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STANDARD
SIST EN 50483-2:2009
EUROPEAN STANDARD EN 50483-2 NORME EUROPÉENNE
EUROPÄISCHE NORM January 2009
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: avenue Marnix 17, B - 1000 Brussels
© 2009 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50483-2:2009 E
ICS 29.240.20
English version
Test requirements for low voltage aerial bundled cable accessories -
Part 2: Tension and suspension clamps for self supporting system
Prescriptions relatives aux essais
des accessoires pour réseaux aériens basse tension torsadés -
Partie 2: Matériels d’ancrage
et de suspension pour réseaux aériens
en conducteurs isolés torsadés auto-portés
Prüfanforderungen für Bauteile für isolierte Niederspannungsfreileitungen -
Teil 2: Abspann- und Tragklemmen
für selbsttragende isolierte Freileitungsseile
This European Standard was approved by CENELEC on 2008-12-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member.
This European Standard exists in 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 Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
SIST EN 50483-2:2009
EN 50483-2:2009 – 2 – Foreword This European Standard was prepared by a sub-group of WG 11 of the Technical Committee CENELEC TC 20, Electric cables. The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50483-2 on 2008-12-01. The following dates were fixed: – latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement
(dop)
2009-12-01 – latest date by which the national standards conflicting with the EN have to be withdrawn
(dow)
2011-12-01 This is Part 2 of CENELEC standard EN 50483 “Test requirements for low voltage aerial bundled cable accessories”, which has six parts: – Part 1: Generalities; – Part 2: Tension and suspension clamps for self supporting system; – Part 3: Tension and suspension clamps for neutral messenger system; – Part 4: Connectors; – Part 5: Electrical ageing test; – Part 6: Environmental testing. __________ SIST EN 50483-2:2009
– 3 – EN 50483-2:2009 Contents 1 Scope . 4 2 Normative references . 4 3 Terms and definitions . 4 4 Symbols . 6 5 Characteristics . 6 6 Marking . 6 7 General test conditions . 6 7.1 Mechanical tests . 6 7.2 Temperature . 6 8 Type tests . 7 8.1 Type tests for tension clamps . 7 8.2 Type tests for suspension clamps . 12 8.3 Dielectrical voltage tests . 20 8.4 Clamp bolt tightening test . 21 8.5 Environmental tests . 22 Bibliography . 26 Figures Figure 1 – Tension clamps – Tensile tests . 8 Figure 2 – Suspension clamp – Tensile tests . 13 Figure 3 – Slip test at ambient temperature . 15 Figure 4 – Test arrangement for slip test at high temperature . 16 Figure 5 – Cycle and temperature profile . 18 Tables Table 1 – Static loads . 10 Table 2 – Static loads . 11 Table 3 – Tensile loads . 13 Table 4 – Tensile loads . 19
SIST EN 50483-2:2009
EN 50483-2:2009 – 4 – 1 Scope 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 Part 2 applies to tensioning devices consisting of tension and suspension clamps designed to be used for installation of self supporting ABC defined in HD 626.
Tests described in this document are type tests.
NOTE
This European standard 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 European Standard. It may be possible, subject to agreement between supplier and purchaser, and/or the relevant conformity assessment body, to demonstrate that conformity to the earlier standard can be used to claim conformity to this standard, provided an assessment is made of any additional type testing that may need to be carried out.
Any such additional testing that is part of a sequence of testing cannot be done separately. 2 Normative references The following referenced documents are indispensable for the application 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 series, Test requirements for low voltage aerial bundled cable accessories HD 626, Overhead distribution cables of rated voltage Uo/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. 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 [IEV 461-08-02, modified] NOTE
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 [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 SIST EN 50483-2:2009
– 5 – EN 50483-2:2009 3.4
clamp bolt bolt which tightens two parts of a clamp together 3.5
conductor insulation insulation applied on a conductor [IEV 461-02-02, modified] 3.6
conductor (of a cable) part of a cable which has the specific function of carrying current [IEV 461-01-01] 3.7
core assembly comprising conductor and its own insulation [IEV 461-04-04, modified] 3.8
fixture (or fitting) device for attaching ABC tension or/and suspension clamps to a pole or to a wall 3.9
insulation (of a cable) insulating materials incorporated in a cable with the specific function of withstanding voltage [IEV 461-02-01] 3.10
minimum breaking load (MBL) minimum breaking load of the conductor given by HD 626 or the cable manufacturer if not defined in the standard, or minimum breaking load of the clamp given by the clamp manufacturer 3.11
self supporting system aerial insulated system where all the cores of the ABC contribute to its support 3.12
sheath uniform and continuous tubular covering of metallic or non metallic material, generally extruded [IEV 461-05-03] 3.13
