SIST EN IEC 61238-1-1:2019

Compression and mechanical connectors for power cables - Part 1-1: Test methods and requirements for compression and mechanical connectors for power cables for rated voltages up to 1 kV (Um = 1,2 kV) tested on non-insulated conductors (IEC 61238-1-1:2018)

This part of EN 61238 applies to compression and mechanical connectors for power cables for rated voltages up to 1 kV (Um = 1,2 kV), for example buried cables or cables installed in buildings, having
a)   conductors complying with EN 60228 having nominal cross-sectional areas between 2,5 mm2 and 1 200 mm2 for copper and between 16 mm2 and 1 200 mm2 for aluminium;
b)   a maximum continuous conductor temperature not exceeding 90 °C.
This document is not applicable to connectors for overhead line conductors nor to connectors with a sliding contact.
The object of this document is to define the type test methods and requirements which apply to compression and mechanical connectors for power cables with copper or aluminium conductors. The reference method is to perform the tests on unused conductors.

Pressverbinder und Schraubverbinder für Starkstromkabel – Teil 1-1: Prüfverfahren für und Anforderungen an Pressverbinder und Schraubverbinder für Starkstromkabel für Nennspannungen bis zu 1 kV (Um = 1,2 kV), geprüft an nicht isolierten Leitern (IEC 61238-1-1:2018)

Raccords sertis et à serrage mécanique pour câbles d'énergie - Partie 1-1: Méthodes et exigences d’essai relatives aux raccords sertis et à serrage mécanique pour câbles d’énergie de tensions assignées inférieures ou égales à 1 kV (Um = 1,2 kV) soumis à essai sur des conducteurs non isolés (IEC 61238-1-1:2018)

L'IEC 61238-1-1:2018 est applicable aux raccords sertis et à serrage mécanique pour câbles d'énergie de tensions assignées inférieures ou égales à 1 kV (U_m = 1,2 kV), par exemple pour les câbles enterrés ou ceux installés à l'intérieur des bâtiments, ayant
a) des âmes conformes à l'IEC 60228, de section nominale comprise entre 2,5 mm² et 1 200 mm² pour le cuivre et entre 16 mm² et 1 200 mm² pour l'aluminium;
b) une température maximale de fonctionnement en service permanent au plus égale à 90 °C.
Le présent document n'est pas applicable aux raccords pour conducteurs de ligne aérienne ni aux raccords équipés d'un contact glissant.
L'objet du présent document est de définir les méthodes d'essais de type et les exigences qui s'appliquent aux raccords sertis et à serrage mécanique utilisables sur les câbles d'énergie à conducteurs en cuivre ou en aluminium. La méthode de référence consiste à réaliser les essais sur des conducteurs neufs.
Cette première édition, conjointement avec l'IEC 61238-1-2 et l'IEC 61238-1-3, annule et remplace l'IEC 61238-1:2003.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'IEC 61238-1:2003:
a) Le domaine d'application a été élargi afin de couvrir les raccords de connexion pour âmes en cuivre jusqu'à 2,5 mm² (précédemment 10 mm²) et il a été limité à 1 200 mm² pour les raccords utilisables sur les âmes en cuivre et en aluminium car les expériences et applications d'essai sont rares pour les âmes de fortes sections.
b) Deux nouvelles classes mécaniques ont été introduites pour répondre à la demande concernant les raccords non soumis aux forces mécaniques ainsi que les raccords soumis à des forces mécaniques supérieures à celles spécifiées en Classe 1 pour les âmes de fortes sections.
c) Pour l'essai électrique, un courant de chauffage maximal élevé a été défini afin d'éviter l'apparition de densités de courant irréalistes pendant l'essai, qui peuvent modifier les propriétés des raccords en essai.
d) Pour l'essai de court-circuit, la méthode de calcul et les exigences ont été mises à jour.
e) Pour l'essai mécanique, les méthodes et exigences ont été mises à jour.

