SIST EN 61000-3-12:2005

Electromagnetic compatibility (EMC) -- Part 3-12: Limits - Limits for harmonic currents produced by equipment connected to public low-voltage systems with input current > 16 A and <= 75 A per phase

Deals with the limitation of harmonic currents injected into the public supply system. The limits given in this International Standard are applicable to electrical and electronic equipment with a rated input current exceeding 16 A and up to and including 75 A per phase, intended to be connected to public low-voltage a.c. distribution systems of the following types: - nominal voltage up to 240 V, single-phase, two or three wires; - nominal voltage up to 690 V, three-phase, three or four wires; - nominal frequency 50 Hz or 60 Hz. Other distribution systems are excluded. The limits given in this edition apply to equipment when connected to 230/400 V, 50 Hz systems. This standard applies to equipment intended to be connected to low-voltage systems interfacing with the public supply at the low-voltage level. It does not apply to equipment intended to be connected only to private low-voltage systems interfacing with the public supply only at the medium- or high-voltage level. This standard defines: a) requirements and emission limits for equipment; b) methods for type tests and simulations. Tests according to this International Standard are type tests of complete pieces of equipment. Conformity with this standard can also be determined by validated simulations.

Elektromagnetische Verträglichkeit (EMV) -- Teil 3-12: Grenzwerte - Grenzwerte für Oberschwingungsströme, verursacht von Geräten und Einrichtungen mit einem Eingangsstrom >16 A und <= 75 A je Leiter, die zum Anschluss an öffentliche Niederspannungsnetze vorgesehen sind

Compatibilité électromagnétique (CEM) -- Partie 3-12: Limites - Limites pour les courants harmoniques produits par les appareils connectés aux réseaux publics basse tension ayant un courant appelé > 16 A et <= 75 A par phase

Traite de la limitation des courants harmoniques injectés dans le réseau public d'alimentation. Les limites définies dans la présente Norme internationale sont applicables aux appareils électriques et électroniques ayant un courant assigné d'entrée supérieur à 16 A et inférieur ou égal à 75 A par phase, destinés à être connectés aux réseaux publics de distribution en courant alternatif basse tension des types suivants: - tension nominale jusqu'à 240 V, monophasé, deux ou trois conducteurs; - tension nominale jusqu'à 690 V, triphasé, trois ou quatre conducteurs; - fréquence nominale 50 Hz ou 60 Hz. Les autres réseaux de distribution sont exclus. Les limites définies dans la présente édition s'appliquent aux appareils connectés aux réseaux 230/400 V, 50 Hz. La présente norme s'applique aux appareils destinés à être raccordés à des réseaux basse tension connectés au réseau public d'alimentation au niveau basse tension. Elle ne s'applique pas aux appareils destinés à être raccordés uniquement à des réseaux basse tension privés connectés au réseau public d'alimentation seulement au niveau moyenne ou haute tension. Cette norme définit: a) les exigences et limites d'émissions pour les appareils; b) les méthodes d'essai de type et de simulation. Les essais réalisés conformément à la présente Norme internationale sont des essais de type sur des équipements complets. La conformité à la présente norme peut également être déterminée au moyen de simulations validées.

Elektromagnetna združljivost (EMC) – 3-12. del: Mejne vrednosti – Mejne vrednosti za harmonske tokove, ki jih povzroča oprema, priključena na nizkonapetostne napajalne sisteme z naznačenim tokom, večjim od 16 A in <= 75 A po liniji (IEC 61000-3-12:2004)

