30101941 pdf BRITISH STANDARD BS EN 50395 2005 Electrical test methods for low voltage energy cables ICS 29 060 20 + A1 201 1 National foreword This British Standard is the UK implementation of EN 503[.]
BRITISH STANDARD Electrical test methods for low voltage energy cables ICS 29.060.20 BS EN 50395:2005 + A1 :201 BS EN 50395:2005+A1:2011 National foreword This British Standard is the UK implementation of EN 50395:2005+A1:2011 It supersedes BS EN 50395:2005, which is withdrawn The start and finish of text introduced or altered by amendment is indicated in the text by tags Tags indicating changes to CENELEC text carry the number of the CENELEC amendment For example, text altered by CENELEC amendment A1 is indicated by !" The UK participation in its preparation was entrusted by Technical Committee GEL/20, Electric cables, to Subcommittee GEL/20/17, Electric Cables - Low voltage A list of organizations represented on this subcommittee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 14 November 2005 Amendments/corrigenda issued since publication Date Comments © BSI 2011 31 October 2011 Implementation of CENELEC amendment A1:2011 ISBN 978 580 67085 EN 50395:2005+A1 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM March 2011 ICS 29.060.20 Partly supersedes HD 21.2 S3:1997 + A1:2002 & HD 22.2 S3:1997 + A1:2002 English version Electrical test methods for low voltage energy cables Méthodes d'essais électriques Elektrische Prüfverfahren für Niederspannungskabel und -leitungen This European Standard was approved by CENELEC on 2005-07-01 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels © 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 50395:2005 E BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) –2– Foreword This European Standard was prepared by the Technical Committee CENELEC TC 20, Electric cables In accordance with the decision of TC 20 at its Setubal meeting (June 2004), the text of the draft was submitted to the formal vote It was approved by CENELEC as EN 50395 on 2005-07-01 This European Standard, together with EN 50396:2005, supersedes HD 21.2 S3:1997 + A1:2002 and HD 22.2 S3:1997 + A1:2002 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) 2006-07-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2008-07-01 Foreword to amendment A1 This amendment was prepared by the Technical Committee CENELEC TC 20, Electric cables The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC as amendment A1 to EN 50395:2005 on 2011-03-14 The following dates were fixed: – – latest date by which the amendment has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2012-03-14 latest date by which the national standards conflicting with the amendment have to be withdrawn (dow) 2014-03-14 –3– BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) Contents Page Introduction Scope Normative references General requirements .6 3.1 Pre-conditioning 3.2 Test temperature 3.3 Test voltage 3.4 Test values .6 Definitions Electrical d.c resistance of conductor 6 Voltage test on completed cable Voltage test on cores in water .7 7.1 Test sample 7.2 Procedure .7 7.3 Requirement Insulation resistance test .7 8.1 8.2 Insulation resistance for cables having maximum conductor temperatures not exceeding 90 °C .7 8.1.1 Test sample .7 8.1.2 Procedure 8.1.3 Requirement Insulation resistance for cables with maximum conductor temperatures exceeding 90 °C .8 8.2.1 8.2.2 8.2.3 Test sample .8 Procedure Requirement Long term resistance of insulation to d.c 9.1 Test sample 9.2 Procedure .9 9.3 Requirement 10 10 Check for the absence of faults in insulation 10 10.1 General 10 10.2 Spark test 10 10.2.1 Procedure 10 10.2.2 Requirement 10 10.3 Voltage test 10 10.3.1 Procedure 10 BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) –4– 10.3.2 Requirement 10 11 Surface resistance of sheath .11 11.1 Test samples 11 11.2 Procedure .11 11.3 Requirement 11 12 Transfer impedance 11 Annex A 12 A.1 Basic formula 12 A.2 Rounding 12 A.3 Examples of calculation 12 Annex B (informative) Source of electrical test methods in EN 50395 13 Bibliography 14 Figure – Positioning of electrodes –5– BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) Introduction EN 50395 contains the electrical test methods that are used for harmonized low voltage energy cables These electrical test methods include all those previously contained in HD 21 and HD 22 Annex B gives a comparison between the original location of each test method and its place in this new European Standard The content of EN 50395 is not, and will not be, restricted only to test methods for cables to HD 21 and HD 22 Other test methods for harmonized LV cables may be included Furthermore, the use of test methods in EN 50395 for cables outside HD 21 and HD 22 is not prohibited, but it is strongly recommended that expert advice be taken before such use, or before any proposal for incorporation into another standard Scope EN 50395 contains electrical test methods required for the testing of harmonized low voltage energy cables, especially those rated at up to and including 450/750 V NOTE A description of the origin of these test methods and the background to this European Standard is given in the Introduction and