EN 50341-2-13:2017/A1:2017

Overhead electrical lines exceeding AC 1 kV - Part 2-13: National Normative Aspects (NNA) for ITALY (based on EN 50341-1:2012)

20170619: No XML for NNA standards
2021: CLC legacy converted by DCLab NISOSTS

Nadzemni električni vodi za izmenične napetosti nad 1 kV - 2-13. del: Nacionalna normativna določila (NNA) za Italijo (na podlagi EN 50341-1:2012) - Dopolnilo A1

General Information

• Status: Published
• Publication Date: 22-Jun-2017
• Withdrawal Date: 16-May-2020
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: CLC/TC 11 - Overhead electrical lines exceeding 1 kV a.c. (1,5 kV d.c.)
• Drafting Committee: CLC/TC 11 - Overhead electrical lines exceeding 1 kV a.c. (1,5 kV d.c.)
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 23-Jun-2017
• Due Date: 23-Jan-2019
• Completion Date: 23-Jun-2017
• Ref Project: SIST EN 50341-2-13:2017/A1:2018 - Overhead electrical lines exceeding AC 1 kV - Part 2-13: National Normative Aspects (NNA) for ITALY (based on EN 50341-1:2012)

Relations

• Amends: EN 50341-2-13:2017 - Overhead electrical lines exceeding AC 1 kV - Part 2-13: National Normative Aspects (NNA) for ITALY (based on EN 50341-1:2012)
• Effective Date: 18-Apr-2017

Overview

EN 50341-2-13:2017/A1:2017 is the Italian National Normative Aspects (NNA/A1) for overhead electrical lines exceeding AC 1 kV, published by CENELEC and adopted nationally by the Italian Electrotechnical Committee (CEI). This amendment complements EN 50341-1:2012 and EN 50341-2-13:2017 by providing Italy‑specific parameters, modified clauses and calculation rules that are normative in Italy and informative elsewhere.

Key topics and technical requirements

• Scope and status
  • Amendment A1 (2017) coordinates Part 1 and Part 2-13 with Italian national practice; the Italian NNA is binding for projects in Italy.
• Snow and ice loading
  • Defines regional snow load categories for Italy with snow density ρ = 500 kg/m³.
  • Provides altitude‑dependent snow depth prescriptions (example: S_k = 24 mm for a ≤ 600 m; S_k = 24 + 20·(a − 600)/1000 mm for a > 600 m) and separate definitions for coastal or southern provinces.
• Temperature effects and conductor tensions
  • Sets EDS (Every Day Stress) temperature = 15°C; at this temperature and in still air, conductor tensile load shall not exceed 25% of breaking load.
  • Notes the importance of the catenary constant (horizontal tension / mass per metre) and flags a reference value of 2000 m for installation attention to vibration control.
• Security loads and broken‑conductor cases
  • Guidance on calculating differential loads when conductors break, including consideration of the swing of suspension insulator strings and using maximum tensile forces of relevant sections.
• Ice reduction factors and standard load cases
  • Specifies reduction factors α for ice loads in load cases 2b/2c/2d (examples included in the NNA) and allows special “slope” conditions for supports on hill peaks.
• Minimum air clearances
  • Detailed formulas for span clearances using conductor sag f, insulator swing I_k, and voltage‑dependent clearance distances D.
  • Coefficients given (e.g., k = 0.6 for homogeneous aluminium conductors; k = 0.5 for other conductors; k1 = 0.75).
  • Special rules for spans where f + I > 40 m and reductions for post‑insulator arrangements.
• Geotechnical and partial‑factor notes
  • Amendment contains national modifications to geotechnical design by calculation and partial factors for conductors (clause references included).

Practical applications and users

This NNA is essential for:

• Transmission and distribution line designers and structural engineers working in Italy
• Utilities and network operators implementing overhead lines >1 kV
• Project specifiers, permitting authorities and regulators ensuring compliance with Italian national rules
• Manufacturers and suppliers of conductors, insulators and support structures who must meet Italian clearances and load conditions

Use the NNA when performing load calculations (snow, wind, ice, conductor break), specifying tower geometry, verifying electrical clearances, and documenting compliance with Italian national requirements.