General Information

• Status: Withdrawn
• Publication Date: 30-Jun-2005
• Withdrawal Date: 23-Nov-2014
• ICS: 33.100.01 - Electromagnetic compatibility in general
• Technical Committee: EMC - Electromagnetic compatibility
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 20-Nov-2014
• Due Date: 13-Dec-2014
• Completion Date: 24-Nov-2014
• Directive: 1999/5/EC - Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio equipment and telecommunications terminal equipment and the mutual recognition of their conformity
• Directive: 2004/108/EU - DIRECTIVE 2004/108/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 15 December 2004 on the approximation of the laws of the Member States relating to electromagnetic compatibility and repealing Directive 89/336/EEC
• Directive: 89/336/EEC - Electromagnetic compatibility (EMC)
• Ref Project: EN 61000-3-12:2005 - Electromagnetic compatibility (EMC) - Part 3-12: Limits - Limits for harmonic currents produced by equipment connected to public low-voltage systems with input current > 16 A and <= 75 A per phase

Relations

• Replaced By: SIST EN 61000-3-12:2012 - Electromagnetic compatibility (EMC) - Part 3-12: Limits - Limits for harmonic currents produced by equipment connected to public low-voltage systems with input current > 16 A and <= 75 A per phase
• Effective Date: 01-Feb-2012
• Replaced By: SIST EN 61000-3-12:2012 - Electromagnetic compatibility (EMC) - Part 3-12: Limits - Limits for harmonic currents produced by equipment connected to public low-voltage systems with input current > 16 A and <= 75 A per phase
• Effective Date: 29-Jan-2023

Standards Content (Sample)

SLOVENSKI SIST EN 61000-3-12:2005

STANDARD
julij 2005
(OHNWURPDJQHWQD]GUXåOMLYRVW(0&±GHO0HMQHYUHGQRVWL±0HMQH
YUHGQRVWL]DKDUPRQVNHWRNRYHNLMLKSRY]URþDRSUHPDSULNOMXþHQDQD
QL]NRQDSHWRVWQHQDSDMDOQHVLVWHPH]QD]QDþHQLPWRNRPYHþMLPRG$LQ 
75 A po liniji (IEC 61000-3-12:2004)
Electromagnetic compatibility (EMC) – Part 3-12: Limits – Limits for harmonic
currents produced by equipment connected to public low-voltage systems with input
current > 16 A and <= 75 A per phase (IEC 61000-3-12:2004)
ICS 5HIHUHQþQDãWHYLOND
33.100.01
SIST EN 61000-3-12:2005(en)
! "#$%!&!%’()*#+’

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD EN 61000-3-12
NORME EUROPÉENNE
EUROPÄISCHE NORM April 2005

ICS 33.100.10


English version


Electromagnetic compatibility (EMC)
Part 3-12: Limits -
Limits for harmonic currents produced by equipment connected to public
low-voltage systems with input current > 16 A and ≤ 75 A per phase
(IEC 61000-3-12:2004)


Compatibilité électromagnétique (CEM) Elektromagnetische Verträglichkeit (EMV)
Partie 3-12: Limites - Teil 3-12: Grenzwerte -
Limites pour les courants harmoniques Grenzwerte für Oberschwingungsströme,
produits par les appareils connectés verursacht von Geräten und Einrichtungen
aux réseaux publics basse tension mit einem Eingangsstrom >16 A und
ayant un courant appelé > 16 A et ≤ 75 A ≤ 75 A je Leiter, die zum Anschluss
par phase an öffentliche Niederspannungsnetze
(CEI 61000-3-12:2004) vorgesehen sind
(IEC 61000-3-12:2004)



This European Standard was approved by CENELEC on 2005-02-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 61000-3-12:2005 E

---------------------- Page: 2 ----------------------

EN 61000-3-12:2005 - 2 -
Foreword
The text of document 77A/470/FDIS, future edition 1 of IEC 61000-3-12, prepared by SC 77A, Low
frequency phenomena, of IEC TC 77, Electromagnetic compatibility, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 61000-3-12 on 2005-02-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2005-11-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-02-01
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of
EC Directives 89/336/EEC and 1999/5/EC. See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61000-3-12:2004 was approved by CENELEC as a
European Standard without any modification.
__________

---------------------- Page: 3 ----------------------

- 3 - EN 61000-3-12:2005
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application 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 Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
1) 2) 3)
IEC 60038 (mod) - IEC standard voltages HD 472 S1 1989

