EN 61472:2013
(Main)Live working - Minimum approach distances for a.c systems in the voltage range 72,5 kV to 800 kV - A method of calculation
Live working - Minimum approach distances for a.c systems in the voltage range 72,5 kV to 800 kV - A method of calculation
IEC 61472:2013 describes a method for calculating the minimum approach distances for live working, at maximum voltages between 72,5 kV and 800 kV. This standard addresses system overvoltages and the working air distances or tool insulation between parts and/or workers at different electric potentials. The required withstand voltage and minimum approach distances calculated by the method described in this standard are evaluated taking into consideration - if the workers are trained for, and skilled in, working in the live working zone; - if the anticipated overvoltages do not exceed the value selected for the determination of the required minimum approach distance; - if transient overvoltages are the determining overvoltages; - if tool insulation has no continuous film of moisture or measurable contamination present on the surface; - if no lightning is seen or heard within 10 km of the work site; - if allowance is made for the effect of conducting components of tools; and - if the effect of altitude, insulators in the gap, etc, on the electric strength is taken into consideration. For conditions other than the above, the evaluation of the minimum approach distances may require specific data, derived by other calculation or obtained from additional laboratory investigations on the actual situation. This third edition cancels and replaces the second edition of IEC 61472 published in 2004. It constitutes a technical revision. Significant changes with regard to the second edition are: - the clarification of the scope; - the review of the definitions; - the clarification of the methodology of determining whether live working is permissible and the calculation of the minimum approach distances; - the modification of the basic equation for calculation of the minimum approach distance; and - the introduction of Table 1 for altitude correction factor simplification ka.
Arbeiten unter Spannung - Mindest-Arbeitsabstände für Wechselspannungsnetze im Spannungsbereich von 72,5 kV bis 800 kV - Berechnungsverfahren
Travaux sous tension - Distances minimales d'approche pour des réseaux à courant alternatif de tension comprise entre 72,5 kV et 800 kV - Une méthode de calcul
La CEI 61472:2013 décrit une méthode de calcul des distances minimales d'approche pour des travaux sous tension réalisés à des tensions maximales comprises entre 72,5 kV et 800 kV. La présente norme traite des surtensions de réseau et des distances de travail dans l'air ou de l'isolation des outils entre des pièces et/ou des travailleurs à des potentiels électriques différents. La tension de tenue requise et les distances minimales d'approche calculées suivant la méthode décrite dans la présente norme sont évaluées en prenant en compte - si les travailleurs sont formés et qualifiés pour travailler dans la zone de travail sous tension; - si les surtensions attendues ne dépassent pas la valeur choisie pour la détermination de la distance minimale d'approche requise; - si les surtensions transitoires sont les surtensions déterminantes; - si l'isolation des outils ne présente pas sur la surface un film continu d'humidité ou un niveau de pollution mesurable; - si aucun éclair n'est vu ni entendu à moins de 10 km du lieu de travail; - si l'influence des parties conductrices des outils est prise en compte; - et si l'effet de l'altitude, de la présence d'isolateurs dans l'intervalle, etc. sur la tenue électrique est pris en compte. Pour des conditions autres que celles ci-dessus, l'évaluation des distances minimales d'approche peut exiger des données spécifiques, provenant d'autres calculs ou obtenues à partir d'études additionnelles en laboratoire sur la situation concrète. Cette troisième édition annule et remplace la deuxième édition de la CEI 61472, publiée en 2004. Elle constitue une révision technique. Les modifications techniques majeures par rapport à la deuxième édition sont: - la clarification du domaine d'application; - la revue des définitions; - la clarification de la méthodologie pour déterminer si le travail sous tension est acceptable et pour calculer les distances minimales d'approche; - la modification de l'équation de base pour calculer la distance minimale d'approche; - et l'introduction du Tableau 1 pour une simplification du facteur de correction en fonction de l'altitude ka.
