SIST EN 50341-2-8:2019

SLOVENSKI STANDARD
01-april-2019
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Overhead electrical lines exceeding AC 1 kV - Part 2-8: National Normative Aspects
(NNA) for France (based on EN 50341-1:2012)
Ta slovenski standard je istoveten z: EN 50341-2-8:2017
ICS:
29.240.20 Daljnovodi Power transmission and
distribution lines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50341-2-8

NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2017
ICS 29.240.20
English Version
Overhead electrical lines exceeding AC 1 kV - Part 2-8: National
Normative Aspects (NNA) for France (based on EN 50341-
1:2012)
This European Standard was approved by CENELEC on 2017-08-09.
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, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50341-2-8:2017 E
Contents
European foreword . 6
0 Introduction . 7
1 Scope . 8
1.1 General . 8
1.2 Field of application . 8
2 Normative references, definitions and symbols . 9
2.1 Normative references . 9
2.2 Definitions .10
2.3 Symbols .10
3 Basis of design . 11
3.2 Requirements of overhead lines .11
3.2.2 Reliability requirements .11
3.2.5 Strength coordination .11
3.2.6 Additional considerations .11
3.3 Limit states .12
3.3.3 Serviceability limit states .12
3.7 Partial factor method and design formula .12
3.7.2 Basic design formula .12
4 Actions on lines . 13
4.1 Introduction .13
4.3 Wind loads .13
4.3.1 Field of application and basic wind velocity .13
4.4 Wind forces on overhead line components .15
4.4.1 Wind forces on conductors .15
4.4.2 Wind forces on insulator sets .15
4.4.3 Wind forces on lattice towers .15
4.4.4 Wind forces on poles.16
4.5 Ice loads .16
4.5.1 General .16
4.6 Combined wind and ice loads .19
4.6.1 Combined probabilities .19
4.7 Temperature effects .20
4.8 Security loads .20
4.8.1 General .20
4.8.2 Torsional loads .20
4.8.3 Longitudinal loads .21
4.9 Safety loads .21
4.9.1 Construction and maintenance loads.21
4.9.2 Loads related to the weight of linesmen .22
4.10 Forces due to short-circuit currents .22

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4.11 Other special forces .22
4.11.1 Avalanches, creeping snow .22
4.11.2 Earthquakes .22
4.12 Load cases .23
4.12.2 Standard load cases .23
4.13 Partial factors for actions .25
5 Electrical requirements . 27
5.2 Currents .27
5.2.2 Short-circuit current .27
5.5 Minimum air clearances to avoid flashover .27
5.5.2 Application of the theoretical method in Annex E .27
5.5.3 Empirical method based on European experience .27
5.6 Load cases for calculation of clearances .28
5.6.2 Maximum conductor temperature .28
5.6.3 Wind loads for determination of electric clearances .28
5.6.3.1 Wind load cases . 28
5.6.3.2 Nominal wind loads for determination of internal and external
clearances . 29
5.6.3.3 Extreme wind loads for determination of internal clearances . 29
5.6.4 Ice loads for determination of electric clearances .29
5.6.5 Combined wind and ice loads .30
5.8 Internal clearances within the span and at the top of the support .31
5.9 External clearances .33
5.9.1 General .33
5.9.2 External clearances to ground in areas remote from buildings, roads, etc.34
5.9.3 External clearances to residential and other buildings .37
5.9.4 External clearances to crossing traffic routes .38
5.9.5 External clearances to adjacent traffic routes .44
5.9.6 External clearances to other power lines or overhead telecommunication
lines 45
5.9.7 External clearances to recreational areas (playgrounds, sports areas, etc.).49
5.10 Corona effect .50
5.10.2 Audible noise .50
5.10.2.3 Noise limits . 50
5.10.3 Corona loss .50
5.11 Electric and magnetic fields .50
5.11.1 Electric and magnetic fields under a line .50
6 Earthing systems . 51
6.1 Introduction .51
6.1.3 Earthing measures against lightning effects .51
6.4 Design calculation with regard to human safety .51
6.4.1 Permissible values for touch voltages.51

