HD 626-S2:2025

Overhead distribution cables of rated voltage U0/U(Um): 0,6/1 (1,2) kV

HD 626 applies to cables of rated voltage U0/U(Um) = 0,6/1(1,2) kV used in overhead power distribution systems mainly for public distribution, of maximum system voltage not exceeding 1,2 kV. This part (Part 1) specifies the general requirements applicable to these cables, unless otherwise specified in the particular sections of this HD. The objects of this Harmonisation Document are: - to standardize cables that are safe and reliable when properly used and equipped with appropriate accessories, in relation to the technical requirements of the system of which they form a part, - to state the characteristics and manufacturing requirements which have a direct or indirect bearing on safety, - and to specify methods for checking conformity with those requirements.

Isolierte Freileitungsseile für oberirdische Verteilungsnetze mit Nennspannungen U0/U(Um): 0,6/1 (1,2) kV

Câbles de distribution aériens de tension assignée U0/U(Um): 0,6/1 (1,2) kV

Nadzemni razvodni kabli za naznačeno napetost Uo/U(Um): 0,6/1 (1,2) kV

General Information

• Status: Published
• Publication Date: 16-Oct-2025
• ICS: 29.060.20 - Cables
• Technical Committee: CLC/TC 20 - Electric cables
• Drafting Committee: CLC/TC 20/WG 09 - Cables for use by electricity supply companies
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 17-Oct-2025
• Due Date: 12-Jun-2021
• Completion Date: 17-Oct-2025
• Directive: 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)
• Directive: 2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Ref Project: SIST HD 626-S2:2025 - Overhead distribution cables of rated voltage U0/U(Um): 0,6/1 (1,2) kV

Relations

• Replaces: HD 626 S1:1996/A2:2002 - Overhead distribution cables of rated voltage Uo/U(Um): 0,6/1 (1,2) kV
• Effective Date: 15-May-2018
• Replaces: HD 626 S1:1996 - Overhead distribution cables of rated voltage Uo/U(Um): 0,6/1 (1,2) kV
• Effective Date: 15-May-2018
• Replaces: HD 626 S1:1996/A1:1997 - Overhead distribution cables of rated voltage Uo/U(Um): 0,6/1 (1,2) kV
• Effective Date: 15-May-2018

Overview

HD 626‑S2:2025 (CENELEC Harmonization Document) defines the general requirements for overhead distribution cables of rated voltage U0/U(Um) = 0,6/1 (1,2) kV. Part 1 sets out scope, constructional principles, marking and identification, tests on completed cables, and guidance for use and selection. The document is applicable to overhead power distribution systems (mainly public distribution) with maximum system voltage not exceeding 1.2 kV and supersedes earlier HD 626 S1 editions.

Key topics and technical requirements

• Scope and object: Standardizes cables that are safe and reliable when used with appropriate accessories and specifies characteristics and manufacturing requirements that affect safety and conformity.
• Constructional requirements: Rules for conductors, insulation/insulating sheath, oversheath where applicable, and assembly of cores. Materials and application methods are addressed at a general level in Part 1, with detailed constructions covered in Parts 3–10 (PE, XLPE, messenger, sheathed types, single core and service cables).
• Marking and core identification: Requirements for durable, legible marking, indication of origin and continuity of marks, and core colouring/identification to ensure correct installation and maintenance.
• Tests and conformity: References to standard test methods such as EN 60228 (conductors), EN 60332‑1 (flame propagation), and EN 60811 (insulation and sheath tests). Part 1 also outlines tests on completed cables.
• Performance topics: Mechanical properties before/after ageing, insulation thickness, sealing and packing, current carrying capacity and minimum bending radius are addressed or referenced; further practical recommendations are given in Annex A.
• Document structure: Part 1 (General Requirements) plus Parts 2–10 that cover additional test methods and specific cable constructions (PE/XLPE, self‑supporting, with messenger, sheathed, single core, service cables).

Practical applications

• Specification, design and procurement of overhead distribution cables for public and private low‑voltage networks (≤1.2 kV).
• Guidance for manufacturers to ensure material selection, marking, testing and packaging conform to harmonized European requirements.
• Reference for utilities, network engineers and contractors when selecting cable types (self‑supporting, messenger, XLPE/PE insulated, single‑core, service cables) and planning installations.
• Basis for conformity assessment and type testing by testing laboratories.

