SIST EN 50483-3:2026

Test requirements for low voltage aerial bundled cable accessories - Part 3: Tension and suspension clamps for neutral messenger system

The EN 50483 series applies to overhead line fittings for tensioning, supporting and connecting aerial bundled cables (ABC) of rated voltage U0/U (Um): 0,6/1 (1,2) kV.
This document applies to tensioning devices consisting of tension and suspension clamps, and tension and suspension assemblies used for the installation of ABC with either insulated or bare neutral messenger.
The tension and suspension clamps are designed to be installed on neutral conductors of ABC defined in HD 626 S2.
Tests described in this document are type tests.

Prüfanforderungen für Bauteile für isolierte Niederspannungsfreileitungen - Teil 3: Abspann- und Tragklemmen für Systeme mit Nullleiter-Tragseil

Prescriptions relatives aux essais des accessoires pour réseaux aériens basse tension torsadés - Partie 3: Matériels d'ancrage et de suspension pour réseaux aériens en conducteurs isolés torsadés avec neutre porteur

Zahteve za preskušanje pribora za nizkonapetostne izolirane nadzemne kable - 3. del: Napenjalne in vzmetne objemke za sisteme z nosilnim nevtralnim vodnikom

Serija EN 50483 se nanaša na opremo za nadzemne vode za napenjanje, podporo in povezovanje samonosilnih izoliranih vodnikov (ABC) z nazivno napetostjo U0/U (Um): 0,6/1 (1,2) kV.
Ta dokument se nanaša na napenjalne naprave, ki jih sestavljajo napenjalne in obešne sponke ter napenjalni in obešni sklopi, ki se uporabljajo za namestitev ABC z izoliranim ali golim nevtralnim nosilcem.
Napenjalne in obešne sponke so zasnovane za namestitev na nevtralne vodnike ABC, opredeljene v HD 626 S2.
Preskusi, opisani v tem dokumentu, so tipski preskusi.

General Information

• Status: Published
• Public Enquiry End Date: 31-Dec-2024
• Publication Date: 16-Apr-2026
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: IEKA - Electric cables
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 09-Apr-2026
• Due Date: 14-Jun-2026
• Completion Date: 17-Apr-2026
• Ref Project: EN 50483-3:2026 - Test requirements for low voltage aerial bundled cable accessories - Part 3: Tension and suspension clamps, fittings and brackets for neutral messenger system

Relations

• Replaces: SIST EN 50483-3:2009 - Test requirements for low voltage aerial bundled cable accessories -- Part 3: Tension and suspension clamps for neutral messenger system
• Effective Date: 01-Jun-2026

Overview

The kSIST FprEN 50483-3:2025 standard, developed by the European Committee for Electrotechnical Standardization (CLC), defines the test requirements for low voltage aerial bundled cable (ABC) accessories, specifically focusing on tension and suspension clamps, fittings, and brackets for neutral messenger systems. This standard is part three in the EN 50483 series, which addresses overhead line fittings used for tensioning, supporting, and connecting ABCs with rated voltages of 0.6/1 (1.2) kV.

This document is critical for manufacturers, testing bodies, and utility companies involved in electrical power distribution, helping ensure mechanical reliability and safety of components used in ABC installations that incorporate insulated or bare neutral messenger systems.

Key Topics

• Scope & Applicability: Targets tensioning devices designed for the neutral messenger of aerial bundled cables, including tension and suspension clamps and assemblies compliant with HD 626 standards.
• Type Tests: Specifies mechanical and environmental testing protocols to verify the suitability of clamps and brackets, including tensile tests at ambient, high, and low temperatures.
• Mechanical Requirements:
  • Clamps must survive tensile loads without slippage exceeding 10 mm or damaging the cable.
  • Tests simulate real-world loading conditions, ensuring clamps can hold the neutral messenger securely.
• Marking & Identification: Accessories must feature consistent marking per prEN 50483-1:2024 to ensure traceability and conformity.
• Test Conditions: Details on setup, including load application procedures, test device configurations, and temperature considerations to mimic operational environments.

Applications

• Overhead Power Distribution: Ensures critical components like tension and suspension clamps reliably support low voltage aerial bundled cables used in urban and rural settings.
• Neutral Messenger Systems: Specifically tailored to systems where the neutral conductor supports the ABC structure.
• Installation & Maintenance: Provides standard testing methods used by manufacturers and utility providers to certify components before installation, minimizing failures in service.
• Component Design Validation: Manufacturers can utilize this standard to validate new clamp designs to meet EU regulatory requirements, ensuring market acceptance.