6.4.2 Touch voltage limits at different locations .51
6.4.3 Basic design of earthing systems with regard to permissible touch voltages .51
7 Supports . 52
7.3 Lattice steel towers .52
7.3.6 Ultimate limit states .52
7.3.6.1 General . 52
7.3.8 Resistance of connections .52
7.3.9 Design assisted by testing .52
7.4 Steel poles .52
7.4.6 Ultimate limit states (EN 1993-1-1:2005 – Chapter 6) .52
7.4.6.1 General . 52
7.4.8 Resistance of connections .53
7.4.8.2 Bolts (other than holding-down bolts) . 53
7.4.8.3 Slip joint connections . 53
7.4.8.5 Welded connections . 53
7.4.8.6 Direct embedding into the concrete . 53
7.4.9 Design assisted by testing .53
7.5 Wood poles .53
7.5.8 Design assisted by testing .53
7.6 Concrete poles .53
7.6.6 Design assisted by testing .53
7.8 Other structures .54
7.9 Corrosion protection and finishes .54
7.9.3 Metal spraying .54
7.10 Maintenance facilities .54
7.10.1 Climbing .54
7.10.3 Safety requirements .54
8 Foundations . 55
8.2 Basis of geotechnical design (EN 1997-1:2004 – Section 2) .55
8.2.2 Geotechnical design by calculation .55
8.2.3 Design by prescriptive measures .56
8.2.4 Load tests and tests on experimental models .56
8.3 Soil investigation and geotechnical data (EN 1997 1:2004 – Section 3) .56
8.6 Interactions between support foundations and soil .56
9 Conductors and earth wires . 57
9.1 Introduction .57
9.2 Aluminium-based conductors .57
9.2.3 Conductor service temperature and grease characteristics .57
9.2.4 Mechanical requirements .57
9.3 Steel-based conductors .57
9.3.3 Conductor service temperature and grease characteristics .57
9.3.4 Mechanical requirements .58

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9.5 Conductors and earth wires containing optical fibre telecommunication circuits .58
9.5.3 Conductor service temperatures .58
9.5.4 Mechanical requirements .58
10 Insulators . 59
10.2 Standard electrical requirements .59
11 Hardware . 60
11.9 Characteristics and dimensions of fittings .60
12 Quality assurance, checks and taking-over . 61
Annex J (normative) Angles in lattice steel towers . 62
Annex K (normative) Steel poles . 63
Annex M (informative) Geotechnical and structural design of foundations . 64

European foreword
1 The French National Committee (NC) is identified by the following address:
AFNOR Normalisation
Département Electrotechnologies
11, rue Francis de Pressensé
93571 La Plaine Saint-Denis Cedex
Tel.: +33 (0)1 41 62 80 00
Fax: +33 (0)1 49 17 90 00
www.afnor.org
2 The French NC has prepared the present EN 50341-2-8:2017 (Part 2-8), listing the French National
Normative Aspects; it is solely responsible for it and has duly incorporated it into the procedures of
CENELEC and CLC/TC 11.
Note The French NC takes full responsibility for the satisfactory technical coordination of the present
Part 2-8 and EN 50341-1:2012. Any quality control/assurance checks necessary have been performed.
However, it should be noted that such quality control/assurance has been performed under the general
responsibility of the French NC pursuant to national laws and regulations.

3 Part 2-8 is normative in France and informative for other countries.

4 Part 2-8 shall be read in conjunction with EN 50341-1:2012 (Part 1). All Clause numbers used in
the present Part 2-8 correspond to the numbering in Part 1. Specific subclauses with the prefix "FR"
shall be read as amendments to the associated text in Part 1. All requests for clarification relating
to the application of Part 2-8 in relation to Part 1 shall be sent to the French NC which, in conjunction
with CLC/TC 11, will clarify the requirements.

When no reference is made to a specific subclause in Part 2-8, Part 1 applies.

5 For the "boxed values" defined in Part 1, any amended values defined in Part 2-8 shall be applied
in France. None of the boxed values present in Part 1 or Part 2-8 shall be amended in such a way
as to increase the risk in a Project Specification.

6 The regulations and standards specifically used in the present Part 2-8 and relating to overhead
electrical lines exceeding AC 1 kV are listed in subclauses 2.1/FR.1 to 2.1/FR.6.

NOTE All national standards referred to in the present Part 2-8 will be replaced by the related European
Standards as they become available and are declared applicable by the French NC and therefore reported to
the secretariat of CLC/TC 11.
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0 Introduction
Part 1 applies without change.

