1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS 7870-3.12:2011Incorporating Corrigendum No. 1LV and MV polymericinsulated cables for use bydistribution and generationutilitiesPart 3: Specification for distributioncables of
2、rated voltage 0.6/1 kVSection 3.12: XLPE insulatedcombined neutral and earth copperwire concentric cables with copperor aluminium conductors, havinglow emission of smoke and corrosivegases when affected by fire(Implementation of HD 603)Publishing and copyright informationThe BSI copyright notice dis
3、played in this document indicates when the documentwas last issued. The British Standards Institution 2012Published by BSI Standards Limited 2012ISBN 978 0 580 78835 2ICS 29.060.20The following BSI references relate to the work on this standard:Committee reference GEL/20/16Draft for comment 11/30214
4、061 DCPublication historyFirst published August 2001Second (present) edition, December 2011Amendments issued since publicationDate Text affectedAugust 2012 See forewordBS 7870-3.12:2011 BRITISH STANDARDContentsForeword ii1 Scope 12 Normative references 13 Voltage designation 24 Phase conductors 25 I
5、nsulation 26 Assembly of cores 27 Bedding for 3-phase cables 28 Concentric neutral/earth conductor 29 Oversheath 310 Marking 311 End sealing 512 Dimensions 513 Tests 814 Routine tests 915 Sample tests 916 Type tests 10AnnexesAnnex A (informative) Guide to selection and use of cables 12Annex B (norma
6、tive) Test for shrinkage of oversheath on cable 13Bibliography 14List of tablesTable 1 Cables with single phase copper conductor and helical concentriccopper neutral/earth conductor 5Table 2 Cables with single phase aluminium conductor and helical concentriccopper neutral/earth conductor 6Table 3 Ca
7、bles with 3-phase copper conductors and helical concentric copperneutral/earth conductor 6Table 4 Cables with 3-phase aluminium conductors and helical concentriccopper neutral/earth conductor 7Table 5 Schedule of tests 8Table 6 Requirements for compatibility of insulation and oversheath 11Table A.1
8、Guide to use 12Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv,pages 1 to 14, an inside back cover and a back cover.BRITISH STANDARD BS 7870-3.12:2011 The British Standards Institution 2012 iForewordPublishing informationThis section of BS 7870 is publishe
9、d by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 31 December 2011. Itwas prepared by Subcommittee GEL/20/16, Medium/High voltage cables, underthe authority of Technical Committee GEL/20, Electric cables. A list oforganizations represented on th
10、ese committees can be obtained on request totheir secretary.SupersessionThis section of BS 7870 supersedes BS 7870-3.12:2001, which is withdrawn.Relationship with other publicationsBS 7870 implements the nationally applicable parts of Harmonization DocumentsHD 603, 605, 620, 626 and 627 published by
11、 the European Committee forElectrotechnical Standardization (CENELEC) in accordance with the decision ofthe CENELEC Technical Board.BS 7870 applies to cables for fixed installations having a rated voltage U0/U upto and including 19/33 kV, and is published as a series of separate parts andsections, a
12、s listed in the table in the foreword of BS 7870-1.BS 7870-3.12 specifies a range of XLPE insulated combined neutral/earth (CNE)service cables having low emission of smoke and corrosive gases when affectedby fire; it implements Part 5S of HD 603 S1 A3, and is to be read in conjunctionwith BS 7870-1
13、and BS 7870-2.Information about this documentThis is a full revision of the standard, and brings the standard up to date inaccordance with current practice in the industry.The start and finish of text introduced or altered by Corrigendum No. 1 isindicated in the text by tagsand.A general guide to us
14、e for the types of cable specified in BS 7870 is given inBS 7870-1 and specific details for the types of cable specified in this section ofBS 7870 are given in Annex A.Hazard warningsWARNING. This British Standard calls for the use of substances and/orprocedures that can be injurious to health if ad
