EN 50423-3:2005
(Main)Overhead electrical lines exceeding AC 1 kV up to and including AC 45 kV - Part 3: Set of National Normative Aspects
Overhead electrical lines exceeding AC 1 kV up to and including AC 45 kV - Part 3: Set of National Normative Aspects
Notes 1, 2 and 3 are normative in Austria: NOTE 2 The construction of lines with covered conductors (KUF) and reduced internal or external clearance is permitted in Austria. NOTE 4 This NNA applies to overhead lines with nominal voltage exceeding AC 1kV up to and including AC 45 kV and a maximum operating voltage of 52 kV according to ÖVE EN 60071-1. Hereinafter the latter will be described as high voltage overhead lines, group I.
Freileitungen über AC 1 kV bis einschließlich AC 45 kV - Teil 3: Nationale Normative Festlegungen
Lignes électriques aériennes dépassant 1 kV AC jusqu'à 45 kV AC - Partie 3: Aspects Normatifs Nationaux
Nadzemni električni vodi za izmenične napetosti nad 1 kV in do vključno 45 kV – 3. del Zbirka nacionalnih normativnih določil
General Information
Relations
Standards Content (Sample)
SLOVENSKI SIST EN 50423-3:2005
STANDARD
julij 2005
Nadzemni električni vodi za izmenične napetosti nad 1 kV in do vključno 45 kV
– 3. del Zbirka nacionalnih normativnih določil
Overhead electrical lines exceeding AC 1 kV up to and including AC 45 kV – Part 3:
Set of National Normative Aspects
ICS 29.240.20 Referenčna številka
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
EUROPEAN STANDARD EN 50423-3
NORME EUROPÉENNE
EUROPÄISCHE NORM January 2005
ICS 29.240.20
English version
Overhead electrical lines exceeding
AC 1 kV up to and including AC 45 kV
Part 3: Set of National Normative Aspects
Lignes électriques aériennes Freileitungen über AC 1 kV
dépassant 1 kV AC jusqu'à 45 kV AC bis einschließlich AC 45 kV
Partie 3: Aspects Normatifs Nationaux Teil 3: Nationale Normative Festlegungen
This European Standard was approved by CENELEC on 2004-10-01. 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 one official version (English). 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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50423-3:2005 E
Foreword
The different parts of this European Standard were prepared by the respective CENELEC National
Committees in cooperation with the Technical Committee CENELEC TC 11, Overhead electrical lines
exceeding 1 kV a.c. (1,5 kV d.c.).
The texts of the drafts were submitted to the Unique Acceptance Procedure and were approved by
CENELEC as EN 50423-3 on 2004-10-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2005-10-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-10-01
__________
Text of EN 50423-3
Please see the subparts specific to each National Committee.
NOTE This Part 3 of EN 50423 is published by CENELEC in English only.
National Normative Aspects (NNA)
for
AUSTRIA
based on EN 50423-1:2005
EN 50423-3-1:2005 - 2/39 - Austria
Contents
1 General scope – Field of application . 4
2 Definitions, symbols and references …………………………………………. 4
2.1 Definitions . 4
2.3 References . 5
4 Actions on lines . 6
4.3.2 Wind loads . 6
4.3.3 Ice loads . 6
4.3.6 Construction and maintenance loads . 7
4.3.10.4 Standard load cases . 7
4.3.11 Partial factors for actions . 12
5 Electrical requirements . 13
5.4 Internal and external clearances . 13
5.4.2.1 General considerations and underlying principles .…. 13
5.4.3 Clearances within the span and at the tower . 17
5.4.4 Clearances to ground in areas remote from buildings, roads,
railways and navigable waterways . 18
5.4.5.2 Clearances to residential and other buildings . 19
5.4.5.3 Clearances to Line near roads, railways, navigable waterways . 21
5.4.5.4 Clearances to other power lines or overhead telecom. lines . 29
5.4.5.5 Clearances to recreational areas . 32
6 Earthing systems . 33
6.3 Construction of earthing systems . 33
6.3.1 Installation of earthing electrodes . 33
8 Foundations ………. 33
8.2 General requirements .…. 33
8.5.2.1 Geotechnical design by calculation, General . 34
8.5.3 Geotechnical design by prescriptive measures . 34
9 Conductors and overhead earthwires (ground wires) with or without
telecommunication circuits . 35
9.1 Introduction .………………………… 35
9.5.6 Test requirements …………………………………. 35
9.6 General requirements . 37
10 Insulators .…. 37
10.1 General .……………………………. 37
10.7 Mechanical requirements . 37
10.10 Characteristics and dimensions of insulators . 37
In addition to the given NNA, the following applies for Austria: . 38
TELECOMMUNICATION LINES CARRIED ON OVERHEAD TRANSMISSION LINES
Austria - 3/39 - EN 50423-3-1:2005
Foreword
1. The Austrian National Committee (NC) is identified by the following address:
Austrian Electrotechnical Committee
Österreichischer Verband für Elektrotechnik (OVE)
Eschenbachgasse 9, A-1010 Vienna, Austria
Phone no. +43.1.587.63.73
Fax no. +43.1.586.74.08
name/number of relevant subcommittee: Fach(normen)ausschuss L
2. The Austrian NC has prepared this Part 3-1 of EN 50423 listing the Austrian national
normative aspects, under its sole responsibility, and duly passed it through the CENELEC
and CLC/TC 11 procedures.