1 Scope
1.1 General
(ncpt) FR.1 Scope of Part 1 and Part 2-8
Part 1 and the present Part 2-8 apply to new overhead lines as defined in 1.1/FR.2 "Definition
of a new overhead line".
(ncpt) FR.2 Definition of a new overhead line
A new overhead line denotes any new overhead electrical line exceeding AC 1 kV built on new
foundations and:
• flanked by two substations or two terminal towers preceding said substations.
or
• flanked by a substation or a terminal tower at one end and in a branch situation
(including branch tower) or tapping situation at the other end.

(ncpt) FR.3 Application to existing overhead lines
This standard does not apply to existing overhead lines exceeding AC 1 kV in France.

(ncpt) FR.4 Application to overhead lines for which technical studies are underway
Any decision to apply the requirements of the present standard to new overhead line projects
for which technical studies are underway shall be stipulated in the Project Specification.

(ncpt) FR.5 Application to overhead lines under construction
The requirements of the present standard do not apply to overhead lines under construction.

1.2 Field of application
(ncpt) FR.1 Application to radio telecommunication equipment
Part 1 and Part 2-8 apply to radio telecommunication equipment mounted on the towers of
new overhead lines, particularly with respect to wind and ice assumptions. Radio equipment
shall be arranged on the support so that it can be accessed and operations performed in
accordance with safety regulations.

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2 Normative references, definitions and symbols
2.1 Normative references
(a-dev) FR.1 Interministerial Decree of 17 May 2001
The Interministerial Decree of 17 May 2001, published in the Official Journal of the French
Republic of 12 June 2001, contains the minimum requirements for the distribution and
transmission of power.
The (a-dev) subclauses of the present Part 2-8 refer to the Interministerial Decree of 17 May
2001 and form a brief description thereof. Reference should be made to the original document
for details of the requirements of the Interministerial Decree.

(a-dev) FR.2 Law no. 91-1414 of 31 December 1991
Law no. 91-1414 of 31 December 1991 amends the French Employment Code and the French
Public Health Code to promote the prevention of occupational risks, and transposes EU
directives relating to occupational health and safety.

(a-dev) FR.3 Law no. 93-1418 of 31 December 1993
Law no. 93-1418 of 31 December 1993 amends the provisions of the French Employment
Code applicable to building and civil engineering operations to ensure the safety and protect
the health of workers, and transposes Council Directive no. 92/57/EEC of 24 June 1992. Said
directive relates to the implementation of minimum safety and health requirements at
temporary or mobile construction sites.

(a-dev) FR.4 Interministerial Decree of 14 May 1963
The Interministerial Decree of 14 May 1963 specifies the characteristics of the safety data
plates to be affixed to power line supports.

(ncpt) FR.5 Standards
Reference Title
Réseaux de distribution publique d’énergie électrique [Public electrical power
NF C11-201
systems]
Opérations sur les ouvrages et installations électriques et dans un
environnement électrique - Prévention du risque électrique [Operations on
NF C18-510
electrical networks and installations and in an electrical environment - Electrical
risk prevention]
NF EN 50540 Conductors for overhead lines. Aluminium conductors steel supported (ACSS)
NF EN 61672-1 Electroacoustics. Sound level meters. Part 1: Specifications
Justification of geotechnical work - National application standards for the
NF P94-261
implementation of Eurocode 7 - Shallow Foundations - Geotechnical design
Justification of geotechnical work - National application standards for the
NF P94-262
implementation of Eurocode 7 - Deep Foundations
Acoustics - Environmental noise characterization and measurement. Special
NF S31-010
measuring methods
Conditions techniques auxquelles doivent satisfaire les distributions d’énergie
UTE C11-001 électrique [Technical conditions to be met by electrical power distribution
systems] – Illustrated Technical Decree of 17 May 2001

(ncpt) FR.6 Reference national standards
Standard UTE C11-001 reproduces, annotates and illustrates the Interministerial Decree of 17
May 2001 (see 2.1/FR.1). Certain subclauses (a-dev or ncpt) of the present Part 2-8 are taken
from this standard.
Standard NF C11-201 defines the construction rules for the structures (overhead lines,
underground networks and substations) forming electrical power distribution networks with a
nominal voltage of less than AC 50 kV. Certain subclauses (ncpt) of the present Part 2-8 are
taken from this standard.
The requirements relating to human safety in relation to electrical hazards during electrical or
non-electrical operations, on networks or installations or in an environment the voltage of
which is less than or equal to 500 kV AC or DC, are given in NF C18-510. The present Part 2-8
is not intended to replace the provisions of this standard.

