EN IEC 62057-1:2023

Electrical energy meters - Test equipment, techniques and procedures - Part 1: Stationary meter test units (MTUs)

IEC 62057-1:2023 applies to stationary meter test units (MTUs) permanently installed in laboratories, used for testing and calibration of electricity meters, in particular for their type test, acceptance test and verification test. It covers the requirements for automatic MTUs for indoor laboratory application and applies to newly manufactured MTUs to test electricity meters on 50 Hz or 60 Hz networks with an AC voltage up to 600 V (phase to neutral). If meters are intended for system voltages not specified in this document, special requirements are agreed between the manufacturer and the purchaser. This document also defines the kind of tests to perform as type tests / routine tests / acceptance tests and commissioning tests for MTUs. It does not apply to: • portable reference meters and portable sources; • electricity meters; • data interfaces to the meter and test procedures of data interface; • transformer operated MTUs; • personal computers supplied together with the MTU.

Elektrische Energiezähler - Prüfgeräte, Techniken und Verfahren - Teil 1: Stationäre Zählerprüfeinrichtungen (MTU)

Compteurs d'énergie électrique - Équipements, techniques et procédures d'essai - Partie 1: Bancs d'essai stationnaires des compteurs d'énergie électrique (MTU)

IEC 62057-1:2023 s'applique aux bancs d'essai stationnaires des compteurs d'énergie électrique (MTU, Meter Test Units) installés en permanence dans les laboratoires, utilisés pour les essais et l'étalonnage des compteurs d'électricité, en particulier pour leurs essais de type, de réception et de vérification. Elle couvre les exigences relatives aux MTU automatisés pour les applications de laboratoire en intérieur et s'applique aux MTU neufs destinés aux essais des compteurs d'électricité sur les réseaux de 50 Hz ou 60 Hz avec une tension alternative allant jusqu'à 600 V (tension entre phase et neutre). Si les compteurs sont conçus pour des tensions de réseau non spécifiées dans le présent document, des exigences particulières font l'objet d'un accord entre le fabricant et l'acheteur. Le présent document définit également le type d'essais à effectuer, par exemple essais de type/essais individuels de série/essais d'acceptation et essais de mise en service des MTU. Il ne s'applique pas: • aux compteurs de référence portatifs et sources portatives; • aux compteurs d'électricité; • aux interfaces de communication avec le compteur et aux procédures d'essai de l'interface de communication; • aux MTU alimentés par transformateur; • aux ordinateurs personnels fournis avec le MTU

Števci električne energije - Merilna oprema, tehnike in postopki - 1. del: Enote za statične števce (MTU) (IEC 62057-1:2023)

Standard IEC 62057-1:2023 se uporablja za enote za statične števce (MTU), ki so trajno nameščene v laboratorijih ter se uporabljajo za preskušanje in umerjanje števcev za elektriko, zlasti za njihov tipski preskus, preskus sprejemljivosti in preskus za preverjanje. Zajema zahteve za samodejne enote za statične števce za uporabo v notranjih laboratorijih in se uporablja za novo izdelane enote za statične števce za preskušanje števcev za elektriko v omrežju 50 Hz ali 60 Hz z izmenično napetostjo do 600 V (fazna napetost).
Če so števci namenjeni za sistemske napetosti, ki niso določene v tem dokumentu, se proizvajalec in kupec dogovorita o posebnih zahtevah.
Ta dokument prav tako določa vrsto preskusov, ki se izvedejo kot tipski preskusi/rutinski preskusi/preskusi sprejemljivosti in zagonski preskusi za enote za statične števce.
Ne uporablja se za:
• prenosne referenčne števce in prenosne vire;
• števce za elektriko;
• podatkovne vmesnike za števec in njihove preskusne postopke;
• enote za statične števce, ki jih upravlja transformator;
• osebne računalnike, dobavljene z enoto za statične števce.

General Information

• Status: Published
• Publication Date: 11-May-2023
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 91.140.50 - Electricity supply systems
• Technical Committee: CLC/TC 13 - Equipment for electrical energy measurement and load control
• Drafting Committee: IEC/TC 13 - IEC_TC_13
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 12-May-2023
• Completion Date: 12-May-2023
• Ref Project: SIST EN IEC 62057-1:2023 - Electrical energy meters - Test equipment, techniques and procedures - Part 1: Stationary meter test units (MTUs) (IEC 62057-1:2023)

Overview

EN IEC 62057-1:2023 (published by CLC / CENELEC) specifies requirements for stationary meter test units (MTUs) used in laboratories for the testing and calibration of electricity meters. The standard applies to automatic MTUs permanently installed indoors for type tests, acceptance tests, verification tests and commissioning of meters on 50 Hz or 60 Hz networks with AC voltages up to 600 V (phase to neutral). It also defines which tests are to be performed as type, routine, acceptance and commissioning tests for MTUs. Exclusions include portable reference meters/sources, electricity meters themselves, transformer-operated MTUs, data-interface test procedures and personal computers supplied with MTUs.