15、equate precautions are nottaken. It refers only to technical suitability and does not absolve the userfrom legal obligations relating to health and safety at any stage.Use of this documentIt has been assumed in the preparation of this British Standard that theexecution of its provisions will be entr
16、usted to appropriately qualified andexperienced people, for whose use it has been produced.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Itsrequirements are expressed in sentences in which the principal auxiliary verb is“shall”.Commentary, expl
17、anation and general informative material is presented insmaller italic type, and does not constitute a normative element.BRITISH STANDARDBS 7870-3.12:2011ii The British Standards Institution 2012Contractual and legal considerationsThis publication does not purport to include all the necessary provis
18、ions of acontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.BRITISH STANDARD BS 7870-3.12:2011 The British Standards Institution 2012 iiiBRITISH STANDARDBS 7870-3.12:2011This page deliberately left blankiv The B
19、ritish Standards Institution 20121 ScopeThis section of BS 7870 specifies requirements for the construction, dimensionsand mechanical and electrical properties of concentric copper wire combinedneutral/earth (CNE) service cables having a rated voltage of 0.6/1 (1.2) kV. It isapplicable to cables tha
20、t, when assessed by the specified tests, produce lowerlevels of smoke and corrosive gases under exposure to fire than cablesconforming to BS 7870-3.11.It specifies requirements for the following types of cable:a) single phase or 3-phase;b) stranded copper or solid aluminium conductors;c) XLPE insula
21、tion and thermoplastic oversheath with low emission of smokeand corrosive gases when affected by fire.This section of BS 7870 is applicable to cables that are designed for a maximumcontinuous conductor operating temperature of 90 C and for a maximum shortcircuit conductor temperature of 250 C.2 Norm
22、ative referencesThe following referenced documents are indispensable for the application ofthis document. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including anyamendments) applies.BS 3988:1970+A3:1989, Specification f
23、or wrought aluminium for electricalpurposes Solid conductors for insulated cablesBS 7870-1, LV and MV polymeric insulated cables for use by distribution andgeneration utilities Part 1: GeneralBS 7870-2, LV and MV polymeric insulated cables for use by distribution andgeneration utilities Part 2: Meth
24、ods of testBS EN 50267-2-1, Common test methods for cables under fire conditions Testson gases evolved during combustion of materials from cables Part 2-1: Procedures Determination of the amount of halogen acid gasBS EN 60228, Specification for conductors in insulated cables and cordsBS EN 60332-1-2
25、:2004, Tests on electric and optical fibre cables under fireconditions Part 1-2: Test for vertical flame propagation for a single insulatedwire or cable Procedure for 1 kW pre-mixed flameBS EN 60332-3-24:2009, Tests on electric and optical fibre cables under fireconditions Part 3-24: Test for vertic
26、al flame spread of vertically-mountedbunched wires or cables Category CBS EN 60811-1-2, Common test methods for insulating and sheathing materialsof electric and optical cables Part 1-2: General application Thermal ageingmethodsBS EN 60811-1-3, Insulating and sheathing materials of electric and opti
27、calcables Common test methods Part 1-3: General application Methods fordetermining the density Water absorption tests Shrinkage testBS EN 61034-1, Measurement of smoke density of cables burning under definedconditions Part 1: ApparatusBS EN 61034-2, Measurement of smoke density of cables burning und
28、er definedconditions Part 2: Test procedure and requirementsBRITISH STANDARD BS 7870-3.12:2011 The British Standards Institution 2012 13 Voltage designationCables shall be designated by the voltages U0, U and Um, expressed in the formU0/U (Um).The voltage designation of cables in this standard shall
29、 be 0.6/1(1.2) kV.The rated voltage of the cable shall be at least equal to the nominal voltage ofthe system for which it is intended.4 Phase conductorsThe phase conductors shall be either stranded (class 2) plain annealed copper orsolid (class 1) aluminium conductors in accordance with BS EN 60228.