(ncpt) FR.7 Scientific publications
[1] Ducloux, H. and Figueroa, L.: Background information about the wind action model of
CENELEC EN 50341-1 (2012) and associated expected reliability of electrical overhead lines,
Journal of Wind Engineering and Industrial Aerodynamics, Volume 157, Pages 104-117,
October 2016, ISSN 0167-6105, doi:10.1016/j.jweia.2016.08.006.

[2] Ducloux, H. and Nygaard, B. E.: 50-year return-period wet-snow load estimation based on
weather station data for overhead line design in France, Nat. Hazards Earth Syst. Sci., Volume
14 Issue 11, Pages 3031-3041, November 2014, ISSN 3031-3041, doi:10.5194/nhess-14-
3031-2014.
[3] Chaigneau, L. and Ducloux, H.: Justification du coefficient de modèle γR;d1 utilisé dans la
norme NF EN 50341-2-8 pour le dimensionnement des micropieux de catégorie 18 utilisés
comme fondations de pylônes de lignes électriques aériennes [Justification of the model factor
γ used in NF EN 50341-2-8 for the design calculation of category 18 micropiles used as
R;d1
overhead power line tower foundations], Revue Française de Géotechnique, Volume 147,
Article number 4, October 2016, DOI: 10.1051/geotech/2016008

2.2 Definitions
(a-dev) FR.1 Voltage range
In Part 2-8, the alternating high voltage ranges used are:
• The HVA range, the nominal voltage U of which is such that 1 kV < U ≤ 50 kV;
n n
• The HVB range, the nominal voltage U of which is such that U > 50 kV.
n n
(ncpt) FR.2 Cable
In Part 2-8, the term cable refers collectively to the conductors defined in 2.2.16 of Part 1
[Source: IEV 466-01-15] and the earth wires defined in 2.2.35 of Part 1 [Source: IEV 466-10-
25].
2.3 Symbols
(ncpt) FR.1 Symbols
Symbol Meaning Reference
c Minimum spacing at mid-span 5.8
d Diameter of cylindrical elements 4.12.2
d Additional distance 5.6.4
add
f Median sag of the conductor 5.8
IN Ice load per length on the cable 4.5.1
K Factor depending on the position of the conductors 5.8
c
K
z Factor depending on the climatic zone 5.8
L Free length of the insulator string 5.8
l Half-sum of the lengths of the suspension insulator strings 5.8
m' Load factor 5.8
N Thickness of the ice accretion on the cable 4.5.1
R
a1 Additional resistance 6.4.2
R Resistance to earth of the standing point 6.4.2
a2
r Resistance ratio 3.7.2
R
t Voltage clearance 5.5.3
i
Swing angle of the cables 5.8
α
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3 Basis of design
3.2 Requirements of overhead lines
3.2.2 Reliability requirements
(a-dev) FR.1 Minimum requirements for the mechanical design of overhead lines
The minimum requirements relating to the mechanical design of overhead lines are stipulated
in Clause 13 "Mechanical strength of constructions" of the Interministerial Decree of 17 May
2001.
(ncpt) FR.2 Minimum reliability level of overhead lines
The minimum reliability level to be taken into account in France is reliability level 1.

(a-dev) FR.3 Minimum requirements for the mechanical design of temporary lines
In accordance with Clauses 99a "Temporary provisions in an emergency" and 99c "Temporary
supply during work", the minimum requirements given in 3.2.2/FR.1 do not apply for the
mechanical design of temporary lines.

(ncpt) FR.4 Reliability level for temporary lines (HVA)
A reliability level of less than 1 may be used for the design of HVA temporary lines installed
for less than one year. The climate assumptions associated with the design of HVA temporary
lines shall be stipulated in the Project Specification.

