EN 60027-7:2010

Letter symbols to be used in electrical technology - Part 7: Power generation, transmission and distribution

IEC 60027-7:2010 is applicable to generation, transmission, and distribution of electric energy. It gives names and letter symbols for quantities and units. In addition, rules for multiple subscripts and their succession are given. It is an addition to IEC 60027-1. Therefore letter symbols already given in IEC 60027-1 are repeated only if they have a special meaning in the field of power generation, transmission, and distribution or if they are used in this field with special subscripts.

Formelzeichen für die Elektrotechnik - Teil 7: Energieerzeugung, -übertragung und -verteilung

Symboles littéraux à utiliser en électrotechnique - Partie 7: Production, transport et distribution de l’énergie électrique

La CEI 60027-7:2010 s'applique à la production, au transport et à la distribution de l'énergie électrique. Elle donne les noms et les symboles littéraux des grandeurs et unités. Elle fixe en outre des règles concernant les indices multiples et leur succession. Elle est une extension de la CEI 60027-1. Les symboles littéraux figurant déjà dans la CEI 60027-1 ne sont donc répétés que s'ils ont une signification particulière dans le domaine de la production, du transport et de la distribution de l'énergie électrique ou s'ils sont utilisés avec des indices particuliers dans ce domaine.

Črkovne oznake za elektrotehniko - 7. del: Proizvodnja, prenos in distribucija električne energije (IEC 60027-7:2010)

Ta del IEC 60027 velja za proizvodnjo, prenos in distribucijo električne energije. Podaja imena in črkovne oznake za količine in enote. Poleg tega podaja pravila v primeru več podpisanega besedila in njihovo zaporedje. Ta del IEC 60027 je dodatek k IEC 60027-1. Zato so črkovne oznake, ki so že podane v IEC 60027-1, ponovljene samo, če imajo poseben pomen na področju proizvodnje, prenosa in distribucije električne energije ali če se na tem področju uporabljajo s posebnim podpisanim besedilom. Navodila glede uporabe velikih in malih črk so podana v IEC 60027-1, 2.1, in navodila glede predstavitve kompleksnih količin so podana v IEC 60027-1, 1.6. Zato je v številnih primerih podan samo U namesto U, U = U ali u.

General Information

• Status: Published
• Publication Date: 09-Sep-2010
• Withdrawal Date: 31-Aug-2013
• ICS: 01.060 - Quantities and units
• Technical Committee: CLC/SR 25 - Quantities and units, and their letter symbols
• Drafting Committee: IEC/TC 25 - IEC_TC_25
• Parallel Committee: IEC/TC 25 - IEC_TC_25
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 10-Sep-2010
• Completion Date: 10-Sep-2010
• Ref Project: SIST EN 60027-7:2010 - Letter symbols to be used in electrical technology - Part 7: Power generation, transmission and distribution (IEC 60027-7:2010)

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2010
ýUNRYQHR]QDNH]DHOHNWURWHKQLNRGHO3URL]YRGQMDSUHQRVLQGLVWULEXFLMD
HOHNWULþQHHQHUJLMH,(&
Letter symbols to be used in electrical technology - Part 7: Power generation,
transmission and distribution (IEC 60027-7:2010)
Formelzeichen für die Elektrotechnik - Teil 7: Energieerzeugung, -übertragung und -
verteilung (IEC 60027-7:2010)
Symboles littéraux à utiliser en électrotechnique - Partie 7: Production, transport et
distribution de l’énergie électrique (CEI 60027-7:2010)
Ta slovenski standard je istoveten z: EN 60027-7:2010
ICS:
01.075 Simboli za znake Character symbols
29.240.01 2PUHåMD]DSUHQRVLQ Power transmission and
GLVWULEXFLMRHOHNWULþQHHQHUJLMH distribution networks in
QDVSORãQR general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60027-7
NORME EUROPÉENNE
September 2010
EUROPÄISCHE NORM
ICS 01.060
English version
Letter symbols to be used in electrical technology -
Part 7: Power generation, transmission and distribution
(IEC 60027-7:2010)
Symboles littéraux à utiliser  Formelzeichen für die Elektrotechnik -
en électrotechnique - Teil 7: Energieerzeugung, -übertragung
Partie 7: Production, transport und -verteilung
et distribution de l’énergie électrique (IEC 60027-7:2010)
(CEI 60027-7:2010)
This European Standard was approved by CENELEC on 2010-09-01. 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, 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, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60027-7:2010 E
Foreword
The text of document 25/391/CDV, future edition 1 of IEC 60027-7, prepared by IEC TC 25, Quantities
and units, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 60027-7 on 2010-09-01.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2011-06-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2013-09-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60027-7:2010 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60027-7:2010
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  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60027-1 1995 Letter symbols to be used in electrical EN 60027-1 2006
+ A1 1997 technology - - -
1)
+ A2 2005 Part 1: General + A2 2007