Delo pod napetostjo - Najmanjše razdalje za dostop do sistemov z izmenično napetostjo v območju od 72,5 kV do 800 kV - Metoda izračuna (IEC 61472:2013)
Ta mednarodni standard opisuje metodo za izračun najmanjših razdalj za dostop za delo pod napetostjo pri največjih napetostih med 72,5 kV in 800 kV. Ta standard obravnava sistemske prenapetosti in zračne razdalje pri delu ali izolacijo orodja med deli in/ali delavci pri različnih električnih potencialih. Zahtevana napetostna trdnost in najmanjše razdalje za dostop, ki se izračunajo z metodo, opisano v tem standardu, se ovrednotijo ob upoštevanju naslednjega: – delavci so usposobljeni za delo na območju pod napetostjo; – pričakovane prenapetosti ne presegajo vrednosti, izbrane za določitev zahtevane najmanjše razdalje za dostop; – tranzientne prenapetosti so določilne prenapetosti; – izolacija orodja na površini nima neprekinjenega filma vlage ali merljive kontaminacije; – 10 km od delovišča ni mogoče videti ali slišati bliskanja; – predvidi se učinek prevodnih komponent orodij; – upošteva se učinek nadmorske višine, izolatorjev v reži itd. na električno moč. Za pogoje, ki niso navedeni zgoraj, so lahko za vrednotenje najmanjših razdalj za dostop potrebni posebni podatki, izpeljani iz drugih izračunov ali pridobljeni z dodatnimi laboratorijskimi preiskavami dejanske situacije.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2013
1DGRPHãþD
SIST EN 61472:2007
'HORSRGQDSHWRVWMR1DMPDQMãHUD]GDOMH]DGRVWRSGRVLVWHPRY]L]PHQLþQR
QDSHWRVWMRYREPRþMXRGN9GRN90HWRGDL]UDþXQD ,(&
Live working - Minimum approach distances for AC systems in the voltage range 72,5 kV
to 800 kV - A method of calculation
Travaux sous tension - Distances minimales d'approche pour des réseaux à courant
alternatif de tension comprise entre 72,5 kV et 800 kV - Une méthode de calcul
Ta slovenski standard je istoveten z: EN 61472:2013
ICS:
13.260 9DUVWYRSUHGHOHNWULþQLP Protection against electric
XGDURP'HORSRGQDSHWRVWMR shock. Live working
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 61472
NORME EUROPÉENNE
July 2013
EUROPÄISCHE NORM
ICS 13.260; 29.240.20; 29.260.99 Supersedes EN 61472:2004
English version
Live working -
Minimum approach distances for a.c systems in the voltage range
72,5 kV to 800 kV -
A method of calculation
(IEC 61472:2013)
Travaux sous tension - Arbeiten unter Spannung -
Distances minimales d'approche pour des Mindest-Arbeitsabstände für
réseaux à courant alternatif de tension Wechselspannungsnetze im
comprise entre 72,5 kV et 800 kV - Spannungsbereich
Une méthode de calcul von 72,5 kV bis 800 kV -
(CEI 61472:2013) Berechnungsverfahren
(IEC 61472:2013)
This European Standard was approved by CENELEC on 2013-05-16. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the CEN-CENELEC Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the CEN-CENELEC Management Centre has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey 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
© 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61472:2013 E
Foreword
The text of document 78/1004/FDIS, future edition 3 of IEC 61472, prepared by IEC/TC 78 "Live working"
was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61472:2013.
The following dates are fixed:
(dop) 2014-02-16
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2016-05-16
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61472:2004.
This document has been prepared according to the requirements of EN 61477: Live working – Minimum
requirements for the utilization of tools, devices and equipment, where applicable.
– clarification of the scope;
– review of the definitions;
– clarification of the methodology of determining whether live working is permissible and the calculation of
the minimum approach distances;
– modification of the basic equation for calculation of the minimum approach distance;
– introduction of Table 1 for altitude correction factor simplification ka;
– introduction of criteria in presence of composite insulator and clarification on the use of insulator factor
ki;
– review of the informative Annex F on the influence of floating conductive objects on the dielectric
strength;
– review of the informative Annex G on live working near contaminated, damaged or moist insulation.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent
rights.