Stisljivi in vijačni konektorji za električne kable - 1-1. del: Preskusne metode in zahteve za stisljive in vijačne konektorje za električne kable za naznačene napetosti do 1 kV (Um = 1,2 kV), preskušene na neizoliranih vodnikih (IEC 61238-1-1:2018)

Ta del standarda EN 61238 se uporablja za stisljive in vijačne konektorje za električne kable za naznačene napetosti do 1 kV (Um = 1,2 kV), na primer za v zemljo položene kable ali kable, vgrajene v stavbah, ki imajo:
a) vodnike, ki so skladni s standardom EN 60228 ter imajo nominalni premer med 2,5 mm2 in 1200 mm2, če so bakreni, ter med 16 mm2 in 1200 mm2, če so aluminijasti;
b) največjo enakomerno temperaturo vodnika, ki ne presega 90 °C.
Ta dokument se ne uporablja za konektorje vodnikov nadzemnih vodov ali za konektorje z drsnimi kontakti.
Namen tega dokumenta je opredeliti metode in zahteve tipskih preskusov, ki se uporabljajo za stisljive in vijačne konektorje za električne kable z bakrenimi ali aluminijastimi vodniki. Referenčna metoda je namenjena za izvajanje preskusov na neuporabljenih vodnikih.

General Information

• Status: Published
• Public Enquiry End Date: 31-Jan-2019
• Publication Date: 03-Oct-2019
• ICS: 29.060.20 - Cables
• ICS: 29.120.20 - Connecting devices
• Technical Committee: IEKA - Electric cables
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Oct-2019
• Due Date: 06-Dec-2019
• Completion Date: 04-Oct-2019
• Ref Project: EN IEC 61238-1-1:2019 - Compression and mechanical connectors for power cables - Part 1-1: Test methods and requirements for compression and mechanical connectors for power cables for rated voltages up to 1 kV (Um = 1,2 kV) tested on non-insulated conductors

Relations

• Replaces: SIST EN 61238-1:2004 - Compression and mechanical connectors for power cables for rated voltages up to 36 kV (Um = 42 kV) - Part 1: Test methods and requirements
• Effective Date: 05-Mar-2019

Overview

EN IEC 61238-1-1:2019 specifies type test methods and requirements for compression and mechanical connectors for power cables for rated voltages up to 1 kV (Um = 1,2 kV) tested on non‑insulated conductors. It covers connectors used on buried cables and cables installed in buildings with copper conductors (EN 60228) from 2.5 mm² to 1200 mm² and aluminium conductors from 16 mm² to 1200 mm², and conductors with a maximum continuous temperature ≤ 90 °C. The standard excludes overhead line connectors and connectors with sliding contacts. The reference test method is to perform tests on unused (new) conductors.

Key topics and technical requirements

• Scope and definitions: types of connectors, conductor sizes and materials, classes of connector performance.
• Electrical tests: procedures for measuring electrical resistance, temperature rise and stability, and heat‑cycling behaviour on test loops assembled with the connector under test.
• Heat‑cycling test: defined sequences to simulate thermal stress during service and to assess long‑term stability of connector resistance and contact.
• Short‑circuit test (Class A): method and assessment for connector performance under fault currents (annexes provide calculation and adiabatic current methods).
• Mechanical test: tensile/axial load tests to verify the mechanical integrity and retention of the connector.
• Measurements and instrumentation: potential measurement points, temperature measurement guidance, and methods to reduce measurement uncertainties (informative annexes).
• Assessment and reporting: criteria for pass/fail, calculation of resistance factors, statistical treatment and required content of test reports.
• Normative annexes: equalizer preparation, measurement procedures, calculation methods for short‑circuit and resistance assessment.

Practical applications

• Qualifying compression and mechanical connectors for use in low‑voltage power distribution (buildings, buried infrastructure).
• Ensuring reliable jointing and termination performance under thermal cycling and fault conditions.
• Supporting product type testing for manufacturers, independent test laboratories and certification bodies.
• Providing technical acceptance criteria for utilities, contractors and specifiers during procurement and installation of power cable accessories.

Who should use this standard

• Connector and cable accessory manufacturers (design and type‑testing).
• Test laboratories performing electrical and mechanical qualification.
• Utilities, electrical contractors and consultants writing specifications or verifying compliance.
• Certification bodies and conformity assessment organizations.

Related standards

• EN 60228 (conductors of insulated cables) - referenced for conductor classes.
• Other parts of IEC/EN 61238 series (e.g., Part 1-2 / 1-3) and IEC 62475 (as referenced in bibliography) for related connector test methods and harmonized requirements.

