SIST EN 50341-2-16:2018

SLOVENSKI STANDARD
SIST EN 50341-2-16:2018
01-februar-2018
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Overhead electrical lines exceeding AC 1 kV - Part 2-16: National Normative Aspects
(NNA) for NORWAY (based on EN 50341-1:2012)
Lignes électriques aériennes dépassant 1 kV en courant alternatif - Partie 2-16 : Aspects
Normatifs Nationaux pour la NORVEGE (Basé sur l'EN 50341-1:2012)
Ta slovenski standard je istoveten z: EN 50341-2-16:2016
ICS:
29.240.20 Daljnovodi Power transmission and
distribution lines
SIST EN 50341-2-16:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 50341-2-16:2018

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SIST EN 50341-2-16:2018


EUROPEAN STANDARD EN 50341-2-16

NORME EUROPÉENNE

EUROPÄISCHE NORM
December 2016
ICS 29.240.20

English Version
Overhead electrical lines exceeding AC 1 kV - Part 2-16:
National Normative Aspects (NNA) for NORWAY (based on EN
50341-1:2012)
Lignes électriques aériennes dépassant 1 kV en courant
alternatif - Partie 2-16 : Aspects Normatifs Nationaux pour
la NORVEGE (Basé sur l'EN 50341-1:2012)
This European Standard was approved by CENELEC on 2016-09-13. 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.



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
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 50341-2-16:2016 E

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SIST EN 50341-2-16:2018
EN 50341-2-16:2016  -2/31 - Norway


Contents
Foreword . 5
1 Scope . 6
2 Normative references, definitions and symbols . 6
2.1 NO.1 Normative references . 6
3 NO.1 Basis of design . 6
3.2    Requirements of overhead lines . 6
3.2.1  NO.1 Basic requirements . 6
4 Actions on lines. 6
4.1    NO.1 Introduction . 6
4.2    NO.1 Permanent loads . 7
4.3  NO.1 Wind Loads . 7
4.3.1  NO.1 Field of application and basic wind velocity . 7
4.3.2  NO.1 Mean wind velocity . 7
4.3.3  NO.1 Mean wind pressure . 7
4.3.4  NO.1 Turbulence intensity and peak wind pressure . 8
4.3.5  NO.1 Wind forces on any overhead line component . 8
4.4    Wind forces on overhead line components . 8
4.4.1  NO.1 Wind forces on conductors . 8
4.4.1.1 NO.1 General . 9
4.4.1.2 NO.1 Structural factor . 9
4.4.1.3 NO.1 Drag factor . 9
4.4.2  NO.1 Wind forces on insulator sets . 9
4.4.3  NO.1 Wind forces on lattice towers . 10
4.4.4  NO.1 Wind forces on poles . 10
4.5    Ice loads . 10
4.5.1  NO.1 General . 10
4.5.2  NO.1 Ice forces on conductors . 10
4.6   NO.1 Combined wind and ice loads . 11
4.6.1  NO.1 Combined probabilities . 11
4.6.2  NO.1 Drag factors and ice densities . 11