Endorsement notice
The text of the International Standard IEC 61472:2013 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60060-1:2010 NOTE Harmonised as EN 60060-1:2010 (not modified).
IEC 60071-1:2006 NOTE Harmonised as EN 60071-1:2006 (not modified).
IEC 60071-2:1996 NOTE Harmonised as EN 60071-2:1997 (not modified).
IEC 60743 NOTE Harmonised as EN 60743.
IEC 61477:2009 NOTE Harmonised as EN 61477:2009 (not modified).
IEC 61472 ®
Edition 3.0 2013-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Live working – Minimum approach distances for a.c. systems in the voltage
range 72,5 kV to 800 kV – A method of calculation
Travaux sous tension – Distances minimales d'approche pour des réseaux à
courant alternatif de tension comprise entre 72,5 kV et 800 kV – Une méthode de
calcul
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 13.260; 29.240.20; 29.260.99 ISBN 978-2-83220-717-8
– 2 – 61472 © IEC:2013
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Terms, definitions and symbols . 6
2.1 Terms and definitions . 6
2.2 Symbols used in the normative part of the document . 8
3 Methodology . 9
4 Factors influencing calculations . 10
4.1 Statistical overvoltage . 10
4.2 Gap strength . 10
4.3 Calculation of electrical distance D . 11
U
4.3.1 General equation . 11
4.3.2 Factors affecting gap strength . 11
5 Evaluation of risks . 16
6 Calculation of minimum approach distance D . 17
A
Annex A (informative) Ergonomic distance . 18
Annex B (informative) Overvoltages . 20
Annex C (informative) Dielectric strength of air . 24
Annex D (informative) Gap factor k . 26
g
Annex E (informative) Allowing for atmospheric conditions . 28
Annex F (informative) Influence of floating conductive objects on the dielectric
strength . 32
Annex G (informative) Live working near contaminated, damaged or moist insulation . 40
Bibliography . 45
Figure 1 – Illustration of two floating conductive objects of different dimensions and at
different distances from the axis of the gap . 13
Figure 2 – Typical live working tasks . 15
Figure B.1 – Ranges of u at the open ended line due to closing and reclosing
e2
according to the type of network (meshed or antenna) with and without closing
resistors and shunt reactors . 22
Figure F.1 – Influence of the length of the floating conductive objects – phase to earth
rod-rod configuration – 250 µs /2 500 µs impulse . 35
Figure F.2 – Influence of the length of the floating conductive objects – phase to phase
conductor-conductor configuration – 250 µs /2 500 µs impulse . 36
Figure F.3 – Reduction of the dielectric strength as a function of the length D for
constant values of β – Phase to earth rod-rod configuration . 37
Figure F.4 – Reduction of the dielectric strength as a function of the length P for
constant values of β – Phase to phase conductor-conductor configuration . 37
Figure G.1 – Strength of composite insulators affected by simulated conductive and
semi-conductive defects . 43
Table 1 – Average k values . 12
a
Table 2 – Floating conductive object factor k . 14
f
Table B.1 – Classification of overvoltages according to IEC 60071-1 . 20
61472 © IEC:2013 – 3 –
Table D.1 – Gap factors for some actual phase to earth configurations . 27
Table E.1 – Atmospheric factor k for different reference altitudes and values of U . 30
a 90
Table G.1 – Example of maximum number of damaged insulators calculation (gap
factor 1,4) . 41
Table G.2 – Example of maximum number of damaged insulators calculation (gap
factor 1,2) . 42
– 4 – 61472 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LIVE WORKING –
MINIMUM APPROACH DISTANCES FOR A.C. SYSTEMS
IN THE VOLTAGE RANGE 72,5 kV TO 800 kV –
A METHOD OF CALCULATION
FOREWORD
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