1)
IEC 60050-161 - International Electrotechnical Vocabulary - -
(IEV)
Chapter 161: Electromagnetic
compatibility

1) 3)
IEC 61000-2-2 - Electromagnetic compatibility (EMC) EN 61000-2-2 -
Part 2-2: Environment - Compatibility
levels for low-frequency conducted
disturbances and signalling in public low-
voltage power supply systems

1) 3)
IEC 61000-2-4 - Part 2-4: Environment - Compatibility EN 61000-2-4 -
levels in industrial plants for low-
frequency conducted disturbances

1) 3)
IEC 61000-3-2 - Part 3-2: Limits - Limits for harmonic EN 61000-3-2 -
(mod) current emissions (equipment input
current up to and including 16 A per
phase)

1) 3)
IEC 61000-4-7 - Part 4-7: Testing and measurement EN 61000-4-7 -
techniques - General guide on harmonics
and interharmonics measurements and
instrumentation, for power supply
systems and equipment connected
thereto



1)
Undated reference.
2)
The title of HD 472 S1 is: Nominal voltages for low voltage public electricity supply systems.
3)
Valid edtion at date of issue.

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

EN 61000-3-12:2005 - 4 -
Annex ZZ
(informative)

Coverage of Essential Requirements of EC Directives
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and within its scope the standard covers only
essential requirements as given in Article 4 a) of the EC Directive 89/336/EEC and the corresponding
essential requirements of article 3.1(b) of the EC Directive 1999/5/EC.
Compliance with this standard provides one means of conformity with the specified essential
requirements of the Directive[s] concerned.
WARNING: Other requirements and other EC Directives may be applicable to the products falling
within the scope of this standard.
__________

---------------------- Page: 5 ----------------------

NORME CEI
INTERNATIONALE
IEC



61000-3-12
INTERNATIONAL


Première édition
STANDARD

First edition

2004-11


Compatibilité électromagnétique (CEM) –
Partie 3-12:
Limites – Limites pour les courants harmoniques
produits par les appareils connectés aux réseaux
publics basse tension ayant un courant appelé
>16 A et ≤≤≤≤75 A par phase

Electromagnetic compatibility (EMC) –
Part 3-12:
Limits – Limits for harmonic currents produced
by equipment connected to public low-voltage
systems with input current >16 A and ≤≤≤≤75 A
per phase
 IEC 2004 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
U
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 6 ----------------------

61000-3-12  IEC:2004 – 3 –
CONTENTS
FOREWORD.5
INTRODUCTION.9

1 Scope.11
2 Normative references.13
3 Terms and definitions .13
4 Measurement conditions.21
4.1 Reference fundamental current.21
4.2 Harmonic current measurement .21
4.3 Equipment consisting of several self-contained items .25
5 Requirements and limits for equipment .25
5.1 Control methods.25
5.2 Limits for emission.27
6 Product documentation.33
7 Test and simulation conditions .35
7.1 Requirements for direct measurement .35
7.2 Requirements for simulation .37
7.3 General conditions for test and simulation.39

Annex A (normative) Illustration of limits for harmonic currents .41
Annex B (normative) Approximate interpolation formulas .43
Annex C (informative) Equipment not complying with the requirements and limits
of this standard .47
Annex D (informative) Information on the PWHD factor.49

Bibliography .53

th
Figure 1 – Definition of the 5 harmonic current phase angle (I leads U , α > 0) .19
5 p1 5
th
Figure 2 – Definition of the 5 harmonic current phase angle (I lags U , α < 0) .21
5 p1 5
th
Figure A.1 – Limits of the 5 harmonic current as functions of R .41
sce

Table 1 – Values of the observation period .25
Table 2 – Current emission limits for equipment other than balanced three-phase
equipment.29
Table 3 – Current emission limits for balanced three-phase equipment .31
Table 4 – Current emission limits for balanced three-phase equipment under specified
conditions .31

---------------------- Page: 7 ----------------------

61000-3-12  IEC:2004 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 3-12: Limits – Limits for harmonic currents
produced by equipment connected to public low-voltage systems with
input current >16 A and ≤≤≤≤75 A per phase


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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 61000-3-12 has been prepared by sub-committee 77A: Low
frequency phenomena, of IEC technical committee 77: Electromagnetic compatibility.
This first edition replaces IEC 61000-3-4, published in 1998, for equipment with input current
≤75 A per phase. For equipment with input current >75 A per phase, IEC 61000-3-4 remains
valid.