3. This EN 50423-3-1 is normative in Austria and informative for other countries;
4. This EN 50423-3-1 has to be read in conjunction with EN 50423-1, hereinafter referred to
as Part 1. All clause numbers used in this Part 3-1 correspond to those of Part 1. Specific
subclauses, which are prefixed „AT“, are to be read as amendments to the relevant text in
Part 1. Any necessary clarification regarding the application of Part 3-1 in conjunction
with Part 1 shall be referred to the Austrian NC who will, in cooperation with CLC/TC 11
clarify the requirements.
When no reference is made in Part 3-1 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 3-1 shall be taken into account in Austria.
However any boxed value, whether in Part 1 or Part 3-1, shall not be amended in the
direction of greater risk in a Project Specification.
6. The Austrian NC declares in accordance with subclause 3.1 of Part 1 that this Part 3-1
follows the „Empirical Approach“ (subclause 4.3), and that consequently subclause 4.2
„General Approach“ is not applicable for Austria.
7. The national Austrian standards/regulations related to overhead electrical lines exceeding
1 kV (A.C.) are identified/listed in 2.3.
NOTE All national standards referred to in this Part 3-1 will be replaced by the relevant European Standards
as soon as they become available and are declared by the Austrian NC to be applicable and thus reported to
the secretary of CLC/TC 11.
EN 50423-3-1:2005 - 4/39 - Austria
Clause National regulation
1 General scope – Field of application
(A-dev) AT.1 Notes 1, 2 and 3 are normative in Austria:
NOTE 2 The construction of lines with covered conductors (KUF) and reduced internal or external
clearance is permitted in Austria.
NOTE 4 This NNA applies to overhead lines with nominal voltage exceeding AC 1kV up to and including
AC 45 kV and a maximum operating voltage of 52 kV according to ÖVE EN 60071-1. Hereinafter the latter
will be described as high voltage overhead lines, group I.
2 Definitions, symbols and references
2.1 Definitions
(A-dev) AT.2.(1)
a conductor crosses an object when, as a result of being deflected by wind blowing in
the direction of that facility, the outline of the conductor intersects the outline of the
object
(A-dev) AT.2.(2) crossing span
a span to which the conditions of AT.2.(1) apply
(A-dev) AT.3
In addition to the definition in Part 1:
Conductors
are understood to mean bare, insulated, or sheathed wires and cables suspended
between the supports of an overhead high-tension power transmission line – regardless
of whether they are energized or not. Included here are lines having multiple functions
(composite cables for conductors and earthwires). OPCON and OPGW are to be
considered as conductors.
Covered conductors (KUF) are not shock-proof, i.e. covered conductors being valid with
regard to prodection of contact as bare conductors. For the minimum requirements of
the design of covered conductors see ÖVE/ÖNORM E 8227
(A-dev) AT.11
line groups
are defined as follows in Table 2.1/AT.11
Table 2.1/AT.11 - Line groups
Line Nominal Maximum Operating Proof Alternating Normal Surge
Group Insulation Voltage, Effective Voltage A (Alternating Level (Surge
(series) Value in kV Voltage Holding Holding Voltage)
Voltage) Peak Value
Effective Value in kV in kV
I till 45kV till 52 till 105 till 250
Austria - 5/39 - EN 50423-3-1:2005
Clause National regulation
(ncpt) AT.30
wooden poles
pylon with a wooden tower body
2.3 References
(A-dev) AT.21 ÖVE-L 1, Construction of overhead power lines up to 1000V
(A-dev) AT.22 ÖNORM B 4007 Scarffoldind – general – use, construction und load
(A-dev) AT.23 ÖNORM B 4700 Reinforced concrete structures – EUROCODE-orientated
analysis, design and detailing
(A-dev) AT.24 ÖVE/ÖNORM E 8227 Covered conductors
(A-dev) AT.25 ÖNORM E 4101 Electrical overhead-lines; Pin insulators type VHD und VHD-G
(A-dev) AT.26 ÖNORM E 4102 Electrical overhead-lines; solid core post insulators VKSt und
VKS
(A-dev) AT.27 ÖVE-EH 41 Earthing in alternating current systems with nominal voltages
exceeding 1 kV
(A-dev) AT.28 ÖVE-L 5, Teil 1 Commissioning report for overhead lines
(A-dev) AT.29 ÖNORM ENV 1994-1-1 Eurocode 4: Design of composite steel and concrete
structures – Part 1-1: General rules and rules for buildings
(A-dev) AT.30 ÖNORM B 4710_1 Concrete – Part 1: Specification, production, use and
verification of conformity
EN 50423-3-1:2005 - 6/39 - Austria
Clause National regulation
4 Actions on lines
4.3.2 Wind loads
(ncpt) AT.3 :
Table 4.3.2/AT.3 Specific wind pressure acting upon the directly affected
components
Values relate to a wind velocity of 120 km/h and a thrust of 700 N/m
Component Specific C . q Reduction
x 120
aerodyn. drag N/m2 factor
coefficient C
x
full flat surfaces 1,6 1112 1
flat lattice walls made of angle profiles 1,4 973 1
made of rods 1,1 765 1
Timber poles, steel poles, concrete poles of 0,7 487 1
circular or near-circular shape
steel poles and concrete poles of hexagonal 1,0 695 1
or octagonal shape
Double poles of in the pole-plane 0,7 487 1
Timber, steel rectangular to pole-plane 0,8 556 1
1)
resp. concrete where e < d
m
wires and d < 15,8 mm 1,15 600 0,75
conductors of
Circular or d > 15,8 mm 1,0 521 0,75
elliptical shape
Aircraft warning and radar sphere d < 1,0 m 0,4 278 1
1)
e . inner distance pole to pole
dm .means diameter of pole
(snc) AT.10: In special cases it may be necessary to assume a greater wind velocity than
indicated in Table 4.3.2/AT.3 (120 km/h).