Who should use this standard

• Cable manufacturers and product designers
• Electric utilities and distribution network operators
• Specifiers, procurement teams and consulting engineers
• Testing laboratories, certification bodies and national standards committees

Related standards

• EN 60228 (conductors)
• EN 60332‑1 series (flame propagation)
• EN 60811 series (insulation/sheath tests)
• Parts 2–10 of HD 626 for specific constructions and additional test methods

Keywords: HD 626‑S2:2025, overhead distribution cables, U0/U(Um) 0,6/1 (1,2) kV, CENELEC, cable standards, PE, XLPE, self‑supporting, messenger, cable testing, marking, core identification.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2025
Nadomešča:
SIST HD 626 S1:1998
SIST HD 626 S1:1998/A1:1998
SIST HD 626 S1:1998/A2:2002
Nadzemni razvodni kabli za naznačeno napetost Uo/U(Um): 0,6/1 (1,2) kV
Overhead distribution cables of rated voltage U0/U(Um): 0,6/1 (1,2) kV
Isolierte Freileitungsseile für oberirdische Verteilungsnetze mit Nennspannungen U0/U
(Um): 0,6/1 (1,2) kV
Câbles de distribution aériens de tension assignée U0/U(Um): 0,6/1 (1,2) kV
Ta slovenski standard je istoveten z: HD 626-S2:2025
ICS:
29.060.20 Kabli Cables
29.240.20 Daljnovodi Power transmission and
distribution lines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

