kot del splošne ocene tveganja za namestitev. Če dobavitelj kodirnika Encoder(SR) ni odgovoren za pogonsko opremo, je načrtovalec namestitve odgovoren za oceno tveganja ter določanje zahtev glede funkcionalnosti in varnostne celovitosti kodirnika Encoder(SR).
Ta dokument se uporablja za kodirnik Encoder(SR), ki uvaja varnostne podfunkcije s stopnjo varnostne celo

General Information

• Status: Published
• Publication Date: 19-Oct-2023
• Withdrawal Date: 29-Nov-2021
• ICS: 13.110 - Safety of machinery
• ICS: 29.130.99 - Other switchgear and controlgear
• ICS: 29.200 - Rectifiers. Convertors. Stabilized power supply
• Technical Committee: CLC/TC 22X - Power electronics
• Drafting Committee: IEC/SC 22G - IEC_SC_22G
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 20-Oct-2023
• Completion Date: 20-Oct-2023
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: SIST EN IEC 61800-5-3:2024 - Adjustable speed electrical power drive systems - Part 5-3: Safety requirements - Functional, electrical and environmental requirements for encoders (IEC 61800-5-3:2021)

Overview

EN IEC 61800-5-3:2023 (identical to EN IEC 61800-5-3:2023 / IEC 61800-5-3:2021) is a product standard that defines functional, electrical and environmental safety requirements for encoders used in adjustable speed electrical power drive systems. It applies where the functional safety of an encoder (denoted Encoder(SR)) is claimed - particularly when operating in high demand or continuous mode - and addresses design, integration, verification and validation of encoders as safety-related sensors or subsystems of a safety-related power drive system (PDS(SR)).

Key topics and technical requirements

The standard focuses on safety performance within the IEC 61508 functional safety framework and includes additional encoder-specific requirements:

• Safety sub-functions: Defines safe incremental position (SIP), safe absolute position (SAP), safe speed value (SSV), safe acceleration value (SAV) and related evaluation/signalling functions.
• Design and development: Requirements for hardware, software, fault detection and diagnostics; design standards and documentation expectations.
• Signal generation & processing: Specific guidance for optical, magnetic, sine/cosine, incremental and absolute encoders, resolvers and square‑wave interfaces.
• Mechanical requirements: Fastenings, connecting elements, bearings, and mechanical immunity considerations.
• Electrical & environmental requirements: EMC/immunity, thermal and mechanical testing (vibration, shock), clearances/creepage and integrated cable integrity.
• Verification & validation: Hardware fault tolerance checks, qualitative FMEDA, quantitative analysis, tests for interpolation suitability, and documented test plans.
• Information for use: Labelling, instructions, parameterization, and modification/change control.
• Test requirements & annexes: Detailed functional, EM, thermal and mechanical test guidance and informative annexes (types of encoders, universal architecture, test examples).

Practical applications - who uses this standard

SIST EN IEC 61800-5-3 is essential for:

• Encoder manufacturers designing Encoder(SR) products to claim functional safety and to support safety sub-functions in PDS(SR).
• Drive and automation system designers integrating safety-related encoders into adjustable speed drives, robotics, conveyors, machine tools, wind turbines and position-monitoring systems.
• Safety engineers and compliance teams performing FMEDA, risk assessment, verification and validation activities.
• Test laboratories and certification bodies executing EMC, thermal, mechanical and functional safety testing.
• Integrators and OEMs preparing documentation, labels and instructions for safe application.

Related standards (context)

• IEC 61508 series (functional safety framework)
• IEC 61800-5-2 (safety requirements - functional)
• IEC 61800-5-1 (safety - electrical/thermal)
• IEC 61000 series (EMC), IEC 60068 (environmental testing), ISO 13849 (machinery safety)

Keywords: EN IEC 61800-5-3:2023, IEC 61800-5-3, encoder functional safety, safety encoders standard, encoder testing, PDS(SR), Encoder(SR).