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4.6.3  NO.1 Mean wind pressure and peak wind pressure . 12
4.6.4  NO.1 Equivalent diameter D of ice covered conductor . 13
4.6.5  NO.1 Wind forces on support for ice covered conductors . 13
4.6.6  Combination of wind velocities and ice loads . 13
4.6.6.1 NO.1 Extreme ice load I combined with a high probability wind velocity V 13
T IH
4.6.6.2 NO.1 Nominal ice load I combined with a low probability wind velocity V 13
3 IL
4.7   NO.1 Temperature effects . 13
4.8    Security loads . 14
4.8.1  NO.1 General . 14
4.8.2  NO.1 Torsional loads . 14
4.8.3  NO.1 Longitudinal loads . 14
4.8.4  NO.1 Mechanical conditions of application . 14
4.9    Safety Loads . 14
4.9.1  NO.1 Construction and maintenance loads . 14
4.9.2  NO.1 Loads related to the weight of linesmen . 15
4.10  NO.1 Forces due to short-circuit currents . 15
4.11  Other special forces . 15
4.11.1 NO.1 Avalanches, creeping snow . 15
4.11.2 NO.1 Earthquakes . 15
4.12   Load cases. 16
4.12.1 NO.1 General . 16
4.12.2 NO.1 Standard load cases . 16
4.13   NO.1 Partial factors for actions . 17
5 Electrical requirements . 21
5.6 Load cases for calculation of clearances . 21
5.6.1  NO.1 Load conditions . 21
5.8   Internal clearances within the span and at the top of support . 22
5.9 NO.1 External clearances . 24
6 Earthing systems . 24
6.2 Ratings with regard to corrosion and mechanical strength. 24
6.2.2  NO.1 Earthing and bonding conductors . 24
6.4 Dimensioning with regard to human safety . 24
6.4.1  NO.1 Permissible values . 24
7 Supports . 25

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7.1   Initial design consideration . 25
7.1.1  NO.1 Introduction . 25
7.1.2  NO.1 Structural design resistance of a pole . 25
7.1.3  NO.1 Buckling resistance . 25
7.2 NO.1 Materials . 25
7.3 NO.1 Lattice steel towers . 25
7.3.6  NO.1 Ultimate limit states . 26
7.3.6.1 NO.1 General . 26
7.4 NO.1 Steel poles . 26
7.5 Wood poles . 26
7.5.5  Ultimate limit states . 26
7.5.5.1 NO.1 Basis . 26
7.5.7  NO.1 Resistance of connections . 26
7.6 NO.1 Concrete poles. 27
7.7 NO.1 Guyed structures . 27
7.7.1  NO.1 General . 27
7.7.4  Ultimate limit states . 27
7.7.4.1 NO.1 Basis . 27
7.8 Other structures . 27
7.9 NO.1 Corrosion protection and finishes. 27
8 Foundations . 27
8.2 Basis of geotechnical design by (EN 1997-1:2004 – Section2) . 27
8.2.3  Design by prescriptive measures . 27
9     Conductors, earthwires and telecommunication cables . 30
10 Insulators . 30
10.7  NO.1 Mechanical requirements . 31
11 Hardware . 31
11.6   NO.1 Mechanical requirements . 31
12 Quality assurance, checks and taking-over . 31

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European foreword

1 The Norwegian National Committee (NC) is identified by the following address:

Norsk Elektroteknisk Komité
Mustads vei 1, NO-0283 Oslo
Phone no. +47 67 83 31 00
E-mail: Nek@nek.no

2 The Norwegian NC has prepared this Part 2-16 of EN 50341-1:2012, listing the Norwegian
national normative aspects, under its sole responsibility, and duly passed it through the
CENELEC and CLC/TC 11 procedures.

NOTE  The Norwegian NC also takes sole responsibility for the technically correct coordination of this
EN 50341-2-16 with EN 50341-1:2012. It has performed the necessary checks in the frame of quality
assurance/control. It is noted however that this quality assurance/control has been made in the framework of the
general responsibility of a standards committee under the national laws/regulations.

3 This EN 50341-2-16 is normative in Norway and informative for other countries.

4 This EN 50341-2-16 has to be read in conjunction with EN 50341-1:2012, hereinafter
referred to as Part 1. All clause numbers used in this Part 2-16 correspond to those of Part
1.

Specific subclauses, which are prefixed “NO”, are to be read as amendments to the
relevant text in Part 1. Any necessary clarification regarding the application of Part 2-16 in
conjunction with Part 1 shall be referred to the Norwegian NC who will, in cooperation with
CLC/TC 11 clarify the requirements.

When no reference is made in Part 2-16 to a specific subclause, then Part 1 applies.