Related standards

• EN 50341-1:2012 (general rules for overhead electrical lines > 1 kV)
• EN 50341-2-13:2017 (Part 2-13 national normative aspects - base document)
• National implementation via CEI / CENELEC procedures

For complete legal/technical application and full formulae, consult the official EN 50341-2-13:2017/A1:2017 text through CENELEC or the Italian national standards body.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2018
1DG]HPQLHOHNWULþQLYRGL]DL]PHQLþQHQDSHWRVWLQDGN9GHO1DFLRQDOQD
QRUPDWLYQDGRORþLOD11$]D,WDOLMRQDSRGODJL(1'RSROQLOR$
Overhead electrical lines exceeding AC 1 kV - Part 2-13: National Normative Aspects
(NNA) for ITALY (based on EN 50341-1:2012)
Ta slovenski standard je istoveten z: EN 50341-2-13:2017/A1:2017
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 50341-2-13:2017/A1

NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2017
ICS 29.240.20
English Version
Overhead electrical lines exceeding AC 1 kV - Part 2-13:
National Normative Aspects (NNA) for ITALY (based on EN
50341-1:2012)
This amendment A1 modifies the European Standard EN 50341-2-13:2017; it was approved by CENELEC on 2017-05-17.
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 50341-2-13:2017/A1:2017 E

Italy - 2/9 - EN 50341-2-13:2017/A1:2017

Contents
European foreword . 3
1 Modifications to 4.5.1 General . 4
2 Modifications to 4.7 Temperature effects . 5
3 Modifications to 4.8 Security loads . 5
4 Modifications to 4.12.2 Standard load cases . 6
5 Modifications to 5.8 Internal clearences within the span and at the top of the
tower . 6
6 Modifications to 8.2.2 Geotechnical design by calculation . 9
7 Modifications to 9.6.2 Partial factor for conductors . 9

Italy - 3/9 - EN 50341-2-13:2017/A1:2017

European foreword
1. The Italian National Committee (NC) is identified by the following address:
Italian Electrotechnical National Committee
Via Saccardo 9
20134 Milano
Italy
Phone n°. ++39 02 21006.1
Fax n°. ++39 02 21006210
Committee 11/7 – Overhead electrical lines
E-Mail [e-mail].
2. The Italian NC has prepared this Part 2-13/A1 (EN 50341-2-13/A1) listing the Italian National
Normative Aspects Amendment 1 (NNA/A1) under its sole responsibility and duly passed
this document through the CENELEC and CLC/TC 11 procedures.
NOTE: The Italian NC takes sole responsibility for the technically correct co-ordination of this EN
50341-2-13/A1 with Part 2-13 (EN 50341-2-13:2017) and with Part 1 (EN 50341-1:2012). It has
performed the necessary checks in the frame of quality assurance/control. However, it has been
noted that this quality control has been already made in the framework of the general responsibility of
a standards committee under the national laws/regulations.
3.  This NNA/A1 is normative in Italy and informative for other countries.
4. This NNA/A1 shall be read in conjunction with Part 2-13 and Part 1. All clause numbers used
in this NNA/A1 correspond to those of Part 2-13 and Part 1. Specific sub-clauses that are
prefixed “IT” are to be read as amendments to the relevant text in Part 1 and Part2-13. Any
necessary clarification regarding the application of NNA/A1 in conjunction with Part 2-13 and
Part 1, shall be referred to the Italian NC who will, in co-operation with CLC/TC 11, clarify
the explanations.
Where no reference is made in this NNA/A1 to a specific sub-clause, then Part 1 shall apply.
5. In case of “boxed values” defined in Part 1, in Italy amended values (if any), which are
defined in this NNA/A1, shall be taken into account.
However no “boxed value” either defined in Part 1 or in this NNA/A1, can be modified in the
direction of increased risk in the Project specifications.
6. The Italian National standards/regulations related to overhead electrical lines exceeding
1 kV AC are listed in subclause 2.1/IT.1 Part 1.
NOTE: All national standards referred to in this NNA/A1 will be replaced by the relevant European
Standards as soon as they become available and are declared by the Italian NC to be applicable and
thus reported to the secretary of CLC/TC 11.

