EN IEC 60051-3:2021

Direct acting indicating analogue electrical measuring instruments and their accessories - Part 3: Special requirements for wattmeters and varmeters

IEC 60051-3:2018 applies to direct acting indicating wattmeters and varmeters having an analogue display. IEC 60051-3:2018 also applies to: • non-interchangeable accessories (as defined in 3.1.23 of IEC 60051-1:2016) used with wattmeters and varmeters; • a combination of the instruments and the accessories provided that the adjustments have been made for the combination; • direct acting indicating electrical measuring instruments whose scale marks do not correspond directly to their electrical input quantity, provided that the relationship between them is known; • instruments and accessories having electronic devices in their measuring and/or auxiliary circuits. IEC 60051-3:2018 does not apply to: • special purpose instruments which are covered by their own IEC standards; • special purpose devices which are covered by their own IEC standards when they are used as accessories. IEC 60051-3:2018 cancels and replaces the fourth edition published in 1984 and Amendment 1:1994. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) updating of content in line with new editions of IEC 60051-1 and IEC 60051-9; b) addition of Annex A to specify the nonconformity classification of test items. IEC 60051-3:2018 is to be used in conjunction with IEC 60051-1:2016.

Direkt wirkend anzeigende analoge elektrische Messgeräte und ihr Zubehör - Teil 3: Spezielle Anforderungen für Wirk- und Blindleistungs-Messgeräte

Appareils mesureurs électriques indicateurs analogiques à action directe et leurs accessoires - Partie 3: Exigences particulières pour les wattmètres et les varmètres

IEC 60051-3:2018 s'applique aux wattmètres et varmètres indicateurs analogiques à action directe. IEC 60051-3:2018 s'applique également aux: • accessoires non interchangeables (définis en 3.1.23 de l'IEC 60051-1:2016) utilisés avec les wattmètres et varmètres; • ensembles d'appareils et leurs accessoires, à condition que les réglages aient été effectués pour l'ensemble; • appareils de mesure électrique à action directe dont les repères de l'échelle ne correspondent pas directement à la grandeur électrique appliquée à l'entrée de l'appareil, à condition que la relation entre ceux-ci soit connue; • appareils et accessoires qui comportent des dispositifs électroniques dans leurs circuits de mesure et/ou auxiliaires. IEC 60051-3:2018 ne s'applique pas aux: • appareils spéciaux couverts par leurs propres normes IEC; • dispositifs spéciaux couverts par leurs propres normes IEC, lorsqu'ils sont utilisés en tant qu'accessoires. IEC 60051-3:2018 annule et remplace la quatrième édition parue en 1984 et l'Amendement 1:1994. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) mise à jour du contenu en fonction des nouvelles éditions de l'IEC 60051-1 et de l'IEC 60051-9; b) ajout de l'Annexe A pour spécifier la classification des non-conformités des éléments d'essai. IEC 60051-3:2018 doit être utilisée conjointement avec l'IEC 60051-1:2016.

Neposredni kazalni analogni električni merilni instrumenti in njihov pribor - 3. del: Posebne zahteve za wattmetre in varmetre (IEC 60051-3:2018)

General Information

• Status: Published
• Publication Date: 29-Apr-2021
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• Technical Committee: CLC/TC 85X - Measuring equipment for electrical and electromagnetic quantities
• Drafting Committee: IEC/TC 85 - IEC_TC_85
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 30-Apr-2021
• Completion Date: 30-Apr-2021
• Directive: 2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Directive: 2014/53/EU - Directive 2014/53/EU of The European Parliament and of the Council of 16 April 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment and repealing Directive 1999/5/EC
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Mandate: M/536 - [C(2015)536] Standardisation request as regards radio equipment in support of Directive 2014/53/EU
• Ref Project: SIST EN IEC 60051-3:2021 - Direct acting indicating analogue electrical measuring instruments and their accessories - Part 3: Special requirements for wattmeters and varmeters (IEC 60051-3:2018)

Relations

• Replaces: EN 60051-3:1989/A1:1995 - Direct acting indicating analogue electrical measuring instruments and their accessories - Part 3: Special requirements for wattmeters and varmeters
• Effective Date: 04-May-2021
• Replaces: EN 60051-3:1989 - Direct acting indicating analogue electrical measuring instruments and their accessories - Part 3: Special requirements for wattmeters and varmeters
• Effective Date: 04-May-2021

Overview - EN IEC 60051-3:2021 (Wattmeters & Varmeters)

EN IEC 60051-3:2021 (based on IEC 60051-3:2018) defines special requirements for direct acting indicating analogue electrical measuring instruments - specifically wattmeters and varmeters - and their non‑interchangeable accessories. It is a technical revision that supersedes earlier editions and is intended to be used together with IEC 60051‑1:2016 (general definitions and requirements). The standard covers instrument description, classification, performance limits and test rules for design, testing, marking and documentation in both international (IEC) and European (CENELEC/CLC) contexts.