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2024
Električni pogonski sistemi z nastavljivo hitrostjo - 5-3. del: Varnostne zahteve -
Funkcionalne, električne in okoljske zahteve za kodirnike (IEC 61800-5-3:2021)
Adjustable speed electrical power drive systems - Part 5-3: Safety requirements -
Functional, electrical and environmental requirements for encoders (IEC 61800-5-
3:2021)
Elektrische Leistungsantriebssysteme mit einstellbarer Drehzahl - Teil 5-3:
Anforderungen an die Sicherheit von Encodern (Gebern) - Funktional, elektrisch und
umwelttechnisch (IEC 61800-5-3:2021)
Entraînements électriques de puissance à vitesse variable - Partie 5-3: Exigences de
sécurité - Exigences fonctionnelle, électrique et environnementale pour codeurs (IEC
61800-5-3:2021)
Ta slovenski standard je istoveten z: EN IEC 61800-5-3:2023
ICS:
29.200 Usmerniki. Pretvorniki. Rectifiers. Convertors.
Stabilizirano električno Stabilized power supply
napajanje
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61800-5-3

NORME EUROPÉENNE
EUROPÄISCHE NORM October 2023
ICS 29.200; 29.130.99; 13.110
English Version
Adjustable speed electrical power drive systems - Part 5-3:
Safety requirements - Functional, electrical and environmental
requirements for encoders
(IEC 61800-5-3:2021)
Entraînements électriques de puissance à vitesse variable - Elektrische Leistungsantriebssysteme mit einstellbarer
Partie 5-3: Exigences de sécurité - Exigences fonctionnelle, Drehzahl - Teil 5-3: Anforderungen an die Sicherheit von
électrique et environnementale pour codeurs Encodern (Gebern) - Funktional, elektrisch und
(IEC 61800-5-3:2021) umwelttechnisch
(IEC 61800-5-3:2021)
This European Standard was approved by CENELEC on 2021-03-30. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61800-5-3:2023 E

European foreword
The text of document 22G/431/FDIS, future edition 1 of IEC 61800-5-3, prepared by SC 22G
"Adjustable speed electric power drive systems (PDS)" of IEC/TC 22 "Power electronic systems and
equipment" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2024-04-20
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2026-10-20
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61800-5-3:2021 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
ISO 12100:2010 NOTE Approved as EN ISO 12100:2010 (not modified)
IEC 61508 (series) NOTE Approved as EN 61508 (series)
IEC 61511 (series) NOTE Approved as EN 61511 (series)
IEC 61513 NOTE Approved as EN 61513
IEC 62061 NOTE Approved as EN IEC 62061
IEC 61709:2017 NOTE Approved as EN 61709:2017 (not modified)
IEC 61508-4:2010 NOTE Approved as EN 61508-4:2010 (not modified)
IEC 61508-6:2010 NOTE Approved as EN 61508-6:2010 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60068-2-1 - Environmental testing - Part 2-1: Tests - Test EN 60068-2-1 -
A: Cold
IEC 60068-2-47 - Environmental testing - Part 2-47: Test - EN 60068-2-47 -
Mounting of specimens for vibration, impact
and similar dynamic tests
IEC 60335-1 - Household and similar electrical appliances - - -
Safety - Part 1: General requirements
IEC 60947-5-2 2019 Low-voltage switchgear and controlgear - Part EN IEC 60947-5-2 2020
5-2: Control circuit devices and switching
elements - Proximity switches
- - + A11 2022
IEC 61000-6-7 2014 Electromagnetic compatibility (EMC) - Part 6-7: EN 61000-6-7 2015
Generic standards - Immunity requirements for
equipment intended to perform functions in a
safety-related system (functional safety) in
industrial locations
IEC 61508-2 2010 Functional safety of EN 61508-2 2010
electrical/electronic/programmable electronic
safety-related systems - Part 2: Requirements
for electrical/electronic/programmable
electronic safety-related systems (see
http://www.iec.ch/functionalsafety Functional
Safety and IEC 61508)
IEC 61800-1 1997 Adjustable speed electrical power drive EN 61800-1 1998
systems - Part 1: General requirments - Rating
specifications for low voltage adjustables
speed d.c. power drive systems
IEC 61800-5-1 2007 Adjustable speed electrical power drive EN 61800-5-1 2007
systems - Part 5-1: Safety requirements -
Electrical, thermal and energy
+ A1 2016 + A1 2017
- - + A11 2021
Publication Year Title EN/HD Year
IEC 61800-5-2 2016 Adjustable speed electrical power drive EN 61800-5-2 2017
systems - Part 5-2: Safety requirements -
Functional
IEC 62368-1 2018 Audio/video, information and communication EN IEC 62368-1 2020
technology equipment - Part 1: Safety
requirements
ISO 13849-1 2015 Safety of machinery - Safety-related parts of - -
control systems - Part 1: General principles for
design
ISO 13849-2 2012 Safety of machinery - Safety-related parts of EN ISO 13849-2 2012
control systems - Part 2: Validation

