IEC 61557-12:2018

Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC - Equipment for testing, measuring or monitoring of protective measures - Part 12: Power metering and monitoring devices (PMD)

IEC 61557-12:2018 specifies requirements for power metering and monitoring devices (PMD) that measure and monitor the electrical quantities within electrical distribution systems, and optionally other external signals. These requirements also define the performance in single- and three-phase AC or DC systems having rated voltages up to 1 000 V AC or up to 1 500 V DC. These devices are fixed or portable. They are intended to be used indoors and/or outdoors. Power metering and monitoring devices (PMD), as defined in this document, give additional safety information, which aids the verification of the installation and enhances the performance of the distribution systems. The power metering and monitoring devices (PMD) for electrical parameters described in this document are used for general industrial and commercial applications. This document does not address functional safety and cyber security aspects. This document is not applicable for:
– electricity metering equipment that complies with IEC 62053-21, IEC 62053-22, IEC 62053-23 and IEC 62053-24. Nevertheless, uncertainties defined in this document for active and reactive energy measurement are derived from those defined in IEC 62053 (all parts);
– the measurement and monitoring of electrical parameters defined in IEC 61557-2 to IEC 61557-9 and IEC 61557-13 or in IEC 62020;
– power quality instrument (PQI) according IEC 62586 (all parts);
– devices covered by IEC 60051 (all parts) (direct acting analogue electrical measuring instrument). IEC 61557-12:2018 cancels and replaces the first edition published in 2007. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) PMD-A has been withdrawn due the fact these devices are now mainly covered by the IEC 62586 series of standards.
b) Three categories of PMD have been created with a list of minimum required functions for each category.
c) Added a new Annex A explaining the different applications linked to the relevant standards and devices, and another new Annex C about the power factor conventions.
The contents of the corrigendum 1 (2022-09) have been included in this copy.

Sécurité électrique dans les réseaux de distribution basse tension jusqu'à 1 000 V c.a. et 1 500 V c.c. - Dispositifs de contrôle, de mesure ou de surveillance de mesures de protection - Partie 12: Dispositifs de comptage et de surveillance du réseau électrique (PMD)

L'IEC 61557-12:2018 spécifie des exigences relatives aux dispositifs de comptage et de surveillance du réseau électrique (PMD) qui mesurent et surveillent les grandeurs électriques dans les réseaux de distribution électrique et, facultativement, d’autres signaux externes. Ces exigences définissent également les performances dans les réseaux alternatifs ou continus monophasés et triphasés ayant des tensions assignées inférieures ou égales à 1 000 V en courant alternatif ou inférieures ou égales à 1 500 V en courant continu. Ces dispositifs sont fixes ou portables. Ils sont destinés à être utilisés à l’intérieur et/ou à l’extérieur. Les dispositifs de comptage et de surveillance du réseau électrique (PMD) tels que définis dans le présent document donnent des informations supplémentaires sur la sécurité, ce qui facilite la vérification de l'installation et augmente les performances des réseaux de distribution. Les dispositifs de comptage et de surveillance du réseau électrique (PMD) relatifs aux paramètres électriques décrits dans le présent document sont utilisés pour des applications industrielles et commerciales générales. Le présent document ne traite pas des aspects liés à la sécurité fonctionnelle et à la cybersécurité. Le présent document n’est pas applicable:
– aux appareils de comptage d’électricité conformes à l’IEC 62053-21, à l’IEC 62053-22, à l’IEC 62053-23 et à l’IEC 62053-24. Néanmoins, les incertitudes définies dans le présent document pour le mesurage de l’énergie active et réactive sont tirées de celles définies dans l'IEC 62053 (toutes les parties);
– au mesurage et à la surveillance des paramètres électriques définis dans l'IEC 61557-2 à l'IEC 61557-9 et dans l'IEC 61557-13 ou dans l’IEC 62020;
– aux instruments de qualité de l’alimentation (PQI – power quality instrument) conformes à l'IEC 62586 (toutes les parties);
– aux dispositifs relevant des domaines d’application de l'IEC 60051 (toutes les parties) (appareils de mesure électriques analogique à action directe). L'IEC 61557-12:2018 annule et remplace la première édition parue en 2007. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) Suppression des PMD-A du fait que ces dispositifs sont à présent largement couverts par la série de normes IEC 62586.
b) Création de trois catégories de PMD accompagnées d’une liste des fonctions minimales exigées pour chacune des catégories.
c) Ajout d’une nouvelle Annexe A décrivant les différentes applications associées aux normes et dispositifs correspondants et d’une autre nouvelle Annexe C portant sur les conventions du facteur de puissance.
Le contenu du corrigendum 1 (2022-09) a été pris en considération dans cet exemplaire.