5 In the case of “boxed values” defined in Part 1, amended values (if any) which are defined
in Part 2-16 shall be taken into account in Norway.

However any “boxed values“, whether in Part 1 or Part 2-16, shall not be amended in the
direction of greater risk in a Project Specification.


6 The national Norwegian standards/regulations related to overhead electrical lines
exceeding 1 kV (AC) are identified in 2.1/NO1.

NOTE  All national standards referred to in this Part 2-16 will be replaced by the relevant European Standards
as soon as they become available and are declared by the Norwegian NC to be applicable and thus reported to
the secretary of CLC/TC 11.

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Clause National regulation
1 Scope
(snc)
This Part 2-16 is applicable for new permanent overhead lines only and generally
not for existing lines in Norway. If some planning/design or execution work on
existing lines in Norway has to be performed, the degree of application of this
Standard shall be agreed upon by the parties concerned and the authorities.


2 Normative references, definitions and symbols

2.1 NO.1 Normative references
(A-dev)
These references shall be added to the list:
Act No. 4 of 24 May 1929 of Supervision of Electrical Installations and Electrical
Equipment Regulations for Electrical Installations – system for generating,
transmission and distribution.

The Norwegian Regulations FEF 2006. Guidelines to the Norwegian Regulations
FEF 2006.

If newer acts and regulations are issued, the ones mentioned above shall be
replaced with the valid version.


3 NO.1 Basis of design
(snc)
Unless mentioned below, the clauses 3.1 - 3.7.4 may be considered as informative.

3.2    Requirements of overhead lines

3.2.1  NO.1 Basic requirements
(snc)
Generally minimum 50 year return periods shall be applied as basic loads.


4 Actions on lines

4.1    NO.1 Introduction
(snc)
May be considered as informative.


(snc)   NO.2 Types of load
Permanent loads include self-weight of supports, insulator sets, other fixed
equipment and of the conductors from the adjacent spans. Aircraft warning spheres
and similar elements are also to be considered as permanent loads.

Climatic loads include wind, ice and combined wind and ice loads on conductors,
insulator sets, lattice towers and poles.

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Clause National regulation
Security loads include wire breakage.

Safety loads take the safety to the linesmen into consideration and also prevent
collapse of the support by including load cases that may occur during construction
and maintenance.

Other loads may include forces that occur due to short-circuit currents, avalanches,
creeping snow, earthquakes etc.


4.2    NO.1 Permanent loads
(snc)
Mentioned in clause 4.1 NO.2.


4.3  NO.1 Wind Loads
(snc)
The text in Main Body may be considered as informative.


4.3.1  NO.1 Field of application and basic wind velocity
(snc)
EN 1991-1-4 should normally be applied, alternatively wind velocities and their
return periods may be asessed by an experienced meteorologist, and include effects
of gust, height above ground, topography and the direction of the power line relative
to that of the wind.


4.3.2  NO.1 Mean wind velocity
(snc)
EN 1991-1-4 should normally be applied. The wind velocity of 10 m above
ground may be considered constant up to 20 m above ground.

In fjords or valleys the given wind velocities in EN 1991-1-4 apply for a line direction
parallel to the main direction of the fjord or valley. If the line direction is
perpendicular to the fjord/valley direction, or if the line along a fjord/valley passes
the mouth of a branch fjord/valley, the calculated wind velocity shall be multiplied by
1,2.

The calculated values may generally be deviated from if separate evaluations are
made by meteorologist. In areas where strong winds are known to occur or may be
expected, it is recommended that a meteorologist should be consulted.


4.3.3  NO.1 Mean wind pressure
(snc)

EN 1991-1-4 should normally be applied.

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Clause National regulation




4.3.4  NO.1 Turbulence intensity and peak wind pressure
(snc)
EN 1991-1-4 should normally be applied. In such case the wind velocity shall
include the effects of gust.