IEC 61800-5-3 ®
Edition 1.0 2021-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Adjustable speed electrical power drive systems –

Part 5-3: Safety requirements – Functional, electrical and environmental

requirements for encoders
Entraînements électriques de puissance à vitesse variable –

Partie 5-3: Exigences de sécurité – Exigences fonctionnelle, électrique et

environnementale pour codeurs
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.110; 29.130.99; 29.200 ISBN 978-2-8322-9400-0

– 2 – IEC 61800-5-3:2021 © IEC 2021
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 11
3 Terms and definitions . 12
4 Safety sub-functions . 20
4.1 General . 20
4.2 Safe incremental position (SIP) . 20
4.3 Safe absolute position (SAP) . 20
4.4 Safe speed value (SSV) . 20
4.5 Safe acceleration value (SAV) . 20
4.6 Safety sub-functions for evaluation and signalling . 21
5 Management of functional safety . 21
6 Requirements for design and development . 21
6.1 General requirements . 21
6.2 Design standards . 25
6.3 Fault detection . 25
6.4 Design requirements for specific types of Encoder(SR) . 26
6.4.1 Design requirements for Encoder(SR) with sine and cosine output
signals . 26
6.4.2 Design requirements for Encoder(SR) with incremental and absolute
output signals . 27
6.4.3 Design requirements for Encoder(SR) with square wave signal interface . 28
6.4.4 Design requirements for Resolver . 28
6.5 Design requirements regarding mechanics . 29
6.5.1 General . 29
6.5.2 Design requirements for mechanical fastenings . 29
6.5.3 Design requirements for mechanical connecting elements . 29
6.5.4 Bearings . 29
6.6 Design requirements for signal generation . 30
6.6.1 General . 30
6.6.2 Design requirements for signal generation of optical Encoder(SR) . 30
6.6.3 Design requirements for signal generation of magnetic Encoder(SR) . 30
6.7 Design requirements for signal processing . 31
6.8 Design requirements for internal evaluation and signaling . 31
6.9 Design requirements for software . 31
6.10 Pre-setting . 31
6.11 Parameterization . 31
6.12 Design requirements for thermal immunity . 31
6.13 Design requirements for mechanical immunity . 31
6.14 Design requirements for integrated connection cables . 31
7 Information for use . 32
7.1 General . 32
7.2 Labels . 32
7.3 Information and instructions for safe application of an Encoder(SR) . 32
8 Verification and validation . 32