Key topics and technical requirements

• Scope & applicability: Applies to analogue, direct‑acting wattmeters and varmeters, including instruments with electronic components in measuring or auxiliary circuits; excludes special‑purpose instruments/devices covered by their own IEC standards.
• Reference conditions & tolerances: Specifies test reference conditions and additional tolerances for influence quantities (see tables in the standard).
• Intrinsic and operating uncertainty: Defines limits of intrinsic uncertainty, fiducial values and the relationship to accuracy class for instrument performance and classification.
• Nominal range and variations: Sets nominal ranges of use and permissible variations (e.g., input ranges, power factor effects) and describes conditions to determine these variations.
• Electrical & safety requirements: Addresses electrical safety, self‑heating, permissible overloads, temperature limits and zero deviation.
• Electromagnetic compatibility (EMC): Includes EMC considerations relevant to accurate analogue measurements.
• Construction & marking: Requirements for damping, scales, sealing, terminals, adjusters, stops, degrees of protection, markings, instructions for use, and packaging.
• Testing & nonconformity: Specifies test rules and includes Annex A for classification of test nonconformities.

Practical applications and users

EN IEC 60051-3:2021 is used by:

• Instrument manufacturers for design, production and conformity of wattmeters and varmeters
• Test laboratories and calibration houses to develop test procedures, performance verification and uncertainty budgets
• Quality and compliance teams for CE/CENELEC alignment and product documentation
• Utilities, electrical engineers and procurement specialists when specifying analogue power measurement instruments and accessories
• Certification bodies assessing compliance with IEC/CENELEC electrotechnical standards

Practical benefits include consistent performance criteria, clear marking and documentation rules, and harmonized test methods that reduce ambiguity during design, testing and procurement.

Related standards

• IEC 60051‑1:2016 - General definitions and common requirements (mandatory companion)
• IEC 60051‑9 - Recommended test methods
• EN IEC 60051‑3:2021 - European adoption (CENELEC/CLC) of IEC 60051‑3:2018

Keywords: EN IEC 60051-3:2021, IEC 60051-3, wattmeter standard, varmeter requirements, analogue measuring instruments, accuracy class, measurement uncertainty, EMC, instrument testing.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2021
Nadomešča:
SIST EN 60051-3:1995
SIST EN 60051-3:1995/A1:1999
Neposredni kazalni analogni električni merilni instrumenti in njihov pribor - 3. del:
Posebne zahteve za wattmetre in varmetre (IEC 60051-3:2018)
Direct acting indicating analogue electrical measuring instruments and their accessories
- Part 3: Special requirements for wattmeters and varmeters (IEC 60051-3:2018)
Direkt wirkend anzeigende analoge elektrische Messgeräte und ihr Zubehör - Teil 3:
Spezielle Anforderungen für Wirk- und Blindleistungs-Messgeräte (IEC 60051-3:2018)
Appareils mesureurs électriques indicateurs analogiques à action directe et leurs
accessoires - Partie 3: Exigences particulières pour les wattmètres et les varmètres (IEC
60051-3:2018
Ta slovenski standard je istoveten z: EN IEC 60051-3:2021
ICS:
17.220.20 Merjenje električnih in Measurement of electrical
magnetnih veličin and magnetic quantities
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60051-3

NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2021
ICS 17.220.20 Supersedes EN 60051-3:1989 and all of its amendments
and corrigenda (if any)
English Version
Direct acting indicating analogue electrical measuring
instruments and their accessories - Part 3: Special requirements
for wattmeters and varmeters
(IEC 60051-3:2018)
Appareils mesureurs électriques indicateurs analogiques à Direkt wirkend anzeigende analoge elektrische Messgeräte
action directe et leurs accessoires - Partie 3: Exigences und ihr Zubehör - Teil 3: Spezielle Anforderungen für Wirk-
particulières pour les wattmètres et les varmètres und Blindleistungs-Messgeräte
(IEC 60051-3:2018) (IEC 60051-3:2018)
This European Standard was approved by CENELEC on 2018-10-04. 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,
Turkey 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
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60051-3:2021 E

European foreword
The text of document 85/556/CDV, future edition 5 of IEC 60051-3, prepared by IEC/TC 85
"Measuring equipment for electrical and electromagnetic quantities" was submitted to the IEC-
CENELEC parallel vote and approved by CENELEC as EN IEC 60051-3:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-10-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-04-30
document have to be withdrawn
This document supersedes EN 60051-3:1989 and all of its amendments and corrigenda (if any).
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.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association.
Endorsement notice
The text of the International Standard IEC 60051-3:2018 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60051-7 NOTE Harmonized as EN IEC 60051-7
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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60051-1 2016 Direct acting indicating analogue electrical EN 60051-1 2017
measuring instruments and their
accessories – Part 1: Definitions and
general requirements common to all parts
IEC 60051-9 - Direct acting indicating analogue electrical EN 60051-9 -
measuring instruments and their
accessories - Part 9: Recommended test
methods
IEC 60051-3 ®
Edition 5.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Direct acting indicating analogue electrical measuring instruments and their

accessories –
Part 3: Special requirements for wattmeters and varmeters

Appareils mesureurs électriques indicateurs analogiques à action directe et

leurs accessoires –
Partie 3: Exigences particulières pour les wattmètres et les varmètres