HARMONIZATION DOCUMENT HD 626-S2

DOCUMENT D'HARMONISATION
HARMONISIERUNGSDOKUMENT October 2025
ICS 29.060.20 Supersedes HD 626 S1:1996; HD 626 S1:1996/A1:1997;
HD 626 S1:1996/A2:2002
English Version
Overhead distribution cables of rated voltage U /U(U ): 0,6/1
0 m
(1,2) kV
Câbles de distribution aériens de tension assignée Isolierte Freileitungsseile für oberirdische Verteilungsnetze
U /U(U ): 0,6/1 (1,2) kV mit Nennspannungen U /U(U ): 0,6/1 (1,2) kV
0 m 0 m
This Harmonization Document was approved by CENELEC on 2025-10-06. CENELEC members are bound to comply with the
CEN/CENELEC Internal Regulations which stipulate the conditions for implementation of this Harmonization Document at national level.
Up-to-date lists and bibliographical references concerning such national implementations may be obtained on application to the CEN-
CENELEC Management Centre or to any CENELEC member.
This Harmonization Document exists in three official versions (English, French, German).
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. HD 626-S2:2025 E
HD 626 S2:2025
Part 1
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 7
1.1 General . 7
1.2 Object . 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 Definitions relating to insulating and sheathing materials . 7
3.2 Definitions relating to the tests. 8
3.3 Other . 9
4 Marking . 9
4.1 Indication of origin . 9
4.1.1 General . 9
4.1.2 Continuity of marks . 10
4.2 Additional marking . 10
4.3 Durability . 10
4.4 Legibility . 10
4.5 Common marking . 10
4.6 Use of the name CENELEC . 10
5 Core identification . 10
6 General requirements for the construction of cables . 12
6.1 General . 12
6.2 Conductors. 12
6.2.1 Material . 12
6.2.2 Electrical resistance . 12
6.2.3 Separator tape . 12
6.3 Insulation or insulating sheath . 12
6.3.1 Material . 12
6.3.2 Application . 12
6.3.3 Colour of the insulation . 12
6.3.4 Thickness . 13
6.3.5 Mechanical properties before and after ageing . 13
6.3.6 Additional properties . 13
6.4 Oversheath (if any) . 13
6.4.1 Material . 13
6.4.2 Application . 13
HD 626 S2:2025
Part 1
6.4.3 Colour of the sheath . 13
6.4.4 Thickness . 13
6.4.5 Mechanical properties before and after ageing . 13
6.4.6 Other properties . 13
6.5 Assembly of cores . 13
7 Tests on completed cables . 14
8 Sealing and packing . 14
9 Current carrying capacity . 14
10 Guide to use and selection of cables . 14
Annex A (normative)  Guide to use and selection of cables . 25
A.1 Recommendations for use . 25
A.1.1 Permissible applications . 25
A.1.2 Highest permissible voltage . 25
A.2 Recommendations for storage and transportation . 25
A.2.1 Delivery . 25
A.2.2 Cable-end sealing . 26
A.2.3 Transport . 26
A.3 Recommendations for cable laying and installation . 27
A.3.1 Installation and operating conditions . 27
A.3.2 Minimum permissible installation temperature . 27
A.3.3 Cable laying . 28
A.3.3.1 Pulling by cable stocking . 28
A.3.3.2 Cable route . 28
A.4 Minimum bending radius . 28
Bibliography . 29
HD 626 S2:2025
Part 1
European foreword
This document (HD 626 S2:2025) has been prepared by CLC/TC 20, “Electric cables”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2026-10-31
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2028-10-31
conflicting with this document have to be
withdrawn
This document supersedes HD 626 S1:1996 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A complete
listing of these bodies can be found on the CENELEC website.
References to other HDs, ENs and International Standards are given in the particular parts or sections.
HD 626 S2:2025
Part 1
Introduction
This edition has been prepared to cover the latest market requests on overhead distribution cables of rated
voltage Uo/U(Um): 0,6/1 (1,2) kV. Since the publication of the first edition in 1996 and the amendments in 1997
and 2002, a number of particular sections have been withdrawn, new sections have been added from countries
not covered in the first edition, technical improvements have been added and a number of references to test
method standards were updated. The Table of Contents indicates even the withdrawn sections.
Part 1 of this document contains the General Requirements applicable to cables for overhead distribution and
service, specified in the particular sections of Parts 3 to 10. In general, bundle assembled cores are specified.
Single core cables are specified in Part 9.
The document contains the following Parts, arranged according to the main constructional features of the cables
covered:
HD 626 Part 1 General Requirements
HD 626 Part 2 Additional Test Methods
HD 626 Part 3 PE insulated self-supporting cables, (bundle assembled cores)
HD 626 Part 4 XLPE insulated self-supporting cables, (bundle assembled cores)
HD 626 Part 5 PE insulated cables with messenger, (bundle assembled cores)
HD 626 Part 6 XLPE insulated cables with messenger, (bundle assembled cores)
HD 626 Part 7 XLPE insulated and sheathed self-supporting cables, (bundle assembled cores)
HD 626 Part 8 XLPE insulated and PVC sheathed cables with messenger, (bundle assembled cores)
HD 626 Part 9 Single core cables
HD 626 Part 10 Service cables with concentric neutral conductor
Each of Parts 3 to 10 inclusive contains a number of Sections, and the Technical Board has agreed (D68/047,
