SANS 10120-3 LC-1981 Code of practice for use with standardized specifications for civil engineering construction and contract documents Part 3 Guidance for design Section LC Cable.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. SABS 0120 : Part 3 Section LC-1981 Cable ducts PART 3 : GUIDANCE POK DESIGN SECTION LC CONICWS Clause Past Number - PRE-TENDER CONSIDEIUIIONS Investigati

4、ons . Records of existing cable ducts and cables . Co-operation with controlling autIority/electricaL engineer Administration . Arrangements to initiate construction As-Built drawings Oocunentation Selection of specifications Cable ducts at road intersections Undesirable combinations of duct and cab

5、le coating . Trench widths Road crossings . Drawings . Records of services Elulti-disciplinary projects DESIGN RE(/UIRl2lENTS Lntersections Materials for Power Ducts Trench Widths for Power Cables . Concrete Encasement APPLICABILITY OF OTHER CODES AND SPECIFICATIONS TEST PROCEDURES Compactibility Fa

6、ctor for Bedding QlJALILY CONTROL AN11 OTHER CONSIDEMIIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Disputes, Mediarions, Arbitrations, and Court Cases Compaction . 1)LUWI NES Urawing LC-3.1 - Typical Concrete Encasenent of Different Sizes of Pipe Ducts for Cable

7、s November 1981 Approved by .he COUNCIL OF THE SOUTl1 AFRICAN BUREAU OF STANDARDS SAW!; 0120 : fart 3 Sect ion 1.C-1981 Cable ducts NOTE: The clause number(s) given at the beginning or after the heading of a clause is/are, unless otherwise ntated, the nnmber(s) of the relevant clause(s) or SAUS 1200

8、 LC. PRE-TIINI)ER CONS1I)ISKAI LONS Records of Kxisting C:ible hcts and C-. Seek out plans or records that disclose the cxistence. location, and depth of cable ducts and cables within the areas that will he aEfected by eowtruction work. Co-operation with ControL1i=1thority/ElectricaL Engineer. Ascer

9、tain the identity of the controlling authority or the consulting electrical engineer concerned and determine the requirements in regard to the cables to be laid on the works and through the cable ducts. (See also 1.3.8 below.) Arrangements to Initiate Cons true=. After designs. drawings, and the pre

10、paration of a11 other - -p- docnmentation raqulred Eor the calling ot tenders have been completed and tenders Iiave been invited, deal with the site inspection and adjudicate and report on tenders received, as more fully set out in Subclarse 7.1 of Section 0. As-hilt Draw=. Ensure that arrangements

11、are made For the designer to produce .W-built drawings -p- of the finished work if this ip not to be done by the contractor. (See 1.3.7 below.) Selection of Specif ications (Subclause 2.1) Except wherr cnhle ducts are to be laid as part of a contract that includes SARS 1200 A, SAHS 1200 AA will cove

12、r the requirements. Where site clearance is to be carried out by the contractor, include SABS 1200 C in the contract. Where work is to be put out to contract hy the GPO, the reqiremants of the latest issue oE SAW Specification 325) will apply. Cable lucts at Road Intersect iow. Cab Le routes are ess

13、entially straight lines from drdw pit to draw pit. Position ducts under road intersectiorrj to make this possible. A typical GPO requirement is as 01 lows : 1.3.3 Undesirable Cnnbinatio OF Duct and Cahle Coating (Subclawe 5.7) 1.3.3.1 Where cables are insulated on the outside with bituminous materia

14、l, do not specify pitch-impregnated fibre pipes for duct work because the bitumen may so adhere to the pitch in the pipe that eventually it will be impossible to withdraw the cable. 1.3.3.2 Where cahles are cwered with hessian or jute serving, do not specify PVC or pitch-impregnated fibre pipes for

15、duct work because in the case of pitch-impregnated fibre pipes the pitch may react with the serving, and in the case of PVC pipes. cases are known of plasticizer migrating from the PVC dielectric to the nnplasticized PVC of the pipes and causing tle cable to become welded to the pipes . l) Civil eng