Keywords: EN IEC 61238-1-1:2019, compression connectors, mechanical connectors, power cables, test methods, 1 kV, non‑insulated conductors, heat cycling, short‑circuit test.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2019
Nadomešča:
SIST EN 61238-1:2004
Stisljivi in vijačni konektorji za električne kable - 1-1. del: Preskusne metode in
zahteve za stisljive in vijačne konektorje za električne kable za naznačene
napetosti do 1 kV (Um = 1,2 kV), preskušene na neizoliranih vodnikih (IEC 61238-1-
1:2018)
Compression and mechanical connectors for power cables - Part 1-1: Test methods and
requirements for compression and mechanical connectors for power cables for rated
voltages up to 1 kV (Um = 1,2 kV) tested on non-insulated conductors (IEC 61238-1-
1:2018)
Pressverbinder und Schraubverbinder für Starkstromkabel – Teil 1-1: Prüfverfahren für
und Anforderungen an Pressverbinder und Schraubverbinder für Starkstromkabel für
Nennspannungen bis zu 1 kV (Um = 1,2 kV), geprüft an nicht isolierten Leitern (IEC
61238-1-1:2018)
Raccords sertis et à serrage mécanique pour câbles d'énergie - Partie 1-1: Méthodes et
exigences d’essai relatives aux raccords sertis et à serrage mécanique pour câbles
d’énergie de tensions assignées inférieures ou égales à 1 kV (Um = 1,2 kV) soumis à
essai sur des conducteurs non isolés (IEC 61238-1-1:2018)
Ta slovenski standard je istoveten z: EN IEC 61238-1-1:2019
ICS:
29.060.20 Kabli Cables
29.120.20 Spojni elementi Connecting devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61238-1-1

NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2019
ICS 29.060.20 Supersedes EN 61238-1:2003 (partially) and all of its
amendments and corrigenda (if any)
English Version
Compression and mechanical connectors for power cables -
Part 1-1: Test methods and requirements for compression and
mechanical connectors for power cables for rated voltages up to
1 kV (U = 1,2 kV) tested on non-insulated conductors
m
(IEC 61238-1-1:2018)
Raccords sertis et à serrage mécanique pour câbles Pressverbinder und Schraubverbinder für Starkstromkabel -
d'énergie - Partie 1-1: Méthodes et exigences d'essai Teil 1-1: Prüfverfahren für und Anforderungen an
relatives aux raccords sertis et à serrage mécanique pour Pressverbinder und Schraubverbinder für Starkstromkabel
câbles d'énergie de tensions assignées inférieures ou für Nennspannungen bis zu 1 kV ( U = 1,2 kV), geprüft an
m
égales à 1 kV (U = 1,2 kV) soumis à essai sur des nicht isolierten Leitern
m
conducteurs non isolés (IEC 61238-1-1:2018)
(IEC 61238-1-1:2018)
This European Standard was approved by CENELEC on 2019-07-19. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, 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,
Turkey 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
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61238-1-1:2019 E

European foreword
This document (EN IEC 61238-1-1:2019) consists of the text of IEC 61238-1-1:2018 prepared by
IEC/TC 20 "Electric cables".
The following dates are fixed:
latest date by which this document has to be
• (dop) 2020-07-19
implemented at national level by publication of an
identical national standard or by endorsement
• latest date by which the national standards (dow) 2022-07-19
conflicting with this document have to be
withdrawn
This document partially supersedes EN 61238-1:2003 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.
Endorsement notice
The text of the International Standard IEC 61238-1-1:2018 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 61238-1 NOTE  Harmonized as EN 61238-1.
IEC 61238-1-2 NOTE  Harmonized as EN IEC 61238-1-2.
IEC 61238-1-3 NOTE  Harmonized as EN IEC 61238-1-3.
IEC 62475:2010 NOTE  Harmonized as EN 62475:2010 (not modified).

