Direct acting indicating analogue electrical measuring instruments and their accessories title - Part 4: Special requirements for frequency meters

IEC 60051-4:2018 applies to direct acting indicating analogue frequency meters of the following types:
• pointer-type frequency meters (as defined in 3.2.11 of IEC 60051-1:2016);
• vibrating-reed frequency meters (as defined in 3.2.12 of IEC 60051-1:2016).
IEC 60051-4:2018 also applies to non-interchangeable accessories (as defined in 3.1.23 of IEC 60051-1:2016) used with frequency meters.
IEC 60051-4:2018 cancels and replaces the fourth edition published in 1984. 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 60051-4:2018 is to be used in conjunction with IEC 60051-1:2016.

Appareils mesureurs électriques indicateurs analogiques à action directe et leurs accessoires - Partie 4: Exigences particulières pour les fréquencemètres

IEC 60051-4:2018 s'applique aux fréquencemètres indicateurs analogiques à action directe des types suivants:
• fréquencemètres à aiguille (définis en 3.2.11 de l'IEC 60051-1:2016);
• fréquencemètres à lames vibrantes (définis en 3.2.12 de l'IEC 60051-1:2016).
IEC 60051-4:2018 s'applique également aux accessoires non interchangeables (définis en 3.1.23 de l'IEC 60051-1:2016) utilisés avec les fréquencemètres.
IEC 60051-4:2018 annule et remplace la quatrième édition parue en 1984. 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 60051-4:2018 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
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IEC 60051-4
Edition 5.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Direct acting indicating analogue electrical measuring instruments and their
accessories title –
Part 4: Special requirements for frequency meters
Appareils mesureurs électriques indicateurs analogiques à action directe et
leurs accessoires –
Partie 4: Exigences particulières pour les fréquencemètres
IEC 60051-4:2018-08(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60051-4
Edition 5.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Direct acting indicating analogue electrical measuring instruments and their
accessories title –
Part 4: Special requirements for frequency meters
Appareils mesureurs électriques indicateurs analogiques à action directe et
leurs accessoires –
Partie 4: Exigences particulières pour les fréquencemètres
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20 ISBN 978-2-8322-5958-0

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 60051-4:2018 © 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

5 Requirements .................................................................................................................. 7

5.1 Reference conditions .............................................................................................. 7

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 .................................................................................................. 8

5.3 Nominal range of use and variations ....................................................................... 8

5.3.1 Nominal range of use ...................................................................................... 8

5.3.2 Limits of variations .......................................................................................... 9

5.3.3 Conditions for the determination of variations .................................................. 9

5.4 Operating uncertainty, overall system uncertainty and variations ............................ 9

5.5 Electrical requirements ........................................................................................... 9

5.5.1 Electrical safety requirements .......................................................................... 9

5.5.2 Self-heating ..................................................................................................... 9

5.5.3 Permissible overloads ...................................................................................... 9

5.5.4 Limiting range of temperature ........................................................................ 10

5.5.5 Deviation from zero ....................................................................................... 10

5.5.6 Electromagnetic compatibility (EMC) ............................................................. 11

5.6 Constructional requirements ................................................................................. 11

5.6.1 General constructional requirements ............................................................. 11

5.6.2 Damping ........................................................................................................ 11

5.6.3 Sealing to prevent access .............................................................................. 11

5.6.4 Scales ........................................................................................................... 11

5.6.5 Stopper.......................................................................................................... 11

5.6.6 Preferred values ............................................................................................ 11

5.6.7 Adjusters, mechanical and/or electrical .......................................................... 11

5.6.8 Effects of vibration and shock ........................................................................ 11

5.6.9 Degrees of protection provided by enclosure ................................................. 11

5.6.10 Terminals ...................................................................................................... 11

6 Information, markings and symbols ............................................................................... 11

6.1 Information ........................................................................................................... 11

6.2 Markings, symbols and their locations ................................................................... 12

6.3 Markings relating to the reference values and nominal ranges of use of

influence quantities ............................................................................................... 12

6.4 The symbols for marking instruments and accessories .......................................... 12

6.5 Markings and symbols for terminals ...................................................................... 12

6.5.1 Requirements for markings ............................................................................ 12

6.5.2 Earthing (grounding) terminals ....................................................................... 12

6.5.3 Measuring circuit terminals ............................................................................ 12

6.5.4 Special markings for terminals ....................................................................... 12

---------------------- Page: 4 ----------------------
IEC 60051-4:2018 © IEC 2018 – 3 –

6.6 Instructions for use ............................................................................................... 12

7 Package ........................................................................................................................ 12

8 Test rules ...................................................................................................................... 12

Annex A (normative) Nonconformity classification of tests ................................................... 13

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 ................................................................................ 9

Table 3 – Overloads of short duration for frequency meters .................................................. 10

Table A.1 – Nonconformity classification of tests .................................................................. 13

---------------------- Page: 5 ----------------------
– 4 – IEC 60051-4:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIRECT ACTING INDICATING ANALOGUE ELECTRICAL
MEASURING INSTRUMENTS AND THEIR ACCESSORIES TITLE –
Part 4: Special requirements for frequency meters
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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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

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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

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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.

