SCOPE OF WORK (ELECTRICAL) - CIDCO Maharashtra Ltd.

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CIDCO OF MAHARASHTRA LTD C.A.No.03/CIDCO/EE(Elect)/2011-12 Sr. Page No. attached with this document. The entire earthing system shall fully comply with the Indian Electricity Act and rules framed thereunder. The contractor shall carry out any changes desired by the Electrical Inspector or the owner, in order to make the installation confirm to the Indian Electricity Rules at no extra cost. The exact location of earth conductors, earth electrodes and earthing points on the equipment shall be determined in field, in consultation with the Engineer-in-charge or his authorized representative. Any changes in the methods, routing, size of conductors etc. shall be subject to approval of the Owner/ Engineer-in- charge before execution. 3.2 Excavation and refilling of earth, necessary for laying underground earth bus loops shall be the responsibility of the contractor. 3.3 The resistance between the earthing system and the general mass of earth shall be as per IS code of practice. The earth loop impendence to any point in the electrical system shall not be in excess of 5.0 ohm, in order to ensure satisfactory operation of protective devices. 3.4 The main earth loop shall be laid at a depth of 300 mm below grade level. Wherever cable trenches are available, the earth lead shall be laid in the trenches and shall be firmly cleated to the walls or run of trays when run in concrete lines trenches. The earthing strip shall be protected against mechanical damage. 3.5 In process unit areas, the earthing cable shall be run along cable trays wherever specified in the layout drawings. The earthing cable shall be suitably cleated and electrically bonded to the cable tray at regular intervals.
CIDCO OF MAHARASHTRA LTD C.A.No.03/CIDCO/EE(Elect)/2011-12 Sr. Page No. 3.6 Joints and tappings in the main earth loop shall be made in such a way that reliable and good electrical connections are permanently ensured. All joints below grade shall be welded and suitably protected by giving two coats of bitumen and covering with hessian tape. All joints above ground shall be by means of connectors/lugs as far as practicable. Tee connectors shall be used for tapping, earth leads from the main earth loop wherever it is installed above ground. Where aluminium cable risers are to be connected to the underground GI earth bus, the aluminium cable riser shall be taken to the nearest earth pit and terminated through a bolted joint. If this is not practicable then a G.I. risers shall be brought above grade and a bolted joint shall be made between this GI riser shall be protected applying two coats of bituminous paint/bitumen on the exposed portion. 3.7 Conduits in which cables have been installed shall be effectively bonded and earthed. Cable armoured shall be earthed at both ends. 4.0 EARTHING ELECTRODES: 4.1 Earth pipe electrodes shall be installed as shown in the earthing layout drawings and in accordance with the standard drawings of reference and IS:3043. Their location shall be marked to enable accurate location by permanent markers. 4.2 All earth electrodes shall preferably be driven to a sufficient depth to reach permanently moist soil. Electrodes shall preferably be situated in a soil which has a fine texture and which is packed by watering and ramming as lightly as possible. Wherever practicable, the soil shall be dug up, all lumps broken and stones removed from the immediate vicinity of the electrode.
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SCOPE OF WORK (ELECTRICAL) - CIDCO Maharashtra Ltd.

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