4.3.3 Ice loads
(A-dev) AT.2: Normal and exceptional additional loads on conductors are to be selected with a
view to the prevailing climatic conditions; the minimum assumptions are:
Normal additional load: (4 + 0,2 x d) in N/m
(d = conductor diameter in mm)
Exceptional additional load 25
Austria - 7/39 - EN 50423-3-1:2005
Clause National regulation
(snc) AT.3: For towers and equipment the following loading conditions apply:
For Normal additional loads:
(1) Conductor: Normal additional load
(2) Insulator strings of glass or porcelain: minimum 20% of their self weight (for
strings of composite insulators eventually higher percentages are to be
considered.)
(3) Tower body: no additional load
(4) Crossarms made of steel profiles: minimum 40% of their self weight
(5) Crossarms made of other materials: minimum 120 N/m2 acting on total surface
4.3.6 Construction and maintenance loads
(ncpt) AT.1: Construction loads are to be assumed as perpendicularly acting single
loads. They act on
(1) crossarms which jut out more than 1,2 metres: at the crossarm´s end
(2) horizontal bracing of crossarms: in the middle of the bracing (crossarm's upper
not horizontal bracings need not to be assumed with construction loads)
(3) all bracing and diagonals inclined at less than 30 degrees to the horizontal, in the
centre of the diagonals. In areas with climbing facilities (e.g. ladder, steps) on
supports: diagonals of these parts need not to be calculated for construction
loads.
(4) all horizontal bracings of tower bodies in the middle of the bracings (e.g. plan
bracing, secondary bracing)
At (1) and (2) loadings of normal conditions according to 4.3.10.4 are to be assumed
additionally, but not in cases (3) and (4).
For material stress the other regular loading conditions are to be assumed according to
relevant regulations (ÖNORM B 4605)
Poles of wooden towers need not to be assumed with construction loads.
4.3.10.4 Standard load cases
Loading cases as from table 4.3.10.4/AT.2 (suspension and angle suspension towers), table
4.3.10.4/AT.3 (tension and angle tension towers) and table 4.3.10.4/AT.4 (tapping towers) are
to be considered.
(ncpt) AT.1:
Tabelle 4.3.10.4/AT.1 Loading cases for the rating of conductor supports
1 2 3
Poles, except Timber
1 Poles Timber poles
poles
Suspension and angle Table 4.3.10.4/AT.2 Table 4.3.10.4/AT.2
suspension towers A, B, C A, B, C, D
Tension and angle Table 4.3.10.4/AT.3 Table 4.3.10.4/AT.3
tension towers A, B/C A, B/C, D
Tapping poles Table 4.3.10.4/AT.4 Table 4.3.10.4/AT.4
A, B, C A, B, C, D
EN 50423-3-1:2005 - 8/39 - Austria
Clause National regulation
(ncpt) AT.2 :
Table 4.3.10.4/AT.2 - Load cases for suspension and angle suspension towers
Normal loading conditions
Horizontal
Wind Load: Wind perpendicular to the direction of the line, in the case of angle suspension
forces
towers in the direction of the bisectors, acting upon: tower, equipment, and ice-free
conductors.
Horizontal conductor pull: of all conductors
Vertical Permanent Loads Normal additional loads and construction
forces loads are to be taken into account for the rating
A Upward and downward pulls
of those components for which the additional
Weight of the normal additional load on
consideration of these loads along with the
crossarms, equipment and conductors
other vertical loads produces the less
of the adjacent span halves
favourable stresses
Construction Load
Selfweight of support
Horizontal Wind Load: Wind in direction of the line, in the case of angle suspension towers vertical to
forces
B the bisector of the angles, acting upon: tower, equipment, and ice-free conductors.
