BS 7870-8 4-2003 LV and MV polymeric insulated cables for use by distribution and generation utilities - Specification for multicore and multipair cables for installation above and.pdf

1、BRITISH STANDARD BS 7870-8.4:2003 LV and MV polymeric insulated cables for use by distribution and generation utilities Part 8: Specification for multicore and multipair cables for installation above and below ground Section 8.4: Single wire or double steel tape armoured and PVC sheathed multipair c

2、able with copper conductors, having reduced fire propagation performance (Implementation of part of HD 627) ICS 29.060.20 BS 7870-8.4:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 16 June 2003 BSI 16 June 2003 The following BSI referen

3、ces relate to the work on this British Standard: Committee reference GEL/20/16 Draft for comment 99/244662 DC ISBN 0 580 37570 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee GEL/20, Cables, to Subcommittee GEL/20/16, M

4、edium/high voltage cables, upon which the following bodies were represented: British Approval Service for Cables British Cables Association British Plastics Association Electricity Association ERA Technology Co-opted members Amendments issued since publication Amd. No. Date CommentsBS 7870-8.4:2003

5、BSI 16 June 2003 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative references 1 3 Rated voltage 1 4C o n d u c t o r s 2 5 Insulation 2 6 Identification of cores 2 7 Assembly of cores, fillers and binders 3 8 Rip cord 3 9 Collective screen 3 10 Bedding la

6、yer 3 11 Armouring 4 12 Oversheath 4 13 Marking 4 14 Dimensions 5 15 Tests 7 16 Routine tests 8 17 Sample tests 8 18 Type tests 10 Annex A (informative) Guide to use 14 Bibliography 17 Table 1 Colour codes 2 Table 2 Multipair cables 6 Table 3 Schedule of tests 7 Table 4 Diameter of armour wire 9 Tab

7、le 5 Type approval tests 10 Table 6 Mass of zinc coating 11 Table 7 Requirements for non-electrical tests for polyvinyl chloride 12BS 7870-8.4:2003 ii BSI 16 June 2003 Foreword This section of BS 7870 has been prepared by Subcommittee GEL/20/16, under the direction of Technical Committee GEL/20. BS

8、7870 implements the nationally applicable parts of Harmonization Documents HD 603, HD 604, HD 605, HD 620, HD 622, HD 626 and HD 627 published by the European Committee for Electrotechnical Standardization (CENELEC) in accordance with the decision of the CENELEC Technical Board. BS 7870 applies to c

9、ables for fixed installations having a rated voltage U 0 /U up to and including 19/33 kV, and is published as a series of separate parts and sections, as listed in the table in the foreword of BS 7870-1. BS 7870-8.4 implements HD 627:Part 5A2 and is to be read in conjunction with BS 7870-1 and BS 78

10、70-2. It has been assumed in the preparation of this British Standard that the execution of its provisions will be entrusted to appropriately qualified and experienced people, for whose use it has been produced. WARNING. This British Standard calls for procedures that may be injurious to health if a

11、dequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct a

12、pplication. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 17 and a back cover. The BSI copyright notice displayed in this document indicates when

13、the document was last issued.BS 7870-8.4:2003 BSI 16 June 2003 1 1 Scope This section of BS 7870 specifies requirements for the construction, dimensions and mechanical and physical properties of multipair PVC insulated and PVC sheathed cables having reduced fire propagation performance conforming to

14、 BS EN 50265-2-1 and BS EN ISO 4589-3. It specifies requirements for: a) multipair cables (2 pairs to 200 pairs) having copper conductors, a collective screen and armouring consisting of a single layer of steel wires; b) multipair cables (20 pairs to 200 pairs) having copper conductors, a collective

15、 screen and armouring consisting of a double layer of steel tapes. This section of BS 7870 is applicable to cables for use in and around power stations and other installations having similar cable densities. NOTE A “guide to use” is given in Annex A. 2 Normative references The following referenced d

16、ocuments 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. BS 6360, Specification for conductors in insulated cables and cords. BS 787

17、0-1, LV and MV polymeric insulated cables for use by distribution and generation utilities Part 1: General. BS 7870-2:1999, LV and MV polymeric insulated cables for use by distribution and generation utilities Part 2: Methods of test. BS 7655-3.1, Specification for insulating and sheathing materials

18、 for cables Part 3: PVC insulating compounds Section 3.1: Harmonized types. BS 7655-4.1, Specification for insulating and sheathing materials for cables Part 4: PVC sheathing compounds Section 4.1: Harmonized types. BS EN 50265-2-1, Common test methods for cables under fire conditions Test for resis

