Introduction section1: general requirements
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SECTION - 7INSTALLATION OF CABLES, EQUIPMENT, ACCESSORIES AND WIRING SYSTEMS ARMOURED CABLES Armoured cables may be installed either directly buried in ground, drawn through ducts, laid in concrete trenches - cleated to wall, or mounted on cable trays. Cables shall be installed & used in association with other equipment in accordance with BS 7671. In special environments the appropriate regulations and standards shall be observed. The current carrying capacity of the cable/s shall be determined only after applying suitable correction factors based on the installation method of the cable/s Cables shall be selected ensuring voltage drop within permissible limit as per Section 4 of this regulation. Only armoured cables shall be used for underground installations. Precautions shall be taken to avoid mechanical damage to the cables before & during installation. The armoured cables, for underground installation shall normally be laid at 90 cm below the ground level and provided with a layer of at least 15 cm impervious soil around. Where protective covers are required, they shall be carefully centred over the cables, throughout their length. The covers shall be of adequate width to protect the cables, with a minimum overlap of 50 mm on each side. Coloured PVC warning tapes shall be laid above the cable after filling, up to 30 cm below the ground level. uPVC ducts with HD (Heavy Duty) manhole cover shall be provided for cables passing through drive ways/roads. The routes of all cables shall be clearly marked by cable route markers/marking tape, at regular intervals not exceeding 10 metres along straight runs and 2 metres at deviations in the route. The route markers shall normally indicate the voltage level in Arabic and English. Heavy duty conduit shall be provided for motor connections, external applications and locations subject to vibration, risk of mechanical damage or exposure to moisture. Cables may be installed on cable trays at specific locations and as recommended under section 6 of this Regulations. In the event of crossing or proximity of underground telecommunication cables and underground power cables, a minimum clearance of 100mm shall be maintained. Minimum internal radius of bend for cable in fixed wiring installation shall not be less than 8 times the overall diameter of the cable. No joints shall be permitted on any cable runs in Consumer's fixed wiring installation. Where cables or wiring system passes through floor, wall, partitions or ceiling, the openings remaining after passage of the wiring systems shall be sealed to the degree of fire resistance required. Cable glands used for armoured cables shall be of brass compression type, complying with BS 6121, with earth tag and PVC shroud. All terminations of cable conductors shall be mechanically and electrically sound. Every termination shall be made by means of a terminal or compression type socket/lug, to the approval of DEWA, and shall not impose any mechanical strain on the terminal or socket/lug. Separate Earth Continuity Conductors (ECCs) shall be installed and terminated for each feeder/circuit, as specified under Section 5 of this Regulation. Non-ferrous cable gland plate shall be used for termination of single core armoured cables. No cables shall run in a lift or hoist shaft unless it forms part of the lift/hoist installation Download 2.29 Mb. Share with your friends:
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