Brussels, June 1991) that National Committees need at present only implement in their national language those
Sections having national applicability. The obligation remains however to announce the full HD in public by titles
and numbers, and also to withdraw any conflicting national standards.
Page numbering reflects the arrangement into Parts and Particular sections, e.g. Page 5-D-6 is Page 6 of
Particular Section D of Part 5.
CONTENTS (HD 626 S2:2025)
PART 0 CONTENTS OF HD 626
PART 1 GENERAL REQUIREMENTS
PART 2 ADDITIONAL TEST METHODS
PART 3 PE INSULATED SELF SUPPORTING CABLES
(bundle assembled cores)
Bundle assembled cores for overhead distribution and service (Type 3A-1)
3 A
(Cables with aluminium conductors)
3 C Withdrawn
Bundle assembled cores for overhead service (Type 3 I-1)
3 I
(Cables with aluminium conductors)
Bundle assembled cores for overhead distribution and service (Type 3L-1)
3 L
(Cables with aluminium conductors)
HD 626 S2:2025
Part 1
PART 4 XLPE INSULATED SELF SUPPORTING CABLES
(bundle assembled cores)
4 B Bundle assembled cores for overhead service (Types 4B-1 and 4B-2)
(Cables with aluminium conductors (Type 4B-1) or with copper conductors (Type 4B-2))
4 E Bundle assembled cores for overhead service (Type 4E-1)
(Cables with aluminium conductors)
4 F Bundle assembled cores for overhead distribution and service (Type 4F-1)
(Cables with aluminium conductors)
4 G Withdrawn
4 J Bundle assembled cores for overhead service (Types 4J-1 and 4J-2)
(Cables with aluminium conductors (Type 4J-1) or with copper conductors (Type 4J-2))
4 K Bundle assembled cores for overhead service (Type 4K 1)
(Cables with aluminium conductors)
4 M Bundle assembled cores for overhead distribution and service (Type 4M-1)
(Cables with aluminium conductors)
4 N Bundle assembled cores for overhead distribution (Type 4N-1)
(Cables with aluminium conductors)
4 O Insulated overhead distribution cables of rated voltage Uo/U(Um): 0,6/1 (1,2) kV
4 P Bundle assembled cores for overhead distribution and service (Type 4P-1 and Type 4P-2)
PART 5 PE INSULATED CABLES WITH MESSENGER
(bundle assembled cores)
5 D Bundle assembled cores for overhead distribution and service (Type 5D-1)
(Cables with aluminium phase conductors and uninsulated aluminium alloy neutral conductor)
5 I Withdrawn
PART 6 XLPE INSULATED CABLES WITH MESSENGER
(bundle assembled cores)
Bundle assembled cores for overhead distribution (Type 6B-1)
6 B
(Cables with aluminium phase conductors and aluminium alloy neutral conductor)
6 D Withdrawn
Bundle assembled cores for overhead distribution (Type 6E-1)
6 E
(Cables with aluminium phase conductors and aluminium alloy neutral conductor)
Bundle assembled cores for overhead distribution (Type 6J-1)
6 J
(Cables with aluminium phase conductors and aluminium alloy neutral conductor)
Bundle assembled cores for overhead distribution (Type 6K-1)
6 K
(Cables with aluminium phase conductors and aluminium alloy neutral conductor)
Bundle assembled cores for overhead distribution (Type 6N-1)
6 N
(Cables with aluminium phase conductors and aluminium alloy neutral conductor)
PART 7 XLPE INSULATED AND SHEATHED SELF SUPPORTING CABLES
(bundle assembled cores)
7 H Bundle assembled cores for overhead distribution and service (type 7H), Self-supporting XLPE
insulated cables
(Cables with tinned copper phase conductors and tinned copper neutral conductor)
PART 8 XLPE INSULATED AND SHEATHED CABLES WITH MESSENGER
(bundle assembled cores)
8 H Bundle assembled cores for overhead distribution and service (type 8H), Neutral conductor
messenger XLPE insulated cables
(Cables with aluminium phase conductors and aluminium alloy neutral conductor)
HD 626 S2:2025
Part 1
PART 9 Single core cables
9 F Withdrawn
9 G Withdrawn
9 I Withdrawn
Single cores for overhead distribution (Type 9N-1 and Type 9N-2)
9 N (EPR insulated and PCP sheath cables with aluminium conductors Type 9N-1 or with copper
conductors Type 9N-2)
PART 10 Service cables with concentric neutral conductor
10 N Single core and three cores service cables with concentric neutral conductor (Type 10N)
(Cables with tinned copper phase conductors and tinned copper concentric neutral conductor)
HD 626 S2:2025
Part 1
1 Scope
1.1 General
This document applies to cables of rated voltage U /U(U ) = 0,6/1(1,2) kV used in overhead power distribution
0 m
systems mainly for public distribution, of maximum system voltage not exceeding 1,2 kV.
This part (Part 1) specifies the general requirements applicable to these cables, unless otherwise specified in
the particular sections of this HD.
Test methods are specified in EN 60228:2005, EN 60332-1 series, EN 60811 series and in HD 605 or in Part 2
of this HD. The particular types of cables are specified in Parts 3 to 10.
1.2 Object
The objects of this document are:
— to standardize cables that are safe and reliable when properly used and equipped with appropriate
accessories, in relation to the technical requirements of the system of which they form a part,
— to state the characteristics and manufacturing requirements which have a direct or indirect bearing on
safety,
— and to specify methods for checking conformity with those requirements.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references, the
latest edition of the referenced document (including any amendments) applies.