(ncpt) FR.5 Reliability level for temporary lines (HVB)
A reliability level of less than 1 may be used for the design of HVB temporary lines installed
for less than one year.
The minimum return periods of the climatic actions to be taken into account for the design of
temporary lines installed for a period of less than one year are given in Table 3/FR.1.

Table 3/FR.1: Return period for temporary lines
Return period
Duration
(years)
≤ 3 days 2
≤ 3 months (but > 3 days) 5
≤ 1 year (but > 3 months) 10
If the return periods cannot be used for determining the ice loads, these loads shall be
stipulated in the Project Specification on the basis of experience.

(ncpt) FR.6 Application of the seasonal coefficient c for temporary lines (HVB)
season
The seasonal coefficient cseason shall be taken as equal to 1.

(ncpt) FR.7 Period of the year during which loads may not be taken into account for the
mechanical design of temporary lines (HVB)
It is not necessary to take into account ice loads for the mechanical design of temporary lines
located in plain zones (altitude below 700 m) and installed during a period between 1 June
and 30 September.
3.2.5 Strength coordination
(a-dev) FR.1 Strength coordination
The mechanical strength coordination of the constituent elements of the construction shall be
verified in accordance with the provisions of Clause 13 "Mechanical strength of constructions"
of the Interministerial Decree of 17 May 2001.

3.2.6 Additional considerations
(ncpt) FR.1 Additional considerations
The construction of a new overhead line shall in particular take into account its environment
(fauna and flora) and human safety.

Where justified, specific devices (bird warning flags, daytime or night-time marking, etc.) shall
be used. These provisions shall be stipulated in the Project Specification.

3.3 Limit states
3.3.3 Serviceability limit states
(ncpt) FR.1 Serviceability limit states
The requirements relating to performance criteria and serviceability limit states shall be
stipulated in the Project Specification.

3.7 Partial factor method and design formula
3.7.2 Basic design formula
The following basic design formula shall be always verified:
R
d
E ≤
d
r
R
Where
E is the design value of the effect of the actions specified in clause 4 of Part 2-8;
d
Rd is the structural design resistance.
For supports and foundations, R is specified in clauses 7 and 8 of Part 2-8.
d
For conductors and earth wires, Rd is defined in clause 9 as the rated tensile
strength.
For insulators and hardware, Rd is defined in clauses 10 and 11 as the minimum
failure load;
rR is the resistance ratio specified in 4.13 of Part 2-8.

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4 Actions on lines
4.1 Introduction
(a-dev) FR.1 Choice of approach for estimating climatic data
The lines shall be designed by applying approach 3.

It has been verified that the reliability of lines designed for the wind loads according to
approach 3 (see 4.3 of Part 2-8) is at least equivalent to reliability level 1 of Part 1 [1].

It has been verified that the reliability of lines designed for the wet snow loads in plains
according to approach 3 (see 4.5 of Part 2-8) is at least equivalent to reliability level 1 of
Part 1 [2].
4.3 Wind loads
4.3.1 Field of application and basic wind velocity
(ncpt) FR.1 Field of application
The wind loads determined according to approach 3 are valid, unless otherwise stipulated in
the Project Specification, up to a total support height of 90 m. A special study is necessary for
heights above 90 m or for exceptions. In this case, the wind pressures will be justified and
stipulated in the Project Specification.

(a-dev) FR.2 Wind zones to be taken into account in mainland France
The three wind zones to be taken into account in mainland France are stipulated in Clause 13
"Mechanical strength of constructions" of the Interministerial Decree of 17 May 2001:
• Normal wind zone (NWZ);
• Strong wind zone (SWZ);
• High wind pressure zone (HWPZ).

The high wind pressure zone relates to HVB overhead lines only.

For the HVB system in mainland France, these wind zones are specified in 4.3.1/FR.3. For all
other cases, these zones shall be stipulated in the Project Specification.

(ncpt) FR.3 Map of wind zones in mainland France (HVB)
For the HVB system in mainland France, the wind zones stated in 4.3.1/FR.2 are associated
with the wind zone map given in Figure 4/FR.1.

Figure 4/FR.1: Map of wind zones to be used in mainland France for HVB overhead
lines
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(a-dev) FR.4 Field of application relating to wind pressures to be taken into account in overseas
departments of France
For overseas departments of France, in accordance with Clause 98 "Climate assumptions in
overseas departments" of the Interministerial Decree of 17 May 2001, the monitoring
department, at the proposal of the operator of the electrical power structures or directly, is
responsible for defining the climate assumptions to be taken into account for the application
of the present decree.
The approach used shall be stipulated in the Project Specification.

