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.

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.

General Information

Status
Published
Publication Date
29-Aug-2018
Current Stage
PPUB - Publication issued
Completion Date
30-Aug-2018
Ref Project

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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
IEC 60051-3:2018-08(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
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

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 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

---------------------- Page: 4 ----------------------
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

---------------------- Page: 5 ----------------------
– 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,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

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

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

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

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

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.

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.

---------------------- Page: 6 ----------------------
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.
---------------------- Page: 7 ----------------------
– 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 conductance meters

Part 7: Special requirements for multi-function instruments
Part 8: Special requirements for accessories
Part 9: Recommended test methods

IEC 60051-3 is not complete in itself and is read in conjunction with IEC 60051-1.

All of these parts are arranged in the same format and a standard relationship between

subject and clause number is maintained throughout these parts. This arrangement will assist

the reader of IEC 60051 to distinguish information relating to the different types of instruments.

---------------------- Page: 8 ----------------------
IEC 60051-3:2018 © IEC 2018 – 7 –
DIRECT ACTING INDICATING ANALOGUE ELECTRICAL
MEASURING INSTRUMENTS AND THEIR ACCESSORIES –
Part 3: Special requirements for wattmeters and varmeters
1 Scope

This part of IEC 60051 applies to direct acting indicating wattmeters and varmeters having an

analogue display.
NOTE For multi-function instruments, see IEC 60051-7.
It 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.
This document 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.
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 60051-1:2016, Direct acting indicating analogue electrical measuring instruments and

their accessories – Part 1: Definitions and general requirements common to all parts

IEC 60051-9, Direct acting indicating analogue electrical measuring instruments and their

accessories – Part 9: Recommended test methods
3 Terms and definitions
See IEC 60051-1:2016.
4 Description, classification and compliance
4.1 Description
See IEC 60051-1:2016.
---------------------- Page: 9 ----------------------
– 8 – IEC 60051-3:2018 © IEC 2018
4.2 Classification
See IEC 60051-1:2016.
4.3 Compliance with the requirements of this standard
See IEC 60051-1:2016.
5 Requirements
5.1 Reference conditions

See IEC 60051-1:2016; the reference value of the influence quantities should be as given in

Table 2 of IEC 60051-1:2016 and Table 1.
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

Influence quantity Reference conditions unless otherwise Tolerance permitted for testing

marked purposes, applicable for a single
reference value

Voltage component of the Rated voltage or any voltage within the ±2 % of the rated value

measured power reference range
Current component of the Any current up to the rated current or up to –
measured power the upper limit of the reference range

Frequency of voltage and Instruments using Reference frequency ±0,1 % of the reference frequency

current components of the phase shifting
measured power devices
Other instruments 45 Hz to 65 Hz ±2 % of the reference frequency
Power factor PF = 1 or rated value 0,01 lagging or leading
c d
Phase balance (for polyphase Symmetrical voltages and currents
instruments)

This tolerance applies when a single reference value is specified in this table or is marked by the

manufacturer. For a reference range, no tolerance is allowed.

Power factor for varmeters. Positive sign for lagging (inductive), negative sign for leading (capacitive).

The difference between any two line-to-line voltages and between any two line-to-neutral voltages shall not

exceed 1 % of the average (line-to-line and line-to-neutral voltages, respectively).

Each of the currents in the phases shall differ by not more than 1 % from the average of the currents.

The angles between each of the currents and the corresponding phase-to-neutral voltages shall differ by not

more than 2°.

Single-phase testing of polyphase instruments is acceptable if permitted by the manufacturer.

5.2 Limits of intrinsic uncertainty, fiducial value
5.2.1 Limits of intrinsic uncertainty
See IEC 60051-1:2016.
5.2.2 Correspondence between intrinsic uncertainty and accuracy class
See IEC 60051-1:2016.
---------------------- Page: 10 ----------------------
IEC 60051-3:2018 © IEC 2018 – 9 –
5.2.3 Fiducial value

5.2.3.1 The fiducial value for a wattmeter or varmeter corresponds to the following.

5.2.3.2 The upper limit of the measuring range for the following:

• instruments with the mechanical and/or electrical zero at one end of the scale;

• instruments with the mechanical zero outside the scale irrespective of the position of the

electrical zero;

• instruments with the electrical zero outside the scale irrespective of the position of the

mechan-ical zero.