EN 853:2015, Rubber hoses and hose assemblies - Wire braid reinforced hydraulic type - Specification
EN 60228:2005, Conductors of insulated cables
HD 60364-5-52:2011, Low-voltage electrical installations - Part 5-52: Selection and erection of electrical
equipment - Wiring systems (IEC 60364-5-52:2009)
HD 605 S3:2019, Electric cables - Additional test methods
IEC 60287-1-1:2006, Electric cables - Calculation of the current rating - Part 1-1: Current rating equations
(100 % load factor) and calculation of losses - General
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1 Definitions relating to insulating and sheathing materials
3.1.1
insulating and sheathing materials
types of insulating and sheathing compounds covered in this document and listed below, together with their
abbreviated designations
HD 626 S2:2025
Part 1
Note 1 to entry: See Table 1.
Table 1
Insulating and Sheathing Compounds  See:
1. Insulating and a) Thermoplastic
a
Insulating compounds based on: (PE) Table 2
insulating sheath ( )
- Polyethylene
b) Cross linked
Insulating compound based on: (XLPE) Table 3
- Cross linked polyethylene
c) Elastomeric
Insulating compound based on: (EPR) Table 5
- Ethylene propylene rubber
2. Sheath a) Cross linked
Sheathing compound based on: (XLPE) Table 4
- Cross linked polyethylene
b) Thermoplastic
Sheathing compound based on: (PVC)
- Polyvinyl chloride
c) Elastomeric
Sheathing compound based on:
(PCP, CSP) Table 6
- Polychloroprene, chlorosulfonated
polyethylene or similar polymer
a
An insulating sheath is an extruded layer which simultaneously acts as an insulation and as a sheath
3.1.2
type of compound
category in which a compound is classified according to its properties is determined by specific tests; the type
designation is not directly related to the composition of the compound
3.2 Definitions relating to the tests
3.2.1
type test
T
test required to be made before supplying a type of cable covered by this document on a general commercial
basis in order to demonstrate satisfactory performance characteristics to meet the intended application
Note 1 to entry: These tests are of such a nature that, after they have been made, they need not be repeated unless
changes are made in the cable material, design or type of manufacturing process which might change the performance
characteristics.
3.2.2
sample test
S
test made on samples of completed cable, or components taken from a completed cable adequate to verify that
the finished product meets the design specifications
3.2.3
routine test
R
test made on all production cable lengths to demonstrate their integrity
HD 626 S2:2025
Part 1
3.2.4
test after installation
test intended to demonstrate the integrity of the cable and its accessories as installed
Note 1 to entry: Tests classified as sample(S) or routine (R) could be required as part of type approval schemes.
3.3
rated voltage
reference voltage for which the cable is designed, and which serves to define the electrical tests
Note 1 to entry: The rated voltage is expressed by the combination of the following values U / U (U ) expressed in kV.
0 rn
U is the rms. value between any insulated conductor and earth;
U = 0,6 kV
U is the rms. value between any two phase-conductors of a multicore cable;
U = 1,0 kV
U is the rms. value of the highest system voltage for which the equipment may be used;
rn
U = 1,2 kV.
rn
Note 2 to entry: In an alternating current system, the rated voltage of a cable shall be at least equal to the nominal voltage
of the system for which it is intended.
Note 3 to entry: The cables of this HD may be used in DC Systems with a maximum voltage against earth not exceeding
0,9 kV.
3.3 Other
3.3.1
messenger
wire or a rope, the primary function of which is to support the cable in aerial installation, which may be separate
from or integral with the cable it supports
Note 1 to entry: In this HD, the messenger is called in some sections “neutral core” and even “messenger neutral core”.
[IEV 461-08-03]
4 Marking
4.1 Indication of origin
4.1.1 General
Cables shall be provided with an indication of origin consisting of:
1. either the manufacturer's identification thread,
2. or the continuous marking of the manufacturer's name or trademark, or (if legally protected)
identification number by one of the two following alternative methods:
a) printed tape within the cable,
b) printing, indenting or embossing on the outer surface of at least one core.
HD 626 S2:2025
Part 1
4.1.2 Continuity of marks
Unless otherwise specified in the particular sections, each specified mark shall be regarded as continuous if the
distance between the end of the mark and the beginning of the next identical mark does not exceed:
— 550 mm if the marking is on the outer surface of the cable;
— 275 mm if the marking is:
— on the insulation of a sheathed cable
— or on a tape within a sheathed cable.
NOTE A “specified mark” is any mandatory mark covered by this Part of the HD or by the particular requirements of
Part 3 onwards of this HD.
The diagram below shows an example of the marking as use on the outer surface of the cable, where the word
'ORIGIN' is for the mandatory information required by the subclause 3.1, and “XYZ” is one of any other
mandatory marks.
Figure 1