Related Standards

• EN 50483 Series:
  • Part 1: General Requirements for Low Voltage ABC Accessories
  • Part 2: Accessories for Self-Supporting Systems
  • Part 4: Connectors
  • Part 5: Electrical Ageing Tests
  • Part 6: Environmental Testing
• HD 626 S1:1996: Covers overhead distribution cables, providing cable specifications relevant to ABC systems.
• IEC 60050-461: Electrotechnical vocabulary relevant for terminology related to cables and accessories.

Practical Value

Compliance with kSIST FprEN 50483-3:2025 ensures that aerial bundled cable accessories, particularly those involving tension and suspension clamps for neutral messenger systems, meet rigorous mechanical and durability tests. This reduces the risk of service interruptions, enhances safety for both installers and end-users, and supports the adoption of standardized components across Europe. By harmonizing testing and performance requirements, the standard fosters interoperability, quality assurance, and long-term reliability in overhead low voltage power distribution networks.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2026
Nadomešča:
SIST EN 50483-3:2009
Zahteve za preskušanje pribora za nizkonapetostne izolirane nadzemne kable - 3.
del: Napenjalne in vzmetne objemke za sisteme z nosilnim nevtralnim vodnikom
Test requirements for low voltage aerial bundled cable accessories - Part 3: Tension and
suspension clamps for neutral messenger system
Prüfanforderungen für Bauteile für isolierte Niederspannungsfreileitungen - Teil 3:
Abspann- und Tragklemmen für Systeme mit Nullleiter-Tragseil
Prescriptions relatives aux essais des accessoires pour réseaux aériens basse tension
torsadés - Partie 3: Matériels d'ancrage et de suspension pour réseaux aériens en
conducteurs isolés torsadés avec neutre porteur
Ta slovenski standard je istoveten z: EN 50483-3:2026
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 50483-3
NORME EUROPÉENNE
EUROPÄISCHE NORM April 2026
ICS 29.240.20 Supersedes EN 50483-3:2009
English Version
Test requirements for low voltage aerial bundled cable
accessories - Part 3: Tension and suspension clamps, fittings
and brackets for neutral messenger system
Prescriptions relatives aux essais des accessoires pour Prüfanforderungen für Bauteile für isolierte
réseaux aériens basse tension torsadés - Partie 3: Niederspannungsfreileitungen - Teil 3: Abspann- und
Matériels d'ancrage et de suspension pour réseaux aériens Tragklemmen für Systeme mit Nullleiter-Tragseil
en conducteurs isolés torsadés avec neutre porteur
This European Standard was approved by CENELEC on 2026-03-09. 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,
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
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50483-3:2026 E
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols . 8
5 Characteristics . 8
6 Marking . 9
7 General test conditions . 9
7.1 Mechanical tests . 9
7.2 Temperature . 9
8 Type tests . 9
8.1 General . 9
8.2 Type tests for tension clamps . 9
8.2.1 General . 9
8.2.2 Tensile test at ambient temperature (and breaking load test) . 9
8.2.3 Tensile test at high temperature . 11
8.2.4 Tensile test at low temperature . 13
8.2.5 Environmental tests . 14
8.2.6 Dielectrical voltage test . 17
8.3 Type tests for suspension clamps . 20
8.3.1 General . 20
8.3.2 Clamp bolt tightening test . 21
8.3.3 Mechanical test . 22
8.3.4 Environmental tests . 25
8.3.5 Dielectrical voltage test (only for insulated messenger clamps) . 28
8.3.6 Swing test (optional) . 31
8.3.7 Slip test at high temperature (optional) . 33
8.4 Type tests for brackets . 36
Bibliography . 37
Figures
Figure 1 — Test arrangement . 10
Figure 2 — Cycle and temperature profile . 12
Figure 3 — Arrangement of the fitting for mechanical test at low temperature . 13
Figure 4 — Voltage test arrangement on tension clamp only . 18
Figure 5 — Dielectrical voltage test arrangement on tension clamp and conductor in air . 19
Figure 6 — Dielectrical voltage test arrangement on tension clamp in water . 20
Figure 7 — Mechanical test arrangement . 22
Figure 8 — Mechanical test arrangement . 23
Figure 9 — Slip test on the suspension clamps . 24
Figure 10 — Slip test on the suspension clamps . 25
Figure 11 — Corrosion test . 26
Figure 12 — Dielectrical voltage test arrangement in air . 29
Figure 13 — Dielectrical voltage test arrangement for metallic body . 29