in Annex B The particular cable standard dictates the tests which need to be performed on the relevant cable type It also specifies whether the specific test is a type test (T), a sample test (S) or a routine test (R) for the particular cable type NOTE T, S and R are defined in the relevant cable standard The requirements to be met during or after the test are specified for the particular cable type in the relevant cable standard However, some test requirements are obvious and universal, such as the fact that no breakdown shall occur during voltage tests, and these are stated in the particular test method Test methods for use specifically in utility power cables are not covered by this European Standard They can be found in HD 605 Test methods for use specifically in communications cables are the responsibility of the Technical Committee CENELEC TC 46X, Communication cables At present such test methods are given in EN 50289 series 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 50289-1-6 2002 Communication cables – Specifications for test methods Part 1-6: Electrical test methods – Electromagnetic performance EN 60228 2005 Conductors of insulated cables !EN 62230 2007 Electric cables – Spark test method" BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) 3.1 –6– General requirements Pre-conditioning All the tests shall be carried out not less than 16 h after the extrusion or cross-linking, if any, of the insulating or sheathing compounds 3.2 Test temperature Unless otherwise specified, tests shall be made at an ambient temperature of (20 ± 15) °C 3.3 Test voltage Unless otherwise specified in the individual clause of this European Standard or in the product standard, the test voltage shall be a.c of approximately sine-wave form and of frequency between 49 Hz and 61 Hz The ratio of peak value to r.m.s value shall be equal to √2 with a tolerance of ± % The values quoted are r.m.s values 3.4 Test values Full test conditions (such as temperatures, durations, etc.) and full test requirements are not specified in this European Standard; it is intended that they should be specified by the standard dealing with the relevant type of cable Any test requirements which are given in this European Standard may be modified by the relevant cable standard to suit the needs of a particular type of cable Definitions For the purposes of this document, the following terms and definitions apply 4.1 median value when several test results have been obtained and ordered in an increasing or decreasing succession, the median value is the middle value if the number of available values is odd, and is the mean of the two middle values if the number is even Electrical d.c resistance of conductor The test shall be carried out in accordance with Annex A of EN 60228 Voltage test on completed cable If the cable has no metallic layer, a sample of the cable as manufactured shall be immersed in water The length of the sample, the temperature of the water and the period of immersion shall be as specified in the cable standard A voltage shall be applied between conductor(s) and groups of conductors in such a way that the insulation on each core is tested against all adjacent cores and the water –7– BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) If the cable has a metallic layer, a sample of the cable shall be taken of the length specified in the cable standard A voltage shall be applied between conductor(s) and groups of conductors in such a way that the insulation on each core is tested against all adjacent cores and the metallic layer, which shall be earthed If the cable has a metallic strain-bearing member, this shall be connected to the water or to the metallic layer, as appropriate In each case, the voltage and the duration of its application shall be as specified in the cable standard The voltage shall be increased gradually on each occasion to the specified value No breakdown of the insulation shall occur during the test Voltage test on cores in water The test applies to sheathed cables, braided cables and flat unsheathed cords NOTE For 1-core unsheathed cables, the test in Clause generally applies, in which case this test on cores is not required 7.1 Test sample Prepare a sample of cable m long, by carefully removing, without damaging the cores, the sheath or the overall braid and any other covering or filling from a length of completed cable In the case of flat unsheathed cord, make a cut in the insulation between the cores, and separate the cores by hand for a length of m 7.2 Procedure Immerse the sample in water at the temperature, and for the period, specified in the cable standard Ensure that the ends of the cores protrude above the water by a distance sufficient to prevent excessive surface leakage when the test voltage is applied Apply a voltage, of the magnitude specified in the cable standard, between the conductors and the water for the time specified in the cable standard 7.3 Requirement No breakdown of the insulation shall occur during the test Insulation resistance test 8.1 8.1.1 Insulation resistance for cables having maximum conductor temperatures not exceeding 90 ¡C Test sample Make the test on a sample of cable m long, previously