30、 Class 1conductors shall also conform to the dimensional requirements specified inBS 3988:1970+A3, 2.4.1.Conformity shall be checked by visual examination and, in the case of class 1conductors, by measurement, as specified in 15.2.The d.c. resistance shall conform to the relevant value given in Tabl
31、e 1 toTable 4, as applicable.Conformity shall be checked by the test method specified in 14.2.5 InsulationThe insulation shall be XLPE compound type DIX 3, conforming to therequirements given in BS 7870-1, Annex B.The insulation shall be applied by extrusion and shall form a compact andhomogeneous l
32、ayer.The thickness of the insulation shall be in accordance with the relevant valuesspecified in Table 1 to Table 4, as applicable.Conformity shall be checked by the test method specified in 15.4.The cores of all cables shall be identified by colours, as follows:a) single-core: brown;b) 3-core: brow
33、n, black and grey.6 Assembly of coresThe cores of 3-phase cables shall be laid up with a right-hand direction of layand a minimum lay length of 550 mm.NOTE Where necessary, fillers of suitable synthetic material may be used.7 Bedding for 3-phase cablesA synthetic tape bedding, having an approximate
34、total thickness of 0.5 mm,shall be applied over the laid-up cores of 3-phase cables.8 Concentric neutral/earth conductorThe neutral/earth conductor shall consist of a single layer of plain annealedcopper wires applied with either a right- or left-hand direction of lay or analternating right- and lef
35、t-hand direction of lay.The gap between adjacent wires shall not exceed 4 mm.BRITISH STANDARDBS 7870-3.12:20112 The British Standards Institution 2012The lay length shall not exceed the relevant value given in Table 1 to Table 4, asapplicable, by more than 50%Conformity shall be checked by visual ex
36、amination and measurement asspecified in 15.3.The d.c. resistance shall conform to the relevant value given in Table 1 toTable 4, as applicable.Conformity shall be checked by the test method specified in 14.2.NOTE 1 Examples of concentric conductor construction are given in Table 1 toTable 4.NOTE 2
37、One or more overlapped synthetic binder tapes may be appliedimmediately over the concentric conductor layer.9 OversheathThe oversheath shall be an extruded layer of compound type DMZ 4,conforming to the requirements given in BS 7870-1, Annex B.NOTE Oversheaths are normally orange but colours other t
38、han orange may beprovided by agreement between the manufacturer and the purchaser, subject totheir suitability for the particular conditions under which the cables are to be used.The thickness of the oversheath shall conform to the relevant value specified inTable 1 to Table 4, as applicable.Conform
39、ity shall be checked by the test methods specified in 15.5.10 Marking10.1 External markingThe external surface of the cable shall be legibly marked with the followingelements:Element Example of markinga) Cable manufacturer Manufacturers name and their uniquefactory identifierNOTE 1 A simplified vers
40、ion of the manufacturers name, or trading name of themanufacturer, may be used in place of the full name.NOTE 2 Any suitable method may be used to unambiguously identify themanufacturers factory.NOTE 3 The manufacturers own trademark or equivalent may be added but thiscannot be used instead of the m
41、anufacturers name and identifier.b) Electric cable ELECTRIC CABLEc) Voltage designation 600/1 000 Vd) British Standard number BS 7870-3.121)1)Marking BS 7870-3.12 on or in relation to a product represents a manufacturersdeclaration of conformity, i.e. a claim by or on behalf of the manufacturer that
42、 theproduct meets the requirements of the standard. The accuracy of the claim is solelythe claimants responsibility. Such a declaration is not to be confused with third-partycertification of conformity.BRITISH STANDARD BS 7870-3.12:2011 The British Standards Institution 2012 3e) Number of cores, typ
43、e and nominalarea of phase conductors, e.g.:3-core cable with 25 mm2aluminium phase conductors325ALsingle-core cable with a 25 mm2copper phase conductor125f) Year of manufacture YYYYNOTE 4 The year of manufacture may take the form of the actual year (e.g. 2011)or a coded year identifier assigned by
44、the manufacturer.The marking of elements a) to f) shall be by embossing or by indenting on theoversheath.For cables with overall diameters greater than 15 mm, as given in Table 1 toTable 4, elements b), c) and d) shall appear, in any sequence that is deemedneither to confuse nor to conflict, on two
45、or more primary lines along the axisof the cable, approximately equally spaced around the circumference of thecable. Elements a), e) and f) shall appear, together or separately, in anysequence that is deemed neither to confuse nor to conflict, either on one of theprimary lines, or on a secondary lin
46、e or lines.For cables with overall diameters of 15 mm or less, as given in Table 1 toTable 4, the elements shall be arranged as for cables of greater than 15 mmdiameter, except that the marking for elements b), c) and d) shall appear on oneor more primary lines.The letters and figures shall consist
47、of upright block characters. The charactersshall have a minimum height of 3 mm.The distance between the end of one element of marking and the beginning ofthe next identical element shall be not greater than 550 mm for elements b), c)and d), and not greater than 1 100 mm for elements a), e) and f).Co
48、nformity shall be checked by visual examination and measurement asspecified in 14.5.10.2 Mark of an approval organizationIf the mark of an approval organization is used, it shall be provided throughoutthe length of the cable, either as an identification thread or by marking on theexternal surface of
49、 the cable, as specified by the approval organization.If the mark is on the external surface of the cable, it shall be in the form of thesymbol(s) specified by the approval organization, and the distance between theend of one element of marking and the beginning of the next identical elementshall be not greater than 1 100 mm.Conformity shall be checked by visual examination and measurement asspecified in 14.5.10.3 Additional markingWhere additional marking is made, it shall be throughout the length of the