IEC 61800-5-3:2021 © IEC 2021 – 3 –
8.1 General . 32
8.2 Verification of hardware fault tolerance . 32
8.3 Additional verification for Encoder(SR) with sine and cosine output signals. 32
8.3.1 Verification of diagnostic measures for Encoder(SR) with sine and
cosine output signals with HFT = 0 . 32
8.3.2 Suitability for interpolation . 32
8.4 Qualitative FMEDA . 33
8.5 Quantification. 34
9 Test requirements . 34
9.1 General . 34
9.2 Planning of tests . 34
9.3 Functional testing . 34
9.4 Electromagnetic (EM) and electrical immunity testing . 34
9.4.1 Electrical tests . 34
9.4.2 Electromagnetic (EM) immunity testing . 35
9.5 Thermal immunity testing . 35
9.5.1 General . 35
9.5.2 Dry cold . 35
9.5.3 Dry heat . 35
9.5.4 Damp heat . 36
9.5.5 Temperature rise test . 36
9.6 Mechanical immunity testing . 36
9.6.1 Clearances and creepage distances . 36
9.6.2 Short-circuit testing of printed wiring boards . 36
9.6.3 Mechanical fastenings . 36
9.6.4 Mechanical connecting elements . 36
9.6.5 Vibration and shock test . 37
9.6.6 Mechanical properties of integrated connecting cables . 38
9.6.7 Testing the non-touchability . 38
9.6.8 Deformation testing . 38
9.7 Material tests . 38
9.8 Suitability of the components and materials used . 38
9.9 Contamination of solid measure . 39
9.10 Labels . 39
9.11 Instructions . 39
9.12 Test documentation . 39
10 Modification . 39
Annex A (informative) Types of Encoder(SR) . 40
Annex B (informative) Universal architecture of Encoder(SR) . 43
B.1 General . 43
B.2 The universal Encoder(SR) architecture . 43
Annex C (informative) Examples of suitable mechanical tests for rotary Encoder(SR) . 44
C.1 General . 44
C.2 Mechanical fastening of the Encoder(SR) . 44
C.2.1 Force-locked connection (e.g. by bolted joints) . 44
C.2.2 Form-locked connection (e.g. by feather key) . 44
C.3 Mechanical connecting elements of the Encoder(SR) – Stator coupling
(torque support) or shaft-rotor coupling . 45
C.3.1 General . 45

– 4 – IEC 61800-5-3:2021 © IEC 2021
C.3.2 Axial loads . 45
C.3.3 Radial loads . 45
Annex D (informative) Extended shock testing for rotary Encoder(SR) mounted to
motors . 47
D.1 General . 47
D.2 Pseudo-velocity shock-response spectrum (PVSRS) . 47
D.3 Verification of resilience . 47
D.4 Testing machine . 48
Annex E (informative) Dimensioning of clearances and creepage distances on printed

wiring boards – Example . 50
E.1 General . 50
E.2 Assumptions . 50
E.3 Application of IEC 61800-5-1:2007, 5.2.2.1 . 50
Annex F (normative) Information and instructions – Detailed list . 51
F.1 Overview. 51
F.2 Detailed list . 51
Annex G (informative) Encoder(SR) fault lists and fault exclusions . 54
Annex H (informative) Quantification . 58
H.1 General . 58
H.2 Safety architecture and safety-related block diagram . 58
H.3 Failure rates . 59
H.4 Failure rates at realistic working temperatures . 60
H.5 Quantitative FMEDA and assessment of diagnostic measures . 61
H.6 Estimation of the common cause factor β (only in case of redundancy) . 62
H.7 Estimation of the PFH . 62
H.8 Safe failure fraction (SFF) . 62
H.9 Determination of the quantitative SIL capability . 63
H.9.1 General . 63
H.9.2 SIL limit by architectural constraints . 63
H.9.3 SIL limit by PFH . 63
H.10 Additional considerations to comply with ISO 13849-1 . 64
H.10.1 General . 64
H.10.2 MTTF of a channel . 64
D
H.10.3 Determination of the quantitative category capability . 64
H.10.4 Determination of the quantitative PL-capability . 64
Annex I (informative) Digital processing of sine/cosine signals . 65
I.1 General . 65
I.2 Sampling of sine and cosine signals . 65
I.3 Consequences . 66
I.4 Measures to improve DC . 67
Annex J (informative) Single channel architecture with ideal fault detection . 68
J.1 General . 68
J.2 Ideal fault detection for Encoder(SR) with sine and cosine output signals . 68
Annex K (informative) Specifics for single channel incremental Encoder(SR) with sine

and cosine output signals . 70
K.1 General . 70
K.2 Single-fault tolerance . 70
K.3 Undetectable faults . 70