suspension clamp device which attaches an aerial insulated cable to a fixture in order to carry its weight and any specified loading [IEV 461-18-02, modified] 3.14
tension clamp device which firmly attaches an aerial insulated cable to a fixture and is designed to transmit the specified mechanical tension in the cable or messenger to the supporting structure [IEV 461-18-01, modified] SIST EN 50483-2:2009
EN 50483-2:2009 – 6 – 3.15
type test test required to be made before supplying a type of material covered by this standard on a general commercial basis, in order to demonstrate satisfactory performance characteristics to meet the intended application
NOTE
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 g15 slippage after 15 cycles g250 slippage after 250 cycles D circumscribed diameter of conductor bundle (mm)
resistivity (Ωm) α maximum angle (°) of deviation of a suspension clamp as recommended by the manufacturer or specified by the customer T tension (N) F sliding force (N) 5 Characteristics These fittings shall be capable of supporting the tensile loads applied to the ABC for which they are designed in accordance with the following tests. Tension and suspension equipment shall be designed to avoid any direct or accidental contact between conductors and between any phase and metallic parts of the clamp. 6 Marking See Clause 6 of EN 50483-1. 7 General test conditions 7.1 Mechanical tests See Clause 9 of EN 50483-1. 7.2 Temperature See Clause 9 of EN 50483-1. SIST EN 50483-2:2009
– 7 – EN 50483-2:2009 8 Type tests 8.1 Type tests for tension clamps The performance characteristics of all tension clamps shall be proven by satisfactorily undergoing the range of tests listed below. Each clamp shall be tested for the smallest and largest bundled conductor size for which it is marked. The following type tests shall be carried out. Test Subclause Tensile test at ambient temperature 8.1.1 Breaking load test 8.1.2 Tensile test at high temperature 8.1.3 Tensile test at low temperature 8.1.4 Dielectrical voltage test (clamp) 8.3.1 Dielectrical voltage test (ABC) 8.3.2 Clamp bolt tightening test 8.4 Environmental tests 8.5 NOTE
The test procedures for 3 core and 4 core ABC are similar. 8.1.1 Tensile test at ambient temperature
8.1.1.1 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. NOTE
Test may be carried out on samples which have been subjected to the climatic ageing test or on the cores (see 8.5.2.1) 8.1.1.2 Test arrangement Two tension clamps shall be assembled on to the ABC, in accordance with the manufacturer’s instructions, and fitted into a tensile testing machine as shown in Figure 1. The length of tails on the unloaded side of the clamps shall be a minimum of 350 mm and with a minimum radius of 250 mm. The span between the two clamps shall be a minimum of 100 × D, where D is the circumscribed diameter of the ABC. The test shall be carried out at ambient temperature. SIST EN 50483-2:2009
EN 50483-2:2009 – 8 – Dimensions in millimetres
Key
1 tension clamp 4 marking 2 second tension clamp undergoing test 5 low temperature zone 3 length of tail ≥ 350 mm 6 arrangement for low temperature testing Figure 1 – Tension clamps – Tensile tests 8.1.1.3 Procedure The tensile load shall be applied within 15 min of the clamp being assembled on to the ABC.
The load shall be increased to 20 % of MBL of the cable, and the cores shall be marked where they exit the clamps. The load shall be maintained at that value ± 10 % for 6 h. NOTE 1
A reduced time period may be agreed between customer and manufacturer. The load shall then be increased to a limit of 80 % of the MBL of the cable for ABC sizes up to, and including, 95 mm². For conductor cross sections above 95 mm² the load shall be reduced to a limit of 60 % of the MBL of the cable. This load shall be held for 60 s before the load is removed. NOTE 2
When a clamp of a different rating is needed the clamp may be tested according to the value agreed by the manufacturer and the customer. 8.1.1.4 Requirements No damage shall occur, which would affect the correct function of the tension clamp. Slippage of the cores of the cable with respect to the clamp parts when in contact shall not exceed 10 mm. SIST EN 50483-2:2009
– 9 – EN 50483-2:2009 The clamp shall pass the dielectrical voltage test detailed in 8.3.1. The cable shall pass the dielectrical voltage test detailed in 8.3.2. 8.1.2 Breaking load test (optional) NOTE
This test may be carried out on samples which have previously been subjected to the corrosion ageing test (8.5.1). In this case it is not necessary to carry out the test before the corrosion test. 8.1.2.1 Principle The tension clamps shall be subjected to increasing mechanical loads, at ambient temperature, in order to ensure that they do not break before loads equal to or greater than the MBL of the maximum ABC size, for which the clamp is designed, are reached. 8.1.2.2 Test arrangement Two tension clamps shall be assembled in accordance with the manufacturer’s instructions on a simulated ABC made of metallic round bars or a suitable conductor of the same diameter as the ABC core and fitted into a tensile testing machine as shown in Figure 1. To avoid any slippage between bars and the clamps, fixed stops may be used on the bars. The test shall be carried out at ambient temperature. 8.1.2.3 Procedure The tensile load shall be applied within 15 min of the clamp being assembled.