Horizontal conductor pull: of all conductors.
Vertical as per loading condition A.
forces
Horizontal Reduction of the horizontal conductor pulls of all conductors in one adjacent span 95%
forces
Horizontal conductor pull of all conductors in the other adjacent span.
C
Vertical as per loading condition A
forces
Horizontal Discontinuation of the horizontal pull of one conductor resp. one bundle conductor in one
forces
adjacent span and reduction of the horizontal conductor pull of this conductor resp.
bundle conductor in the other adjacent span to the following percentages:
for single conductors 40 %
for bundle conductors 20 % of the entire bundle conductor
D
Horizontal conductor pull in all other conductors
Vertical as per loading condition A
forces
For the conductor or bundle conductor with discontinued horizontal conductor pull the upward
or downward pull is discontinued.
For the conductor or bundle conductor with reduced horizontal conductor pull the upward or
downward pull is to be reduced to the same percentage as the horizontal pull.
Austria - 9/39 - EN 50423-3-1:2005
Clause National regulation
(ncpt) AT.3 :
Table 4.3.10.4/AT.3 - Load cases for tension and angle tension towers
(analogously for terminal tension towers)
Normal loading conditions
Horizontal Wind Load: Wind perpendicular to the direction of the line, in case of angle tension towers in
forces the direction of the bisectors or in that of the main axis of the support which deviates least
from the direction of the resultant horizontal conductor pull, acting upon: tower, equipment,
and ice-free conductors.
Horizontal conductor pull: of all conductors
A Vertical Permanent Loads Normal additional loads and construction
forces loads are to be taken into account for the
Upward and downward pulls
rating of those components for which the
Weight of the normal additional load on
additional consideration of those loads along
crossarms, equipment, and conductors
with the other vertical loads produces the less
of the adjacent span halves
favourable stressing
Construction Load
Selfweight of support
Horizontal Wind Load: Wind in direction of the line, in the case of angle tension towers perpendicular to
forces the bisectors of the angle or vertical to that main axis of the support which deviates least
from the direction of the resultant horizontal conductor pull, acting upon: tower, equipment,
and ice-free conductors.
Reduction of horizontal conductor pulls of all conductors in one adjacent span to 50 %.
B/C
Horizontal conductor pull of all conductors in the other adjacent span.
vertical as per loading condition A.
forces In the case of conductors with reduced horizontal conductor pulls the upward and downward
pulls are to be reduced to 50 %.
Horizontal Discontinuation of the horizontal pull of one tensioned conductor or bundle conductor whilst
forces
D the full horizontal conductor pull is being considered by all other conductors tensioned on
the tower.
Vertical as per loading condition A
forces For the conductor or bundle conductor with discontinued horizontal conductor pull the upward
or downward pull is discontinued.
EN 50423-3-1:2005 - 10/39 - Austria
Clause National regulation
(ncpt) AT.4:
Table 4.3.10.4/AT.4 - Load cases for tapping towers
Normal loading conditions
Horizon- Wind Load: Wind in the direction of that main axis of the tower which deviates least from
tal forces
the resultant horizontal conductor pulls.
acting upon: the tower, equipment, and conductors free of ice.
Horizontal conductor pull: of all conductors
A Vertical Permanent Loads Normal additional loads and construction
forces loads are to be taken into account for the
Upward and downward pulls
rating of those components for which the
Weight of the normal additional load on
additional consideration of those loads
crossarms, equipment, and conductors
along with the other vertical loads
of the adjacent span halves
produces the less favourable stressing
Construction Load
Selfweight of support
Horizon- Wind Load: Wind perpendicular to that main axis of the tower which deviates least from the
tal forces
resultant horizontal line pulls,
acting upon: the tower, equipment, and conductors free of ice.
Horizontal conductor pulls of all conductors
B
vertical as per loading condition A.
forces
Horizon- Wind Load: Wind perpendicular to that main axis of the tower which deviates least from the
C tal forces
resultant horizontal line pulls, acting upon: the tower, the equipment, and the ice-free
conductors.
Terminated Conductors: Reduction of the horizontal conductor pulls of all conductors in an
adjacent span or more adjacent spans to 50%. In case of wooden tapping poles in A-pole
form only the conductor pulls of non-terminated conductors need to be considered for the
through conductor. Horizontal conductor pulls of all conductors in all other adjacent spans.
Non-terminated Conductors: Reduction of the horizontal conductor pulls of all conductors in
an adjacent span or more adjacent spans to 95%
Horizontal conductor pull of all conductors in the other adjacent spans.
Vertical as per loading condition A
forces In the case of terminated conductors with reduced horizontal conductor pulls the upward and
downward pulls are to be reduced to 50%.
Horizon-
D Horizontal forces Terminated Conductors: Discontinuation of the horizontal conductor
tal forces
pull of a conductor or bundle conductor in a span of the through system whilst in the other
span the full horizontal conductor pull is exerted, and possible simultaneous discontinuation
of the horizontal conductor pull of a conductor or bundle conductor of the tapping system.