IEC 61800-5-3:2021 © IEC 2021 – 5 –
K.4 Fault detection (DC) . 70
Annex L (normative) Static analysis of signal evaluation and fault detection . 72
L.1 General . 72
L.2 Motivation for the analysis of signal evaluation and fault detection . 72
L.3 What does "static analysis of signal processing" mean? . 72
L.4 Standard test signals . 76
L.4.1 Make test signal available (step 1) . 76
L.4.2 Test signal 1 . 79
L.4.3 Test signal 2 . 79
L.4.4 Test signal 3 . 80
L.4.5 Test signal 4 . 80
L.4.6 Test signal 5 . 81
L.5 Simulation of signal processing to specification . 81
L.5.1 General . 81
L.5.2 Form differential signals (step 2). 83
L.5.3 Form square-wave signals to specification (Schmitt trigger, step 3) . 83
L.5.4 Perform specified diagnostics (step 4) . 83
L.6 Assessment of the signal processing specification . 84
L.6.1 General . 84
L.6.2 Assessment concept for the signal processing specification . 85
L.7 FMEDA Encoder(SR) for verification of the diagnostic coverage . 88
L.7.1 General . 88
L.7.2 Explanation of the problem . 88
L.7.3 Procedure for FMEDA . 90
L.8 List of variables used for performing static analysis . 92
L.9 MS Excel tool for performance of static analysis . 93
Annex M (informative) Aspects of diagnostic measures for obtaining incremental

position values . 94
M.1 General . 94
M.2 Obtaining position values from incremental signals . 94
M.3 Phase error of the sine and the cosine signals . 96
M.3.1 General . 96
M.3.2 Phase errors with absolute values < 90° . 96
M.3.3 Phase errors with absolute values > 90° . 99
M.4 Threshold errors of the square wave signal shapers . 100
M.4.1 General . 100
M.4.2 Asymmetric switching thresholds . 101
M.4.3 Unequal switching hysteresis at the square wave shaping for sine and
cosine . 101
Bibliography . 103

Figure 1 – Context of Encoder(SR) . 11
Figure 2 – Example of hardware architecture of Encoder(SR) with incremental and

absolute output signal . 28
Figure B.1 – Universal Encoder(SR) architecture . 43
Figure C.1 – Example of an additional ring for assembly with eccentricity x . 46
Figure D.1 – Sample shock and corresponding PVSRS on 4CP . 47
Figure D.2 – Testing machine . 48

– 6 – IEC 61800-5-3:2021 © IEC 2021
Figure I.1 – Digital sampling of sine and cosine signals – Hardware architecture,
example . 65
Figure I.2 – Lissajous figures of the sine and cosine signals A and B . 66
Figure L.1 – Static analysis concept . 73
Figure L.2 – Static analysis procedure (for one test signal) with variable

denominations . 76
Figure L.3 – Substitute circuit for Encoder(SR)’s outbound interface . 77
Figure L.4 – Example of a circuit for evaluation of the output signals and diagnostics
of Encoder(SR) faults . 82
Figure L.5 – Lissajous diagrams (representation of signal B over signal A) in two fault
cases . 90
Figure L.6 – Examples of the dual effect of a single component fault . 91
Figure M.1 – Obtaining position values from incremental signals . 95
Figure M.2 – Counting pulse generation, faultless case . 96
Figure M.3 – Counting pulse generation with a phase error of 20° . 97
Figure M.4 – Lissajous diagram with a phase error ∆ϕ = 20° . 98
Figure M.5 – Square-wave signal generation by means of a Schmitt trigger . 100
Figure M.6 – Counting pulse generation with asymmetric switching thresholds . 101
Figure M.7 – Counting pulse generation with unequal switching hysteresis . 102

Table 1 – List of terms . 13
Table 2 – Applicable subclauses of IEC 61800-5-2:2016 for Encoder(SR) and
respective modifications . 21
Table 3 – Applicable references of IEC 61800-5-1:2007 and IEC 61800-5-
1:2007/AMD1:2016 for Encoder(SR) and respective modifications . 23
Table A.1 – Types of Encoder(SR) . 40
Table B.1 – Function blocks of the universal Encoder(SR) architecture . 43
Table G.1 – Encoder(SR) – Mechanic fault list and fault exclusions . 55
Table G.2 – Faults and fault exclusions for the selection, mounting and operation of
rolling bearings . 56
Table G.3 – Factors influencing the malfunctioning of rolling bearings –
Considerations for selection, mounting and operation . 56
Table H.1 – Components for Encoder(SR) and their inclusion in quantification. 59

IEC 61800-5-3:2021 © IEC 2021 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ADJUSTABLE SPEED ELECTRICAL POWER DRIVE SYSTEMS –

Part 5-3: Safety requirements –
Functional, electrical and environmental requirements for encoders

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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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.
International Standard IEC 61800-5-3 has been prepared by subcommittee 22G: Adjustable
speed electric power drive systems (PDS), of IEC technical committee 22: Power electronic
systems and equipment.
The text of this International Standard is based on the following documents:
FDIS Report on voting
22G/431/FDIS 22G/434/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.
Terms in italics are defined in Clause 3.