4.2 Additional marking
Additional marking requirements may be specified in the particular sections.
4.3 Durability
Printed markings shall be durable. Durability shall be checked by the test given in HD 605 S3:2019, 2.5.4. The
printed legend shall be legible after carrying out the test.
4.4 Legibility
All markings shall be legible. Printed markings shall be in contrasting colours. The colours of the identification
threads shall be easy to recognize or easily be made recognizable, if necessary, by cleaning with a suitable
solvent. The printed legend shall be legible after carrying out the test.
4.5 Common marking
Under consideration.
4.6 Use of the name CENELEC
The name CENELEC, in full or abbreviated, shall not be marked directly on, or in, the cables.
5 Core identification
The cores shall be identified by ribs (examples of the code method is given hereafter) or by numbers (printing,
indenting or embossing on the outer surface of the core), or both of them. For a two cores cable, this core
identification is valid too.
HD 626 S2:2025
Part 1
Figure 2
HD 626 S2:2025
Part 1
The colour or numbering or coding schemes relevant to the various types of cables are given in the particular
sections of this HD.
When identification is made by numbers, they shall be printed in a colour which contrasts with the core colour.
Marking shall comply with EN 853:2015 unless otherwise specified.
The colours or numbers shall be clearly identifiable and durable. Durability shall be checked by the test specified
in HD 605 S3:2019, 2.5.4.
Compliance with these requirements shall be verified by visual examination.
6 General requirements for the construction of cables
6.1 General
Compliance with the requirements given in subclauses 6.2 to 6.5 and in the particular sections of this document
shall be checked by inspection and by measurements according to the test methods in documents listed in the
Scope of the HD 626 S2:2020, Part 1, Subclause 1.1. or in particular sections.
6.2 Conductors
6.2.1 Material
Conductors shall be either of plain or metal-coated hard-drawn copper or of aluminium or aluminium alloy in
accordance with EN 60228:2005 or with particular requirements in particular sections of this HD.
Conductors shall be circular and stranded or shall comply with particular requirements in particular sections of
this HD.
6.2.2 Electrical resistance
The resistance of each conductor at 20°C shall be in accordance with the requirements in EN 60228:2005 for
the given class of conductor or with particular requirements in particular sections of this HD.
6.2.3 Separator tape
A separator tape may be placed between the conductor and the insulation.
It shall be easily removable from the conductor.
6.3 Insulation or insulating sheath
6.3.1 Material
Insulation shall be extruded solid compound of one of the types listed in 3.1.1 and as given for each type of
cable in the particular sections of HD 626.
Test requirements for the insulating compounds are specified in Tables 2, 3 and 5.
6.3.2 Application
The insulation may consist of one or more bonded layers. It shall be so applied that it fits closely on the conductor
or over the separator tape, and it shall be possible to remove it without damage to the conductor or to the metal
coating if any. The insulation shall be applied by a suitable extrusion process, and shall form a compact and
homogeneous body.
6.3.3 Colour of the insulation
The colour of the insulation or of the insulating sheath shall be black, grey or another colour according to the
particular sections.
HD 626 S2:2025
Part 1
6.3.4 Thickness
The insulation thickness values are specified in the particular sections, for each cable type and size. The mean
value of the thickness of insulation shall be not less than the specified value.
However, the thickness at any place may be less than the specified value provided that the difference does not
exceed 0,1 mm + 10 % of the specified value.
Compliance shall be checked by the test method specified in HD 605 S3:2019, 2.1.1.
6.3.5 Mechanical properties before and after ageing
The insulation material shall have the characteristics specified in Tables 2, 3 or 5 as appropriate.
6.3.6 Additional properties
These are specified in the particular sections.
6.4 Oversheath (if any)
6.4.1 Material
The oversheath shall be of a compound suitable for the conductor temperature and of the type specified in the
particular sections.
The test requirements for these compounds are specified in Tables 4 and 6 unless stated otherwise in the
particular sections.
6.4.2 Application
The oversheath shall be extruded and may consist of one or more layers.
Unless otherwise specified in the particular sections of this HD, the sheath shall not adhere to the cores. A
separator, consisting of a film or tape, may be placed under the sheath.
6.4.3 Colour of the sheath
The colour of the sheath shall be grey or another colour according to the particular sections.
6.4.4 Thickness
The mean value of the thickness of the oversheath shall be not less than the specified value for each type and
size of cable in the particular sections.
However, the thickness at any place may be less than the specified value provided that the difference does not
exceed 0,1 mm + 15 % of the specified value.