General Information

• Status: Published
• Publication Date: 21-Oct-2018
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.080.01 - Electrical insulation in general
• ICS: 29.240.01 - Power transmission and distribution networks in general
• Technical Committee: TC 85 - Measuring equipment for electrical and electromagnetic quantities
• Drafting Committee: WG 20 - TC 85/WG 20
• Current Stage: PPUB - Publication issued
• Start Date: 28-Sep-2018
• Completion Date: 22-Oct-2018

Relations

• Amended By: IEC 61557-12:2018/AMD1:2021 - Amendment 1 - Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC - Equipment for testing, measuring or monitoring of protective measures - Part 12: Power metering and monitoring devices (PMD)
• Effective Date: 05-Sep-2023
• Corrected By: IEC 61557-12:2018/COR1:2022 - Corrigendum 1 - Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC - Equipment for testing, measuring or monitoring of protective measures - Part 12: Power metering and monitoring devices (PMD)
• Effective Date: 05-Sep-2023
• Revises: IEC 61557-12:2007 - Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. - Equipment for testing, measuring or monitoring of protective measures - Part 12: Performance measuring and monitoring devices (PMD)
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61557-12 ®
Edition 2.0 2018-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC. – Equipment for testing, measuring or monitoring of protective
measures –
Part 12: Performance measuring Power metering and monitoring devices (PMD)

All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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Switzerland
About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC 61557-12 ®
Edition 2.0 2018-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and

1 500 V DC. – Equipment for testing, measuring or monitoring of protective

measures –
Part 12: Performance measuring Power metering and monitoring devices (PMD)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220.20; 29.080.01; 29.240.01 ISBN 978-2-8322-6183-5

– 2 – IEC 61557-12:2018 RLV © IEC 2018
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
2 Normative references. 12
3 Terms, definitions and notations. 13
3.1 General definitions . 13
3.2 Definitions related to uncertainty and performance . 16
3.3 Definitions related to electric phenomena . 20
3.4 Definitions related to measurement techniques . 23
3.5 Notations . 23
3.5.1 Functions . 23
3.5.2 Symbols and abbreviations . 25
3.5.3 Indices . 25
4 Requirements . 25
4.1 General requirements . 25
4.2 PMD general architecture . 26
4.3 Classification of PMD . 26
4.4 Structure of PMD. 27
4.4.1 Structure of PMD related to sensors . 27
4.4.2 Requirements for self-powered PMD . 28
4.5 List of applicable performance classes . 28
List of applicable function performance classes for PMD without
external sensors .
List of applicable system performance classes for PMD with
external sensors .
4.6 Operating and reference conditions for PMD . 30
4.6.1 Reference conditions . 30
4.6.2 Rated operating conditions . 30
4.7 Start-up conditions . 32
4.8 Requirements for PMD functions . 32
4.8.1 General requirements . 32
4.8.2 Active power (P) and active energy (E ) measurements . 33
a
4.8.3 Reactive power (Q , Q ) and reactive energy (E , E ) measurements . 39
A V rA rV
4.8.4 Apparent power (S , S ) and apparent energy (E , E )
A V apA apV
measurements . 43
4.8.5 Frequency (f) measurements . 45
4.8.6 RMS phase current (I) and neutral current (I , I ) measurements . 46
N Nc
4.8.7 RMS voltage (U) measurements . 50
4.8.8 Power factor (PF , PF ) measurements . 52
A V
4.8.9 Short term flicker (P ) and long term flicker (P ) measurements . 52
st lt
4.8.10 Voltage dip (U ) and voltage swell (U ) measurements . 53
dip swl
4.8.11 Voltage interruption (U ) measurements . 58
int
4.8.12 Transient overvoltage (U ) measurements . 59
tr
4.8.13 Voltage unbalance (U , U ) measurements . 60
nb nba
4.8.14 Voltage harmonics (U ) and voltage THD (THD and THD-R )
h u u
measurements . 60