Italy - 4/9 - EN 50341-2-13:2017/A1:2017

1 Modifications to 4.5.1 General
Replace:
Load type 2 (snow)
Regions: Valle d’Aosta, Piemonte, Liguria, Lombardia, Trentino Alto Adige,
Emilia Romagna, Friuli Venezia Giulia, Veneto e Marche, Abruzzo, Molise,
Toscana (with exclusion of the provinces of Livorno and Grosseto), Umbria,
Lazio (with exclusion of the provinces of Viterbo, Roma and Latina), Campania
(with exclusion of the provinces of Napoli and Caserta), Puglia (with exclusion of
the provinces of Brindisi and Lecce), Basilicata, Calabria (with exclusion of the
province of Reggio Calabria):
Snow density ρ = 500 kg/m³
i
S =24 mm    for a ≤ 600 m
k s
Sk =24 + 20 (as - 600)/1000 mm for as > 600 m.
Load type 3 (snow)
Regions: Toscana (provinces of Livorno e Grosseto), Lazio (provinces of
Viterbo, Roma and Latina); Campania (provinces of Napoli and Caserta), Puglia
(provinces of Brindisi and Lecce), Sardegna, Calabria (province of Reggio
Calabria), Sicilia:
Snow density ρ = 500 kg/m³
i
S = 0 mm     for a ≤ 600 m
k s
S = 20 + 15 (a - 600) /1000 mm  for a > 600 m
k s s
with:
Load type 2 (snow)
Regions: Valle d’Aosta, Piemonte, Liguria, Lombardia, Trentino Alto Adige,
Emilia Romagna, Friuli Venezia Giulia, Veneto, Marche, Abruzzo, Molise,
Toscana (with exclusion of the provinces of Pisa, Livorno and Grosseto),
Umbria, Lazio (with exclusion of the provinces of Viterbo, Roma and Latina),
Campania (with exclusion of the provinces of Napoli and Caserta), Puglia (with
exclusion of the provinces of Brindisi and Lecce), Basilicata, Calabria (with
exclusion of the provinces of Vibo Valentia and Reggio Calabria):
Snow density ρ = 500 kg/m³
i
Sk =24 mm    for as ≤ 600 m
S =24 + 20 (a - 600)/1000 mm for a > 600 m.
k s s
Load type 3 (snow)
Regions: Toscana (provinces of Pisa, Livorno and Grosseto), Lazio (provinces
of Viterbo, Roma and Latina); Campania (provinces of Napoli and Caserta),
Puglia (provinces of Brindisi and Lecce), Sardegna, Calabria (provinces of Vibo
Valentia and Reggio Calabria), Sicilia:
Snow density ρ = 500 kg/m³
i
S = 0 mm    for a ≤ 600 m
k s
S = 20 + 15 (a - 600) /1000 mm  for a > 600 m
k s s
Italy - 5/9 - EN 50341-2-13:2017/A1:2017

2 Modifications to 4.7 Temperature effects
Replace:
(snc) IT.1 Temperature effects
For the calculation of the tensile load on conductors and earth-wires, and of
related forces transmitted to supports, as well as for geometrical verifications of
height above ground for electrical clearances and insulating distances, the
temperatures below reported shall apply:
a) EDS temperature (Every Day Stress) is 15°C: in this condition, in absence of
wind, the tensile load of conductors shall not be greater than 25% of the
breakage load.
On the basis of specific project conditions, to limit wind vibration effects,
special attention should be paid to laying conditions when the parameter
value (the ratio, between the horizontal tension and the mass per linear
meter of conductor = 2000 m) is exceeded. Criteria and conditions of
installation should be defined in project specifications.
with:
(snc) IT.1 Temperature effects
For the calculation of the tensile load on conductors and earth-wires, and of
related forces transmitted to supports, as well as for geometrical verifications of
height above ground for electrical clearances and insulating distances, the
temperatures below reported shall apply:
a) EDS temperature (Every Day Stress) is 15°C: in this condition, in absence of
wind, the tensile load of conductors shall not be greater than 25% of the
breaking load.
On the basis of specific project conditions, to limit wind vibration effects,
special attention should be paid to laying conditions when the catenary
constant (the ratio, between the horizontal tension and the mass per linear
meter of conductor) exceeds a value of 2000 m. Criteria and conditions of
installation should be defined in project specifications.

3 Modifications to 4.8 Security loads
Replace:
(ncpt) IT.1 Breaking of conductors case
For conductors supported by suspension insulator sets, the differential loads
shall be calculated taking into consideration the swing of the string. For
calculating the actions due to a broken conductor (single o in a bundle) on a
support, the maximum tensile load of the section inside which the supported is
...