Horizontal conductor pull in all other conductors of the adjacent spans.
Horizontal forces Non-terminated Conductors: Discontinuation of the horizontal
conductor pull of a conductor or a bundle conductor in an adjacent span and reduction of the
horizontal conductor pull of this conductor or bundle conductor in the other adjacent span of
each conductor system to the following percentages:
for single conductors 40%,
for bundle conductors 20% of the entire bundle conductor.
Horizontal conductor pull in all other conductors.
Vertical as per loading conditions A
forces In the case of the terminated conductors with discontinued horizontal conductor pull the
upward or downward pull is discontinued. In the case of nonterminated conductors for which
the horizontal conductor pull is discontinued, the upward or downward pull is also
discontinued. In the case of conductors with reduced horizontal conductor pull the upward or
downward pull is reduced to the same percentage as for the horizontal conductor pulls.
Austria - 11/39 - EN 50423-3-1:2005
Clause National regulation
1)
(ncpt) AT.4: For timber poles of lines Group II with nominal insulation 45 the following applies:
Table 4.3.10.4/AT.4 - Loading assumptions for timber poles
Timber poles lines group II Loading assumption
1)
nominal insulation 45 kV
Suspension and angle suspension towers Table 4.3.10.4/AT.1 A, B, C
Tension and angle tension towers Table 4.3.10.4/AT.2 A, B/C
Tapping poles Table 4.3.10.4/AT.3 A, B, C
1)
Calculation of wooden towers of other Group II -lines (above 45kV) which remain in service for only
a short period is also covered here, provided that they do not violate the Protective Zone of a facility
where Enhanced Safety applies. In the event of violation of the said Protective Zone, complete
loading conditions apply also for timber poles as from 4.3.10.4/AT.1 .AT.3 of lines Group II which
remain in service for only a short period of time.
(ncpt) AT.5: Depending upon the porpuse for which they are used, distinctions are drawn
between:
(1) Suspension and angle suspension towers
(2) Tension and angle tension towers
(3) Tapping poles
(ncpt) AT.6: Table 4.3.10.4/AT.1 shows the loading conditions under which these supports
are to be rated. Table 4.3.10.4/AT.2 to Tabelle 4.3.10.4/AT.4 show the loading
assumptions for these loading conditions
(ncpt) AT.7: If, under special conditions, it is to be assumed that conductor pulls will be
reduced or discontinued completely, it must be assumed that as a result the relevant
least favourable stressing of the component to be rated will apply.
(ncpt) AT.8: If suitable measures are adopted at suspension towers and angle suspension
towers to ensure that there is no stress as per loading conditions D (discontinuation of
the conductor pull of one conductor) or loading conditions C (differential pull), these
loading conditions need not be taken into account. However, if the said measures
ensure only partial relief, the percentages shown in Table 4.3.10.4/AT.1 must be
adjusted to the extent of the effective relief. Reference for loading condition C is on the
basis of the assumption that the conductor on one side of the tower is stressed with the
normal additional load at -5°C whilst on the other side there is no additional load.
Reference for loading condition D is on the basis of the assumption that on one side of
the tower a conductor or a conductor of a bundle conductor has ruptured whereby on
the opposing side the conductor pull reduced by the said special measures must be
taken into account.
In the case of lines equipped with suspension strings it may be additionally assumed for
the purposes of loading conditions C and D that between the tower in question and the
next conductor termination there are three level spans with normal span lengths and
similarly equipped suspension towers.
(ncpt) AT.9: If towers of a multiple-circuit line are initially only partially utilised, this is to be
taken into account in the rating.
(ncpt) AT.10: In unusual cases, under particularly unfavourable climatic conditions, it may be
necessary to assume an additional loading assumption with wind pressure on ice-
covered components
EN 50423-3-1:2005 - 12/39 - Austria
Clause National regulation
(ncpt) AT.11: If multiple strings are used, for the purpose of rating these supports and the
components of these supports are also to be rated for the case of an individual string
failing in the most unfavourable position.
4.3.11 Partial factors for actions
(ncpt) AT.1:
Table 4.3.11/AT.1 - Partial factors for actions - Ultimate limit states
Values given below supersede those given in tables of Part 1
Type of Partial
Loading condition
tower factors γ
A B C D
Suspension γ 1,3 1,3 1,3 1,3
G
and angle
γ 1,3 1,3 n.a. n.a.
W
suspension
1,3 1,3 1,3 1,3
γ
I
towers
γ n.a. n.a. n.a. n.a.
A
1,3 1,3 1,3 1,3
γ
C
A B/C D
1,3 1,3 1,3
γ
G
Tension
γ 1,3 1,3 1,3
W
and angle
1,3 1,3 1,3
γ
I
tension
γ n.a. n.a. n.a.