4.8.15 Current unbalance (I , I ) measurements . 62
nb nba
4.8.16 Current harmonics (I ) and current THD (THD and THD-R )
h i i
measurements . 62
4.8.17 Minimum, maximum, peak, three-phases average and demand
measurements . 64
Requirements for PMD-A functions .
4.9 General mechanical requirements . 65
4.9.1 Vibration requirements . 65
4.9.2 IP requirements . 65
4.10 Safety requirements . 66
4.10.1 Protection against electrical hazards . 66
4.10.2 Protection against mechanical hazards . 67
4.10.3 Protection against other hazards . 67
4.11 EMC requirements . 67
4.11.1 Immunity . 67
4.11.2 Emission . 67
4.12 Inputs and/or outputs . 67
4.12.1 General . 67
4.12.2 Analog outputs . 67
4.12.3 Pulse outputs . 68
4.12.4 Control outputs . 68
4.12.5 Analog inputs . 68
4.12.6 Pulse and control inputs . 68
5 Marking and operating instructions . 69
5.1 General . 69
5.2 Marking . 69
5.3 Operating, installation and maintenance instructions . 69
5.3.1 General . 69
5.3.2 General characteristics . 69
5.3.3 Essential characteristics . 70
6 Tests . 72
6.1 General . 72
6.2 Type tests of PMD . 72
6.2.1 General . 72
6.2.2 Tests of intrinsic uncertainty . 73
6.2.3 Tests of variation of uncertainty with influence quantities . 73
6.2.4 Test of temperature influence . 73
6.2.5 Active power . 73
6.2.6 Apparent power . 76
6.2.7 Power factor . 77
6.2.8 Common mode voltage rejection test . 77
6.2.9 Frequency. 77
6.2.10 Measurement of voltage harmonics and THD . 78
u
6.2.11 Measurement of current harmonics and THD . 79
i
6.2.12 Dips and swells . 79
6.2.13 Voltage interruptions . 79
6.2.14 Outputs tests . 79
6.2.15 Climatic tests . 80
6.2.16 EMC tests . 81

– 4 – IEC 61557-12:2018 RLV © IEC 2018
6.2.17 Start-up tests .
...

IEC 61557-12 ®
Edition 2.0 2018-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC. – Equipment for testing, measuring or monitoring of protective
measures –
Part 12: Power metering and monitoring devices (PMD)

Sécurité électrique dans les réseaux de distribution basse tension jusqu’à
1 000 V c.a. et 1 500 V c.c. – Dispositifs de contrôle, de mesure ou de
surveillance de mesures de protection –
Partie 12: Dispositifs de comptage et de surveillance du réseau électrique (PMD)

All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

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The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

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The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

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IEC 61557-12 ®
Edition 2.0 2018-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and

1 500 V DC. – Equipment for testing, measuring or monitoring of protective

measures –
Part 12: Power metering and monitoring devices (PMD)

Sécurité électrique dans les réseaux de distribution basse tension jusqu’à

1 000 V c.a. et 1 500 V c.c. – Dispositifs de contrôle, de mesure ou de

surveillance de mesures de protection –

Partie 12: Dispositifs de comptage et de surveillance du réseau électrique (PMD)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 29.080.01; 29.240.01 ISBN 978-2-8322-6077-7

