BS 7870-8 1-2003 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 7870-8.1:2003 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 8.1: Single wire armoured and PVC sheathed multicore cable with copper cond

2、uctors (Implementation of part of HD 627) ICS 29.060.20 BS 7870-8.1:2003 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 references relate to the work on this British Standard: Committee referen

3、ce GEL/20/16 Draft for comment 99/244662 DC ISBN 0 580 37567 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, Medium/high voltage cables, upon which the following bodies were re

4、presented: 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 7870-8.1:2003 BSI 16 June 2003 i Contents Page Committees responsible Inside fro

5、nt cover Foreword ii 1S c o p e 1 2 Normative references 1 3 Voltage designation 1 4C o n d u c t o r s 1 5 Insulation 1 6 Identification of cores 2 7 Assembly of cores, fillers and binders 2 8 Bedding layer 2 9A r m o u r i n g 2 10 Oversheath 2 11 Marking 3 12 Dimensions 4 13 Tests 6 14 Routine te

6、sts 6 15 Sample tests 7 16 Type tests 8 Annex A (informative) Guide to use 10 Bibliography 13 Table 1 Cable construction 5 Table 2 Schedule of tests 6 Table 3 Diameter of armour wire 8 Table 4 Mass of zinc coating 9 Table 5 Requirements for compatibility of insulation and oversheath 9BS 7870-8.1:200

7、3 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 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

8、the European Committee for Electrotechnical Standardization (CENELEC) in accordance with the decision of the CENELEC Technical Board. BS 7870 applies to cables 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 secti

9、ons, as listed in the table in the foreword of BS 7870-1. BS 7870-8.1 implements HD 627-3A1 and is to be read in conjunction with BS 7870-1 and BS 7870-2. It has been assumed in the preparation of this British Standard that the execution of its provisions will be entrusted to appropriately qualified

10、 and experienced people, for whose use it has been produced. WARNING. This British Standard calls for procedures that may 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

11、safety at any stage. 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 does not of itself confer immunity from legal obligations. Summary of pages This document comprises a fr

12、ont cover, an inside front cover, pages i and ii, pages 1 to 13 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS 7870-8.1:2003 BSI 16 June 2003 1 1 Scope This section of BS 7870 specifies requirements for the construction, dimension

13、s and mechanical and electrical properties of multicore PVC insulated and PVC sheathed cables. It specifies requirements for steel wire armoured multicore cables (2-core to 37-core) with copper conductors. This section of BS 7870 is applicable to cables for use underground in wet conditions and also

14、 for withstanding high levels of induced voltage. NOTE A “guide to use” is given in Annex A. 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 edit

15、ion of the referenced document (including any amendments) applies. BS 6360, Specification for conductors in insulated cables and cords. BS 7655-3.1, Specification for insulating and sheathing materials for cables Part 3: PVC insulating compounds Section 3.1: Harmonized types. BS 7655-4.1, Specificat

16、ion for insulating and sheathing materials for cables Part 4: PVC sheathing compounds Section 4.1: Harmonized types. BS 7870-1, 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 distr

17、ibution and generation utilities Part 2: Methods of test. 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 for determining the mechanical properties. 3 Voltage designati

18、on Cables shall be designated by the voltages U 0 , U and U m , expressed in the form U 0 /U (U m ). The voltage designation of cables in this standard is 0.6/1 (1.2) kV. 4 Conductors Conductors shall be 2.5 mm 2plain copper stranded circular class 2, conforming to the requirements of BS 6360. Confo

19、rmity shall be checked by visual examination as specified in 15.2. NOTE A separator tape may be applied over the conductor. 5 Insulation The insulation shall be PVC compound type TI 1, conforming to the requirements of BS 7655-3.1. The insulation shall be applied so that it fits closely on the condu

20、ctor 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 and shall form a compact and homogenous body. The thickness of the insulation shall conform to the requirements specified in Table 1