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20 ISBN 978-2-8322-5957-3

– 2 – IEC 60051-3:2018 © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Description, classification and compliance . 7
4.1 Description . 7
4.2 Classification . 8
4.3 Compliance with the requirements of this standard . 8
5 Requirements . 8
5.1 Reference conditions . 8
5.2 Limits of intrinsic uncertainty, fiducial value . 8
5.2.1 Limits of intrinsic uncertainty . 8
5.2.2 Correspondence between intrinsic uncertainty and accuracy class . 8
5.2.3 Fiducial value . 9
5.3 Nominal range of use and variations . 9
5.3.1 Nominal range of use . 9
5.3.2 Limits of variations. 12
5.3.3 Conditions for the determination of variations . 12
5.3.4 Determination of variation due to power factor . 12
5.3.5 Special tests for variations . 12
5.4 Operating uncertainty, overall system uncertainty and variations . 12
5.5 Electrical requirements . 12
5.5.1 Electrical safety requirements . 12
5.5.2 Self-heating . 12
5.5.3 Permissible overloads . 12
5.5.4 Limiting range of temperature . 13
5.5.5 Deviation from zero . 14
5.5.6 Electromagnetic compatibility (EMC) . 14
5.6 Constructional requirements . 14
5.6.1 General constructional requirements . 14
5.6.2 Damping . 14
5.6.3 Sealing to prevent access . 15
5.6.4 Scales . 15
5.6.5 Stopper. 15
5.6.6 Preferred values . 15
5.6.7 Adjusters, mechanical and/or electrical . 15
5.6.8 Effects of vibration and shock . 15
5.6.9 Degrees of protection provided by enclosure . 15
5.6.10 Terminals . 15
6 Information, markings and symbols . 15
6.1 Information . 15
6.2 Markings, symbols and their locations . 15
6.3 Markings relating to the reference values and nominal ranges of use of
influence quantities . 15
6.4 The symbols for marking instruments and accessories . 16

IEC 60051-3:2018 © IEC 2018 – 3 –
6.5 Markings and symbols for terminals . 16
6.5.1 Requirements for markings . 16
6.5.2 Earthing (grounding) terminals . 16
6.5.3 Measuring circuit terminals . 16
6.5.4 Special markings for terminals . 16
6.6 Instructions for use . 16
7 Package . 16
8 Test rules . 16
Annex A (normative) Nonconformity classification of tests . 17
Bibliography . 18

Table 1 – Reference conditions and tolerances, in addition to those given in Table 2 of
IEC 60051-1:2016, for testing purposes relating to the influence quantities . 8
Table 2 – Limits of the nominal range of use and permissible variations in addition to
those given in Table 3 of IEC 60051-1:2016 . 10
Table 3 – Overloads of short duration . 13
Table A.1 – Nonconformity classification of tests . 17

– 4 – IEC 60051-3:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIRECT ACTING INDICATING ANALOGUE ELECTRICAL
MEASURING INSTRUMENTS AND THEIR ACCESSORIES –

Part 3: Special requirements for wattmeters and varmeters

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
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
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misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
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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 60051-3 has been prepared by IEC technical committee 85:
Measuring equipment for electrical and electromagnetic quantities.
This fifth edition cancels and replaces the fourth edition published in 1984 and
Amendment 1:1994. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) updating of content in line with new editions of IEC 60051-1 and IEC 60051-9;
b) addition of Annex A to specify the nonconformity classification of test items.

IEC 60051-3:2018 © IEC 2018 – 5 –
The text of this International Standard is based on the following documents:
CDV Report on voting
85/556/CDV 85/579A/RVC
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.
This International Standard is to be used in conjunction with IEC 60051-1:2016.
A list of all parts in the IEC 60051 series, published under the general title Direct acting
indicating analogue electrical measuring instruments and their accessories, 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.
– 6 – IEC 60051-3:2018 © IEC 2018
INTRODUCTION
IEC 60051 is published in separate parts according to the following structure and under the
general title: Direct acting indicating analogue electrical measuring instruments and their
accessories.
Part 1: Definitions and general requirements common to all parts
Part 2: Special requirements for ammeters and voltmeters
Part 3: Special requirements for wattmeters and varmeters
Part 4: Special requirements for frequency meters
Part 5: Special requirements for phase meters, power factor meters and synchroscopes
Part 6: Special requirements for ohmmeters (impedance meters) and cond
...