Figure 14 — Dielectrical voltage test arrangement in water . 31
Figure 15 — Swing test arrangement . 32
Figure 16 — Swing test temperature measurement . 33
Figure 17 — Test arrangement for slip test at high temperature . 34
Figure 18 — Cycle and temperature profile . 36
Tables
Table 1 — Tensile loads . 23
European foreword
This document (EN 50483-3:2026) has been prepared by CLC/TC 20 “Electric cables”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2027-04-30
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2029-04-30
conflicting with this document have to be
withdrawn
This document supersedes EN 50483-3:2009 and all of its amendments and corrigenda (if any).
— Scope was extended to brackets.
This is Part 3 of the EN 50483 series “Test requirements for low voltage aerial bundled cable accessories”,
which has six parts:
— Part 1: Generalities;
— Part 2: Tension and suspension clamps, fittings and brackets for self-supporting system;
— Part 3: Tension and suspension clamps, fittings and brackets for neutral messenger system;
— Part 4: Connectors;
— Part 5: Electrical ageing test;
— Part 6: Environmental testing.
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.
Introduction
The objective of the EN 50483 series is to provide a method of testing the suitability of accessories when used
under normal operating conditions with low voltage aerial bundled cables (ABC) complying with HD 626 S2.
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. It may
be possible, subject to agreement between the customer and the manufacturer and/or the supplier, and/or the
relevant conformity assessment body, to demonstrate that conformity to the earlier standard can be used to
claim conformity to this document, provided an assessment is made of any additional type testing that might
need to be carried out. Any such additional testing that is part of a sequence of testing cannot be done
separately.
1 Scope
The EN 50483 series applies to overhead line fittings for tensioning, supporting and connecting aerial bundled
cables (ABC) of rated voltage U /U (U ): 0,6/1 (1,2) kV.
0 m
This document applies to tensioning devices consisting of tension and suspension clamps, and tension and
suspension assemblies used for the installation of ABC with either insulated or bare neutral messenger.
The tension and suspension clamps are designed to be installed on neutral conductors of ABC defined in
HD 626 S2.
Tests described in this document are type tests.
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 50483-1:2026, Test requirements for low voltage aerial bundled cable accessories — Part 1: Generalities
EN 50483-2:2026, Test requirements for low voltage aerial bundled cable accessories — Part 2: Tension and
suspension clamps, fittings and brackets for self-supporting system
EN 50483-6:2026, Test requirements for low voltage aerial bundled cable accessories — Part 6:
Environmental testing
HD 626 S2:2025, Overhead distribution cables of rated voltage U /U(Um): 0,6/1 (1,2) kV
IEC 60050-461, International Electrotechnical Vocabulary (IEV) – Part 461: Electric cables
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 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 https://www.electropedia.org/
3.1
aerial bundled cable
ABC
aerial cable consisting of a group of insulated conductors which are twisted together including, or not, a non-
insulated conductor
[SOURCE: IEV 461-08-02, modified]
Note 1 to entry: The terms bundled conductors, bundled cables, bundled cores, conductor bundles and bundle could be
used as equivalent to the term aerial bundled cable (ABC).
3.2
aerial insulated cable
insulated cable designed to be suspended overhead and outdoors
[SOURCE: IEV 461-08-01]
3.3
angle of deviation
complementary angle to the angle defined by the two parts of the cable on both sides of the suspension clamp
3.4
clamp bolt
bolt which tightens two parts of a clamp together
3.5
conductor insulation
insulation applied on a conductor
[SOURCE: IEV 461-02-02, modified]
3.6
conductor
part of a cable which has the specific function of carrying current
[SOURCE: IEV 461-01-01]
3.7
core
assembly comprising conductor and its own insulation
[SOURCE: IEV 461-04-04, modified]
3.8
bracket
fitting
device for attaching ABC tension or/and suspension clamps to a pole or to a wall
3.9
insulation
insulating materials incorporated in a cable with the specific function of withstanding voltage