21、. Conformity shall be checked by the test methods specified in 15.3.BS 7870-8.1:2003 2 BSI 16 June 2003 6 Identification of cores The cores shall be black or white with printed numbers in a contrasting colour. The cores shall be numbered in sequence from 1 to 37 as follows: a) 2-core: 1 and 2; b) 3-

22、core: 1, 2 and 3; c) 4-core: 1, 2, 3 and 4; d) 7-core: centre core numbered 1; six cores around numbered 2 to 7; e) 12-core: centre three cores numbered 1, 2 and 3; nine cores around numbered 4 to 12; f) 19-core: centre cores as for 7-core; 12 cores around numbered 8 to 19; g) 27-core: centre cores

23、as for 12-core; 15 cores around numbered 13 to 27; h) 37-core: centre cores as for 19-core; 18 cores around numbered 20 to 37. Cores shall be clearly identifiable and the printing shall be durable. Conformity shall be checked by visual examination as specified in 15.4. 7 Assembly of cores, fillers a

24、nd binders The direction of lay shall alternate for each successive layer. Up to seven cores shall be laid up with either a right- or left-hand direction of lay or an alternating right- and left-hand direction of lay. Conformity shall be checked by visual examination as specified in 15.5. NOTE 1 Whe

25、re necessary, fillers of suitable synthetic material may be used. NOTE 2 At the discretion of the manufacturer, a synthetic binder tape may be applied over the laid-up cores. 8 Bedding layer The bedding shall be an extruded layer of polymer compound, conforming to the requirements specified in Table

26、 1. NOTE Tapes may be applied over the bedding. 9 Armouring The armouring shall consist of a single layer of galvanized steel wires applied in the opposite direction to the outer layer of cores. Joints in the steel wire armour shall be brazed or welded and any surface irregularity shall be removed.

27、Any joint in any wire shall be not less than 1 m from the nearest joint in any other armour wire in the complete cable. NOTE A layer of waterproof compound may be applied over the wires by agreement between the manufacturer and the purchaser. 10 Oversheath The oversheath shall be an extruded layer o

28、f black PVC compound type TM 1, conforming to the requirements of BS 7655-4.1. When required by the purchaser an outer semi-conducting coating shall be applied to serve as an electrode for a voltage test on the oversheath.BS 7870-8.1:2003 BSI 16 June 2003 3 11 Marking 11.1 External marking The exter

29、nal 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) and c) shall appear, in any sequence that is deemed neither

30、 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 a secondary line. For cables with tabulated 2)approximat

31、e 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 consist of upright block characters. The characters shall hav

32、e 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). Conformity shall be checked by visual examination and measureme

33、nt as specified in 14.7. 11.2 Identification of year of manufacture A means of identifying the year of manufacture of the cable shall be provided throughout the length of the cable, either internally or by use of an identification thread or externally by marking on the surface of the cable. If the i

34、dentification is internal, the distance between the end of one mark and the beginning of the next mark shall be not greater than 550 mm. If the identification is by marking on the external surface, the distance between the end of one element of marking and the beginning of the next identical element

35、 shall be not greater than 1 100 mm. Conformity shall be checked by visual examination and measurement as specified in 14.7. 11.3 Mark of an approval organization If the mark of an approval organization is used, it shall be provided throughout the length of the cable, either as an identification thr

36、ead or by marking on the external surface of 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 the symbol(s) specified by the approval organization, and the distance between the end of one element of marking and the

37、beginning of the next identical element shall be not greater than 1 100 mm. Conformity shall be checked by visual examination and measurement as specified in 14.7. 1) Marking BS 7870-8.1:2003 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on b

38、ehalf of the manufacturer that the product meets the requirements of the standard. 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) V

39、oltage designation 600/1 000 V AUX c) British Standard number 1) BS 7870-8.1 d) Manufacturers identification XYZ 2) See Table 1.BS 7870-8.1:2003 4 BSI 16 June 2003 11.4 Additional marking Where additional marking is made, it shall be throughout the length of the cable, and on the external surface of