Key topics and technical requirements

• Scope and definitions: terminology for MTU elements, active/reactive/apparent power, influence quantities and accuracy.
• Meter test methods: energy comparison, power–time (wattmeter) and pulse comparison methods for meter accuracy testing.
• Standard electrical values: required mains, test voltage/current ranges, phase angle, frequency (50/60 Hz), harmonics and limits for testing.
• Standard (reference) meter requirements: accuracy classes and performance for use as references in MTUs.
• Constructional requirements: mechanical design, meter mounting systems, terminals, sources and standard meter integration.
• Error calculation and automation: functional requirements for error calculation systems and parameters for automated testing.
• Safety, EMC and environmental conditions: compliance with laboratory safety, insulation, clearances, climatic and electromagnetic compatibility standards for reliable operation.
• Information & marking: manufacturer documentation, installation, commissioning, maintenance and performance data required for MTUs.

Practical applications

• Calibration and verification of electricity meters in metrology laboratories, utility test facilities and manufacturer test benches.
• Type testing and acceptance testing during procurement or after design changes to electricity meters or MTUs.
• Commissioning and in-service re-verification of MTU installations used for meter certification.
• Selection and specification of MTUs for lab accreditation or compliance with national/regional meter regulation.

Who should use this standard

• MTU manufacturers and designers
• Calibration and testing laboratories
• Utility meter test facilities and metrology institutes
• Procurement engineers and conformity assessment bodies
• Laboratory accreditors aligning test procedures with ISO/IEC 17025

Related standards

Relevant referenced documents include IEC/EN standards for safety, EMC and metering such as IEC 61010-1, IEC 61326-1, IEC 62052-11, the IEC 62053 series and ISO/IEC 17025 for laboratory competence - all useful when implementing EN IEC 62057-1:2023 for robust, compliant MTU installations.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2023
Števci električne energije - Merilna oprema, tehnike in postopki - 1. del: Enote za
statične števce (MTU) (IEC 62057-1:2023)
Electrical energy meters - Test equipment, techniques and procedures - Part 1:
Stationary meter test units (MTUs) (IEC 62057-1:2023)
Prüfgeräte, Techniken und Verfahren für elektrische Energiezähler - Teil 1: Stationäre
Zählerprüfeinrichtungen (MTU) (IEC 62057-1:2023)
Equipements, techniques et procédures d'essai des compteurs d'énergie électrique -
Partie 1: Bancs d'essai stationnaires des compteurs d'énergie électrique (MTU) (IEC
62057-1:2023)
Ta slovenski standard je istoveten z: EN IEC 62057-1:2023
ICS:
17.220.20 Merjenje električnih in Measurement of electrical
magnetnih veličin and magnetic quantities
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62057-1

NORME EUROPÉENNE
EUROPÄISCHE NORM May 2023
ICS 17.220.20; 91.140.50
English Version
Electrical energy meters - Test equipment, techniques and
procedures - Part 1: Stationary meter test units (MTUs)
(IEC 62057-1:2023)
Compteurs d'énergie électrique - Équipements, techniques Elektrische Energiezähler - Prüfgeräte, Techniken und
et procédures d'essai - Partie 1: Bancs d'essai stationnaires Verfahren - Teil 1: Stationäre Zählerprüfeinrichtungen
des compteurs d'énergie électrique (MTU) (MTU)
(IEC 62057-1:2023) (IEC 62057-1:2023)
This European Standard was approved by CENELEC on 2023-05-03. 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 62057-1:2023 E