A
towers
γ 1,3 1,3 1,3
C
A B C D
1,3 1,3 1,3 1,3
γ
G
Tapping γ 1,3 1,3 n.a. n.a.
W
towers
γ 1,3 1,3 1,3 1,3
I
n.a. n.a. n.a. n.a.
γ
A
γ 1,3 1,3 1,3 1,3
C
Remarks: = Partial Factor for Self Loads
γ
G
γ = Partial Factor for Wind Loads
W
γ = Partial Factor Additional Loads
I
γ = Partial Factor Exceptional loads
A
γ = Partial Factor for Conductor Pull
C
n.a. not applicable
Austria - 13/39 - EN 50423-3-1:2005
Clause National regulation
5 Electrical requirements
5.4 Internal and external clearances
5.4.2.1 General considerations and underlying principles
(A-dev) AT.1 Overhead HV-lines are to be so constructed that:
(1) conductors which are live are kept at such a distance from one another and from
earthed components of their supports that electrical arc-over will be avoided. This
condition can be said to be satisfied if the internal clearances required in 5.4.3 are
not fallen short of.
(2) the chance contacting of parts under voltage without the use of any special means
is prevented. This condition is regarded as being satisfied if
(2.1) the values stipulated in relevant clauses for the clearances between live
conductors and the ground are not fallen short of, and
(2.2) the lateral clearance between live conductors and facilities as stipulated in
relevant clauses are not fallen short of. If the lateral clearances are fallen
short of with the result that the overhead line runs in the vicinity of facilities (as
per 5.4.5.2 to 5.4.5.5) the current carrying conductors must be so arranged
that the clearance stipulated in the relevant clauses is not fallen short of.
(3) their supports and the foundations of their supports are built at an adequate distance
from certain facilities. This condition is fulfilled when at least the measurements for
these lateral clearances are observed.
(4) the additional measures called for in the event of line routing in the vicinity of certain
facilities are adopted. In this context distinctions are drawn between different types of
facilities.
(5) In the case of facilities not specified in 5.4.5.2 to 5.4.5.5 these present regulations
for the determination of clearances and safety measures are to be applied
analogously. There are separate technical regulations concerning clearances and
safety measures to be adopted when working in the vicinity of overhead high-
tension power transmission lines (ÖVE-E5 resp. ÖVE EN 50110-1 and
ÖNORM B 4007).
(A-dev) AT.3 : In addition to the prescriptions found in relevant items of clause 5 the following
applies:
When crossing or routing conductors within the protective zone of certain objects
or facilities, the following measures for „Enhanced Safety“ are to be considered if
requested in the relevant clauses.
Measures for enhanced safety:
(1) Line routing
In the event of a shortfall in the relevant lateral clearance in the vicinity of a facility with
the result of a conductor runs within the prodective zone acc. to 2.1/AT. 5 of a facility,
unimportant whether the object is crossed or not, the demanded clearances must be
adhered to. Measures for enhanced safety acc. to 5.4.2.1/AT.3 and 5.4.2.1/AT.4 are to
be adopt acc. to tabe 5.4.2.1/AT.5.
EN 50423-3-1:2005 - 14/39 - Austria
Clause National regulation
(2) Attaching of conductors
(2.1) Pin insulators on suspension towers
(2.1.1) The conductor carrying current is to be fastened to a pin insulator by means of a
clamp construction, bridle ring or insulator lashing spiral. Simply securing by
means of wire lashing is not permitted.
(2.1.2) In the case of angle towers the conductor is to be so arranged that the resulting
pull of the conductor will be initiated directly or via fittings.
(2.2) Insulator stings as tension insulators
(2.2.1) On tension towers the conductors are to be fastened by means of multiple
tension set strings as per 5.4.2.1/AT.3 (2.2.2) at the span in direction of the
crossing span.
(2.2.2) In the case of multi-unti insulator strings the tensioning is to be such that, in the
event of an individual string failing, the electromechanical or mechanical nominal
load for the remaining insulators and the maximum loads as per 2.1/AT.25 to 28
of the remaining fittings are at least equivalent to the pull of the conductor under
exceptional laoding conditions.
(2.3) Insulator strings on suspension towers
Multi-unit insulator strings are to be used in the crossing span. In the event of
one single insulator string failing, the electromechanical or mechanical nominal
load for the remaining insulators and the maximum loads as per 2.1/AT.25 bis 28
of the remaining fittings are at least equivalent to the loading under exceptional
loading conditions.
(A-dev) AT.4: Additional requests and measures for enhanced safety
(1) Additional requests and measures for objects acc. to 5.4.5.3/AT13,
5.4.5.3/AT19, 5.4.5.3/AT20 and 5.4.5.3/AT22
(1.1.1) On tension towers the conductors are to be fastened by means of multiple
tension set strings as per 5.4.2.1/AT.3 (2.2.2) at the span in direction of the
crossing span.