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-461 -  International Electrotechnical Vocabulary - - -
Part 461: Electric cables
IEC 60228 -  Conductors of insulated cables EN 60228 -
IEC 60493-1 -  Guide for the statistical analysis of ageing - -
test data - Part 1: Methods based on mean
values of normally distributed test results
IEC 60949 1988 Calculation of thermally permissible short- - -
+A1 2008 circuit currents, taking into account non-
adiabatic heating effects
IEC 61238-1-1 ®
Edition 1.0 2018-05
INTERNATIONAL
STANDARD
Compression and mechanical connectors for power cables –

Part 1-1: Test methods and requirements for compression and mechanical

connectors for power cables for rated voltages up to 1 kV (U = 1,2 kV) tested on
m
non-insulated conductors
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.060.20 ISBN 978-2-8322-5645-9

– 2 – IEC 61238-1-1:2018 © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Symbols . 9
5 General . 10
5.1 Definition of classes . 10
5.2 Conductor . 11
5.3 Connectors and installation procedure . 11
5.4 Range of approval. 11
6 Electrical tests . 12
6.1 Installation . 12
6.1.1 General . 12
6.1.2 Through connectors and terminations . 13
6.1.3 Branch connectors . 13
6.2 Measurements . 13
6.2.1 General . 13
6.2.2 Electrical resistance measurements . 14
6.2.3 Temperature measurements . 14
6.3 Heat cycling test . 14
6.3.1 General . 14
6.3.2 First heat cycle . 15
6.3.3 Second heat cycle . 15
6.3.4 Subsequent heat cycles . 17
6.4 Short-circuit test for connectors according to Class A . 17
6.4.1 General . 17
6.4.2 Aluminium conductors with cross-sectional areas below 1 000 mm and
copper conductors with cross-sectional areas below 630 mm . 18
6.4.3 Aluminium conductors with cross-sectional areas ≥ 1 000 mm and
copper conductors with cross-sectional areas ≥ 630 mm . 18
6.5 Assessment of results . 19
6.6 Requirements . 19
6.7 Examples of electrical test loop configurations and associated parameters . 19
7 Mechanical test . 25
7.1 General . 25
7.2 Method . 25
7.3 Requirements . 25
8 Test reports . 26
8.1 General . 26
8.2 Electrical tests . 26
8.3 Mechanical test . 26
Annex A (normative) Equalizers and their preparation . 27
A.1 Requirements for equalizers . 27
A.2 Recommendations for welding equalizers . 27
Annex B (normative) Measurements . 29

IEC 61238-1-1:2018 © IEC 2018 – 3 –
B.1 Potential measuring positions for typical connectors . 29
B.2 Temperature measurement . 29
B.3 Equivalent conductor resistance . 29
Annex C (informative) Recommendations to decrease uncertainties of measurement . 30
C.1 Handling the test loop . 30
C.2 Measurements, instruments and readings . 30
Annex D (normative) Calculation of adiabatic short-circuit current . 31
Annex E (informative) Determination of the value of the short-circuit current . 32
Annex F (normative) Calculation method . 33
F.1 General . 33
F.2 Measurements made . 33
F.3 Connector resistance factor k . 33
F.4 Initial scatter δ . 34
F.5 Mean scatter β . 34
F.6 Change in resistance factor of each connector . 36
F.6.1 General . 36
F.6.2 Line of best fit . 36
F.6.3 Confidence interval δ . 36
i
F.6.4 Change in resistance factor D . 37
F.7 Resistance factor ratio λ. 37
F.8 Maximum temperatures θ . 37
max
Annex G (informative) Explanation on assessment of results of electrical tests on
connectors . 38
G.1 History . 38
G.2 Short examination of the assessment methods of IEC 61238-1 compared

with the Italian standard CEI 20-28 and the British standard BS 4579-3 . 38
G.3 The IEC 61238-1 method of assessing test results . 39
Bibliography . 41

Figure 1 – Example of second heat cycle profile . 17
Figure 2 – Typical electrical test loops for through connectors and terminal lugs . 21
Figure 3 – Typical electrical test loop for branch connectors . 22
Figure 4 – Typical cases of resistance measurements . 24
Figure A.1 – Preparation of equalizers . 28
Figure E.1 – Determination of equivalent RMS value of current during the short-circuit test . 32
Figure F.1 – Graphic example of assessment of a Class A individual connector . 35

Table 1 – Minimum period of temperature stability . 15
Table 2 – Electrical resistance measurements during the electrical test . 17
Table 3 – Electrical test requirements . 19
Table 4 – Selection of tensile force withstand values for the mechanical test . 25
Table D.1 – Material properties . 31
Table G.1 – Summary of assessed behaviour of a tested connector . 40