Test methods are given in HD 605 S3:2019, 2.1.2.
6.4.5 Mechanical properties before and after ageing
The sheath shall have appropriate mechanical characteristics within the temperature limits to which it may be
exposed in normal use.
Compliance shall be checked by carrying out the tests given in Tables 4 and 6, unless stated otherwise in the
particular sections.
6.4.6 Other properties
These are specified in the particular sections.
6.5 Assembly of cores
In multicore cables, the cores shall be laid-up helically. For cables having a messenger, the phase and auxiliary
cores shall be cabled helically around it.
HD 626 S2:2025
Part 1
Auxiliary cores, if any, shall be laid up in the interstices between main cores, allowed number and requirements
thereof are given in the particular sections.
7 Tests on completed cables
All cables shall comply with the requirements specified in 6.2 to 6.5 and in the particular sections of this HD.
Compliance shall be checked by inspection and by measurements according to the test methods in documents
listed in the Scope of Part 1 of this HD, Subclause 1.1.
8 Sealing and packing
Prior to storage or shipment, cable ends shall be sealed by appropriate caps, hot dipping or other suitable
method so that water ingress is efficiently prevented.
Cables shall be packed as coils or on drums according to the particular sections.
9 Current carrying capacity
The current that cables to this document can carry is determined by different conditions, either electrical (voltage
drop) or thermal, whichever is most demanding.
The current carrying capacity resulting from thermal limitations shall be calculated according to
IEC 60287-1-1:2006.
These calculations shall take into account the actual network parameters and installation conditions.
Tabulated current carrying capacity values according to the cable type for typical installation conditions may be
found in particular sections.
10 Guide to use and selection of cables
General requirements for use and selection of cables are given in HD 60364-5-52:2011.
For further information, some recommendations are provided in the guide to use which is given in the informative
Annex A of this Part. It supplies some general recommendations for the storage, transportation and installation
of cables. For particular use and for special recommendation, see particular sections of this HD.
When selecting the cables, attention is drawn to the fact that national conditions or regulations, covering, e.g.
climatic conditions or installation requirements, may exist. These should therefore be followed in conjunction
with this HD.
NOTE Safety requirements, rules of installation as well as project criteria (poles, devices selection, etc.) are
not considered in this guide to use, as they are covered by the relevant regulations and laws, as well as by
utility's specifications.
Table 2 — Requirement of insulating compound: PE
Compound No. UNITS TIP-1 TIP-2 TIP-3 TIP-4 TIP-5
Material type  PE PE PE PE PE
Maximum operating temperature °C 70 70 70 65 70
MECHANICAL PROPERTIES
Before ageing on sample
Minimum tensile strength MPa 10 10 10 10 10
Minimum elongation at break % 250 350 350 350 350
After ageing on sample
Temperature °C 80 100 100 100 100
HD 626 S2:2025
Part 1
Compound No. UNITS TIP-1 TIP-2 TIP-3 TIP-4 TIP-5
Material type  PE PE PE PE PE
Maximum operating temperature °C 70 70 70 65 70
Duration T1 h 168 168 240 168 240
Minimum tensile strength MPa 10
Maximum variation T1/T0 %  ±25 ±25 ±25
Minimum elongation at break % 250  300  300
Maximum variation T1/T0 %  ±25 ±25 ±25
PHYSICAL AND CHEMICAL PROPERTIES
Water absorption
Temperature °C  85
Duration h  336
Maximum variation of mass mg/cm  1
Shrinkage test
Duration h  1 1
Temperature °C  100 100
Maximum shrinkage %  4 4
Pressure test at high temperature
Duration h 4 4  4
Temperature °C 70 80  80
Coefficient k  0,8 0,8  0,8
Depth of indentation % 50 50  50
Bending test at low temperature
Temperature °C   −40
Carbon black content
2,5 ± 0, 2,5 ± 0, 2,5 ± 0, 2,5 ± 0,
% ≥ 2,0
5 5 5 5
Insulation resistance
Volume resistivity at 50 °C Ω.cm    4 exp13
Melt index
Temperature °C 190 190   190
Load kg 2,16 2,16   2,16
Maximum  0,5 0,5   0,4
- After ageing on sample
Temperature °C     80
Duration T1 H     240
Maximum variation T1/T0 %     50
NOTE  1MPa = 1N/mm
Remark: The tolerance on temperature values are given in HD 626 S2:2020, Part 2, 1.5.2 but others may be given in specific
sections
HD 626 S2:2025
Part 1
Table 3 — Requirement of insulating compound: XLPE
Compound No. UNITS TIX-1 TIX-2 TIX-3 TIX-4 TIX-5 TIX-6 TIX-7 TIX-8 TIX-9
Material type  XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE
Maximum operating temperature °C 90 90 90 90 90 80 90 90 90
MECHANICAL PROPERTIES
Before ageing on sample
Minimum tensile strength MPa 12,5 12,5 14,5 12,5 14,5 12,5 14,5 14,5 12,5
Minimum elongation at break % 200 200 200 200 200 200 200 200 200
After ageing on sample
Temperature °C 150 135 150 135 150 135 150 150 135
Duration T1 h 240 168 240 168 240 168 240 240 168
Minimum tensile strength MPa      12,5
Maximum variation T1/T0 % ±25 ±25 ±25 ±25 ±25 ±25 ±25 ±25 ±25
Minimum elongation at break %
Maximum variation T1/T0 % ±25 ±25 ±25 ±25 ±25 ±25 ±25 ±25 ±25
After ageing in air bomb at 0,55 Mpa
Temperature °C       127
Duration T1 h       240