International Standard IEC 60051-4 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. 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 60051-4:2018 © IEC 2018 – 5 –
The text of this International Standard is based on the following documents:
CDV Report on voting
85/557/CDV 85/580B/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 60051-4:2018 © 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 60051-4 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 60051-4:2018 © IEC 2018 – 7 –
DIRECT ACTING INDICATING ANALOGUE ELECTRICAL
MEASURING INSTRUMENTS AND THEIR ACCESSORIES TITLE –
Part 4: Special requirements for frequency meters
1 Scope

This part of IEC 60051 applies to direct acting indicating analogue frequency meters of the

following types:
• pointer-type frequency meters (as defined in 3.2.11 of IEC 60051-1:2016);
• vibrating-reed frequency meters (as defined in 3.2.12 of IEC 60051-1:2016).

This document also applies to non-interchangeable accessories (as defined in 3.1.23 of

IEC 60051-1:2016) used with frequency meters.
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
See IEC 60051-1:2016.
5 Requirements
5.1 Reference conditions
See Table 1.
---------------------- Page: 9 ----------------------
– 8 – IEC 60051-4:2018 © IEC 2018

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 condition unless Tolerance permitted for testing
otherwise marked purposes, applicable for a single
reference value

Voltage of AC measured quantity Nominal value or any voltage within ±2 % of the nominal value

the nominal range)
For a nominal range, no tolerance is allowed.
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.
5.2.3 Fiducial value
5.2.3.1 General
The fiducial value for a frequency meter corresponds to:
a) The upper limit of the measuring range.

b) For vibrating-reed frequency meters that have several rows of reeds, each row is

considered to be a separate range, and each row has its own fiducial value that is the

upper limit of the measuring range of that row.
5.2.3.2 Special requirements for vibrating reed frequency meters
For vibrating reed frequency meters, the following shall also apply:

a) The difference between the nominal frequencies of two adjacent reeds shall not exceed

twice the limit of the permissible intrinsic uncertainty.

b) With a uniform rate of change of frequency, reeds shall reach their maximum amplitudes

of vibration in the sequence implied by their nominal frequencies.
c) The uncertainty is taken as the greatest value of the frequency differences:

1) between the nominal frequency for each reed and the frequency at which that reed has

its maximum amplitude of vibration, or
2) between the mean of the nominal frequencies of any two adjacent reeds and the
frequency at which these reeds have the same amplitude of vibration.
5.3 Nominal range of use and variations
5.3.1 Nominal range of use
See Table 2.
---------------------- Page: 10 ----------------------
IEC 60051-4:2018 © IEC 2018 – 9 –
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 Permissible variation expressed

use unless otherwise marked as a percentage of the class
index
Voltage of measured quantity Nominal voltage ±15 % or lower 100 %
limit of nominal range -15 % and
upper limit of nominal range +15 %
Distortion of voltage of measured 15 % 100 %
quantity
5.3.2 Limits of variations
See IEC 60051-1:2016.
5.3.3 Conditions for the determination of variations
See IEC 60051-1:2016.
5.4 Operating uncertainty, overall system uncertainty and variations
See IEC 60051-1:2016.
5.5 Electrical requirements
5.5.1 Electrical safety requirements
See IEC 60051-1:2016.
5.5.2 Self-heating
See IEC 60051-1:2016.
5.5.3 Permissible overloads
5.5.3.1 Continuous overload

Frequency meters, together with their non-interchangeable accessory(ies), if any,

except for instruments fitted with a non-locking switch, shall be subjected to a

continuous voltage overload of 120 % of the nominal voltage or 120 % of the upper limit

of the nominal range for a period of 2 h.

After having cooled to its reference temperature, the frequency meter, together with its

non-interchangeable accessory(ies), if any, shall comply with its accuracy requirements;

however, the overload shall not be repeated.