– 4 – IEC 61238-1-1:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
COMPRESSION AND MECHANICAL
CONNECTORS FOR POWER CABLES –
Part 1-1: Test methods and requirements for compression and
mechanical connectors for power cables for rated voltages up to 1 kV
(U = 1,2 kV) tested on non-insulated conductors
m
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61238-1-1 has been prepared by IEC technical committee 20:
Electric cables.
This first edition, together with IEC 61238-1-2 and IEC 61238-1-3, cancels and replaces
IEC 61238-1:2003.
This edition includes the following significant technical changes with respect to
IEC 61238-1:2003:
a) The scope has been widened to cover connectors for copper conductors from 10 mm
2 2
down to 2,5 mm and has been limited to 1 200 mm for connectors for copper and
aluminium conductors because test experience and applications are rare for conductors of
larger cross-sectional areas.
IEC 61238-1-1:2018 © IEC 2018 – 5 –
b) Two new mechanical classes have been introduced to satisfy the demand for connectors
subjected to no mechanical force and for connectors subjected to higher mechanical
forces than those specified in Class 1 for conductors of larger cross-sectional areas.
c) For the electrical test, a maximum elevated heating current has been set in order to avoid
unrealistic current densities during testing which may change properties of tested
connectors.
d) For the short-circuit test, the method of calculation and requirements have been updated.
e) For the mechanical test, the methods and requirements have been updated.
The text of this International Standard is based on the following documents:
FDIS Report on voting
20/1788/FDIS 20/1803/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61238 series, published under the general title Compression and
mechanical connectors for power cables, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – IEC 61238-1-1:2018 © IEC 2018
INTRODUCTION
The IEC 61238 series has been divided into the following parts:
Part 1-1: Test methods and requirements for compression and mechanical connectors for
power cables for rated voltages up to 1 kV (U = 1,2 kV) tested on non-insulated
m
conductors
Part 1-2: Test methods and requirements for insulation piercing connectors for power
cables for rated voltages up to 1 kV (U = 1,2 kV) tested on insulated conductors
m
Part 1-3: Test methods and requirements for compression and mechanical connectors for
power cables for rated voltages above 1 kV (U = 1,2 kV) up to 30 kV
m
(U = 36 kV) tested on non-insulated conductors
m
This Part 1-1 of IEC 61238 deals with type tests for compression and mechanical connectors
for use on copper or aluminium conductors of power cables for rated voltages up to 1 kV
(U = 1,2 kV).
m
When a design of connector meets the requirements of this document, then it is expected that
in service:
a) the resistance of the connection will remain stable within specified limits;
b) the temperature of the connector will be of the same order or less than that of the
conductor during current heating;
c) if the intended use demands it, application of short-circuit currents will not affect a) and b);
d) independently from the electrical performance, conforming axial tensile strength will
ensure an acceptable mechanical performance for the connections to the cable
conductors, when applicable.
It should be stressed that, although the object of the electrical and mechanical tests specified
in this document is to prove the suitability of connectors for most operating conditions, they do
not necessarily apply to situations where a connector may be raised to a high temperature by
virtue of connection to a highly rated plant, to corrosive conditions, or where the connector is
subjected to external mechanical stresses such as excessive vibration, shock and large
displacement after installation. In these instances, the tests in this document may need to be
supplemented by special tests agreed between supplier and purchaser.
This document does not invalidate existing approvals of products achieved on the basis of
national standards and specifications and/or the demonstration of satisfactory service
performance. However, products approved according to such national standards or
specifications cannot directly claim approval to this document.
Once successfully completed, these tests are not repeated unless changes are made in
material, manufacturing process and design which might adversely change the connector
performance characteristics.
IEC 61238-1-1:2018 © IEC 2018 – 7 –
COMPRESSION AND MECHANICAL
CONNECTORS FOR POWER CABLES –
Part 1-1: Test methods and requirements for compression and
mechanical connectors for power cables for rated voltages up to 1 kV
(U = 1,2 kV) tested on non-insulated conductors
m
1 Scope
This part of IEC 61238 applies to compression and mechanical connectors for power cables
for rated voltages up to 1 kV (U = 1,2 kV), for example buried cables or cables installed in
m
buildings, having
a) conductors complying with IEC 60228 having nominal cross-sectional areas between
2 2 2 2
2,5 mm and 1 200 mm for copper and between 16 mm and 1 200 mm for aluminium;
b) a maximum continuous conductor temperature not exceeding 90 °C.
This document is not applicable to connectors for overhead line conductors nor to connectors
with a sliding contact.
The object of this document is to define the type test methods and requirements which apply
to compression and mechanical connectors for power cables with copper or aluminium
conductors. The reference method is to perform the tests on unused conductors.
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.
IEC 60050-461, International Electrotechnical Vocabulary – Part 461: Electric cables
(available at http://www.electropedia.org)
IEC 60228, Conductors of insulated cables
IEC 60493-1, Guide for the statistical analysis of ageing test data – Part 1: Methods based on
mean values of normally distributed test results
IEC 60949:1988, Calculation of thermally permissible short-circuit currents, taking into
account non-adiabatic heating effects
IEC 60949:1988/AMD1:2008
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-461 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
– 8 – IEC 61238-1-1:2018 © IEC 2018
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
connector
device for connecting a conductor to an equipment terminal or for connecting two
or more conductors to each other
[SOURCE: IEC 60050-461:2008, 461-17-03, modified – the definition has been revised.]
3.2
through connector
device for connecting two consecutive lengths of conductor together
[SOURCE: IEC 60050-461:2008, 461-17-04, modified – the term "joint ferrule" has been
deleted and the definition revised.]
3.3
branch connector
device for connecting a branch conductor to a main conductor at an intermediate point on the
latter
[SOURCE: IEC 60050-461:2008, 461-17-05, modified – the term "branch ferrule" has been
deleted and in the definition "metallic" has been deleted.]
3.4
termination
device fitted to the end of a cable conductor to ensure electrical connection with other parts of
the system
[SOURCE: IEC 60050-461:2008, 461-10-01, modified – "conductor" has been added and "and
to maintain the insulation up to the point of connection" has been deleted.]
3.5
terminal lug
device to connect a cable conductor to other electrical equipment
[SOURCE: IEC 60050-461:2008, 461-17-01, modified – "metallic" has been deleted.]
3.6
palm
part of a terminal lug used to make the connection to electrical equipment
[SOURCE: IEC 60050-461:2008, 461-17-07]
3.7
barrel
part of a device into which the conductor to be connected
is introduced
[SOURCE: IEC 60050-461:2008, 461-17-06]
3.8
reference conductor
length of unjointed bare conductor or conductor with the insulation removed, which is included
in the test loop and which enables the reference temperature and reference resistance to be
determined
IEC 61238-1-1:2018 © IEC 2018 – 9 –
3.9
equalizer
arrangement used in the test loop to ensure a point of equipotential and uniform current
distribution in a stranded conductor
3.10
compression jointing
method of securing a connector to a conductor by using a special tool to produce permanent
deformation of the connector and the conductor
3.11
mechanical jointing
method of securing a connector to a conductor, for example by means of a bolt or screw
acting on the latter or by alternative methods
3.12
median connector
connector which during the first heat cycle records the third highest temperature of the six
connectors in the test loop
3.13
conductor
part of a cable which has the specific function of carrying current
[SOURCE: IEC 60050-461:2008, 461-01-01]
3.14
family of connectors
group of connectors of a manufacturer to be considered of the same design criteria, the same
material characteristic and the same installation procedure
4 Symbols
A nominal cross-sectional area of the conductor
D change in the resistance factor of the connector
I direct current flowing through a connection during resistance measurement
I equivalent RMS short-circuit current
RMS
I alternating current necessary to maintain the reference conductor at its
N
equilibrium temperature
I direct current flowing through the reference conductor/conductors during
r
resistance measurement
k
connector resistance factor: ratio of the resistance of a connector to that of the
resistance of the equivalent length of the reference conductor
k initial connector resistance factor: ratio of the resistance of a connector to that of
the resistance of the equivalent length of the reference conductor at cycle no. 0
l , l , l lengths of each connector assembly associated with the measurement positions
a b j
in the test setup after installation
l
length of the reference conductor between measurement positions
r
R measured resistance value of connector/conductor installation under an electrical test
corrected to 20 °C
R measured resistance value of the reference conductor corrected to 20 °C
r
R length related calculated resistance value of a connector under an electrical test
j
corrected to 20 °C
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t heating time
t time necessary for the connectors and the reference conductor to cool to a value
equal to or less than 35 °C
U potential difference between measurement positions while current I is applied
U potential difference between measurement positions on a reference conductor
r
while current I is applied
r
temperature coefficient of resistance at 20 °C
α
mean scatter of the connector resistance factors
β
initial scatter of the connector resistance factors
δ
λ resistance factor ratio: the actual resistance factor of the connector at each
measurement stage divided by its initial resistance factor
θ temperature of a connector
maximum temperature recorded on a connector over the total period of test
θ
max
during heat cycling
temperature of the reference conductor determined in the first heat cycle
θ
R
temperature of the related reference conductor at the moment of measuring
θ
ref
θ
max
5 General
5.1 Definition of classes
Although it is not possible to define precisely the service conditions for all applications, the
following requirements have been identified.
a) Electrical requirements:
Class A
These are connectors intended for electricity distribution or industrial networks in which
they can be subjected to short-circuits of relatively high intensity and duration. As a
consequence, Class A connectors are suitable for the majority of applications.
Class B
These are connectors for networks in which overloads or short-circuits are rapidly cleared
by the installed protective devices, for example fast-acting fuses.
b) Mechanical requirements:
Class 0
Connectors subjected to practically no mechanical pull-out force. These are for example,
connectors inside switchgear where the cable or conductors are secured or anchored.
Class 1
Connectors subjected to a mechanical pull-out force related to the conductor nominal
cross-sectional area and material (according to Table 4) but limited to a 20 kN pull-out
force. These are for example connectors for underground cable joints.
Class 2
Connectors subjected to a mechanical pull-out force above 20 kN and related to the
conductor nominal cross-sectional area and material (according to Table 4). This Class 2
is only applicable to conductor nominal cross-sectional areas ≥ 400 mm for copper and
≥ 630 mm for aluminium. These are for example connectors in cable installations where
thermomechanical forces are estimated to exceed 20 kN.
Hence, the five classes correspond to the following tests:

IEC 61238-1-1:2018 © IEC 2018 – 11 –
Class A: heat cycling and short-circuit tests;
Class B: heat cycling test only;
Class 0: no mechanical test;
Class 1: mechanical test with limited maximum tensile force;
Class 2: mechanical test with no maximum tensile force.
5.2 Conductor
The following information shall be recorded in the test report:
– conductor material;
– nominal cross-sectional area, dimensions and shape;
– detail of conductor construction shall be given when known, or can be determined by
inspection, for example:
• class according to IEC 60228 (solid, stranded and flexible);
• compacted or non-compacted for stranded conductor;
• number and arrangement of strands;
• type of plating, if applicable;
• type of impregnation, water blocking, etc., if applicable.
5.3 Connectors and installation procedure
The following information shall be recorded in the test report:
– the assembly method or the installation instruction that is to be used;
– tooling, dies and any necessary setting;
– if not part of the delivered product, for example at cable conductor termination: bolts, nuts,
washers, lubricant, torque, etc.;
– preparation of contact surfaces, if applicable, for example cleaning, brushing and/or
greasing of inner and/or outer conductor and/or connector surfaces;
– identification of the connector, for example name of the supplier, drawing, reference
number, type.
5.4 Range of approval
In general, tests made on one type of connector/conductor combination apply to that
arrangement only. However, to limit the number of tests, when using the same conductor
material, the following is permitted:
– a connector which can be used on stranded round conductors or on stranded sector-
shaped conductors which have been rounded, is approved for both types if satisfactory
results are obtained on a compacted round conductor;
– a connector which covers a range of consecutive cross-sectional areas shall be approved,
if satisfactory results are obtained on the smallest and the largest cross-sectional areas;
– if a connector is a through connector for two conductors of different cross-sectional areas,
shapes, or materials, and if the jointing method and the connector barrels used have
already been tested separately for each cross-sectional area, no additional test is
necessary. If not, and if it is required for bimetallic through connectors, additional tests
shall be made using the conductor having the highest temperature of the two conductors,
as reference conductor;
– if a type test for a range taking mechanical connector is passed on the biggest possible
conductor cross-sectional area, this result is also valid for similar connector designs with
the same material of the connector body but bigger outer diameter provided that the
design of the conductor clamping channel (inner diameter, shape, etc.), quantity and