European foreword
The text of document 13/1879/FDIS, future edition 1 of IEC 62057-1, prepared by IEC/TC 13
"Electrical energy measurement and control" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 62057-1:2023.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2024-02-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2026-05-03
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 62057-1:2023 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:
IEC 60375:2018 NOTE Approved as EN IEC 60375:2018 (not modified)
IEC 62052-21:2004 NOTE Approved as EN 62052-21:2004 (not modified)
IEC 62053-11:2003 NOTE Approved as EN 62053-11:2003 (not modified)
IEC 62053-21:2020 NOTE Approved as EN IEC 62053-21:2021 (not modified) +A11:2021
IEC 62053-22:2020 NOTE Approved as EN IEC 62053-22:2021 (not modified) +A11:2021
IEC 62053-23:2020 NOTE Approved as EN IEC 62053-23:2021 (not modified) +A11:2021
IEC 62053-24:2020 NOTE Approved as EN IEC 62053-24:2021 (not modified) +A11:2021
IEC 62055-31:2022 NOTE Approved as EN IEC 62055-31:2022 (not modified)
IEC 62477-1:2022 NOTE Approved as EN IEC 62477-1:— (not modified)
ISO/IEC 17025 NOTE Approved as EN ISO/IEC 17025

To be published. Stage at time of publication: FprEN IEC 62477-1:2023.
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 60417 - Graphical symbols for use on equipment - -
IEC 60617 - Graphical symbols for diagrams - -
IEC 60664-1 2020 Insulation coordination for equipment EN IEC 60664-1 2020
within low-voltage supply systems - Part 1:
Principles, requirements and tests
IEC 60721-3-2 2018 Classification of environmental conditions - EN IEC 60721-3-2 2018
Part 3-2: Classification of groups of
environmental parameters and their
severities - Transportation and Handling
IEC 60721-3-3 2019 Classification of environmental conditions - EN IEC 60721-3-3 2019
Part 3-3: Classification of groups of
environmental parameters and their
severities - Stationary use at
weatherprotected locations
IEC 61010-1 2010 Safety requirements for electrical EN 61010-1 2010
equipment for measurement, control, and
laboratory use - Part 1: General
requirements
+ A1 (mod) 2016  + A1 2019
IEC 61010-031 2015 Safety requirements for electrical EN 61010-031 2015
equipment for measurement, control and
laboratory use - Part 031: Safety
requirements for hand-held probe
assemblies for electrical measurement and
test
+ A1 2018  + A1 2021
IEC 61140 2016 Protection against electric shock - EN 61140 2016
Common aspects for installation and
equipment
IEC 61326-1 2020 Electrical equipment for measurement, EN IEC 61326-1 2021
control and laboratory use - EMC
requirements - Part 1: General
requirements
IEC 62052-11 2020 Electricity metering equipment - General EN IEC 62052-11 2021
requirements, tests and test conditions -
Part 11: Metering equipment
- - /A11 2022
IEC 62052-31 2015 Electricity metering equipment (AC) - EN 62052-31 2016
General requirements, tests and test
conditions - Part 31: Product safety
requirements and tests
IEC 62053 series Electricity metering equipment EN IEC 62053 series
CISPR 11 (mod) 2015 Industrial, scientific and medical equipment EN 55011 2016
- Radio-frequency disturbance
characteristics - Limits and methods of
measurement
+ A1 2016  + A1 2017
- -  + A11 2020
+ A2 2019  + A2 2021
- - Voltage characteristics of electricity EN 50160 -
supplied by public electricity networks
- - Electricity metering equipment (a.c.) EN 50470 series
ISO 3864-1 2011 Graphical symbols - Safety colours and - -
safety signs - Part 1: Design principles for
safety signs and safety markings
ISO 7000 - Graphical symbols for use on equipment - - -
Registered symbols
ISO 13732-1 2006 Ergonomics of the thermal environment - EN ISO 13732-1 2008
Methods for the assessment of human
responses to contact with surfaces - Part 1:
Hot surfaces
IEC 62057-1 ®
Edition 1.0 2023-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical energy meters – Test equipment, techniques and procedures –

Part 1: Stationary meter test units (MTUs)

Compteurs d'énergie électrique – Équipements, techniques et procédures

d'essai –
Partie 1: Bancs d'essai stationnaires des compteurs d'énergie électrique (MTU)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 91.140.50 ISBN 978-2-8322-6437-9