2)
IEC 60027-2 2005 Letter symbols to be used in electrical EN 60027-2 2007
technology -
Part 2: Telecommunications and electronics

IEC 60038 2009 IEC standard voltages - -

IEC 60050-121 1998 International Electrotechnical Vocabulary - -
+ A1 2002 (IEV) - - -
Part 121: Electromagnetism
IEC 60050-131 2002 International Electrotechnical Vocabulary - -
+ A1 2008 (IEV) - - -
Part 131: Circuit theory
IEC 60050-141 2004 International electrotechnical vocabulary - - -
Part 141: Polyphase systems and circuits

IEC 60050-151 2001 International Electrotechnical Vocabulary - -
(IEV) -
Part 151: Electrical and magnetic devices

IEC 60050-195 1998 International Electrotechnical Vocabulary - -
+ A1 2001 (IEV) - - -
Chapter 195: Earthing and protection against
electric shock
IEC 60050-411 1996 International Electrotechnical Vocabulary - -
+ A1 2007 (IEV) - - -
Chapter 411: Rotating machinery

IEC 60050-421 1990 International electrotechnical vocabulary - -
(IEV) -
Chapter 421: Power transformers and
reactors
IEC 60050-441 1984 International Electrotechnical Vocabulary - -
+ A1 2000 (IEV) - - -
Chapter 441: Switchgear, controlgear and
fuses
1)
EN 60027-1 includes A1 to IEC 60027-1.
2)
EN 60027-2 is superseded by EN 80000-13:2008, which is based on IEC 80000-13:2008.

Publication Year Title EN/HD Year

IEC 60050-442 1998 International Electrotechnical Vocabulary - - -
Part 442: Electrical accessories

IEC 60050-448 1995 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 448: Power system protection

IEC 60050-466 1990 International electrotechnical vocabulary - -
(IEV) -
Chapter 466: Overhead lines
IEC 60050-601 1985 International Electrotechnical Vocabulary - -
+ A1 1998 (IEV) - - -
Chapter 601: Generation, transmission and
distribution of electricity - General

IEC 60050-603 1986 International electrotechnical vocabulary - - -
+ A1 1998 Chapter 603: Generation, transmission and - -
distribution of electricity - Power system
planning and management
IEC 60050-604 1987 International Electrotechnical Vocabulary - -
+ A1 1998 (IEV) - - -
Chapter 604: Generation, transmission and
distribution of electricity - Operation

IEC 60050-811 1991 International electrotechnical vocabulary - -
(IEV) -
Chapter 811: Electric traction

IEC 60909-0 2001 Short-circuit currents in three-phase a.c. EN 60909-0 2001
systems -
Part 0: Calculation of currents

IEC/TR 60909-1 2002 Short-circuit currents in three-phase e.c. -
-
systems -
Part 1: Factors for the calculation of short-
circuit currents according to IEC 60909-0

IEC/TR 60909-2 2008 Short-circuit currents in three-phase a.c. -
-
systems -
Part 2: Data of electrical equipment for short-
circuit current calculations
3)
IEC 60909-3 2003 Short-circuit currents in three-phase a.c EN 60909-3 2003
systems -
Part 3: Currents during two separate
simultaneous line-to-earth short-circuits and
partial short-circuit currents flowing through
earth
IEC 62428 2008 Electric power engineering - Modal EN 62428 2008
components in three-phase a.c. systems -
Quantities and transformations

IEC 80000-6 2008 Quantities and units - EN 80000-6 2008
Part 6: Electromagnetism
3)
EN 60909-3 is superseded by EN 60909-3:2010, which is based on IEC 60909-3:2009.

IEC 60027-7 ®
Edition 1.0 2010-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Letter symbols to be used in electrical technology –
Part 7: Power generation, transmission, and distribution

Symboles littéraux à utiliser en électrotechnique –
Partie 7: Production, transport et distribution de l’énergie électrique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
U
CODE PRIX
ICS 01.060 ISBN 978-2-88910-921-0
– 2 – 60027-7 © IEC:2010
CONTENTS
FOREWORD.3
1 Scope.5
2 Normative references .5
3 Letter symbols for AC, three-phase AC, and other network quantities.7
4 Letter symbols for space and time .17
5 Letter symbols for numerical values and ratios of quantities .20
6 Subscripts and superscripts.24
6.1 Subscripts for natural quantities and components in three-phase AC systems.24
6.2 Subscripts for operating conditions.25
6.3 Subscripts for electrical equipment.25
6.4 Subscripts for locations, reference points, and fault locations.27
6.5 Superscripts .28
6.6 Multiple subscripts and their succession.28
Bibliography.29

60027-7 © IEC:2010 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LETTER SYMBOLS TO BE USED
IN ELECTRICAL TECHNOLOGY –
Part 7: Power generation, transmission, and distribution

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 60027-7 has been prepared by IEC technical committee 25:
Quantities and units.
The text of this standard is based on the following documents:
CDV Report on voting
25/391/CDV 25/406/RVC
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 publi
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