For wind on the conductors an average direction factor of 0,9 may be applied to
reduce the wind velocity when EN 1991-1-4 is applied. This reduction factor does
not apply for wind pressure on the towers or any of their components.


4.3.5  NO.1 Wind forces on any overhead line component
(snc)
The value of the wind force, Q due to wind blowing horizontally at reference
W
height above ground, h, perpendicular to any line component, is given by:

                  Q = 0,5ρ(V )² C A
W T

3
ρ   = The air density. Normally considered constant as 1,292 kg/m .

V  = The wind velocity with return period T.
T

C   = The drag factor (or force coefficient) depending on the shape of the line
      component being considered.

A  = The area of the line component being considered, projected on a plane
     perpendicular to the wind direction.

To arrive at the actual design values according to the reliability class, the values of
wind velocity or wind pressure have to be factored with their respective conversion
factor given in Table 4.3.5/NO.1.

Table 4.3.5/NO.1

Return period Conversion factor Conversion factor
T  V /V  q /q
T 50 T 50

3 0,763 0,58
50 1,000 1,00
150 1,087 1,18
500 1,182 1,40


4.4    Wind forces on overhead line components

4.4.1  NO.1 Wind forces on conductors
(snc)
Wind pressure on conductors gives forces transversal to the direction of the line as
well as higher tension in the conductors. In addition to the components from the

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Clause National regulation
conductor tension the wind load from each of the adjacent spans on the support
may be calculated as:

2
       F = ζ 0,5 C d ρ [(V )² G 0,5L + (V )² G 0,5L )]
C C T1 L1 1 T2 L2 2

where
ζ      : 0,9 (average conductor direction factor when EN 1991-1-4 is used).
ζ      : 1,0 when wind velocities are given by a meteorologist.
C   : drag coefficient for the conductor. For ordinary stranded conductors and
C
        regular wind speeds, C = 1,0. For smooth conductors C = 1,1.
C C

d   : diameter of conductor.
3
ρ : the air density, 1,292 kg/m .

V , V : the wind velocity with return period T acting normal to the conductor for L
T1 T2 1
        and L respectively and simultaneosly.
2
G , G : span factor (see below) for L and L respectively. .
L1 L2 1 2
L , L   : length of span L and L on their respective side of the support.
1 2 1 2

The total wind pressure on bundled conductors is set equal to the sum of that on the
individual conductor without taking into accout possible sheltering effects on leeward
conductors.

The span factor can be calculated as follows:

G = 1  for span lengths up to 100 m
L
G = 1 - (L - 100)/1 000 for span lengths between 100 and 450 m
L
G = 0,65  for span lengths exceeding 450 m
L

Other span factors can be used after consulting a meteorologist, or as documented
otherwise.


4.4.1.1 NO.1 General
(snc)
May be considered as informative.


4.4.1.2 NO.1 Structural factor
(snc)
Not to be used.


4.4.1.3 NO.1 Drag factor
(snc)
May be considered as informative.


4.4.2  NO.1 Wind forces on insulator sets
(snc)
These shall be specified in Project Specification.

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Clause National regulation


4.4.3  NO.1 Wind forces on lattice towers
(snc)
These shall be specified in Project Specification. Clauses 4.4.3.1-3 may be
considered as informative.


4.4.4  NO.1 Wind forces on poles
(snc)
These shall be considered.

For round timber a drag factor not less than 0,8 may be applied. For gluelam poles a
drag factor of 2,0 is recommended.


4.5    Ice loads

4.5.1  NO.1 General
(snc)
Wet snow and hard rime ice are the two types of ice considered for design.


      NO.2 Characteristic ice load

Table 4.5.1/NO.1 gives general 50 year values for the different regions in Norway,
and is ment to be the basis for design where no other information is available. The
given values will be currently adjusted as new information is available. The given
values may be deviated from if separate evaluations are made by meteorologist.

For regions not covered in the table, meteorlogist should be consulted.