Min. tensile strength - maximum variation T1/T0 %       ±25
Min. elongation at break – maximum variation T1/T0 %       ±25
PHYSICAL AND CHEMICAL PROPERTIES
Hot set test
Temperature °C 200 200 200 200 200 200 150 200 200
Duration m 15 15 15 15 15 15 15 15 15
Mechanical stress MPa 0,3 0,2 0,3 0,2 0,3 0,2 0,4 0,3 0,2
HD 626 S2:2025
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Compound No. UNITS TIX-1 TIX-2 TIX-3 TIX-4 TIX-5 TIX-6 TIX-7 TIX-8 TIX-9
Material type  XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE
Maximum operating temperature °C 90 90 90 90 90 80 90 90 90
Maximum elongation under load % 100 175 100 175 100 175 70 100 175
Maximum residual elongation % 15 15 15 15 15 15 10 15 15
Water absorption
Temperature °C  85  85  85 85  85
Duration h  336  336  336 336  336
Maximum variation of mass  1  1  1 5  1
mg/cm
Shrinkage test
Duration h 1 1 1 1 1 1  1 1
Temperature °C 130 130 100 130 100 130  100 130
Maximum shrinkage % 4 4 4 4 4 4  4 4
Pressure test at high temperature
Duration h      4   4/6
Temperature °C      85   80
Coefficient k       0,8   0,6/0,8
Depth of indentation %      50   50
Tests at low temperature
Elongation or bending test at low temperature
Temperature °C       −25
Minimum elongation %       50
Impact test at low temperature
Temperature °C −20      −20
Bending test at low temperature
Temperature °C −20   −40
HD 626 S2:2025
Part 1
Compound No. UNITS TIX-1 TIX-2 TIX-3 TIX-4 TIX-5 TIX-6 TIX-7 TIX-8 TIX-9
Material type  XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE
Maximum operating temperature °C 90 90 90 90 90 80 90 90 90
Tests at low temperature after ageing
Temperature °C 150      150
Duration h 240      240
Elongation or bending test at low temperature
Temperature °C       −20
Minimum elongation %       50
Impact test at low temperature
Temperature °C −20      −20
Mass of the hammer g       1000
Bending test at low temperature
Temperature °C −20
Carbon black content
2,5 ± 0, ≥ 2,0   ≥ 2,0
% ≥ 3,0 ≥ 2,0
Insulation resistance
Insulation constant Ki at temperature of 20 °C MΩ.km       10000
Ki at temperature of 80 °C MΩ.km     1000  1000 1000
1,4x
Volume resistivity at temperature of 20 °C Ω.cm
10exp1
10exp1 10exp1  10exp1
at temperature of 80 °C Ω.cm
2 2 2
10exp1 10exp1
at temperature of 90 °C Ω.cm 1,1x
2 2
HD 626 S2:2025
Part 1
Compound No. UNITS TIX-1 TIX-2 TIX-3 TIX-4 TIX-5 TIX-6 TIX-7 TIX-8 TIX-9
Material type  XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE XLPE
Maximum operating temperature °C 90 90 90 90 90 80 90 90 90
10exp1
Ozone resistance test
Duration h       24
250–
Ozone concentration ppm
Temperature °C       25
Solvent extraction test
Extraction %       ≤ 15
NOTE  1MPa = 1N/mm
Remark: The tolerance on temperature values are given in HD 626 S2:2020, Part 2, 1.5.2 but others may be given in specific sections
HD 626 S2:2025
Part 1
Table 4 — Requirement of sheathing compound: XLPE
UNITS TMX-1
Compound No.
Material type  XLPE
Maximum operating temperature °C 90
MECHANICAL PROPERTIES
Before ageing on sample
Minimum tensile strength MPa 14,5
Minimum elongation at break % 200
After ageing on sample
Temperature °C 150
Duration T1 h 240
Minimum tensile strength
Maximum variation T1/T0 % ±25
Minimum elongation at break
Maximum variation T1/T0 % ±25
After ageing in air bomb at 0,55 Mpa
Temperature °C 127
Duration T1 h 240
Min. tensile strength - maximum variation T1/T0 % ±25
Min. elongation at break – maximum variation T1/T0 % ±25
PHYSICAL AND CHEMICAL PROPERTIES
Hot set test
Temperature °C 150
Duration m 15
Mechanical stress MPa 0,4
Maximum elongation under load % 70
Maximum residual elongation % 10
Water absorption
Temperature °C 85
Duration h 336
Maximum variation of mass 5
mg/cm
Tests at low temperature
Elongation or bending test at low temperature
Temperature °C −25
Minimum elongation % 50
Impact test at low temperature
Temperature °C −20
Mass of the hammer g 1000
HD 626 S2:2025
Part 1
UNITS TMX-1
Compound No.
Material type  XLPE
Maximum operating temperature °C 90
Bending test at low temperature
Temperature °C −25
Tests at low temperature after ageing
Temperature °C 150
Duration h 240
Elongation or bending test at low temperature
Temperature °C −20
Minimum elongation % 50
Bending test at low temperature
Temperature °C −25
Insulation resistance
Insulation constant Ki at temperature of 20 °C MΩ.km 10000
Ki at temperature of 80 °C MΩ.km 1000
Ozone resistance test
Duration h 24
Ozone concentration ppm 250–300
Temperature °C 25
Solvent extraction test
Extraction % ≤ 15
NOTE  1MPa = 1N/mm
Remark: The tolerance on temperature values are given in HD 626 S2:2020, Part 2, 1.5.2 but others may be given
in specific sections
HD 626 S2:2025
Part 1
Table 5 — Requirement of insulating compound: EPR
UNITS TIE-1
Compound No.
Material type  EPR
Maximum operating temperature °C 90
MECHANICAL PROPERTIES
Before ageing on sample
Minimum tensile strength MPa 4,2
Minimum elongation at break % 200
After ageing on sample
Temperature °C 135 ± 3
Duration T1 h 168
Minimum tensile strength
Maximum variation T1/T0 % ±30
Minimum elongation at break
Maximum variation T1/T0 % ±30
After ageing in air bomb at 0,55 Mpa
Temperature °C 127
Duration T1 h 40
Min. tensile strength - maximum variat
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