[SOURCE: IEV 461-02-01]
3.10
messenger
wire or rope, the primary function of which is to support the cable in aerial installations, which may be separate
from or integral with the cable it supports
[SOURCE: IEV 461-08-03]
3.11
minimum breaking load
MBL
minimum breaking load of the conductor given by HD 626 S2 or the cable manufacturer if not defined in the
standard or minimum breaking load of the clamp given by the clamp manufacturer
3.12
mobile link
device linking the suspension clamp to the bracket
3.13
neutral messenger system
aerial insulated system where only the neutral messenger supports the ABC
3.14
sheath
uniform and continuous tubular covering of metallic or non-metallic material, generally extruded
[SOURCE: IEV 461-05-03]
3.15
suspension clamp
device which attaches an aerial insulated cable to a bracket in order to carry its weight and any specified
loading
[SOURCE: IEV 461-18-02, modified]
3.16
suspension or tension assembly
clamp with mobile link, or not, and associated bracket
3.17
tension clamp
device which firmly attaches an aerial insulated cable to a bracket and is designed to transmit the specified
mechanical tension in the cable or messenger to the supporting structure
[SOURCE: IEV 461-18-01, modified]
3.18
type test
test required to be made before supplying a type of material 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 to the accessory materials, design or type of manufacturing process which might change the
performance characteristics.
4 Symbols
g slippage after 2 cycles
g slippage after 15 cycles
g slippage after 250 cycles
g slippage after 500 cycles
d diameter of core
α maximum angle (°) of deviation of a suspension clamp as recommended by the manufacturer or
specified by the customer
5 Characteristics
These fittings shall be capable of supporting the tensile loads applied to the ABC for which they are designed,
referring to the neutral messenger specified MBL, in accordance with the following tests.
Tension and suspension equipment shall be designed to avoid any direct or accidental contact between any
phase conductor and metallic parts of the clamp.
6 Marking
See Clause 6 of EN 50483-1:2026.
7 General test conditions
7.1 Mechanical tests
See Clause 9 of EN 50483-1:2026.
Where an assembly is to be tested, each bracket should be secured in accordance with the manufacturer’s
installation instructions.
7.2 Temperature
See Clause 9 of EN 50483-1:2026.
8 Type tests
8.1 General
Each clamp shall be tested for the smallest and largest messenger size except for environmental tests where
only the largest size is used.
8.2 Type tests for tension clamps
8.2.1 General
The following type tests shall be carried out.
Test Applicability Subclause
Tensile test at ambient temperature insulated and bare neutral messenger 8.2.2
Tensile test at high temperature insulated neutral messenger only 8.2.3
Tensile test at low temperature insulated neutral messenger only 8.2.4
Environmental tests insulated and bare neutral messenger 8.2.5
Clamp bolt tightening test common for both suspension and tension clamps 8.3.1
If a cable breaks beyond any part of the tension clamp, the test result shall be declared void without
discrediting the tension clamp. Tests shall be repeated using a new tension clamp and a new cable.
In order to find the possible cause of the failure, the test shall be repeated with a reference tension clamp as
specified in HD 626 S2:2025, Part 2, 2.3.1.
When agreed between the manufacturer and the customer, the mechanical test loads may be defined by the
smallest cable for the clamp but in this case the clamp may only be considered to conform to this document
for the smaller cable size.
8.2.2 Tensile test at ambient temperature (and breaking load test)
8.2.2.1 Principle
The tension clamps shall be subjected to high mechanical loads at ambient temperature in order to ensure
that they are capable of sustaining loads likely to be encountered in service without being damaged or
damaging the conductor.
The test shall be carried out for the maximum and minimum insulated neutral messenger cross-sections, for
which the clamp is designed.
8.2.2.2 Test arrangement
Figure 1 shows a typical test arrangement. The test configuration can differ from this arrangement as long as
it complies with the neutral messenger lengths.
Dimensions in metres
Key
1 neutral messenger tension clamp