---------------------- Page: 8 ----------------------

61000-3-12  IEC:2004 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
77A/470/FDIS 77A/478/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

---------------------- Page: 9 ----------------------

61000-3-12  IEC:2004 – 9 –
INTRODUCTION
IEC 61000 is published in separate parts according to the following structure:
Part 1: General
General considerations (introduction, fundamental principles)
Definitions, terminology
Part 2: Environment
Description of the environment
Classification of the environment
Compatibility levels
Part 3: Limits
Emission limits
Immunity limits (in so far as they do not fall under the responsibility of the product
committees)
Part 4: Testing and measurement techniques
Measurement techniques
Testing techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic standards
Part 9: Miscellaneous
Each part is further subdivided into several parts, published either as International Standards
or as technical specifications or technical reports, some of which have already been published
as sections. Others will be published with the part number followed by a dash and a second
number identifying the subdivision (example: 61000-6-1).
This International Standard is a Product Family Standard.

---------------------- Page: 10 ----------------------

61000-3-12  IEC:2004 – 11 –
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 3-12: Limits – Limits for harmonic currents
produced by equipment connected to public low-voltage systems with
input current >16 A and ≤≤75 A per phase
≤≤



1 Scope
This part of IEC 61000 deals with the limitation of harmonic currents injected into the public
supply system. The limits given in this International Standard are applicable to electrical and
electronic equipment with a rated input current exceeding 16 A and up to and including 75 A
per phase, intended to be connected to public low-voltage a.c. distribution systems of the
following types:
• nominal voltage up to 240 V, single-phase, two or three wires;
• nominal voltage up to 690 V, three-phase, three or four wires;
• nominal frequency 50 Hz or 60 Hz.
Other distribution systems are excluded. The limits given in this edition apply to equipment
when connected to 230/400 V, 50 Hz systems. See also Clause 5.
NOTE The limits for the other systems will be added in a future edition of this standard.
This standard applies to equipment intended to be connected to low-voltage systems
interfacing with the public supply at the low-voltage level. It does not apply to equipment
intended to be connected only to private low-voltage systems interfacing with the public supply
only at the medium- or high-voltage level.
NOTE 1 The scope of this standard is limited to equipment connected to public low voltage systems because
emissions from equipment installed in private low voltage systems can be controlled in aggregate at the MV point of
common coupling using procedures defined in IEC 61000-3-6 and/or by means of contractual agreements between
the distribution network operator and the customer. It is expected that operators of private systems will manage the
EMC environment in a manner that ensures compliance with the provisions given in IEC 61000-3-6 and/or the
contractual agreements.
NOTE 2 If the equipment is intended to be connected only to private systems, the manufacturer should make this
very clear in the product documentation.
NOTE 3 Professional equipment with input current ≤ 16 A per phase and that does not comply with the
requirements and limits of standard IEC 61000-3-2 may be permitted to be connected to certain types of low voltage
supplies, in the same way as equipment with input current > 16 A per phase and that does not comply with the
requirements and limits of the present standard IEC 61000-3-12 (see Annex C).
NOTE 4 The limits in this standard are not applicable to stand-alone harmonic filters.
This standard defines:
a) requirements and emission limits for equipment;
b) methods for type tests and simulations.
Tests according to this International Standard are type tests of complete pieces of equipment.
Conformity with this standard can also be determined by validated simulations.