– 2 – IEC 61557-12:2018 © IEC 2018
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references. 11
3 Terms, definitions and notations. 11
3.1 General definitions . 11
3.2 Definitions related to uncertainty and performance . 13
3.3 Definitions related to electric phenomena . 17
3.4 Definitions related to measurement techniques . 20
3.5 Notations . 21
3.5.1 Functions . 21
3.5.2 Symbols and abbreviations . 21
3.5.3 Indices . 22
4 Requirements . 22
4.1 General requirements . 22
4.2 PMD general architecture . 22
4.3 Classification of PMD . 23
4.4 Structure of PMD. 24
4.4.1 Structure of PMD related to sensors . 24
4.4.2 Requirements for self-powered PMD . 24
4.5 List of applicable performance classes . 25
4.6 Operating and reference conditions for PMD . 25
4.6.1 Reference conditions . 25
4.6.2 Rated operating conditions . 26
4.7 Start-up conditions . 28
4.8 Requirements for PMD functions . 28
4.8.1 General requirements . 28
4.8.2 Active power (P) and active energy (E ) measurements . 29
a
4.8.3 Reactive power (Q , Q ) and reactive energy (E , E ) measurements . 35
A V rA rV
4.8.4 Apparent power (S , S ) and apparent energy (E , E )
A V apA apV
measurements . 38
4.8.5 Frequency (f) measurements . 40
4.8.6 RMS phase current (I) and neutral current (I , I ) measurements . 41
N Nc
4.8.7 RMS voltage (U) measurements . 45
4.8.8 Power factor (PF , PF ) measurements . 47
A V
4.8.9 Short term flicker (P ) and long term flicker (P ) measurements . 47
st lt
4.8.10 Voltage dip (U ) and voltage swell (U ) measurements . 48
dip swl
4.8.11 Voltage interruption (U ) measurements . 53
int
4.8.12 Transient overvoltage (U ) measurements . 54
tr
4.8.13 Voltage unbalance (U , U ) measurements . 54
nb nba
4.8.14 Voltage harmonics (U ) and voltage THD (THD and THD-R )
h u u
measurements . 55
4.8.15 Current unbalance (I , I ) measurements . 56
nb nba
4.8.16 Current harmonics (I ) and current THD (THD and THD-R )
h i i
measurements . 57

4.8.17 Minimum, maximum, peak, three-phases average and demand
measurements . 58
4.9 General mechanical requirements . 58
4.9.1 Vibration requirements . 58
4.9.2 IP requirements . 58
4.10 Safety requirements . 59
4.10.1 Protection against electrical hazards . 59
4.10.2 Protection against mechanical hazards . 60
4.10.3 Protection against other hazards . 60
4.11 EMC requirements . 60
4.11.1 Immunity . 60
4.11.2 Emission . 60
4.12 Inputs and/or outputs . 60
4.12.1 General . 60
4.12.2 Analog outputs . 60
4.12.3 Pulse outputs . 61
4.12.4 Control outputs . 61
4.12.5 Analog inputs . 61
4.12.6 Pulse and control inputs . 61
5 Marking and operating instructions . 61
5.1 General . 61
5.2 Marking .
...

IEC 61557-12 ®
Edition 2.1 2021-05
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC – Equipment for testing, measuring or monitoring of protective
measures –
Part 12: Power metering and monitoring devices (PMD)

Sécurité électrique dans les réseaux de distribution basse tension jusqu’à
1 000 V en courant alternatif et 1 500 V en courant continu – Dispositifs de
contrôle, de mesure ou de surveillance de mesures de protection –
Partie 12: Dispositifs de comptage et de surveillance du réseau électrique (PMD)
All rights reserved. Unless otherwise specified, 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
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copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
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les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

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Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

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IEC 61557-12 ®
Edition 2.1 2021-05
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and

1 500 V DC – Equipment for testing, measuring or monitoring of protective

measures –
Part 12: Power metering and monitoring devices (PMD)