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design of clamping screws (torque, material, size, shear-off characteristic, etc.) are
identical;
– if a manufacturer can clearly demonstrate that common and relevant connector design
criteria were used for a family of connectors, conformity to this document is achieved by
successfully testing the largest, the smallest and two intermediate connector sizes;
exception no.1: for a family of connectors consisting of five sizes, only the largest
connector, the smallest connector, and one connector of a representative intermediate
size need to be tested;
exception no.2: for a family of connectors consisting of four sizes or less, only the
largest connector and the smallest connector need to be tested;
– if conformity to this document is achieved by successfully testing a connector on a dry
conductor then approval is achieved for the same conductor used in an impregnated paper
insulated cable;
– for connectors where one or both sides are designed for a range of cross-sectional areas,
and a common clamping or crimping arrangement serves for the connection of the
different cross-sectional areas, then mechanical tests on conductors with the largest and
smallest cross-sectional areas shall be carried out according to Clause 7 for connectors
according to Class 1 or Class 2;
– if conformity to this document is achieved by successfully testing a mechanical connector
on round stranded aluminium conductors, this type test approval can be applied to solid
aluminium conductors of the same cross-sectional area(s);
– if conformity to this document is achieved by successful testing of a through connector,
this type test approval can apply to the barrel of a termination which uses the same design
criteria. Approval of the complete termination can be achieved if the termination
connection does not influence the barrel performance, proven through design parameters,
drawings or through thermal verification tests;
– if conformity to this document is achieved by successfully testing a connector on a
conductor with water blocking, approval is achieved for the same conductor without any
water blocking but not for the same conductor with different types of water blocking;
– if conformity to IEC 61238-1-3 is achieved by successfully testing a connector, approval is
achieved for the same classes and conductors in this document.
6 Electrical tests
6.1 Installation
6.1.1 General
All conductors of the same nominal cross-sectional area in the test loop shall be taken from
the same conductor length.
For each series of tests, six connectors shall be installed in accordance with the
manufacturer’s instructions, on a bare conductor or on a conductor that has had the insulation
removed before assembly, to form a test loop together with the corresponding reference
conductor.
For stranded conductors, potential differences between the strands at potential measuring
positions can cause errors in measuring electrical resistance. Equalizers according to
Annex A shall be used to overcome this problem and to ensure uniform current distribution in
the reference conductor and between connectors at the equalizer positions. The
recommended method is to prepare equalizers on the test loop before installing connectors.
The test loop shall be installed in a location where the air is calm.
The ambient temperature of the test location shall be between 15 °C and 30 °C.