(1.1.2) The conductors are to be fastened on suspension towers acc. to 5.4.2.1/AT.3
(2.1) and 5.4.2.1/AT.3 (2.3), when the suspension towers
- making the end of a crossing span
- making a span within a protective zone (see 2.1/AT. 4) of facilities acc. to
5.4.5.3/AT10, 5.4.5.3/AT13, 5.4.5.3/AT14, 5.4.5.3/AT119, 5.4.5.3/AT20,
5.4.5.3/AT22 and 5.4.5.4/AT4 begrenzen.
In the case of earthed supports with pin or solid core pin insulators two insulators
must be arranged perpendicularly to the direction of the line or in the direction of
the bisector of the angles. The fastening of the conductor and of the safety
jumper (made of the same material and having the same cross-section as the
conductor) to the insulator is to be as per 5.4.2.1/AT.3 (2.1.1) and 5.4.2.1/AT.3
(2.1.2)
Austria - 15/39 - EN 50423-3-1:2005
Clause National regulation
(3) Ground wires are to be terminated on the tension tower in the section.
(1.2) In case of wooden poles the following applies:
(1.2.1) They are to be provided with footing which may not be constructed of wood.
(1.2.2) Tension towers must be A-poles (cross-braced, A-pole plane in the line direction)
or a combination af A-poles.
(1.2.3) Angle suspension towers must be A-poles (A-pole in the bisectors of the angles).
(1.2.4) Tower top configurations must be deisigned as steel constructions. They are not
to be secured by means of wood thread screws. Bent pins/supports are not
permitted.
(1.2.5) Oil switches and transformers may not be mounted on suspension towers. They
may be mounted on tension towers if their connections to the conductors
(jumpers) are not connected to conductors which are under tension.
(2) Additional requests for the crossing of objects acc. to 5.4.5.3/AT.10,
5.4.5.3/AT.14 and 5.4.5.4/AT.4
Where a conductor crosses objects acc. to 5.4.5.3/AT.10, 5.4.5.3/AT.14 and
5.4.5.4/AT.4 shortfalls of the required protective clearances in each case are not
permitted, even allowing for the following unusual position of the conductor:
(1) The crossing span of the line is under the regular additional load and all other
spans of the line are not under load (unequal ice-load).
(2) Failure of an individual string of a multi-termination in case of regular loading
condition. In this case deflection of the conductor due to wind need not be taken
into account.
EN 50423-3-1:2005 - 16/39 - Austria
Clause National regulation
(A-dev): AT.5 – Overview measures for objects of greater importance
1 2 3 4 5 6
Protective
zone and
1 Protective zone Crossing span
crossing
span
2 For Enhanced saftey
Measures
3 Acc. 5.4.2.1/AT.35.4.2.1/AT.4
In the section, In the
In the concerned which includes concer
4 Section Object
span the concerend ned
span span
5.4.5.3/
5 federal motorways type S and B, country roads yes - - - -
AT.9(1)
5.4.5.3/
6 traffic areas, etc. yes - - - -
AT.9(2)
5.4.5.2/ residential – and school buildings, industrial or
7 yes - - - -
AT.3 trading complexes, and similar
5.4.5.3/ tramcar, trollybus wires, freight railways and
8 yes - - - -
AT.15 electrical towing systems
5.4.5.5/
9 sports grounds yes - - - -
AT.1
5.4.5.4/
10 overhead power lines yes - - - -
AT.1
5.4.5.3/ freight-carrying cable railways, agricultural and
11 yes - - - -
AT.17 forestry ropeways
5.4.5.3/
12 funicular railways for goods transport yes - - - -
AT.18
5.4.5.4/
13 overhead telecommunication lines, group A yes - - - -
AT.3
5.4.5.2/
14 outdoor antenna installations yes - - - -
AT.6
5.4.5.3/A
15 cable lifts yes yes - - yes
T.19
providing public
5.4.5.3/A
passenger
16 cable railways yes yes yes yes yes
T.20
transport service
5.4.5.3/A
17 funicular railways yes yes - yes yes
T.22
5.4.5.3/A
18 waterways yes yes - - yes
T.13
5.4.5.3/A
19 railways for public passenger service yes yes yes yes yes
T.14
20 - branch lines yes yes - - yes
5.4.5.4/A
21 overhead telecommunication lines, group B yes yes yes yes yes
T.4
Overhead telecommunication lines for cable lifts acc.
22 - yes yes - - yes
5.4.5.3/AT.19
5.4.5.3/
23 motorways type A yes yes - - yes
AT.10
Austria - 17/39 - EN 50423-3-1:2005
Clause National regulation
5.4.3 Clearances within the span and at the tower
(ncpt) AT.2 : If conductors are made of the same material, having the same cross-section and
the same sag, it is permissible to determine the minimal distance D between the non-
deflected conductors in the middle of a span from the formula :
D = k x SQR(f + L ) + Z
whereby the value 0,8 metres may not be fallen short of.