2 mechanical load measurement device mechanical junction allowing rotation

3 tensioning device current source connection

4 minimum 1 m mechanical tension adjustment

Figure 1 — Test arrangement
8.2.2.3 Procedure
For the maximum and minimum neutral messenger cross-sections, for which the clamp is designed, a tension
clamp shall be installed at a minimum of 1 m from the end of the cable sample. The tension clamp shall be
secured to a device similar to the one used for its attachment to the support. At the other end, which is not
stripped for insulated messenger, an appropriate tension device shall be attached to the neutral messenger by
means of a tension clamp or other appropriate device.
A different distance between the clamps (from 2 m to 10 m), may be agreed between the manufacturer and
the customer.
A load shall be applied and increased until it reaches 80 % of MBL of the messenger. The load shall then be
reduced to 20 % of MBL of the messenger.
The neutral messenger shall then be marked where it leaves the clamp so that any slippage can be seen with
respect to the clamp.
The load shall then be increased to 90 % of MBL of the messenger for both insulated and bare neutral
messenger. This load shall be maintained for 60 s.
The speed of load application is defined in EN 50483-1:2026, 9.1.5.
8.2.2.4 Requirements
The clamp shall not slip by more than 10 mm with respect to the mark on the neutral messenger.
No damage shall occur which could affect the correct function of the tension clamp.
When agreed between the customer and the manufacturer, an additional test may be carried out as follows.
The previous test arrangement should be used again with a new tension clamp and the messenger should be
replaced with a steel wire of cross section equivalent to the neutral messenger. The assembly should be
subjected to an increasing load until the clamp breaks or the load reaches 110 % of the MBL of the
messenger. When a breaking occurs, the load at which the breaking occurs should be recorded. For practical
reason, to avoid any slippage between steel wire and clamp, fixed stops may be used.
8.2.3 Tensile test at high temperature
8.2.3.1 Principle
The purpose of this test is to ensure that the tension clamp does not slip excessively on the insulated neutral
messenger during service and that any movement does not damage the insulation. It combines heat cycles
with mechanical load.
8.2.3.2 Test arrangement
Figure 1 shows a typical test arrangement. The test configuration may differ from this arrangement as long as
it complies with the neutral messenger lengths.
The test shall be carried out for the maximum and minimum insulated neutral messenger cross-sections, for
which the clamp is designed.
8.2.3.3 Procedure
Tension clamps and the neutral messenger shall be subjected to this test, which comprises of 500 cycles, of
90 min each in which a heat cycle is combined with mechanical loads.
A tension clamp shall be fitted at least 1 m from both ends of the section of neutral messenger. The distance
between the clamps shall be at least 2 m.
A different distance between the clamps (from 2 m to 10 m) may be agreed between the manufacturer and the
customer.
Before starting the first cycle the neutral messenger shall be subjected to 10 % of its MBL and the sheath shall
be marked so that any slippage can be measured with respect to the clamp.
An alternating current shall be passed through the neutral messenger until its temperature rises to (60 ± 3) °C.
The temperature rise shall be achieved within 15 min and then maintained at this temperature for the next
30 min or until the total time is 45 min if the temperature is achieved more quickly.
The temperature of the neutral messenger shall be measured underneath the insulation with a thermocouple.
NOTE For further information on thermocouple application, see EN 50483-5:2026, 5.4.1.
The temperature can be measured at a position that is not under mechanical tension. The measuring position
shall be at least 1 m from the clamp and the end of the neutral messenger. It shall also be at the same
horizontal level as the clamp in order to avoid any difference in air temperature.
The neutral messenger shall be allowed to cool to (25 ± 3) °C during the next 30 min. This temperature shall
be maintained for the next 15 min until the end of the cycle.
A mechanical load of 25 % of the MBL of the neutral messenger shall be applied, and maintained, for the first
75 min of the cycle. During the last 15 min once the neutral messenger has cooled to 25 °C, the load shall be
increased to 45 % of the MBL of the neutral messenger. This increase in load shall be gradually applied in not
less than 5 s and not more than 60 s.
If accelerated cooling is used, it shall act on the whole of the loop, and use air within ambient temperature
limits.
The cycle and the theoretical temperature profile are shown diagrammatically in Figure 2.

Key
1 selected value of mechanical load
2 selected value of temperature
3 temperature profile
4 one cycle
X time in minutes
Y temperature in °C
Y mechanical load in % of MBL of the neutral messenger
Figure 2 — Cycle and temperature profile
8.2.3.4 Requirements
8.2.3.4.1 Slippage checking
The neutral messenger sheath slippage with regard to the clamp shall comply with the following conditions:
— slippage after 2 cycles: g ≤ 4 mm;
— slippage after 500 cycles: g ≤ 10 mm.
8.2.3.4.2 Dielectrical voltage test
The clamp and conductors shall meet the requirements of the dielectrical voltage test as detailed in 8.2.6.3.
8.2.4 Tensile test at low temperature
8.2.4.1 Principle
The purpose of this test is to ensure that the tension clamp is suitable for use at −10 °C.
NOTE See EN 50483-1:2026, 9.1, for information on the use of a lower temperature.
8.2.4.2 Test arrangement
Figure 3 shows a typical test arrangement.
The test shall be carried out for the maximum and minimum insulated neutral messenger cross-sections, for
which the clamp is designed.
Key
1 neutral messenger tension clamp tested

