BS 7835-2007 Electric cables – nArmoured cables with nthermosetting insulation nfor rated voltages from n3 8 6 6 kV to 19 33 kV nhaving low emission of nsmoke and corrosive gases n.pdf

1、BS 7835:2007Electric cables Armoured cables with thermosetting insulation for rated voltages from 3.8/6.6 kV to 19/33 kV having low emission of smoke and corrosive gases when affected by fire Requirements and test methodsICS 29.060.20NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT

2、 LAWBRITISH STANDARDIncorporatingCorrigendum No. 1Publishing and copyright informationThe BSI copyright notice displayed in this document indicates when the document was last issued. BSI 2008ISBN 978 0 580 64040 7The following BSI references relate to the work on this standard:Committee reference GE

3、L/20/16Draft for comment 07/30143023 DCPublication historyFirst published June 1996Second edition, December 2000Third edition, November 2007Amendments issued since publicationAmd. no. Date Text affectedC1 August 2008 See 21.6 and 21.7BS 7835:2007 BSI 2008 iBS 7835:2007ContentsForeword iii1 Scope 12

4、Normative references 13 Terms and definitions 24 Voltage designation 45 Non-metallic materials 46 Conductors 47 Conductor screen 48 Insulation 49 Insulation screen 510 Assembly of three-core cables, including inner coverings andfillers 511 Metallic layer 712 Metallic armour 813 Oversheath 914 Markin

5、g 1015 End sealing 1116 Schedule of tests 1217 Test conditions 1418 Routine tests 1419 Sample tests 1620 Type tests Materials 2121 Type tests Electrical 25AnnexesAnnex A (informative) Recommendations for the selection of cables 29Annex B (normative) Information to be supplied and items to be agreed

6、32Annex C (informative) Recommendations for the installation of cables 33Annex D (informative) Guide to use of cables 36Annex E (normative) Fictitious calculation method for determination of dimensions of protective coverings 38Annex F (normative) Rounding of numbers 43Annex G (informative) Guidance

7、 on the scope of type tests 44Annex H (normative) Thickness measurements 47Annex I (normative) Test method for cold strippability of the extruded semi-conducting layer of an insulation screen 47Annex J (normative) Method for measurement of resistivity of extruded semi-conducting conductor screen and

8、 insulation screen 48Annex K (normative) Method for measurement of resistivity of lapped inner covering 51Annex L (normative) Wet compatibility test for galvanized steel wires and semi-conducting tape layers 52Annex M (normative) Abrasion test 53Annex N (normative) Test for shrinkage of oversheath o

9、n cable 54Annex O (normative) Insulation resistance constant test on oversheath 55Bibliography 56BS 7835:2007ii BSI 2008List of figuresFigure J.1 Test piece and arrangement of electrodes for measurement of resistivity of the conductor screen 50Figure J.2 Test piece and arrangement of electrodes for

10、measurement of resistivity of the insulation screen 51Figure L.1 Test cell for wet compatibility test of galvanized steel wires and semi-conducting tape layers 52Figure M.1 Abrasion test 54List of tablesTable 1 Nominal thickness of insulation 5Table 2 Thickness of extruded inner covering 6Table 3 No

11、minal diameter of round armour wires 8Table 4 Schedule of tests 12Table 5 Tolerances on temperature values 14Table 6 DC resistance of copper wire screen 15Table 7 Voltage for partial discharge test 15Table 8 Voltage test on complete cable 16Table 9 Number of samples for the four-hour voltage test, t

12、he hot set test on the insulation and the smoke emission test 17Table 10 Minimum transmittance levels 20Table 11 Voltages for four-hour voltage test 21Table 12 Mass of zinc coating 22Table 13 Compatibility requirements 24Table 14 Tan in relation to voltage 26Table 15 Tan in relation to temperature 2

13、6Table 16 Voltage for impulse voltage test 27Table A.1 Selection of cables for three-phase a.c. systems 30Table C.1 Bending radius during installation 33Table C.2 Bending radius during installation for cables adjacent to joints or terminations 33Table E.1 Fictitious diameter of conductor 40Table E.2

14、 Increase of diameter for concentric conductors and metallic screens 41Table M.1 Vertical force on cable during abrasion test 53Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iii, a blank page, pages 1 to 56, an inside back cover and a back cover. BSI 2008 i

15、iiBS 7835:2007ForewordPublishing informationThis British Standard is published by BSI and came into effect on 30 November 2007. It was prepared by Subcommittee GEL/20/16, Medium/high voltage cables, under the authority of Technical Committee GEL/20, Electric cables. A list of organizations represent