– 2 – IEC 62057-1:2023 © IEC 2023
CONTENTS
FOREWORD . 7
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
3.1 Definitions related to the elements of the MTU . 11
3.2 Definitions of active, reactive and apparent power . 12
3.3 Definitions related to influence quantities . 15
3.4 Definitions related to accuracy . 16
3.5 Definitions related to testing. 17
4 Meter test units and automated meter test units. 18
5 Meter accuracy test methods . 19
5.1 General . 19
5.2 Energy comparison method . 19
5.3 Power–time measurement method (wattmeter method with register reading) . 20
5.4 Pulse comparison method . 20
6 Standard electrical values. 21
6.1 Mains supply . 21
6.2 Output values and ranges of the test circuits . 22
6.2.1 Test voltage circuit . 22
6.2.2 Test current circuit . 22
6.2.3 Phase angle . 23
6.2.4 Frequency . 23
6.2.5 Harmonics . 24
6.3 Standard meter . 24
6.3.1 Accuracy class . 24
6.3.2 Standard electrical values . 24
6.4 Magnetic field of the MTU . 25
6.5 Electrical and mechanical values for the scanning head(s) . 25
6.6 Error calculation system . 26
6.6.1 Functional requirements . 26
6.6.2 Parameters . 26
7 Constructional requirements of the MTU . 26
7.1 General requirements . 26
7.2 Source and standard meter . 26
7.3 Meter mounting system . 27
7.3.1 General . 27
7.3.2 Terminals . 27
8 Information and marking requirements . 28
8.1 General . 28
8.2 Labels, signs and signals . 29
8.3 Information for selection . 30
8.3.1 General . 30
8.3.2 General information . 30
8.3.3 Information related to standard meters . 30
8.3.4 Information related to sources, error calculation systems and frequency
generators . 31

IEC 62057-1:2023 © IEC 2023 – 3 –
8.3.5 Information related to the ICTs and MSVTs . 31
8.3.6 For the communication interfaces and error calculation systems . 31
8.4 Information for installation and commissioning . 32
8.4.1 General . 32
8.4.2 Dimensions and mass . 32
8.4.3 Connection . 32
8.4.4 Protection – Protective class and earthing . 32
8.4.5 Self-consumption . 33
8.5 Information for use . 33
8.5.1 General . 33
8.5.2 Display, push buttons and other controls . 33
8.5.3 Connection to user’s equipment . 33
8.5.4 External protection devices . 33
8.5.5 Cleaning . 33
8.5.6 Information for maintenance . 33
9 Climatic conditions for the MTU . 34
9.1 Normal environmental conditions . 34
9.2 Extreme environmental conditions. 34
9.3 Temperature limits and resistance to heat . 34
10 Electrical requirements of the MTU . 35
10.1 Influence of mains supply. 35
10.2 Insulation . 35
10.2.1 General . 35
10.2.2 Clearances and creepage distances . 35
10.2.3 Verification of clearances and creepage distances . 35
10.2.4 AC voltage test . 35
11 Electromagnetic compatibility . 36
11.1 General requirements and performance criteria . 36
11.2 General test conditions . 37
11.2.1 General . 37
11.2.2 Test of immunity to electrostatic discharges. 37
11.2.3 Test of immunity of electromagnetic RF Fields . 37
11.2.4 Immunity to power frequency magnetic fields of external origin . 38
11.2.5 Test of immunity to fast transient bursts . 38
11.2.6 Test of immunity to surges . 38
11.2.7 Test of immunity to conducted disturbances, induced by RF (radio
frequency) fields . 38
11.2.8 Radio interference suppression . 39
12 Standard meter . 39
12.1 General . 39
12.2 Accuracy requirements under reference conditions . 39
12.3 Limits of error due to influence quantities . 40
12.4 Accuracy tests in the presence of harmonics . 42
th
12.4.1 Test with 5 harmonic in the current and voltage . 42
12.4.2 Tests of the influence of odd and sub-harmonics . 42
13 Software requirements . 42
13.1 Application . 42
13.2 Identification . 42