2 cold enclosure mechanical junction allowing rotation

3 mechanical load measurement device mechanical tension adjustment

4 tensioning device
Figure 3 — Arrangement of the fitting for mechanical test at low temperature
8.2.4.3 Procedure
The tension clamp shall be installed at a distance of a minimum 1 m from the end of a minimum 4 m long
neutral messenger sample. The tension clamp shall be secured to a device similar to the one used for its
fixing on the support. At the other end, which is not stripped, an appropriate tensioning device shall be set up.
During the tensile test, the clamp shall be located in an enclosure with a temperature of (−10 ± 3) °C.
A time period of 12 h is suggested which will allow the clamp to cool to −10 °C. However, if the temperature of
the clamp can be measured the time period can be less, but shall not be less than 2 h as long as the
temperature of the clamp reaches −10 °C.
Under these conditions the tension clamp shall be gradually subjected to 25 % of the MBL of the neutral
messenger, within ± 5 % of the applied load, which shall be maintained at this value for 60 s. The conductor
shall then be marked where it leaves the clamp, and the load released. A load of 45 % of the MBL of the
neutral messenger shall be applied. The rise of the load between 10 % and 45 % shall take less than 2s.
Once 45 % achieved, the load can be released.
NOTE See EN 50483-1:2026, 9.1, for information on the use of a lower temperature.
8.2.4.4 Requirements
There shall be
— no damage that could affect the correct function of the tension clamp,
— no slippage by more than 10 mm with respect to the mark on the insulated neutral messenger.
The clamp and conductor shall meet the requirements of the dielectrical voltage test as detailed in 8.2.6.3.
8.2.5 Environmental tests
8.2.5.1 General
In order to meet the requirements of the type tests at least one of the three corrosion tests (detailed in 8.2.5.2)
and one of the two climatic test methods (detailed in 8.2.5.5) shall be carried out. When a clamp that consists
only of metallic parts is designed for use on a bare messenger then, there is no requirement to carry out the
climatic tests. The choice of the test shall be agreed between the manufacturer and the customer.
8.2.5.2 Corrosion ageing test
See EN 50483-6:2026, 8.4, modified in accordance with 8.2.5.3 or 8.2.5.4 below.
8.2.5.3 Salt mist test
8.2.5.3.1 Test criteria
See EN 50483-6:2026, 8.4.1.
The following criteria shall be used during this test:
— Number of tension clamps shall be 2.
— Number of cycles shall be 4 (4 weeks).
— The cross section of the neutral messenger shall be the largest for which the clamp is designed.
8.2.5.3.2 Procedure
A tension clamp shall be installed at both ends of a neutral messenger section. The free length between
tension clamps shall be not less than 0,5 m.
The tension clamp and its attached fittings may be tested together if requested by the customer.
A load of 25 % of the MBL of the neutral messenger shall be smoothly applied to the device and maintained
for 10 min.
The clamps shall be placed in a horizontal position in a corrosion chamber with the tension clamps
longitudinal opening turned towards the ground.
8.2.5.3.3 Requirements
Visual inspection shall be carried out and there shall be no significant trace of red rust.
NOTE Significant rusting would constitute more than 10 % of the exposed surface area of the metallic parts.
The clamp’s identification marking shall be legible when examined with normal or corrected vision, without
magnification.
No damage shall occur which could affect the correct function of the tension clamp.
For tension clamps for insulated messenger the requirements of 8.2.2 shall be met except that the length of
the neutral messenger can be reduced to approximately 0,5 m. After the corrosion test, test defined in 8.2.2 is
carried out using a reduced value of 75 % of the test loads.
If necessary, for tension clamps for bare messenger, the clamps shall be removed from the bare messenger
and re-installed onto a new bare messenger in accordance with the test arrangement of 8.2.2.2. The clamps
shall meet the requirements of 8.2.2.4. The bare messenger that has been exposed to the corrosion test shall
be examined to ensure that the conductor has not deteriorated in the area where the clamp has been
installed.
8.2.5.4 Gas atmosphere test
8.2.5.4.1 Test criteria – Method 1 – Combined test
See EN 50483-6:2026, 8.4.1 and EN 50483-6:2026, 8.4.2.1.
The following criteria shall be used during this test:
— Number of tension clamps shall be 2.
— There shall be 4 cycles of 14 days. This 14-day cycle consists of 7 days of salt mist and 7 days in SO
atmosphere as defined in EN 50483-6:2026, 8.4.1 and EN 50483-6:2026, 8.4.2.1.
— The cross section of the neutral messenger shall be the largest for which the clamp is designed. A
tension clamp shall be installed at both ends of a neutral messenger section. The free length between
tension clamps shall be approximately 0,5 m. The tension clamp and its attached fittings may be tested
together if requested by the customer.
— A load of 25 % of the MBL of the neutral messenger shall be smoothly applied to the device and