19、tance to vertical flame propagation for a single insulated conductor or cable Part 2-1: Procedures 1 kW pre-mixed flame. BS EN 60811-1-1:1995, Insulating and sheathing materials of electric cables Common test methods Part 1-1: General application Measurement of thickness and overall dimensions Tests

20、 for determining the mechanical properties. BS EN 60811-1-4:1995, Insulating and sheathing materials for electric cables Common test methods Part 1-4: General application Test at low temperatures. BS EN 60811-3-1:1995, Insulating and sheathing materials for electric cables Common test methods Part 3

21、-1: Methods specific to PVC compounds Pressure test at high temperature Tests for resistance to cracking. BS EN 60811-3-2:1995, Insulating and sheathing materials for electric cables Common test methods Part 3-2: Methods specific to PVC compounds Loss of mass test Thermal stability test. BS EN ISO 4

22、589-3, Plastics Determination of burning behaviour by oxygen index Part 3: Elevated temperature test. IEC 60189-1:1986, Low frequency cables and wires with PVC insulation and PVC sheath Part 1: General test and measuring methods. IEC 60189-2:1986, Low frequency cables and wires with PVC insulation a

23、nd PVC sheath Part 2: Cables in pairs, triples, quads and quintuples for inside installation. 3 Rated voltage The rated voltage of cables in this standard is 100 V a.c. or 150 V d.c.BS 7870-8.4:2003 2 BSI 16 June 2003 4 Conductors Conductors shall be of plain copper wire consisting of a single stran

24、d of 0.8 mm nominal diameter, conforming to the requirements of BS 6360. Conformity shall be checked by visual examination as specified in 17.2. 5 Insulation The insulation shall be PVC compound type TI X, conforming to the requirements specified in Table 2. The insulation shall be applied so that i

25、t fits closely on the conductor and it shall be possible to remove it without damage to the insulation itself or to the conductor. The insulation shall be applied by a suitable extrusion process, cross-linked where required, and shall form a compact and homogenous body. Conformity shall be checked b

26、y the test methods specified in 17.3. 6 Identification of cores 6.1 Cores With the exception of 2-pair cables, the insulation of cores shall be colour coded in accordance with the code given in IEC 60189-2 and in Table 1 using cabling elements 1 to 20 inclusive, in sequence. The cores of 2-pair cabl

27、es shall be laid up as a quad in the sequence white, red, blue, orange. Table 1 Colour codes Conformity shall be checked by visual examination as specified in 17.5.1. Cabling element Colour of insulation Wire a Wire b 1 White Blue 2W h i t eO r a n g e 3W h i t eG r e e n 4W h i t eB r o w n 5W h i

28、t eG r e y 6R e dB l u e 7R e dO r a n g e 8 Red Green 9R e dB r o w n 10 Red Grey 11 Black Blue 12 Black Orange 13 Black Green 14 Black Brown 15 Black Grey 16 Yellow Blue 17 Yellow Orange 18 Yellow Green 19 Yellow Brown 20 Yellow GreyBS 7870-8.4:2003 BSI 16 June 2003 3 6.2 Pairs, quads and units Th

29、e cores of 2-pair cables shall be colour coded as detailed in 6.1 and shall be laid up in quad formation and bound overall with non-hygroscopic tape binder as detailed below. 5-pair and 10-pair cables shall consist of cabling elements colour coded 1 to 5 and 1 to 10 respectively as detailed in Table

30、 1, and shall be laid up to form a compact and symmetrical cable. The laid-up group shall be bound overall with a non-hygroscopic tape binder as detailed below. Non-hygroscopic fillers shall be used if necessary for the 2-pair, 5-pair and 10-pair constructions in order to form a compact and symmetri

31、cal cable. 20-pair to 200-pair cables shall be constructed from the required number of cabling units. Each cabling unit shall consist of 20 cabling elements colour coded 1 to 20 as detailed above, laid up in concentric layers to form a compact and symmetrical unit. The cabling unit shall be bound ov

32、erall with non-hygroscopic tape binder of minimum thickness 0.023 mm and shall be applied with a minimum overlap of 25 %. The required number of cabling units, individually identified as detailed below, shall be laid up in concentric layers to form a compact and symmetrical cable and shall be bound