Sécurité électrique dans les réseaux de distribution basse tension jusqu’à

1 000 V en courant alternatif et 1 500 V en courant continu – Dispositifs de

contrôle, de mesure ou de surveillance de mesures de protection –

Partie 12: Dispositifs de comptage et de surveillance du réseau électrique (PMD)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 29.080.01; 29.240.01 ISBN 978-2-8322-9845-9

IEC 61557-12 ®
Edition 2.1 2021-05
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC – Equipment for testing, measuring or monitoring of protective
measures –
Part 12: Power metering and monitoring devices (PMD)

Sécurité électrique dans les réseaux de distribution basse tension jusqu’à
1 000 V en courant alternatif et 1 500 V en courant continu – Dispositifs de
contrôle, de mesure ou de surveillance de mesures de protection –
Partie 12: Dispositifs de comptage et de surveillance du réseau électrique (PMD)

– 2 – IEC 61557-12:2018+AMD1:2021 CSV
© IEC 2021
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 13
3 Terms, definitions and notations . 13
3.1 General definitions . 14
3.2 Definitions related to uncertainty and performance . 16
3.3 Definitions related to electric phenomena . 19
3.4 Definitions related to measurement techniques . 22
3.5 Notations . 23
3.5.1 Functions . 23
3.5.2 Symbols and abbreviations . 23
3.5.3 Indices . 24
4 Requirements . 24
4.1 General requirements . 24
4.2 PMD general architecture . 24
4.3 Classification of PMD . 25
4.4 Structure of PMD . 26
4.4.1 Structure of PMD related to sensors . 26
4.4.2 Requirements for self-powered PMD . 26
4.5 List of applicable performance classes . 27
4.6 Operating and reference conditions for PMD . 27
4.6.1 Reference conditions . 27
4.6.2 Rated operating conditions . 28
4.7 Start-up conditions . 30
4.8 Requirements for PMD functions . 30
4.8.1 General requirements . 30
4.8.2 Active power (P) and active energy (E ) measurements . 31
a
4.8.3 Reactive power (Q , Q ) and reactive energy (E , E ) measurements . 37
A V rA rV
4.8.4 Apparent power (S , S ) and apparent energy (E , E )
A V apA apV
measurements . 40
4.8.5 Frequency (f) measurements . 42
4.8.6 RMS phase current (I) and neutral current (I , I ) measurements . 43
N Nc
4.8.7 RMS voltage (U) measurements . 47
4.8.8 Power factor (PF , PF ) measurements . 49
A V
4.8.9 Short term flicker (P ) and long term flicker (P ) measurements . 49
st lt
4.8.10 Voltage dip (U ) and voltage swell (U ) measurements . 50
dip swl
4.8.11 Voltage interruption (U ) measurements . 55
int
4.8.12 Transient overvoltage (U ) measurements . 56
tr
4.8.13 Voltage unbalance (U , U ) measurements . 56
nb nba
4.8.14 Voltage harmonics (U ) and voltage THD (THD and THD-R )
h u u
measurements . 57
4.8.15 Current unbalance (I , I ) measurements . 58
nb nba
4.8.16 Current harmonics (I ) and current THD (THD and THD-R )
h i i
measurements . 59

© IEC 2021
4.8.17 Minimum, maximum, peak, three-phases average and demand
measurements . 60
4.9 General mechanical requirements . 60
4.9.1 Vibration requirements . 60
4.9.2 IP requirements . 60
4.10 Safety requirements . 61
4.10.1 Protection against electrical hazards . 61
4.10.2 Protection against mechanical hazards . 62
4.10.3 Protection against other hazards . 62
4.11 EMC requirements . 62
4.11.1 Immunity . 62
4.11.2 Emission . 62
4.12 Inputs and/or outputs . 62
4.12.1 General . 62
4.12.2 Analog outputs . 62
4.12.3 Pulse outputs . 63
4.12.4 Control outputs . 63
4.12.5 Analog inputs . 63
4.12.6 Pulse and control inputs . 63
5 Marking and operating instructions .
...