4.4 Wind forces on overhead line components
4.4.1 Wind forces on conductors
(a-dev) FR.1 Wind pressures to be taken into account on cables
Clause 13 "Mechanical strength of constructions" of the Interministerial Decree of 17 May 2001
stipulates the wind pressures to be taken into account on cables when verifying the mechanical
strength of the construction (Assumption A):
• Normal wind zone: 570 Pa;
• Strong wind zone: 640 Pa;
• High wind pressure zone: 720 Pa.

The associated cable temperature is defined in 4.7/FR.1.

4.4.2 Wind forces on insulator sets
(ncpt) FR.1 Wind pressures to be taken into account on insulator sets (HVA)
For HVA overhead lines, the wind pressure to be taken into account on insulator sets shall be
stipulated in the Project Specification.

(ncpt) FR.2 Wind pressures to be taken into account on insulator sets (HVB)
The forces exerted on the support by insulator sets due to wind shall be taken into account
when designing HVB supports.
The wind pressure to be used is the pressure stipulated for cables in Clause 13 "Mechanical
strength of constructions" of the Interministerial Decree of 17 May 2001 (see 4.4.1/FR.1).

4.4.3 Wind forces on lattice towers
(a-dev) FR.1 Wind pressures to be taken into account on lattice towers
Clause 13 "Mechanical strength of constructions" of the Interministerial Decree of 17 May 2001
stipulates the wind pressures to be taken into account on lattice towers when verifying the
mechanical strength of the construction (Assumption A):
• Normal wind zone: 1200 Pa;
• Strong wind zone: 1330 Pa;
• High wind pressure zone: 1515 Pa.

(ncpt) FR.2 Method for determining wind forces on lattice towers
The forces due to wind pressure on the towers themselves shall be determined according to
the principle described in 4.4.3.3 of Part 1. The wind pressures on the towers to be used are
those given in 4.4.3/FR.1.
(ncpt) FR.3 Uniformity of wind pressure on lattice towers
The wind pressure on the lattice tower is considered to be uniform over the whole structure,
regardless of the height thereof or the height of the elements in question.

4.4.4 Wind forces on poles
(a-dev) FR.1 Wind pressures to be taken into account on circular poles
Clause 13 "Mechanical strength of constructions" of the Interministerial Decree of 17 May 2001
stipulates the wind pressures to be taken into account on circular poles when verifying the
mechanical strength of the construction (Assumption A):
• Normal wind zone: 475 Pa;
• Strong wind zone: 530 Pa;
• High wind pressure zone: 600 Pa.

(a-dev) FR.2 Wind pressures to be taken into account on rectangular poles
Clause 13 "Mechanical strength of constructions" of the Interministerial Decree of 17 May 2001
stipulates the wind pressures to be taken into account on the planar surfaces of rectangular
poles when verifying the mechanical strength of the construction (Assumption A):
• Normal wind zone: 1200 Pa;
• Strong wind zone: 1330 Pa;
• High wind pressure zone: 1515 Pa.

(a-dev) FR.3 Wind pressures to be taken into account on other poles
The Project Specification shall stipulate the pressure to be used for the mechanical design of
poles that are neither circular nor rectangular.

(ncpt) FR.4 Uniformity of wind pressure on poles
The wind pressure on the pole is considered to be uniform over the whole structure, regardless
of the height thereof or the height of the elements in question.