IEC 61238-1-1:2018 © IEC 2018 – 13 –
For conductor cross-sectional areas above 1 000 mm , it is allowed to increase the ambient
temperature range of the test location between 15 °C and 40 °C. At the end of the cooling
phase the ambient temperature shall be between 15 °C and 30 °C.
In the case of solid conductors, the potential measuring positions shall be as close as
possible to the connector in order to reduce l and l close to zero.
a b
The test loop may be of any shape according to Figure 2 or Figure 3 provided that it is
arranged in such a way that there is no adverse effect from the floor, walls and ceiling, other
test loops and adjacent test branches.
To facilitate the short-circuit test for connectors according to Class A, the loop may be
disassembled as shown in Figure 2 b). In this case, the sectioning connections shall not
influence the temperatures of the test objects during heating.
Retightening of bolts or screws of the connectors under test is not permitted.
6.1.2 Through connectors and terminations
The test loop shown in Figure 2 indicates the dimensions that shall be used.
Where terminal lugs or mechanical connectors for terminal bars are to be tested, they shall be
bolted to linking bars in accordance with the manufacturer's instructions or other relevant
standards/specifications defining methods and instructions for fastening terminations. These
linking bars shall, at the point of connection, be of the same dimensions and thickness as the
palm, and also of the same material.
It may be necessary to adjust the thermal characteristics of the linking bar outside the point of
connection, to achieve the temperatures specified in 6.3.
For terminal lugs, the use of linking bars is the recommended test method although it is
alternatively possible to test terminal lugs with palms connected directly to palms.
If it is requested that the terminal lug test includes an evaluation of the performance of the
bolted palm when connected to a specified plant terminal, then the linking bar method shall be
used and the linking bar ends, or an intermediate piece, shall be defined and described in
material, size and sur
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