EN IEC 60721-2-2:2024
(Main)Classification of environmental conditions - Part 2-2: Environmental conditions appearing in nature - Precipitation and wind
Classification of environmental conditions - Part 2-2: Environmental conditions appearing in nature - Precipitation and wind
IEC 60721-2-2:2024 presents fundamental properties, quantities for characterization, and a classification of environmental conditions dependent on precipitation and wind relevant to electrotechnical products. This third edition cancels and replaces the second edition published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the layout of the information provided has been re-organized; b) the information provided has been extensively enhanced and revised; c) new information on wind severities has been included.
Klassifizierung von Umgebungsbedingungen - Teil 2-2: Natürliche Umgebungsbedingungen - Niederschlag und Wind
Classification des conditions d'environnement - Partie 2-2: Conditions d'environnement présentes dans la nature - Précipitations et vent
L'IEC 60721-2-2:2024 fournit les propriétés fondamentales, les grandeurs de caractérisation et une classification des conditions d'environnement qui dépendent des précipitations et du vent en ce qui concerne les produits électrotechniques. Cette troisième édition annule et remplace la deuxième édition parue en 2012. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) la présentation des informations fournies a été réorganisée; b) les informations fournies ont été largement améliorées et révisées; c) de nouvelles informations concernant les sévérités relatives au vent ont été ajoutées.
Klasifikacija okoljskih pogojev - 2-2. del: Okoljski pogoji v naravi - Padavine in veter (IEC 60721-2-2:2024)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2025
Klasifikacija okoljskih pogojev - 2-2. del: Okoljski pogoji v naravi - Padavine in
veter (IEC 60721-2-2:2024)
Classification of environmental conditions - Part 2-2: Environmental conditions appearing
in nature - Precipitation and wind (IEC 60721-2-2:2024)
Klassifizierung von Umgebungsbedingungen - Teil 2-2: Natürliche
Umgebungsbedingungen - Niederschlag und Wind (IEC 60721-2-2:2024)
Classification des conditions d'environnement - Partie 2-2: Conditions d'environnement
présentes dans la nature - Précipitations et vent (IEC 60721-2-2:2024)
Ta slovenski standard je istoveten z: EN IEC 60721-2-2:2024
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 60721-2-2
NORME EUROPÉENNE
EUROPÄISCHE NORM December 2024
ICS 19.040 Supersedes EN 60721-2-2:2013
English Version
Classification of environmental conditions - Part 2-2:
Environmental conditions appearing in nature - Precipitation and
wind
(IEC 60721-2-2:2024)
Classification des conditions d'environnement - Partie 2-2: Klassifizierung von Umgebungsbedingungen - Teil 2-2:
Conditions d'environnement présentes dans la nature - Natürliche Umgebungsbedingungen - Niederschlag und
Précipitations et vent Wind
(IEC 60721-2-2:2024) (IEC 60721-2-2:2024)
This European Standard was approved by CENELEC on 2024-11-29. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
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Türkiye and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60721-2-2:2024 E
European foreword
The text of document 104/1066/FDIS, future edition 3 of IEC 60721-2-2, prepared by TC 104
"Environmental conditions, classification and methods of test" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 60721-2-2:2024.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2025-12-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-12-31
document have to be withdrawn
This document supersedes EN 60721-2-2:2013 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60721-2-2:2024 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60721-2-1 NOTE Approved as EN 60721-2-1
IEC 60721-2-2 ®
Edition 3.0 2024-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Classification of environmental conditions –
Part 2-2: Environmental conditions appearing in nature – Precipitation and wind
Classification des conditions d'environnement –
Partie 2-2: Conditions d'environnement présentes dans la nature –
Précipitations et vent
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 19.040 ISBN 978-2-8322-9873-2
– 2 – IEC 60721-2-2:2024 © IEC 2024
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Rain . 8
4.1 General . 8
4.2 Global distribution of rainfall . 9
4.3 Characteristics of rain . 11
4.3.1 Formation . 11
4.3.2 Types of rain . 11
4.3.3 Distribution of raindrop sizes . 12
4.3.4 Terminal velocity . 12
4.4 Rates of rainfall . 13
4.4.1 Instantaneous rates and clock-hour totals . 13
4.4.2 Frequency of instantaneous rates . 14
4.5 Heavy rates of rainfall . 15
4.5.1 Thunderstorm rain . 15
4.5.2 Prolonged heavy rain . 15
4.5.3 Worldwide extremes . 15
4.6 Spatial variations of rainfall rate . 16
4.6.1 General . 16
4.6.2 Rainfall rates below 2 mm/h . 17
4.6.3 Rainfall rates between 2 mm/h and 10 mm/h . 17
4.6.4 Rainfall rates between 10 mm/h and 25 mm/h . 17
4.6.5 Rainfall rates exceeding 25 mm/h . 18
4.7 Rainfall probabilities along a line . 18
5 Snow . 19
5.1 General . 19
5.2 Global distribution of the incidence of snowy weather . 19
5.3 Global distribution of the incidence and depth of lying snow . 22
5.4 Mass, size, and fall-speed of snow . 22
6 Hail. 26
6.1 General . 26
6.2 Global distribution of hailstones . 26
6.3 Seasonal variations in global distribution . 27
6.4 Diurnal variation . 28
6.5 Size of hail . 28
6.6 Terminal velocity . 30
6.7 Duration and diameter of hail cell . 31
7 Ice . 32
7.1 General . 32
7.2 Hoar frost . 32
7.3 Rime ice (including in-cloud icing and freezing fog) . 32
7.4 Glazed frost (including freezing rain and freezing drizzle) . 33
7.5 Wet snow accretion . 34
IEC 60721-2-2:2024 © IEC 2024 – 3 –
7.6 Water content of fog and cloud at temperatures below 0 °C . 34
7.7 Altitude variations . 35
8 Wind . 35
8.1 General . 35
8.2 Mean wind speed . 36
8.2.1 General . 36
8.2.2 Variation of mean wind speed with height . 37
8.2.3 Frequency of winds. 39
8.3 Gustiness . 46
8.3.1 General . 46
8.3.2 Gust factor . 46
8.3.3 Gust ratios . 46
8.3.4 Variation of gust speed with height . 47
8.4 Effects of topography . 48
8.5 Wind types and extreme winds . 48
8.6 Effects of wind . 50
8.7 Wind in conjunction with other damaging agents . 52
Bibliography . 53
Figure 1 – Average annual rainfall (AAR) for global land areas, based on 1961 to 1990
data [1] . 9
Figure 2 – Estimated conversion factor for converting to hours at instantaneous rate [1] . 14
Figure 3 – Average decay of correlation with distance, of 1 min rainfall rate and total
storm rainfall rate [1] . 17
Figure 4 – Estimated percentage of days on which an amount of snow equivalent to at
least 1 mm of rainfall falls in northern and southern hemispheres [1] . 21
Figure 5 – Satellite derived average rainfall equivalent of lying snow and ice [1] . 25
Figure 6 – Estimated average annual number of days per year with hail of diameter
≥ 15 mm [1]. 27
Figure 7 – Estimated average seasonal number of days per year with hail of diameter
≥ 15 mm, based on post-processed global mode
...
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