The class index for these wattmeters or varmeters is marked using Symbol E-1 given in

Table 6 of IEC 60051-1:2016 (see Clause 6 of IEC 60051-1:2016).

5.2.3.3 The sum of the absolute values of the upper and lower limit of the measuring

range when both the mechanical and the electrical zeros are displaced within the scale.

The class index for these wattmeters or varmeters is marked using Symbol E-1 given in

Table 6 of IEC 60051-1:2016 (see Clause 6 of IEC 60051-1:2016).

5.2.3.4 The span for an instrument whose scale marks do not correspond directly to its

electrical input quantity.

The class index for these wattmeters or varmeters is marked using Symbol E-10 given in

Table 6 of IEC 60051-1:2016 (see Clause 6 of IEC 60051-1:2016).

This does not apply to a wattmeter or varmeter designed to be used in conjunction with one or

more shunt(s), series resistor(s) (impedance(s)) or (an) instrument transformer(s). These

instruments are treated in accordance with 5.2.3.2 or 5.2.3.3 as appropriate.
5.3 Nominal range of use and variations
5.3.1 Nominal range of use

See IEC 60051-1:2016; the limits of the nominal range of use for influence quantities shall be

as given in Table 3 of IEC 60051-1:2016 and Table 2.
---------------------- Page: 11 ----------------------
– 10 – IEC 60051-3:2018 © IEC 2018
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

Influence quantity Limits of the nominal range of use Permissible variation expressed

unless otherwise marked

Distortion of AC voltage or Distortion factor Instruments using phase shifting 5 % 100 %

current components of the devices
measured power
Other instruments 20 %
a b
Peak factor 1 to 3 200 %

Frequency of AC voltage and Instruments using Reference frequency ± 1 % or lower limit of 100 %

current components of the phase shifting reference range - 1 % and upper limit of

measured power devices reference range + 1 %
Other instruments Reference frequency ± 10 % or lower limit
of reference range - 10 % and upper limit
of reference range + 10 %

Voltage components of the measured power Reference voltage ± 15 % or lower limit of 100 %

reference range - 15 % and upper limit of
reference range + 15 %
Power factor for wattmeters Class indices 0,3 and Any: lagging or leading 100 %
smaller
Class indices 0,5 and lagging (inductive)
Phase angle 0° ... 60°
greater
Power factor for varmeters Class indices 0,3 and Any: lagging or leading 100 %
smaller
Class indices 0,5 and Phase angle 0° ... 60° lagging (inductive)
greater

Phase balance (for polyphase instruments) Disconnection of one current component of 200 %

the measured power

Interaction between measuring elements of polyphase Disconnection of one voltage component of 200 %

instruments the measured power
---------------------- Page: 12 ----------------------
IEC 60051-3:2018 © IEC 2018 – 11 – –

Influence quantity Limits of the nominal range of use Permissible variation expressed

unless otherwise marked
Magnetic field of external origin 0,4kA/m Class indices Class indices
0,3 and smaller 0,5 and greater
Electrodynamic 3 % of the fiducial 6 % of the fiducial
e e
instruments if not values values
static and/or not
having a magnetic
screen
Ferrodynamic 1,5 % of the fiducial 3 % of the fiducial
e e
instruments if not
values values
static and/or not
having a magnetic
screen
All other instruments 0,75 % of the fiducial 1,5 % of the fiducial
e e
values values
For instruments having electronic devices in their measuring circuits.

The permissible variation due to a peak factor of other than (corresponding to a sine wave) is included in the permissible variation due to distortion of the measured

power.

For instruments having a peak factor capability greater than 3, the manufacturer shall state:

1) the instrument peak factor capability producing a variation of 100 % of the class index;

2) the upper and lower limits of the frequency response (bandwidth) to 0,707 times the indication at the reference frequency;

3) the effective maximum rate of change of internal instrument AC amplifier response (slew rate), expressed in volts per second using appropriate SI prefixes.

...

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