16、ineering works associated with the installation of underground teleplinne calles. SABS 0120 : Part 3 Section LC-1981 Cable ducts 1.3.4 Trench Widtls (Subclauses 5.1.1 and 5.6). Ensure that suitable clauses are included and that the necessary i tens are scheduled to (.over the particular requirements

17、 for the arraugemeni of power rind telephone cables that are required to be accommodated in ducts at each crossing of such cbles with one another or with other services. (See 2.3 below.) 1.3.5 Road Crossings (Subclause 5.8). Ensure that the ducts scledulcd for road crossings are 1.1rge encfilgl to e

18、nable them to receive the cable. NOTE: Where there is no concrete encasement, the Transvaal Provincial Adisinisiraion rcqtlircs a ninimun cover of l ni below the lowest point of the road reserve. 1.3.6 Drawings. For particular applications, particularly concrete encasement, consider tile va-ious cab

19、le duct conf iguraiions shown in Drawing IX-3.1. 1.3.7 Records of Services. Inconvenience and expense are caused from time to time by the destrtlction cf cables by construction teams during the construction of roads and the laying of sewers and water mains. Lt is very important, therefore, on comple

20、tion of the work, to produce precise as-built drawings showing ihe exact posiiion of all cables and ducts. The production of such drawings may be made the contractors responsibility, by means of an appropriate requirement in the project: specification. However, not all contractors are equipped or co

21、mpeient to produce satisfactory as-built drawings, and because the operation occurs late in the contract, the requirement may be difficult to enforce. 1.3.8 flulti-Disciplinary Projects. See Subclause 3.2.5 of Section LC of Part 2 of the code. 2. DESIGN REQUIREMENTS 2.1 INTERSECT1 ONS (See 1.3.2 abo

22、ve) 2.2 b1ATEKIAI.S FOR POIJER DUCIS (Sulclause 3.1). Although all the materials Listed in Subclauzc 3.1 of SABS 1200 IX are generally acceptable, uPVC is (except for the applications referred to in 1.3.3.2 abovej, preferred for power cable ducts, as it is more flexible and less Liable to be broken

23、if struck with a pick by accident than pipes made from the more brittle materials, 2.3 TRENCH WIIYIHS FOR POkTIl CABLES (Subclause 5.1.1 ) . The spacing between individual power cables (and therefore between the ducts that carry them) is usually a requirement of tile manufacturer of tlie cable and i

24、s dependent on the design of the cable and the power it carries. This requirement msy vary from 1 m in the case of 33 000 kV cables down to nil in the case of 380 V cables. For these reasons talere are no standard sparings except that low voltage cables in batches may be spaced in the same manner as

25、 nests of telephone cables as shown on Drawing LC-I of SABS 1200 LC. 2.4 CONCRETE ENCASEMENZ (Subclause 5.5). Unless a duct (for any size or type of cable) is designed to withstand the Loads imposed by fill material and traffic, a duct laid under a subsiclized or proclaimed road must be encased in c

26、oncrete. Wherever high power and important cables cross highways or roadways that carry heavy traffic, ducts, regardless of the material of which they are made, should be encased in concrete to ensure permanent accessibility without the need to tear up the road surfaces. Where ducts are to be encase

27、d in concrete, the spacing between adjoining durts must be sufficient to ensure that the concrete can be placed properly under, around, and between all ducts. See Drawin!; 1.C-3.1 for typical arrangements for encasing different sizes of ducts. 3. APPLICARLLlTY OF OTllER COOES AND SPECIFICATIONS 3.1

28、Refer to SARS 01 12) for information on “PVC pipelines. 3.2 Refer to the applicable codes and specifications of the GPO and ESCOM. 4. TEST PROCEDURES 4.1 C0MYACTIBlJ.l.TY FACTOR FOR BEDI)ING (Subclause 3.2.2). The procedure and evaluation of results given in Subclause 3.4.2 of Section 1.R is applica

29、ble to bedding (padding) for cable ducts, 5. QUALITY CONTROI. AND UTllER CONSIDEUATIONS 5.1 DISPUTES, MEDIATlONS, ARBITRATIONS, AND COURT CASES 5.1.1 Compaction. See Subclause 4.2 of Section LC of Part 5 of the code. W- 2) The installation of polyethylene and unplasticized polyvinyl clloride pipes.