submitted to the test specified in Clause or, in the case of 1-core unsheathed cable, to the test described in Clause BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) 8.1.2 –8– Procedure Immerse the sample in water previously heated to the temperature specified in the cable standard, with a length of about 250 mm at each end of the sample projecting above the water, for the period of time specified in the cable standard Apply a d.c voltage of between 80 V and 500 V between each conductor and the water Measure the insulation resistance of each core after application of the voltage Use this value to calculate the insulation resistance of a km length of each core 8.1.3 Requirement None of the resulting values shall be below the minimum insulation resistance value specified in the cable standard 8.2 Insulation resistance for cables with maximum conductor temperatures exceeding 90 ¡C NOTE Further basic information on this test method may be obtained from HD 429, Clause “Test pieces for the volume resistivity measurement” 8.2.1 Test sample Make the test on the same sample of cable used for the voltage test in Clause or, in the case of 1-core unsheathed cable, to the test described in Clause 8.2.2 Procedure Cut a test piece 1,40 m long from the cable or core to be tested Cover this test piece with a semiconducting layer, and over this layer apply a metal braid or a metal tape in such a way as to obtain an active measuring length of 1,0 m At both ends of the active measuring length, leaving a gap mm wide, apply a protective wire binding of approximately mm length (see Figure 1) Wind the test piece to form a ring with a diameter of approximately 15D but at least 0,20 m (D = nominal outer diameter of insulation) Maintain the test piece in an air oven for at least h at the test temperature specified in the relevant cable standard, leaving a clearance between the sample and the walls of the air oven of at least 50 mm After the conditioning period a d.c voltage between 80 V and 500 V shall be applied between the conductor and the screen (semi-conducting layer and metal braid/metal tape including the protective wire binding), the sample still being kept in the air oven The insulation resistance shall be measured after application of the voltage and this value shall be used to calculate the insulation resistance of a km length of cable 8.2.3 Requirement None of the resulting values shall be below the minimum insulation resistance value specified in the cable standard NOTE Annex A shows the calculation method for minimum insulation resistance –9– BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) Key guard electrode (protective wire binding) screen electrode Figure —Positioning of electrodes 9.1 Long term resistance of insulation to d.c Test sample Carry out the test on a sample of cable of m length from which all coverings have been removed The cores of flat unsheathed cords shall not be separated For cables having up to five cores, each core shall be tested For multicore cables having more than five cores, one core of each colour in the cable shall be tested, and where the number of colours is less than 5, duplicate coloured cores shall be tested as necessary to bring the number of cores tested up to a minimum of Take care to avoid damage to the core(s) during removal of the coverings 9.2 Procedure Immerse the sample, for the period and at the temperature given in the relevant cable standard, in an aqueous solution of sodium chloride having a concentration of 10 g/l, with a length of about 250 mm at each end of the sample projecting above the solution Connect the negative pole of a 220 V d.c supply to the conductor(s) of the sample and the positive pole to a copper electrode immersed in the solution for the time given in the relevant cable standard BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) 9.3 – 10 – Requirement No breakdown of the insulation shall occur during the test and, after the test, the exterior of the insulation shall show no sign of damage NOTE Discoloration of the insulation should be ignored 10 Check for the absence of faults in insulation 10.1 General Test all cable that is in the final stage of manufacture, whether it is in delivery lengths or in manufacturing lengths prior to being cut into delivery lengths Test single core cables, whether sheathed or unsheathed, by the spark test in accordance with 10.2 Test all other cables, including sheathed flat cables, by the voltage test in accordance with 10.3 The requirements of 3.1 of this European Standard not apply when the check for absence of faults is carried out as a Routine (R) test 10.2 Spark test 10.2.1 Procedure Carry out the test ac c ording to ! EN 62230 " , exc ept that the option to use a pulsed waveform high voltage source is not permitted 10.2.2 Requirement No faults shall be detected during the test 10.3 Voltage test 10.3.1 Procedure With the cable in the dry state and at ambient temperature apply a voltage of the magnitude given in the relevant cable standard, supplied either from an a.c source or from a d.c source, between each conductor and all the other conductors and, if any, the metallic layer connected to earth Increase the voltage