The load shall be increased to the MBL of the largest size of ABC core for which the clamp is designed. It shall be maintained at this load for 60 s. The load shall then be increased until the breaking of the tension clamp occurs. NOTE 1
When requested by the customer a different load may be increased to the MBL of the clamp given by the manufacturer to check the breaking load of the clamp. The clamps shall not be tightened or adjusted during the test. NOTE 2
The failure value may be noted for information. 8.1.2.4 Requirements Neither tension clamp shall break until the test load has been held for 60 s and the MBL of the cable is reached. 8.1.3 Tensile test at high temperature
8.1.3.1 Principle The tension clamps shall be subjected to steady load, whilst the cable temperature is varied. The test shall be carried out in order to ensure that the cable does not slip through the clamp and that the clamp and the cable remain undamaged. NOTE
When a clamp of lower rating is required, for example a service clamp, this test may be omitted when agreed between the customer and manufacturer. SIST EN 50483-2:2009
EN 50483-2:2009 – 10 – 8.1.3.2 Test arrangement Two tension clamps shall be assembled on to the ABC in accordance with the manufacturer’s instructions and fitted into a tensile testing machine as shown in Figure 1. The span between the two clamps shall be a minimum of 100 × D, where D is the circumscribed diameter of the ABC.
The test shall be carried out with a static load, which shall be found from Table 1. Table 1 – Static loads Number of cores in the ABC Tension load (T) for the tensile test at high temperature 2 18 % of the ABC MBL 4 20 % of the ABC MBL NOTE
When a clamp of lower rating is needed, the clamp may be tested according to another value agreed between the manufacturer and the customer.
8.1.3.3 Procedure The temperature shall be varied by passing current through the conductors. For 2-conductor ABC the current shall flow in both conductors and for 4-conductor ABC the current shall flow in 3 conductors.
Tails of a minimum 350 mm long shall remain outside the two tension clamps to provide connection to the current source.
When the test load is reached for the first time; the cores shall be marked where they exit from the clamps. These marks shall be used for reference purposes to measure slippage. The clamps shall not be tightened or adjusted during the test. The test shall comprise of 100 heat cycles at a rate of 2 cycles per day during which time the tensile load shall be stabilised at ± 10 % or adjusted at least once a day within ± 5 % of the value defined in 8.1.3.2. The temperature shall be measured underneath the insulation with a thermocouple. NOTE 1
For further information on thermocouple application, see EN 50483-5, 5.4.1. NOTE 2
The temperature should be measured at a position which is not under mechanical tension. The measuring position may be at least 1 m from the tension clamp and the end of the ABC. It may also be at the same horizontal level as the tension clamp in order to avoid any difference in air temperature. Each temperature cycle shall consist of • initial temperature shall be ambient, • the conductor temperature shall be gradually increased to (70 ± 3) °C, in less than 2 h, • this high temperature shall be maintained for 8 h, • the conductor shall be allowed to cool naturally to ambient temperature before the next cycle begins. SIST EN 50483-2:2009
– 11 – EN 50483-2:2009 8.1.3.4 Requirements No damage shall occur, which could affect the correct function of the tension clamp. After 10 days of testing, the slippage of the cores or core of the cable with respect to the clamp parts that are in contact with the cores shall not exceed 10 mm. At the end of the testing, slippage of the cores or core of the cable with respect to the clamp parts that are in contact with the cores shall not exceed 12 mm from the starting position. The clamp shall pass the dielectrical voltage test detailed in 8.3.1. The ABC core shall pass the dielectrical voltage test detailed in 8.3.2. 8.1.4 Tensile test at low temperature
8.1.4.1 Principle The tension clamps shall be subjected to a steady load, whilst at least one tension clamp and the part of the cable close to the clamp are held at low temperature. The test shall be carried out in order to ensure that the cable does not slip through the clamp and that the clamp and the cable remain undamaged. 8.1.4.2 Test arrangement Two tension clamps shall be assembled on to the ABC in accordance with the manufacturer’s instructions and fitted into a tensile testing machine as shown in Figure 1. The span between the two clamps shall be a minimum of 100 x D, where D is the circumscribed diameter of the ABC.
The test is carried out with a static load, which shall be found from Table 2. Table 2 – Static loads Number of cores in the ABC Tension load (T) for the tensile test at low temperature 2 40 % of the ABC MBL 4 25 % of the ABC MBL NOTE
When a clamp of lower rating is needed, the clamp may be tested according to another value agreed between the manufacturer and the customer.
8.1.4.3 Procedure The cores shall be marked at the point where they exit the tension clamps. These marks shall be used for reference purposes to measure slippage. Marking shall be applied at a core loading of 10 N/mm² before initial cooling. At least one tension clamp and a 300 mm section of the ABC shall be cooled to -10 °C for 24 h during which time a tensile load is maintained at the value determined from Table 2 with a tolerance of ± 10 %. NOTE
See EN 50483-1, 9.1, for information on the use of a lower temperature. The tension clamps and cable shall be maintained at the above load and temperature for 24 h. The clamps shall not be tightened or adjusted during the test. SIST EN 50
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