33、overall with a double layer of clear non-hygroscopic tape, the layers being applied in opposite directions. Open spiral inter-layer tapes shall be applied if necessary. The cable construction shall consist of the required number of cabling units, using non-hygroscopic fillers where necessary, to for

34、m a compact and symmetrical cable. The cabling units in cables having 40 pairs or more shall be individually identified by printed numbers of a contrasting colour to the natural base. The printed numbers shall be applied direct on to the tape forming the unit binder or on a separate longitudinal tap

35、e applied under a (clear) unit binder tape. The numbers shall run from one upwards in units of one. The height of the figures shall be not less than 2 mm and shall be spaced such that ready identification of all units is possible in any 50 mm of cable. The figures shall be applied with an ink that i

36、s capable of withstanding the effect of wiping with a dry or wet cloth, and that will remain identifiable after the removal of the cable bedding and collective screen. Conformity shall be checked by visual examination as specified in 17.5.2. 7 Assembly of cores, fillers and binders Cables shall be t

37、winned and where required formed into separate identifiable units, which shall then be laid up to form a compact and symmetrical cable using non-hygroscopic fillers and binders as required. Conformity shall be checked by visual examination as specified in 17.6. 8 Rip cord A terylene rip cord shall b

38、e included to facilitate stripping. 9 Collective screen 2-pair cables with binding tape shall have a plain aluminium tape of minimum thickness 0.075 mm, applied helically with a minimum 25 % overlap, in contact with which shall be a 1/0.8 mm tinned copper drain wire or stranded conductor of equivale

39、nt cross-sectional area. 5-pair and above cables shall have a collective aluminium screen with a backing which will ensure adhesion to the bedding. The laminated screen tape shall be applied longitudinally over the rip cord and drain wire and shall be in electrical contact with the latter, which sha

40、ll be a 1/0.8 mm diameter tinned copper wire. The laminated screen shall be a minimum thickness of 0.15 mm aluminium bonded to a suitable backing material. Conformity shall be checked by measurement as specified in 17.8. 10 Bedding layer The bedding layer shall be PVC compound type TI 1, conforming

41、to the requirements of BS 7655-3.1.BS 7870-8.4:2003 4 BSI 16 June 2003 11 Armouring Cables shall be armoured either with a single layer of galvanized steel wires, applied with a direction of lay opposite to that of the pairs, or (for 20-pair to 200-pair cables) with a double layer of galvanized stee

42、l tape, each 0.5 mm thick. The tapes shall be applied helically with the outer tape covering the gap between the turns of the inner tape. Joints in the steel wire armour shall be brazed or welded and any surface irregularity shall be removed. Any joint in any wire shall be not less than 1 m from the

43、 nearest joint in any other armour wire in the complete cable. NOTE Tapes may be applied over the armour layer. Conformity shall be checked by visual examination as specified in 17.11. 12 Oversheath The oversheath shall be an extruded layer of PVC compound type TM 1, conforming to the requirements o

44、f BS 7655-4.1. 13 Marking 13.1 External marking The external surface of the cable shall be legibly marked with the following elements: 1) The marking shall be by indenting or embossing on the oversheath. For cables with tabulated 2)approximate overall diameters greater than 15 mm, elements a), b) an

45、d c) shall appear, in any sequence that is deemed neither to confuse nor to conflict, on two or more primary lines along the axis of the cable, approximately equally spaced around the circumference of the cable. Element d) shall appear upon at least one line, which may be one of the primary lines or

46、 a secondary line. For cables with tabulated 2)approximate overall diameters of 15 mm or less, the elements shall be arranged as for cables of greater than 15 mm diameter, except that the marking for elements a), b) and c) shall appear on one or more primary lines. The letters and figures shall cons

47、ist of upright block characters. The characters shall have a minimum height of 3 mm. The distance between the end of one element of marking and the beginning of the next identical element shall be not greater than 550 mm for elements a), b) and c) and not greater than 1 100 mm for element d). Confor

48、mity shall be checked by visual examination and measurement as specified in 16.6. 1) Marking BS 7870-8.4:2003 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the requirements of the standard.

49、 The accuracy of the claim is solely the claimants responsibility. Such a declaration is not to be confused with third-party certification of conformity. Element Example of marking a) Electric cable ELECTRIC CABLE b) Voltage designation 100 V c) British Standard number 1) BS 7870-8.4 d) Manufacturers identification XYZ 2) See Table 2.BS 7870-8.4:2003 BSI 16 June 2003 5 13.2 Identification of year of manufacture A means o