---------------------- Page: 11 ----------------------

61000-3-12  IEC:2004 – 13 –
2 Normative references
The following referenced documents are indispensable for the application 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 60038, IEC standard voltages
IEC 60050-161, International Electrotechnical Vocabulary (IEV) – Chapter 161: Electro-
magnetic compatibility
IEC 61000-2-2, Electromagnetic compatibility (EMC) – Part 2-2: Environment – Compatibility
levels for low-frequency conducted disturbances and signalling in public low-voltage power
supply systems
IEC 61000-2-4, Electromagnetic compatibility (EMC) – Part 2-4: Environment – Compatibility
levels in industrial plants for low-frequency conducted disturbances
IEC 61000-3-2, Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for harmonic
current emissions (equipment input current ≤ 16 A per phase)
IEC 61000-4-7, Electromagnetic compatibility (EMC) – Part 4-7: Testing and measurement
techniques – General guide on harmonics and interharmonics measurements and
instrumentation, for power supply systems and equipment connected thereto
3 Terms and definitions
For the purposes of this document, the definitions given in IEC 60050(161) and the following

definitions apply.
3.1
total harmonic distortion
THD
ratio of the r.m.s. value of the harmonics (in this context harmonic currents I of the order n) to
n
the r.m.s. value of the fundamental, viz.
2
40
 I 
n
 
THD =

∑
 
I
 1
n=2
NOTE This definition has been chosen in accordance with the relevant standard, IEC 61000-2-2.
3.2
partial weighted harmonic distortion
PWHD
ratio of the r.m.s. value of a selected group of higher order harmonics (in this International
Standard beginning from the fourteenth harmonic), weighted with the harmonic order n, to the
r.m.s. value of the fundamental:

---------------------- Page: 12 ----------------------

61000-3-12  IEC:2004 – 15 –
2
40
 I 
n
PWHD = n 

∑
 
I
1
 
n=14
The partial weighted harmonic distortion is employed in order to ensure that the effects of the
higher order harmonic currents on the results are reduced sufficiently and individual limits need
not be specified.
3.3
point of common coupling
PCC
point in the public system which is closest to the customer concerned and to which other
customers are or may be connected
3.4
single-phase equipment
equipment which is connected between one line conductor and the neutral conductor
NOTE This includes equipment in which separate loads are connected from one or more line conductors to the
neutral conductor
3.5
interphase equipment
equipment which is connected between two line conductors (phases)
The neutral conductor is not used as a current-carrying conductor under normal operating
conditions.
3.6
three-phase equipment
equipment which is connected to the three line conductors
The neutral conductor is not used as a current-carrying conductor under normal operating
conditions.
NOTE Equipment intended to be connected to all three phases and to the neutral and where the neutral conductor
is used as a current-carrying conductor, is considered as three separate single-phase items.
3.6.1
balanced three-phase equipment
three-phase equipment which is connected to the three line conductors of a three-phase supply
and in which the three line or phase currents are designed to be identical in amplitude and
wave-shape, each being displaced from the other two by one-third of a fundamental period
3.6.2
unbalanced three-phase equipment
three-phase equipment which is connected to the three line conductors of a three-phase supply
and in which the three line or phase currents are not designed to be identical in amplitude or
wave-shape, or the displacement between any two is other than one-third of a fundamental period
3.7
hybrid equipment
combination of a balanced three-phase load and one or more loads connected between phase
and neutral or between phases