– 4 – IEC 62057-1:2023 © IEC 2023
13.3 Protection . 42
13.4 Functional requirements . 43
13.5 Control and supervision of the MTU by the software . 43
13.6 Creation, protection and storage of test programs . 44
13.7 Protection and storage of test results and test protocols . 44
13.8 Documentation of the software . 44
13.9 Software logs . 44
14 Accuracy requirements and tests . 45
14.1 General . 45
14.2 Test methods for determination of the MTU accuracy . 45
14.3 Test points – Selection of voltage and current ranges . 46
14.4 Accuracy requirements . 47
14.4.1 Limits of maximum permissible error . 47
14.4.2 Correction of the error δW of the MTU . 47
14.4.3 Mean value and repeatability of the measurements . 48
14.5 Check of measurement results of the MTU . 49
14.5.1 Basic measurements of the MTU . 49
14.5.2 Maintenance measurement of the MTU . 49
14.6 Tests and testing procedures . 49
14.6.1 Type tests . 49
14.6.2 Routine tests . 49
14.6.3 Acceptance test . 51
14.6.4 Commissioning test . 51
Annex A (informative) Symbols according to IEC 60417 . 52
Annex B (normative) Reference conditions . 53
Annex C (informative) Test circuits and test signals for testing in the presence of
harmonics . 54
C.1 General . 54
C.2 Phase fired control (odd harmonics) . 54
C.3 Burst control (sub-harmonics) . 56
Annex D (informative) Calculation of errors and the associated expanded
measurement uncertainty . 58
D.1 General . 58
D.2 Degrees of freedom and sensitivity coefficient . 58
D.3 Method for the determination of the standard measurement uncertainty . 59
D.3.1 Type A . 59
D.3.2 Type B . 60
D.4 Examples for the calculation of the measurement uncertainty . 61
D.4.1 Measuring principle . 61
D.4.2 Model equation . 61
D.4.3 Measurement uncertainty budget considering the specification for the
working standard . 62
D.4.4 Measurement uncertainty budget considering the error of the working

standard . 65
D.5 Indication of the measurement uncertainty . 67
Annex E (informative) Guidelines for overall laboratory setup . 68
E.1 General . 68
E.2 General conditions . 68
E.3 Quality of mains supply . 68

IEC 62057-1:2023 © IEC 2023 – 5 –
E.4 Reference standard . 69
Annex F (normative) Multi-secondary voltage transformer . 70
F.1 General . 70
F.2 Definitions. 70
F.3 Application . 70
F.4 Technical requirements . 71
F.5 Total accuracy of MTU with MSVT . 72
Annex G (normative) Isolating current transformer (ICT) . 73
G.1 General . 73
G.2 Definitions. 73
G.3 Application . 73
G.4 Technical requirements . 74
G.5 Wiring and terminals . 74
G.6 Total accuracy of MTU with ICT . 74
Bibliography . 76

Figure C.1 – Test circuit diagram (informative) . 54
Figure C.2 – Phase fired waveform . 55
Figure C.3 – Informative distribution of harmonic content of phase fired waveform (the
Fourier analysis is not complete) . 55
Figure C.4 – Burst fired waveform . 56
Figure C.5 – Informative distribution of harmonics (the Fourier analysis is not
complete) . 57
Figure D.1 – Measuring setup of the meter test arrangement . 61
Figure F.1 – Testing of single-phase meters with closed link between the voltage and
current circuits (variant 1) . 71
Figure F.2 – Testing of single-phase meters with closed link between the voltage and
current circuits (variant 2) . 71
Figure G.1 – Testing of three-phase meters with closed link between the voltage and

current circuits . 73

Table 1 – Mains power supply condition . 22
Table 2 – Test voltage circuit for each phase . 22
Table 3 – Test current circuit for each phase . 23
Table 4 – Setting of phase angle between each phase voltage and current circuit . 23
Table 5 – Setting of frequency . 23
Table 6 – Setting of harmonics. 24
Table 7 – Standard electrical values for the standard meter . 25
Table 8 – Electrical and mechanical values for the scanning head(s) . 25
Table 9 – Parameters for the error calculation system. 26
Table 10 – Information requirements . 28
Table 11 – Climatic conditions . 34
Table 12 – Surface temperature limits . 34
Table 13 – AC voltage tests . 36
Table 14 – Limits of variation of error of standard meters during immunity test . 37
Table 15 – Relative error limits for the standard meter . 40

– 6 – IEC 62057-1:2023 © IEC 2023
Table 16 – Influence quantities . 41
Table 17 – Recommended accuracy class of reference standard meter . 46
Table 18 – Basic measurement table (recommended test points) . 46
Table 19 – Limits of maximum permissible error (δW ) of the complete MTU related
max
to DUT . 47
Table 20 – Limits of permissible values of standard deviation of MTU . 48
Table A.1 – Symbols which may be used on metering equipment . 52
Table B.1 – Reference conditions . 53
Table D.1 – Coverage factors k for different effective degrees of freedom V . 59
eff
Table D.2 – List 1 of quantities . 63
Table D.3 – Readings 1 of the DUT . 63
Table D.4 – Reading 1 of the standard meter . 64
Table D.5 – Measurement uncertainty budget 1 . 64
Table D.6 – List 2 of quantities . 65
Table D.7 – Readings 2 of the DUT . 65
Table D.8 – Reading 2 of the standard meter . 66
Table D.9 – Measurement uncertainty budget 2 . 67
Table E.1 – Mains supply quality . 69
Table F.1 – Technical requirements of MSVTs . 72
Table F.2 – Maximum permissible limits of error of MTU with MSVT . 72
Table G.1 – Technical requirements of ICT . 74
Table G.2 – Maximum permissible limits of error of MTU with ICT . 75