maintained for 10 min.
— The clamps shall be placed in a horizontal position in a corrosion chamber with the tension clamps
longitudinal opening turned towards the ground.
8.2.5.4.2 Test criteria – Method 2
See EN 50483-6:2026, 8.4.2.2.
The following criteria shall be used during this test:
— Number of tension clamps shall be 2.
— There shall be 500 cycles of 2 h (approximately 6 weeks).
— The cross section of the neutral messenger shall be the largest for which the clamp is designed. A
tension clamp shall be installed at both ends of a neutral messenger section. The free length between
tension clamps shall be approximately 0,5 m. The tension clamp and its attached fittings may be tested
together if requested by the customer.
— A load of 25 % of the MBL of the neutral messenger shall be smoothly applied to the device and
maintained for 10 min.
— The clamps shall be placed in a horizontal position in a corrosion chamber with the tension clamps
longitudinal opening turned towards the ground.
8.2.5.4.3 Requirements (Method 1 and Method 2)
Visual inspection shall be carried out and there shall be no significant trace of red rust.
NOTE Significant rusting would constitute more than 10 % of the exposed surface area of the metallic parts.
The clamp’s identification marking shall be legible when examined with normal or corrected vision, without
magnification.
No damage shall occur which would affect the correct function of the tension clamp.
For tension clamps for insulated messenger the requirements of 8.2.2 shall be met except that the length of
the neutral messenger can be reduced to approximately 0,5 m. After the corrosion test, test defined in 8.2.2 is
carried out using a reduced value of 75 % of the test loads.
If necessary, for tension clamps for bare messenger, the clamps shall be removed from the bare messenger
and re-installed onto a new bare messenger in accordance with the test arrangement of 8.2.2.2. The clamps
shall meet the requirements of 8.2.2.4. The bare messenger that has been exposed to the corrosion test shall
be examined to ensure that the conductor has not deteriorated in the area where the clamp has been
installed.
8.2.5.5 Climatic ageing test
8.2.5.5.1 General
See EN 50483-6:2026, 8.5.
NOTE The climatic test is not necessary on bare messenger when the clamp has only metallic parts.
8.2.5.5.2 Test criteria – Method 1
See EN 50483-6:2026, 8.5.1.
The following criteria shall be used during this test:
— Number of tension clamps shall be 2.
— The free conductor length between tension clamps could be reduced but shall be not less than 0,5 m.
— There shall be 6 cycles of 1 week.
— The temperature during periods A and C shall be 70 °C. The temperature may be varied if agreed
between the customer and the manufacturer.
— A load of 25 % of the MBL of the neutral messenger shall be smoothly applied to the device and
maintained for 10 min.
— The tension clamps shall be installed on the largest cross section of neutral messenger, for which the
clamp is designed, in such a way that the longitudinal opening of the clamps shall be facing the light
source.
8.2.5.5.3 Test criteria – Method 2
See EN 50483-6:2026, 8.5.2.
The following criteria shall be used during this test:
— Number of tension clamps shall be 2.
— The free conductor length between tension clamps could be reduced but shall be not less than 0,5 m.
— There shall be 56 cycles of 1 day (8 weeks).
— A load of 25 % of the MBL of the neutral messenger shall be smoothly applied to the device and
maintained for 10 min.
— The tension clamps shall be installed on the largest cross section of neutral messenger, for which the
clamp is designed, in such a way that the longitudinal opening of the clamps shall be facing the light
source.
8.2.5.5.4 Requirements (Method 1 and Method 2)
This test shall be carried out after 24 h and within 72 h of completion of the climatic ageing test.
The clamp’s identification marking shall be legible when examined with normal or corrected vision, without
magnification.
No damage shall occur which could affect the correct function of the tension clamp.
The clamps shall meet the requirements of the dielectrical voltage test given in 8.2.6.2.
For tension clamps, the requirements of 8.2.2 shall be met except that the length of the neutral messenger
can be reduced to a minimum of 0,5 m and the test loads are reduced to 75 % of the test loads.
8.2.6 Dielectrical voltage test
8.2.6.1 Dielectrical voltage test in air – Tension clamp only
8.2.6.1.1 Principle
This test is designed to prove that the withstand voltage of the clamp body and other parts is acceptable.
8.2.6.1.2 Test arrangement
Number of tension clamps shall be 2. An uninsulated conductive rod or suitable conductor shall be used to
replace the neutral messenger in the tension clamp. The diameter of the rod or conductor shall be determined
by the average diameter, over the insulation, of all the insulated neutral messengers for which the clamp is
designed.
The rod or conductor shall protrude by a minimum of 5 cm from either side of the clamp. If necessary, those
parts of the rod that protrude from the clamp can be insulated in order to prevent flash over to earthed parts.