---------------------- Page: 13 ----------------------

61000-3-12  IEC:2004 – 17 –
3.8
short-circuit power
S
sc
value of the three-phase short-circuit power calculated from the nominal interphase system
voltage U and the line impedance Z of the system at the PCC:
nominal
2
S = U / Z
sc nominal
where Z is the system impedance at the power frequency
3.9
rated apparent power of the equipment
S
equ
value calculated from the rated line current I of the piece of equipment stated by the
equ
manufacturer and the rated voltage U (single phase) or U (interphase) as follows:
p i
a) S = U I for single-phase equipment and the single-phase part of hybrid
equ p equ
equipment;
b) S = U I for interphase equipment;
equ i equ
c) S = 3 U I for balanced three-phase equipment and the three-phase part of
equ i equ
hybrid equipment;
d) S = 3 U I for unbalanced three-phase equipment, where I is the
equ p equ max equ max
maximum of the r.m.s. currents flowing in any one of the three
phases
In the case of a voltage range, U or U is a nominal system voltage according to IEC 60038
p i
(for example: 120 V or 230 V for single-phase or 400 V line-line for three-phase).
3.10
short-circuit ratio
R
sce
characteristic value of a piece of equipment defined as follows:
a) R = S / (3 S ) for single-phase equipment and the single-phase part of hybrid
sce sc equ
equipment;
b) R = S / (2 S ) for interphase equipment;
sce sc equ
c) R = S / S for all three-phase equipment and the three-phase part of hybrid
sce sc equ
equipment
NOTE 1 R may be related directly to basic known quantities by means of the equations:
sce
R = U/(√3 × Z × I ) for single-phase equipment and the single phase part of hybrid equipment;
sce equ
R = U/(2 × Z × I ) for interphase equipment;
sce equ
R = U/(√3 × Z × I ) for balanced three-phase equipment and the three-phase part of hybrid equipment;
sce equ
R = U/(√3 × Z × I ) for unbalanced three-phase equipment
sce equ max
where U = U , and is assumed to be equal to U or √3 × U , whichever is relevant.
nominal i p
NOTE 2 R is not the same as R , as defined in IEC 61000-2-6.
sce sc
NOTE 3 For hybrid equipment, the method of calculating a single R value is given in 5.2.
sce
3.11
reference fundamental current
I
1
r.m.s. value of the fundamental component of the rated line current I of the equipment (see
equ
also 4.1)

---------------------- Page: 14 ----------------------

61000-3-12  IEC:2004 – 19 –
3.12
total harmonic current
THC
the total r.m.s. value of the harmonic current components of orders 2 to 40
40
2
THC = I
∑ n
n=2

3.13
stand-by mode
a non-operational, low power consumption mode (usually indicated in some way on the
equipment) that can persist for an indefinite time
NOTE This mode is sometimes termed 'sleep mode'.
3.14
phase angle of I related to the fundamental phase voltage U
5 p1
th
the phase angle of the 5 harmonic current is determined as described in Figures 1 and 2
3.15
professional equipment
equipment for use in trades, professions, or industries and which is not intended for sale to the
general public. The designation is specified by the manufacturer

U
P1
I
5
0
α
5
IEC  1503/04
+ 180°

th
Figure 1 – Definition of the 5 harmonic current phase angle
(I leads U , αααα > 0)
5 p1 5

---------------------- Page: 15 ----------------------

61000-3-12  IEC:2004 – 21 –

U
p1
I
5
0
α
5
IEC  1504/04
− 180°

th
Figure 2 – Definition of the 5 harmonic current phase angle
(I lags U , αα < 0)
αα
5 p1 5
4 Measurement conditions
4.1 Reference fundamental current
The reference fundamental current I , as defined in 3.11, shall be either measured, or
1
calculated as follows.
a) If the reference fundamental current is measured, the measurement of its average value
shall be performed as defined in 4.2.1 for harmonic currents. During the measurement of
the reference fundamental current, the r.m.s. line current shall be equal to the rated line
current I stated by the manufacturer
equ
b) If the reference fundamental current is calculated, the calculation is made using the rated
line current I as follows:
equ
I
equ
I =

1
2
1+ THD
This value of the reference fundamental current shall be specified by the manufacturer and
documented in the test report. This value shall be used in Tables 2 to 4 for establishing the
harmonic current emission limits.
The value of the reference fundamental current found by measurement during emission tests
other than the original manufacturer’s conformity assessment test, measured according to the
terms of this clause, shall not be less than 90 % nor greater than 110 % of the reference
fundamental current value specified by the manufacturer in the test report. In the event that the
measured value is outside of this tolerance band around the specified val
...