16、ed on this committee can be obtained on request to its secretary. SupersessionThis British Standard supersedes BS 7835:2000, which is withdrawn.Information about this documentThis revision of BS 7835 has been prepared to bring the requirements up to date in accordance with current practice in the in

17、dustry and to align with the methods used for calculating cable component dimensions given in IEC 60502-2.This standard specifies requirements for cables in the rated voltage range from 3.8/6.6 kV up to 19/33 kV which are insulated with cross-linked polyethylene (XLPE) or ethylene propylene rubber c

18、ompound (EPR), with improved performance under fire conditions compared to the cables specified in BS 6622.Hazard warningsUse of this documentIt has been assumed in the preparation of this British Standard that the execution of its provisions will be entrusted to appropriately qualified and experien

19、ced people, for whose use it has been produced.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Its requirements are expressed in sentences in which the principal auxiliary verb is “shall”.Commentary, explanation and general informative material i

20、s presented in smaller italic type and does not constitute a normative element.Contractual and legal considerationsThis publication does not purport to include all necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer i

21、mmunity from legal obligations.WARNING. This British Standard calls for the use of substances and/or procedures that can be injurious to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations relating to health and s

22、afety at any stage.iv BSI 2008 This page deliberately left blankBS 7835:2007 BSI 2008 1BS 7835:20071 ScopeThis British Standard specifies requirements and test methods for the construction, dimensions and mechanical and electrical properties of armoured cables with thermosetting insulation for rated

23、 voltages from 3.8/6.6 (7.2) kV up to 19/33 (36) kV inclusive which, when assessed by the specified tests, produce lower levels of smoke and corrosive gases on exposure to fire compared to the cables specified in BS 6622. It covers cables designed for a maximum continuous conductor operating tempera

24、ture of 90 C and for a maximum short circuit conductor temperature of 250 C, for use in fixed installations such as networks or industrial installations. This British Standard specifies single-core and three-core cables for voltages in the range 3.8/6.6 (7.2) kV up to 19/33 (36) kV, with: a stranded

25、 copper, stranded aluminium or solid aluminium conductor or conductors; cross-linked polyethylene or cross-linked ethylene propylene rubber insulation; a metallic screening layer of copper wire or copper tape and/or a metallic armour of aluminium or galvanized steel wire; a thermoplastic oversheath.

26、NOTE Guidance on the selection of cables is given in Annex A. Information to be supplied by the purchaser, and items to be agreed between the purchaser and the manufacturer, at the time of enquiryand/or order, are given in Annex B. Recommendations for the installation of cables are given in Annex C.

27、 Guidance on the use of cables is given in Annex D.2 Normative referencesThe 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 a

28、ny amendments) applies.BS 5099, Electric cables Voltage levels for spark testingBS 7655-1.2, Specification for insulating and sheathing materials for cables Part 1: Cross-linked elastomeric insulating compounds Section 1.2: General 90 C applicationBS 7655-1.3, Specification for insulating and sheath

29、ing materials for cables Part 1: Cross-linked elastomeric insulating compounds Section 1.3: XLPEBS 7655-6.1, Specification for insulating and sheathing materials for cables Part 6: Thermoplastic sheathing compounds having low emission of corrosive gases and suitable for use in cables having low emis

30、sion of smoke when affected by fire Section 6.1: General application thermoplastic typesBS EN 10002-1, Metallic materials Tensile testing Part 1: Method of test at ambient temperatureBS EN 10244-2, Steel wire and wire products Non-ferrous metallic coatings on steel wire Part 2: Zinc or zinc alloy co

31、atingsBS 7835:20072 BSI 2008BS EN 50266-2-4:2001, Common test methods for cables under fire conditions Test for vertical flame spread of vertically mounted bunched wires or cables Part 2-4: Procedures Category CBS EN 50267-2-1, Common test methods for cables under fire conditions Tests on gases evol

32、ved during combustion of materials from cables Part 2-1: Procedures Determination of amount of halogen acid gasBS EN 50356, Method for spark testing of cablesBS EN 60228, Conductors of insulated cablesBS EN 60230, Impulse tests on cables and their accessoriesBS EN 60332-1-2:2004, Tests on electric a

33、nd optical fibre cables under fire conditions Part 1-2: Test for vertical flame propagation for a single insulated wire or cable Procedure for 1 kW pre-mixed flameBS EN 60811-1-1, Insulating and sheathing materials of electric and optical cables Common test methods Part 1-1: General application Meas