The test shall be carried out without any mechanical tension.
The test arrangement is shown in Figure 4.
All conductive parts of the tension clamps shall be earthed.
8.2.6.1.3 Procedure
An a.c. voltage of 4 kV shall be applied between the rod or conductor and the conductive parts of the clamp at
a rate of approximately 1 kV/s.
A voltage of 6 kV may be used when this is agreed, between customer and manufacturer.
This voltage shall be maintained for 60 s.
Dimensions in centimetres
Key
1 conductive part
2 clamp body
3 bare metallic rod or conductor
4 added insulation
5 test voltage
Figure 4 — Voltage test arrangement on tension clamp only
8.2.6.1.4 Requirements
No failure or flashover shall occur. The maximum leakage current is defined in EN 50483-1:2026, 9.1.6.
8.2.6.2 Dielectrical voltage test in air – Tension clamp and conductor
8.2.6.2.1 Principle
The purpose of this test is to ensure that the tension clamp has not suffered damage that would adversely
affect its dielectrical properties.
8.2.6.2.2 Test arrangement
The end of the neutral insulated messenger, on which the tension clamp is fitted, shall be capped in order to
avoid any flashover. All conductive parts shall be earthed.
The test arrangement is shown in Figure 5.
8.2.6.2.3 Procedure
An a.c. voltage shall be applied between the conductive parts of the clamp and the insulated neutral
messenger conductor, the test connection to the conductor being made at the remote end of the cable. The
voltage shall then be increased to 4 kV at a rate of approximately 1 kV/s. The voltage shall be maintained for
30 min.
A higher voltage up to a maximum of 10 kV may be used when agreed between customer and manufacturer.
Key
1 conductive part
2 clamp body
3 insulated cap
4 neutral messenger
5 test voltage
Figure 5 — Dielectrical voltage test arrangement on tension clamp
and conductor in air
8.2.6.2.4 Requirements
No failure or flashover shall occur. The maximum leakage current is defined in EN 50483-1:2026, 9.1.6.
8.2.6.3 Dielectrical voltage test in water – Tension clamp and conductor
8.2.6.3.1 Principle
This test shall be carried out shortly after the tensile test at high temperature defined in 8.2.3 and the tensile
test at low temperature defined in 8.2.4.
This test shall be carried out to ensure that the insulation properties of the tension clamps have not been
damaged during testing.
8.2.6.3.2 Test arrangement
The insulated neutral messenger core and its tension clamps shall be immersed to a depth of at least 30 cm
of water.
The neutral messenger may be cut on both sides of the tension clamps before immersion.
The resistivity of the water shall be less than 200 Ω.m.
NOTE Normally tap water will meet this requirement.
The water shall be at ambient temperature.
The test arrangement is shown in Figure 6.
8.2.6.3.3 Procedure
After a minimum of 30 min immersion, an a.c. voltage of 4 kV shall be applied to the sample for 60 s. The a.c.
voltage shall be applied at a rate of approximately 1 kV/s.
A voltage up to a maximum of 10 kV may be used when this is agreed between customer and manufacturer.
Dimensions in centimetres
Key
1 test voltage
2 electrode
3 conductive part
4 clamp body
5 neutral messenger
6 water
Figure 6 — Dielectrical voltage test arrangement on tension clamp in water
8.2.6.3.4 Requirements
No failure or flashover shall occur. The maximum leakage current is defined in EN 50483-1:2026, 9.1.6.
8.2.6.4 Clamp bolt tightening test
See 8.3.2.
8.3 Type tests for suspension clamps
8.3.1 General
The following type tests shall be carried out on the suspension clamps.
Test Applicability Subclause
Clamp bolt tightening test insulated and bare neutral messenger 8.3.2
Mechanical test insulated and bare neutral messenger 8.3.3
Corrosion test insulated and bare neutral messenger 8.3.4.1
Climatic ageing test insulated and bare neutral messenger 8.3.4.4
Dielectrical voltage test insulated neutral messenger only 8.3.5
Swing test insulated neutral messenger only 8.3.6
Slip test at high temperature insulated neutral messenger only 8.3.7
The tests 8.3.3, 8.3.4.1, 8.3.5.1 and 8.3.6 may be performed with the suspension assembly if requested by the
customer.
If a cable fails beyond any part of suspension devices, the test result shall be declared void without
discrediting the suspension device. Tests shall be repeated using a new suspension device and a new cable.
When agreed between the manufacturer and the customer, the mechanical test loads may be defined by the
smallest cable for the clamp but in this case the clamp may only be considered to conform to this document
for the smaller cable size.
8.3.2 Clamp bolt tightening test
8.3.2.1 Principle
This test is common for both suspension and tension clamps equipped with bolts.
The purpose of this test is to ensure that the clamp bolts are not damaged or do not damage the clamp.
8.3.2.2 Test arrangement
Two clamps shall be tested.
The test shall be carried out at ambient temperature.
If applicable, the test shall be carried out on all suspension clamps specified.
The test shall be performed by installing the clamp on a conductor or cable with a diameter equal to that for
which the clamp is
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