– 8 – IEC 61800-5-3:2021 © IEC 2021
A list of all parts in the IEC 61800 series, published under the general title Adjustable speed
electrical power drive systems, 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
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

IEC 61800-5-3:2021 © IEC 2021 – 9 –
INTRODUCTION
As a result of automation, demand for increased production and reduced operator physical
effort, control systems of machinery and plant items play an increasing role in the achievement
of overall safety. These control systems increasingly employ complex
electrical/electronic/programmable electronic devices and systems.
Prominent amongst these devices and systems are encoder which are for example applied to
measure angle and position of machine parts for use in safety-related applications
(Encoder(SR)). Based on the Encoder(SR)’s output signals, PDS(SR) or other evaluation units
calculate for example speed, acceleration, absolute position, etc., to perform their safety sub-
functions SLS, SLA, SLP and others (see IEC 61800-5-2:2016, Clause 4). The signal
processing necessary to perform some of these safety sub-functions may also be included in
the Encoder(SR).
Examples of industrial applications are:
• machine tools, robots, production test equipment, test benches;
• papermaking machines, textile production machines, calendars in the rubber industry;
• plastics processing lines, chemicals or metal production lines, rolling-mills;
• cement crushing machines, cement kilns, mixers, centrifuges, extrusion machines;
• drilling machines;
• conveyors, materials handling machines, hoisting equipment (cranes, gantries, etc.);
• pumps, fans, etc.
This document can also be used as a reference for developers using Encoder(SR) for other
applications, for example in wind power plants.
Users of this document should be aware that some type C standards for machinery currently
refer to ISO 13849-1 for safety-related control systems. In this case, Encoder(SR)
manufacturers may be requested to provide further information (e.g. category and performance
level PL) to facilitate the integration of an Encoder(SR) into the safety-related control systems
of such machinery. This has been considered during development of this document and
corresponding indications are included where appropriate.
NOTE "Type C standards" are defined in ISO 12100 [1] as machine safety standards dealing with detailed safety
requirements for a particular machine or group of machines.
There are many situations where control systems that incorporate Encoder(SR) are employed,
for example as part of safety measures that have been provided to achieve risk reduction. A
typical case is reducing the speed during start-up in order to protect personnel from hazards
arising by unexpected fast movements of machine parts. This document gives a methodology
to identify the contribution made by an Encoder(SR) to identified safety sub-functions and to
enable the appropriate design of the Encoder(SR) and verification that it achieves the required
performance.
Measures are given to co-ordinate the safety performance of the Encoder(SR) with the intended
risk reduction taking into account the probabilities and consequences of its random and
systematic faults.
– 10 – IEC 61800-5-3:2021 © IEC 2021
ADJUSTABLE SPEED ELECTRICAL POWER DRIVE SYSTEMS –

Part 5-3: Safety requirements –
Functional, electrical and environmental requirements for encoders

1 Scope
This part of IEC 61800, which is a product standard, specifies requirements and makes
recommendations for the design and development, integration and validation of safety-related
encoder (Encoder(SR)) in terms of their functional safety considerations, electrical safety and
environmental conditions. It applies to Encoder(SR), being sensors as part of a PDS(SR).
NOTE 1 The term "integration" refers to the Encoder(SR) itself, not to its incorporation into the safety-related
application.
This document can also be referred to and used for Encoder(SR) in any other safety-related
application, for example safety-related position monitoring.
NOTE 2 This document specifies only complementary functional safety, electrical safety and environmental condition
requirements that are not clearly provided by other parts of the IEC 61800 series.
This document is applicable where functional safety of an encoder is claimed and the
Encoder(SR) is operating mainly in the high demand or continuous mode.
NOTE
...