4.5 Ice loads
4.5.1 General
(ncpt) FR.1 Ice loads (HVA)
The ice loads to be taken into account for HVA overhead lines are expressed as a function of
the load per length of the ice accretion IN formed on the cable. A uniform load of at least
1 kg/m is to be taken into account in France. Higher uniform loads (for example 3, 5, 8 kg/m)
may be taken into account for altitudes above 600 m or for regions subject to wet snow
(Languedoc-Roussillon, Alsace and the lower Rhône valley). The ice zones shall be stipulated
in the Project Specification.
(ncpt) FR.2 Ice loads (HVB)
The ice loads to be taken into account for HVB overhead lines are expressed as a function of
the thickness of the uniform ice accretion N formed on the cable at a density of 600 kg/m . For
mainland France, the ice accretion thicknesses to be taken into account on HVB overhead
lines are specified in Table 4/FR.1. This table is associated with the ice load map given in
4.5.1/FR.3.
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Table 4/FR.1: Ice accretion thicknesses on cables to be taken into account
Thickness N
Altitude H
of the
Topography of the zone
accretion
(m)
(cm)
H < 500 2
Plain
500 ≤ H < 700 3
Valley
H < 700 with particular risk of
Dale
wet snow
700 ≤ H < 850 4
Mountain (*) 850 ≤ H < 1 700 (**) 5
1 700 ≤ H (**) 6
(*) As an exception, in a mountain zone, an accretion thickness
greater than 6 cm can be envisaged.
(**) For spans longer than 2 000 m located at an altitude above
1 500 m, it is accepted that the ice load on the span is not uniform
and that the equivalent mean thickness of the accretion is 4 cm.

(ncpt) FR.3 Ice load map (HVB)
For HVB overhead lines in mainland France, the ice loads stated in 4.5.1/FR.1 are associated
with the ice load map given in Figure 4/FR.2.

Figure 4/FR.2: Map of ice loads to be used in mainland France for HVB overhead lines

France - 19/65 - EN 50341-2-8:2017
(a-dev) FR.4 Field of application relating to ice loads to be taken into account in overseas
departments of France
For overseas departments of France, in accordance with Clause 98 "Climate assumptions in
overseas departments" of the Interministerial Decree of 17 May 2001, the monitoring
department, at the proposal of the operator of the electrical power structures or directly, is
responsible for defining the climate assumptions to be taken into account for the application
of the present decree.
The approach used shall be stipulated in the Project Specification.

4.6 Combined wind and ice loads
4.6.1 Combined probabilities
(a-dev) FR.1 Minimum combined wind and ice loads
Only the combination of an extremely low probability ice load associated with a high probability
wind velocity shall be taken into account. Minimum symmetrical and asymmetrical uniform
combined wind and ice loads are stipulated in Clause 13 "Mechanical strength of
constructions" of the Interministerial Decree of 17 May 2001.

(ncpt) FR.2 Combined wind and ice loads to be taken into account on cables and supports
(HVA)
The combined wind and ice loads to be taken into account for HVA overhead line cables and
supports are specified in Table 4/FR.2:

Table 4/FR.2: Combined wind and ice loads to be taken into account for HVA
cables and supports
Ice load per length IN on cables (kg/m)
1 3 or 5
[Low probability]
Wind pressure to be applied to planar elements (Pa)
300 150
[High probability]
Wind pressure to be applied to cables (Pa)
480 (*) 480 (*)
[High probability]
Wind pressure to be applied to cylindrical elements (Pa)
180 90
[High probability]
(*) This wind pressure is to be applied to the ice-free cable.

The cable temperature to be used is defined in 4.7/FR.3.

(ncpt) FR.3 Symmetrical and asymmetrical combined wind and ice loads to be taken into
account on cables and supports (HVB)
Symmetrical ice loads: the cables on all of the spans of the construction or construction
portion in question shall be covered by the ice accretion N.

NOTE In Clause 13 "Mechanical strength of constructions" of the Interministerial
Decree of 17 May 2001, "symmetrical combined loads" are referred to as "uniform loads".

Asymmetrical ice loads: a 2 cm difference in ice accretion thickness on the cables of the
spans of the section located on either side of the support to be designed shall be taken into
account.
The symmetrical and asymmetrical ice loads to be taken into account for HVB overhead line
cables and supports are combined with wind loads. These combined loads are given in
Table 4/FR.3:
Table 4/FR.3: Symmetrical and asymmetrical combined wind and ice loads to be
taken into account on HVB cables and supports
Ice load zone Light Medium Heavy
Symmetrical load case 3 5
Ice accretion thickness N on cables (cm) 2 or or
[Low probability] 4 6
Asymmetrical load case 3 and 1 5 and 3
Asymmetry of ice accretion thicknesses on cables (cm) 2 and 0 or or
[Low probability] 4 and 2 6 and 4
Structure dead load factor 1 2 (*) 2 (*)
Win
...