34、urement of thickness and overall dimensions Tests for determining the mechanical properties BS EN 60811-1-2, Common test methods for insulating and sheathing materials of electric and optical cables Part 1-2: General application Thermal ageing methods BS EN 60811-1-3, Insulating and sheathing materi

35、als of electric and optical cables Common test methods Part 1-3: General application Methods for determining the density Water absorption tests Shrinkage testBS EN 60885-3, Electrical test methods for electric cables Part 3: Test methods for partial discharge measurements on lengths of extruded powe

36、r cablesBS EN 61034-2, Measurement of smoke density of cables burning under defined conditions Part 2: Test procedure and requirementsIEC 60050-461, International Electrotechnical Vocabulary Part 461: Electric cables3 Terms and definitionsFor the purposes of this British Standard, the terms and defi

37、nitions given in IEC 60050-461 and the following apply.3.1 rated voltagereference voltage for which the cable is designed NOTE This is expressed as a combination of the values U0, U and Um.3.2 rated voltage U0nominal power-frequency voltage between any conductor and earth or metallic screen for whic

38、h the cable is suitable3.3 rated voltage Unominal power-frequency voltage between phase conductors for which the cable is suitable BSI 2008 3BS 7835:20073.4 maximum voltage Ummaximum sustained power-frequency voltage between phase conductors for which the cable is suitable3.5 cross-linked polyethyle

39、ne (XLPE)thermosetting material formed by the cross-linking of thermoplastic polyethylene compound 3.6 ethylene propylene rubber compound (EPR)thermosetting material comprising a cross-linked compound in which the elastomer is ethylene-propylene 3.7 nominal valuevalue, often used in tables, by which

40、 a quantity is designated NOTE In this standard, actual values to be checked by measurement, and on which tolerances are given, are usually specified in relation to particular nominal values. 3.8 approximate valuevalue which is only indicativeNOTE In this standard, values described as “approximate”

41、do not constitute requirements to be checked by measurements.3.9 fictitious valuevalue calculated in accordance with the “fictitious method” described in Annex E IEC 60502-2:2005, 3.1.4NOTE The fictitious values referred to in the present standard are “fictitious diameters”.3.10 routine teststests p

42、erformed by the manufacturer on each manufactured length of cable to check whether the whole of each length meets the specified requirements3.11 sample teststests performed by the manufacturer on samples of completed cable, or components taken from a completed cable, at a specified frequency, to det

43、ermine whether the finished product meets the specified requirements3.12 type teststests made before supplying a particular type of cable on a general commercial basis, to determine whether the cable has satisfactory performance characteristics to be suitable for the intended application NOTE Type t

44、ests are of such a nature that, after they have been performed, they need not be repeated unless changes are made in the cable materials or design or manufacturing process which might change the performance characteristics.BS 7835:20074 BSI 20084 Voltage designationCables shall be designated by the

45、voltages U0, U and Umexpressed in the form U0/U (Um).NOTE The voltage designations of cables specified in this standard are as follows: 3.8/6.6 (7.2) kV; 6.35/11 (12) kV; 8.7/15 (17.5) kV; 12.7/22 (24) kV; 19/33 (36) kV.5 Non-metallic materialsIn addition to the particular requirements specified for

46、 each material, all non-metallic materials shall meet the performance requirement for corrosive and acid gas specified in 20.2.6 ConductorsConductors shall be either plain annealed copper or aluminium, circular, and shall conform to BS EN 60228. Copper conductors shall be stranded (class 2) and alum

47、inium conductors shall be either solid (class 1) or stranded (class 2). Conductors shall be compacted or uncompacted and be between 70 mm2and 1 000 mm2for copper or aluminium stranded conductors (class 2) and 70 mm2to 300 mm2for solid aluminium conductors (class 1).7 Conductor screenA conductor scre

48、en consisting of an extruded layer of a cross-linkable semi-conducting compound shall be applied over the conductor and shall cover the surface of the conductor completely.NOTE A semi-conducting tape may be applied prior to the extruded layer, at the discretion of the manufacturer.The conductor scre

49、en shall be applied in the same operation as the insulation and shall be fully bonded to the insulation.8InsulationThe insulation shall be either XLPE (type GP 8) conforming to BS 7655-1.3 or EPR (type GP 7) conforming to BS 7655-1.2.The insulation shall be applied by extrusion and cross-linked to form a compact and homogeneous layer.NOTE The colour of the insul