D is the distance between conductors in metres in the middle of the span;
f is the sag in the middle of the span in metres for those normal loading conditions
according to Table 4.3.10.3AT.2, which produces the greater value;
L is the length of the insulator string in metres (if the conductors are so fixed at
the support that any deflection of insulators in a direction vertical to the axis of
the line is prevented, then L = 0);
Z is a supplement in metres which is allocated in Table 5.4.3/AT.10 depending on
the nominal insulation of the line;
k is the factor derived from Table 5.4.3/AT.3 which depends on the angle of
deflection of the conductor and on the conductor arrangement on the support.
On overhead lines with covered conductors acc. to 2.1/AT.3, the calculated minimal
distance D acc. 5.4.3/AT.2 may be reduced on 40 % in the middle of the span, in which
0,5 m may not be fallen below.
(A-dev) AT.10 :
Table 5.4.3/AT.10 – Distances
(all values not indicated are given in metres)
Group I Application
according
to
Nominal Insulation 10 15 20 25 30 45
to clause
3)
Peak Operating Voltage (effective value) kV 12 17,5 24 30 36 52
(37,5)
Z as a function of the nominal insulation 0,12 0,17 0,20 0,30 5.4.3 span
Distance E from non deflected parts or cond. 0,12 0,17 0,22 0,26 0,30 0,40 5.4.3
components tower
deflected parts or cond. 0,12 0,17 0,20 0,30
1)
normal air clearance 0,120,170,220,26 0,32 0,48 5.4.3 /
AT.7
2)
increased air clearance 0,15,2050,260,32 0,38 0,57
1)
Minimal clearance (internal) between conductors of the same system.
2)
Minimal clearance (internal) between conductors of one system to conductors of another system.
3)
Where extending existing 35 kV networks with peak operating voltage of 37,5 kV insulation may be in accordance
with nominal insulation of 30 kV.
EN 50423-3-1:2005 - 18/39 - Austria
Clause National regulation
5.4.4 Clearances to ground in areas remote from buildings, roads, railways and
navigable waterways
(A-dev) AT.1 : Clearances to ground in unobstructed countryside (expression in German:
„Geländeoberfläche“): the following applies:
additional requirements: none .
Clearances between conductors and the ground are to be measured right-angled to the
surface of the ground. Minor unevenness in the ground may be ignored here.
Clearance of conductors
(1) under normal conditions
(1.1) above normal ground 5 m
(1.2) above ground inaccessible to heavy
road vehicles carrying high loads 5 m
(1.3) above steeply sloping ground, normally not frequented 4 m
(1.4) from rock faces, laterally measured rectangular to rock face 3 m
(2) under exceptional loading conditions in cases (1.1).(1.4) 3 m
(A-dev) AT.2 : for Haystacks (expression in German: „Strohtristen“) the following applies :
additional requirements: none
(1) Lateral distance between conductors and the haystack 10 m
(2) Clearance between conductors and the
haystack under normal loading conditions 20 m
(A-dev) AT.3 : Clearances to trees under the line and to trees beside the line (Forest
aisles and isolated trees and shrubs), the following applies:
additional requirements: none .
The following minimum clearances may not be fallen short of. They apply to the branch-
free space, i.e. these minimum clearances may not be violated by treetops or branches
either. Should the safety of operational of the line so require, these clearances are to be
increased as necessary (diseased, hanging, or shallow-rooting trees, on steep slopes or
where there is a risk of landslide, etc.). The height to which trees will grow until ready for
harvesting, the nature of the soil, breakdown of the tree population, and the prevailing wind
directions shall be taken into account.
Minimum clearances
(1) laterally of the conductor 3 m
(2) below the conductor
(2.1) under normal loading conditions 3 m
(2.2) under exceptional loading conditions 0,5 m
Provided that it is not an overhead line with covered conductors, the protective zone
determined by the lateral clearance according to 5.4.4 AT.3 (1) is to be kept free of
branches above the conductor to the full height of the tree. Overhead lines with covered
conductors has to be kept free of branches above the conductor at least to the height
of 3 m.
Austria - 19/39 - EN 50423-3-1:2005
Clause National regulation
At the crossing of woods (lanes) or with the line routing along to the forest the lateral
distance for overhead lines with covered conductors may be reduced to 1,5 m. This
distance is valid also to bare, voltage-carrying parts in the immediate area of the pylon (e.g.
conductor attachment, earthing connections, clamps).
In order to facilitate the maintenance of overhead lines in forested areas any necessary
timber or trimming of trees should be carried out regularly.
5.4.5.2 Clearances to residential and other buildings
(A-dev) AT.4 : For all buildings mentioned in 5.4.5.2/AT.2 and 5.4.5.2/AT.3 the following applies:
(1) lateral distance of conductors from the nearest part
of the building 3 m
(2) clearance of conductors from nearest part of building
(2.1) under normal loading conditions 3 m
(2.2) under exceptional loading conditions 2,5 m
(3) clearance of conductors from flat roofs having up to 15 degree pitch,
and flat constructions such as balconies and terraces, etc.
(3.1) under normal loading conditions 4 m
(3.2) under exceptional loading conditions
...
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