To arrive at the actual design values according to the reliability class, the values of
Table 4.5.1/NO.1 has to be multiplied by the conversion factor given in
Table 4.5.1/NO.2.

Table 4.5.1/NO.2

Return period Conversion factor
1)
T I /I
T 50

3 0,35
50 1,00
150 1,25
500 1,50

1) I and I are ice loads with return periods of T and 50 years periods respectively.
T 50


4.5.2  NO.1 Ice forces on conductors
(snc)
The weight span method does not apply. Loads from the conductors shall be based

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Clause National regulation
on the exact method.

      NO.2 Ice load on bundled conductors

If bundled conductor is applied, the ice load may be reduced:

I ≤ I     : no reduction
T m
I < I ≤ I : I =I *(1-[(I -I )/(I -I )]*(1-c))
m T h Tred T T m h m
I > I     : I =I *c
T h Tred T

I = 50 N/m. I =250 N/m. c=0,6.
m h


4.6   NO.1 Combined wind and ice loads
(snc)
This load case may be omitted where adviced by meteorologist. In such case the
wind pressure q shall be applied. This applies normally for the areas 1, 2, 4
h500
and 5 in table 4.5.1/NO.1.


4.6.1  NO.1 Combined probabilities
(snc)
Ice load with high probability to occur: I , T=3.
T
2
Wind pressure with low probability to occur: B ·q , T=50, 150 or 500.
I hT
B is given in table 4.6.2/NO.1
I


4.6.2  NO.1 Drag factors and ice densities
(snc)
3
Table 4.6.2/NO.1– Drag factors C , density ρ (kg/m ) and velocity reduction
cI I
factor B for various types of ice
I

          Ice type Wet snow Hard rime ice
C 1,0 1,1
cI
ρ 600 700
I
B 0,7 0,85
I

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Clause National regulation
Table 4.5.1/NO.1 - Design ice loads

No Region Height Design ice
above sea load (N/m)
level (m) 50 year
return period

1 Main areas of the South East 0 - 200 30
*)
region

2 Main areas of the South East 200 - 400 40
*)
region

3 Main areas of the South East 400 - 600 50
region

4 Østfold and Vestfold 0 - 200 20

5 Telemark and Agder 0 - 200 35

6 Telemark and Agder 200 - 400 50

7 The coast Rogaland – Stad 0 - 200 35

8 Fjordane Rogaland – Stad 0 - 400 40

9 The coast Stad – Namdalen 0 - 200 40

10 The fjords Stad – Namdalen 0 - 400 40

11 The coast Namdalen – Lofoten 0 - 200 40

12 The inland of Nordland 0 - 200 30

13 The coast Vesterålen – Nordkapp 0 - 100 35

14 The inland Troms - Vest- 0 - 200 30
Finnmark

15 The coast of Aust-Finnmark 0 - 100 30

16 The inland of Aust-Finnmark 0 - 200 20
*)
Except areas mentioned in no 3 and 4.

NOTE: In areas 1, 2, 4 and 5, combined ice and wind loads may be replaced by
applying V on ice free conductors. For insulated overhead cables other return
500
periods may be applied.

In areas 3 and 6-16, combined ice and wind loads shall be applied. This may be
deviated from by advice from a meteorologist.


4.6.3  NO.1 Mean wind pressure and peak wind pressure
(snc)
This clause shall be considered as informative.

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Clause National regulation

4.6.4  NO.1 Equivalent diameter D of ice covered conductor
(snc)
2 0,5
D = [d + 4 I/(g π ρ )]
I

D (m)   : diameter ice covered conductor
d (m)    : conductor diameter
I (N/m)  : ice load distribution per meter of the conductor according to the actual
         load case
2
g (m/s )  : 9,81
3
ρ (kg/m ) : ice density according to type of ice in table 4.6.2/NO.1
I


4.6.5  NO.1 Wind forces on support for
...