40、 the cable, or by means of a tape or thread within the cable, or by a combination of these methods. If the additional marking is applied to the surface of the cable it shall not render illegible the marking specified in 11.1, 11.2 and 11.3. The additional marking, however made, shall be repeated at

41、intervals not exceeding 1 100 mm. Conformity shall be checked by visual examination and measurement as specified in 14.7. 12 Dimensions The dimensions of the component layers shall be as specified in Table 1.BS 7870-8.1:2003 BSI 16 June 2003 5 Table 1 Cable construction Dimensions in millimetres Cab

42、le type Conductor Mean thickness of insulation Thickness of bedding Approximate diameter Armour wire diameter Thickness of oversheath Approximate overall diameter No. of wires Nominal diameter of wires Under bedding Over bedding Without semi-conducting coating With semi-conducting coating Without se

43、mi-conducting coating With semi-conducting coating 2-core 7 0.67 0.7 0.8 7.3 8.9 0.9 1.4 1.8 13.6 14.4 3-core 7 0.67 0.7 0.8 7.8 9.4 0.9 1.4 1.8 14.1 14.9 4-core 7 0.67 0.7 0.8 8.7 10.3 0.9 1.4 1.8 15.0 15.8 7-core 7 0.67 0.7 0.8 10.8 12.4 1.25 1.5 1.8 18.0 18.6 12-core 7 0.67 0.7 0.8 14.8 16.4 1.25

44、 1.6 1.8 22.3 22.7 19-core 7 0.67 0.7 1.0 17.8 19.8 1.6 1.7 1.8 26.6 26.8 27-core 7 0.67 0.7 1.0 21.8 23.9 1.6 1.8 1.9 30.7 30.9 37-core 7 0.67 0.7 1.0 24.8 26.8 1.6 1.9 2.0 34.0 34.2BS 7870-8.1:2003 6 BSI 16 June 2003 13 Tests Testing shall be performed in accordance with the schedule of tests spec

45、ified in Table 2. Table 2 Schedule of tests 14 Routine tests 14.1 General Routine tests shall be performed in accordance with the schedule of tests in Table 2 and 14.2 to 14.7. 14.2 Conductor resistance When measured in accordance with BS 7870-2:1999, 3.1.1, the resistance of each conductor at 20 C

46、shall be in accordance with the requirements of BS 6360 for the given class of conductor. 14.3 Insulation resistance When measured in accordance with BS 7870-2:1999, 3.3.2, the insulation resistance shall be not less than 9 M /km. 14.4 Voltage test When the voltage test is carried out in accordance

47、with BS 7870-2:1999, 3.2, using either 5 kV a.c. or 7.5 kV d.c. for 1 min between each conductor and the remaining conductors connected to the armour and earthed, no breakdown of the insulation shall occur. Test Category of test Test method described in Requirements given in Electrical tests Conduct

48、or resistance R BS 7870-2:1999, 3.1.1 14.2 Insulation resistance at 20 C R BS 7870-2:1999, 3.3.2 14.3 Voltage test R BS 7870-2:1999, 3.2.1.2 14.4 Star capacitance T 16.3 16.3 Spark test on oversheath R BS 7870-2:1999, 3.6.1 14.5 Voltage test on oversheath R BS 7870-2:1999, 3.2.3.1 14.6 Provisions co

49、vering constructional and dimensional characteristics Conductor material and construction S Visual examination 15.2 Insulation: application S Visual examination 15.3 thickness S BS 7870-2:1999, 2.1.1 15.3 Core identification S Visual examination and BS 7870-2:1999, 2.5.4 15.4 Laid-up cores S Visual examination 15.5 Bedding layer S BS 7870-2:1999, 2.1.2 15.6 Armour wire: wire diameter S BS 7870-2:1999, 2.1.4.3a) 15.7 mass of zinc coating T BS 7870-2:1999,