gradually and maintain it at the full value for the duration given in the relevant cable standard 10.3.2 Requirement No breakdown of the insulation shall occur during the test – 11 – BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) 11 Surface resistance of sheath 11.1 Test samples Carry out the test on three samples of completed cable, each about 250 mm in length 11.2 Procedure Clean the sheath of each of the samples with industrial methylated spirit, and apply to each sample two electrodes, consisting of wire helices of copper wire of between 0,2 mm and 0,6 mm diameter, at a distance of (100 ± 2) mm from each other After the wire has been applied, clean the surface of the sheath again thoroughly between the electrodes Condition the samples with electrodes attached in a conditioning chamber at a temperature of (20 ± 2) °C and a relative humidity of (65 ± 5) % for 24 h Immediately after removal from the conditioning chamber, apply a d.c voltage of between 100 V and 500 V between the electrodes, and measure the resistance after Multiply the measured resistance of each sample, in ohms, by a/100, where a is the circumference of the sheath of the sample, in millimetres Record the median of the three values so obtained as the surface resistance of the sheath 11.3 Requirement The median of the three values so obtained shall be not lower than the value in the cable standard 12 Transfer impedance The test shall be carried out in accordance with EN 50289-1-6, clause NOTE EN 50289-1-6 is maintained by the Technical Committee CENELEC TC 46X, Communication cables BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) – 12 – Annex A (informative) Calculation of minimum insulation resistance A.1 Basic formula The general basic formula is: D R = 0,0367.ρ 10 −8 log d where: R = = insulation resistance in M.km volume resistivity in .m d = the diameter of the bare conductor as given in EN 60719 Table (class and class conductors) or Table (class and class conductors) D = d + twice the specified mean value of the thickness of the insulation and any mandatory separator between conductor and insulation ! NOTE For many common insulation compounds, for instance those based on PVC or on thermoplastic polyolefines, the volume resistivity at the operating temperature of the relevant cable is assumed to be 10 +8 Ω ⋅ m In these cases the general formula reduces to: D R = 0,0367 ⋅ log M Ω ⋅ km " d A.2 Rounding As the requirement in cable standards is for a minimum value the calculated value of R should be rounded down to two significant figures A.3 Examples of calculation HD 21.3 S3, Table 1, H07V-R Conductor crosssection Insulation thickness Conductor diameter (d) Overall diameter R R (rounded) mm² mm mm mm M.km M.km 1,5 0,7 1,45 2,85 0,010 77 0,010 35 1,2 7,0 9,4 0,004 699 0,004 50 1,4 8,2 11,0 0,004 682 0,004 BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) – 13 – Annex B (informative) Source of electrical test methods in EN 50395 Test Source (subclause number) Clause in EN 50395 HD 21.2 S3 HD 22.2 S3 Electrical resistance of conductor 2.1 2.1 Voltage test on completed cable 2.2 2.2 Voltage test on cores 2.3 2.3 Insulation resistance 2.4 2.4 Long term resistance of insulation to d.c 2.5 2.5 Test to check absence of faults on insulation 2.6 2.6 10 Transfer impedance (Screening efficiency) 2.7 - 12 Surface resistance of sheath 2.8 2.7 11 BS EN 50395:2005+A1:2011 EN 50395:2005+A1:2011 (E) – 14 – Bibliography The following documents are referred to in the text for information HD 21.2 S3:1997 Cables of rated voltages up to and including 450/750 V and having thermoplastic insulation - Part 2: Test methods HD 22.2 S3:1997 Cables of rated voltages up to and including 450/750 V and having crosslinked insulation - Part 2: Test methods HD 429 Methods of test for volume resistivity and surface resistivity of solid electrical insulating materials (IEC 60093) HD 605 Electric cables - Additional test methods EN 50289 Series Communication cables - Specifications for test methods blank BS EN 50395:2005 + A1 :201 BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: +44 (0)20 8996 9000 Fax: +44 (0)20 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: +44 (0)20 8996 9001 Fax: +44 (0)20 8996 7001 Email: orders@bsigroup.com You may also buy directly using a debit/credit card from the BSI Shop on the Website http://www.bsigroup.com/shop In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact Information Centre Tel: +44 (0)20 8996 7111 Fax: +44 (0)20 8996 7048 Email: info@bsigroup.com Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: +44 (0)20 8996 7002 Fax: +44 (0)20 8996 7001 Email: membership@bsigroup.com Information regarding online access to British Standards via British Standards Online can be found at http://www.bsigroup.com/BSOL Further information about BSI is available on the BSI website at http:// www.bsigroup.com Copyright BSI Group Headquarters 389 Chiswick High Road, London, W4 4AL, UK Tel +44 (0)20 8996 9001 Fax +44 (0)20 8996 7001 www.bsigroup.com/ standards Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained Details and advice can be obtained from the Copyright and Licensing Manager Tel: +44 (0)20 8996 7070 Email: copyright@bsigroup.com