INSTALLATION OF CABLES:

16.0.3.1 The Contractor shall prepare cable schedules for all the cable circuits associated with the equipment in 33 kV switchyard showing length, size and routing of each cable which shall be given suitable code numbers and submit the same for the purchaser's/Engineer's

approval. Cable and Conduit laying shall be done strictly in accordance with the approved cable schedules.

16.0.3.2 The control cables in the outdoor area shall be laid in conduits, concrete pipes, ducts, trays or cable trenches unless indicated otherwise. Cables shall be cleated to the cable tray after properly dressing the angle supports.

16.0.3.3 Ducts shall be provided wherever cable trenches cross roads and railway tracks.

16.0.3.4 All civil works, viz, excavations, sand cover, providing brick cover on directly laid cables, construction of foundations, trenches with cable tray supports, cable ducts under roads, back filling, finishing associated with cabling work shall be included.

16.0.3.5 The Contractor shall supply and install all the surface mounted/ embedded, rigid and flexible conduits, their connections, and associated clamps, bushings, lock-nuts, caps etc required in the cabling work.

16.0.3.6 All conduits shall be made of PVC pipe with threads as per BIS Specifications. The internal bore of all pipes shall be smooth and suitable for pulling PVC sheathed cables without damage. All conduit accessories shall be galvanized.

16.0.3.7 The Contractor shall supply all fittings including inspection and ordinary tees and elbows, check nuts, male and female fittings, pull boxes, junction boxes, conduit outlets, outlet boxes, splice boxes, terminal boxes, gaskets and box covers, saddles and all supporting steel work and all such arrangements which are required to complete the conduit installations.

16.0.3.8 Contractor shall supply and install cable, cable trays and accessories, supporting brackets, hangers and all other miscellaneous materials required to make a complete cable tray installation in the cable space below the control, relay and metering panels, in the control room. The arrangement of the cables and their supports in the control room cable space shall be subject to approval of the Purchaser/Engineer.

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16.0.3.9 All the apparatus, connections and cable work shall be designed and arranged to eliminate the risk of fire and minimize damage which might be caused in the event of fire. Wherever

cables pass through floor or wall openings or other partitions, suitable bushes of approved type shall be supplied and put in position by the Contractor.

16.0.3.10 Standard cable grips, reels and rollers shall be utilized for cable pulling.

16.0.3.11 Each cable shall be provided with a metallic or plastic tag of an approved type, bearing cable reference number indicated in the cable schedule prepared by the Contractor, at every 10 metre run and at both ends of the cable, adjacent to the terminations as well as where cables enter or leave ducts. Cable routing shall be so done that cables are accessible for identification and maintenance easily, and are arranged neatly.

16.0.3.12 In no case the cables shall be bent sharply or kinked with the radius of bending falling below 10D where D is the overall diameter of the cable.

16.0.3.13 wherever cables cross roads, water, oil, sewage or gas-lines, special care shall be taken while designing the trenches/ducts for protection of the cables.

16.0.3.14 In each cable run, some extra length shall be provided at a suitable location to enable making of one or two straight-through joints for carrying out repairs if the cable develops fault at a later date.

16.0.3.15 Cable splices shall not be permitted except where called for as per the construction drawings, or where permitted by the Engineer. Straight-through joints in the run of cables wherever unavoidable shall be through joint-boxes.

16.0.3.16 The termination of cables at the various equipment shall be carefully made in accordance with the manufacturer's instructions and detailed connection diagrams.

16.0.3.17 Termination materials for all cables shall match with the type of cable insulation and have thermal and electrical ratings and chemical properties similar to those of the associated cable.

16.0.3.18 All terminating materials except for those already supplied with the electrical equipment shall be provided by the Contractor.

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16.0.3.19 Control cable terminations shall be made in accordance with the colour code marked wiring diagrams of control circuits. Multi-conductor control cable jackets shall be removed as required to terminate the conductors. The cable jacket shall be left on the cable, to the extent possible. The insulated conductors from which the jacket is removed shall be neatly trained in bundles and terminated. The bundles shall be firmly, but not tightly, tied utilizing plastic or nylon ties or specially treated fungus-proof cord.

16.0.3.20 Jointing of cables shall be made in accordance with the applicable Bureau of Indian Standards Code of practice and manufacturer's special instructions. The materials and tools required for cable jointing work shall be in the Contractor's scope.

16.0.3.21 The design of joint boxes shall be such that it ensures higher actual insulation strength between phases and to earth than that obtaining in associated cable and eliminates any possibility of moisture entering the joint.

16.0.3.22 The supply of joint boxes shall include all hardware fittings, compounds, tapes and other materials required for making the joints.

16.0.3.23 Special tools, clips and saddles, glands, seals, PVC sealing compound, locknut, etc, required for connection and termination of cables shall be in the Contractor's scope.

16.0.3.24 All cables shall be megger-tested before jointing. After jointing is completed all L.V cables shall be megger-tested.

Cable cores shall be tested for:

a. Continuity

b. Absence of cross-phasing c. Insulation resistance to earth

d. Insulation resistance between conductors