The continuous overload test shall be carried out under reference conditions, except for

the voltage, at any frequency within the measuring range.
For the recommended test, see IEC 60051-9.
5.5.3.2 Overloads of short duration
non-interchangeable accessory(ies), if any, shall be
Frequency meters together with their
subjected to voltage overloads of short duration.
---------------------- Page: 11 ----------------------
– 10 – IEC 60051-4:2018 © IEC 2018

The values of voltage for the overloads of short duration shall be the product of the

relevant factor given in Table 3 and the value of the nominal voltage or the upper limit of the

nominal range for voltage, unless other values are stated by the manufacturer.

The full duration of each overload shall be applied except when an automatic circuit breaker

(or fuse) fitted to the instrument has interrupted the circuit in less than the time specified

in Table 3 .

The automatic circuit breaker shall be reset (or the fuse replaced) before the application

of the next overload.
Table 3 – Overloads of short duration for frequency meters
Voltage factor Number of overloads Duration of each Interval between
overload successive overloads
(s) (s)
Class indices 0,3 and smaller
2 5 1 15
Class indices 0,5 and greater
2 9 0,5 60
2 1 5 –

Where two series of tests are specified, they should both be carried out, in the order given.

After having been subjected to the overloads of short duration and after having cooled to

the reference temperature, the frequency meter together with its non-interchangeable

accessory(ies), if any, shall comply with its accuracy requirements; however, the

overloads shall not be repeated.

The short duration overload test shall be carried out under reference conditions, except for

the voltage, at any frequency within the measuring range.
For the recommended tests, see IEC 60051-9.
5.5.4 Limiting range of temperature
See IEC 60051-1:2016.
5.5.5 Deviation from zero
The requirements of 5.5.5 do not apply to vibrating reed frequency meters.

If a frequency meter has a setting mark (zero scale mark) on the scale, it shall be tested for

return to that mark when de-energized.
The test shall be carried out under reference conditions.

After a period of energization of 30 s at the upper limit of the measuring range, the deviation

of the index from the setting mark (zero scale mark), expressed as a percentage of the scale

not exceed a value corresponding to 50 % of the class index.
length, shall
For the recommended test, see IEC 60051-9.
---------------------- Page: 12 ----------------------
IEC 60051-4:2018 © IEC 2018 – 11 –
5.5.6 Electromagnetic compatibility (EMC)
See IEC 60051-1:2016.
5.6 Constructional requirements
5.6.1 General constructional requirements
See IEC 60051-1:2016.
5.6.2 Damping

The requirements of IEC 60051-1:2016 do not apply to vibrating-reed frequency meters

and, for pointer-type frequency meters only, the requirements of 5.6.2.2 and 5.6.2.3 of

IEC 60051-1:2016 apply.
5.6.3 Sealing to prevent access
See IEC 60051-1:2016.
5.6.4 Scales
See IEC 60051-1:2016.
5.6.5 Stopper
See IEC 60051-1:2016.
5.6.6 Preferred values

The values of frequency and voltage are to be agreed between manufacturer and user.

5.6.7 Adjusters, mechanical and/or electrical

Frequency meters having a mechanical zero position on the scale shall have a setting mark

(zero scale mark) at that position.

Frequency meters not having a determinate mechanical zero (e.g. quotient-meters) or

having a mechanical zero that is outside the scale shall not be provided with an accessible

zero adjuster.
5.6.8 Effects of vibration and shock
See IEC 60051-1:2016.
5.6.9 Degrees of protection provided by enclosure
See IEC 60051-1:2016.
5.6.10 Terminals
See IEC 60051-1:2016.
6 Information, markings and symbols
6.1 Information
See IEC 60051-1:2016.
---------------------- Page: 13 ----------------------
– 12 – IEC 60051-4:2018 © IEC 2018
6.2 Markings, symbols and their locations
See IEC 60051-1:2016.

6.3 Markings relating to the reference values and nominal ranges of use of influence

quantities
See IEC 60051-1:2016.
6.4 The symbols for marking instruments and accessories
See IEC 60051-1:2016.
6.5 Markings and symbols for terminals
6.5.1 Requirements for markings
See IEC 60051-1:2016.
6.5.2 Earthing (grounding) terminals
See IEC 60051-1:2016.
6.5.3 Measuring circuit terminals
See IEC 60051-1:2016.
6.5.4 Special markings for terminals
6.5.4.1 Self-contained frequency meters (i.e. without an accessory)

No markings of measuring circuit terminals are required, but see IEC 60051-1:2016, 6.5.3.

6.5.4.2 Frequency meters having (an) accessory(ies)

The terminals intended to be connected to an external measuring circuit shall be marked

in accordance with 6.5.4.1. The terminal(s) on the frequency meter which is (are) intended

to be connected to (a) terminal(s) on the acces
...

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