IEC 62057-1:2023 © IEC 2023 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL ENERGY METERS –
TEST EQUIPMENT, TECHNIQUES AND PROCEDURES –

Part 1: Stationary meter test units (MTUs)

FOREWORD
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expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
IEC 62057-1 has been prepared by IEC technical committee 13: Electrical energy measurement
and control. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
13/1879/FDIS 13/1886/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

– 8 – IEC 62057-1:2023 © IEC 2023
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 62057 series, published under the general title Electrical energy
meters – Test equipment, techniques and procedures, 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 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.
IEC 62057-1:2023 © IEC 2023 – 9 –
ELECTRICAL ENERGY METERS –
TEST EQUIPMENT, TECHNIQUES AND PROCEDURES –

Part 1: Stationary meter test units (MTUs)

1 Scope
This part of IEC 62057 applies to stationary meter test units (MTUs) permanently installed in
laboratories, used for testing and calibration of electricity meters, in particular for their type test,
acceptance test and verification test. It covers the requirements for automatic MTUs for indoor
laboratory application and applies to newly manufactured MTUs to test electricity meters on
50 Hz or 60 Hz networks with an AC voltage up to 600 V (phase to neutral).
If meters are intended for system voltages not specified in this document, special requirements
are agreed between the manufacturer and the purchaser.
This document also defines the kind of tests to perform as type tests / routine tests / acceptance
tests and commissioning tests for MTUs.
It does not apply to:
• portable reference meters and portable sources;
• electricity meters;
• data interfaces to the meter and test procedures of data interface;
• transformer operated MTUs;
• personal computers supplied together with the MTU.
2 Normative references
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.
IEC 60417, Graphical symbols for use on equipment (available at http://www.graphical-
symbols.info/equipment)
IEC 60617, Graphical symbols for diagrams (available at http://std.iec.ch/iec60617)
IEC 60664-1:2020, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60721-3-2:2018, Classification of environmental conditions – Part 3-2: Classification of
groups of environmental parameters and their severities – Transportation and handling
IEC 60721-3-3:2019, Classification of environmental conditions – Part 3-3: Classification of
groups of environmental parameters and their severities – Stationary use at weatherprotected
locations
– 10 – IEC 62057-1:2023 © IEC 2023
IEC 61010-031:2015, Safety requirements for electrical equipment for measurement, control
and laboratory use – Part 031: Safety requirements for hand-held probe assemblies for
electrical measurement and test
IEC 61010-031:2015/AMD1:2018
IEC 61010-1:2010, Safety requirements for electrical equipment for measurement, control, and
laboratory use – Part 1: General requirements
IEC 61010-1:2010/AMD1:2016
IEC 61140:2016, Protection against electric shock – Common aspects for installation and
equipment
IEC 61326-1:2020, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 1: General requirements
IEC 62052-11:2020, Electricity metering equipment – General requirements, tests and test
conditions – Part 11: Metering equipment
IEC 62052-31:2015, Electricity metering equipment (AC) – General requirements, tests and test
conditions – Part 31: Product safety requirements and tests
IEC 62053 (all parts), Electricity metering equipment
CISPR 11:2015, Industrial, scientific and medical equipment – Radio-frequency disturbance
characteristics – Limits and methods of measurement
CISPR 11:2015/AMD1:2016
CISPR 11:2015/AMD2:2019
EN 50160, Voltage characteristics of electricity supplied by public electricity networks
EN 50470 (all parts), Electricity metering equipment (a.c.)
ISO 3864-1:2011, Graphical symbols – Safety colours and safety signs – Part 1: Design
principles for safety signs and safety markings
ISO 7000, Graphical symbols for use on equipment – Registered symbols (available at
http://www.graphical-symbols.info/equipment)
ISO 13732-1:2006, Ergonomics of the thermal environment – Methods for the assessment of
human responses to contact with surfaces – Part 1: Hot surfaces
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

IEC 62057-1:2023 © IEC 2023 – 11 –
3.1 Definitions related to the elements of the MTU
3.1.1
device under test
DUT
meter intended to measure active and/or reactive energy by integrating active and/or reactive
power with respect to time
Note 1 to entry: For the definition of various types of energy meters and their elements, see I
...