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Method for Installation of Cable & Wire (Part-1)

METHOD FOR INSTALLATION OF CABLE & WIRE (PART-1)

PURPOSE:

  • The method explains the Procedures or activity for safely installation and Testing of MV cable in directly buries in ground, in trenches, in to cable trays or in underground ducts as per the standard Practice and Code.

GENERAL EQUIPMENT & TOOLS:

  • Testing Equipment for Cable * LV / HV Insulation Resistance tester (250V to 5KV) * Multi-meter * Continuity Tester * AC High Voltage Test Kit

STORAGE & MATERIAL HANDLING:

  • The storage area must be free from dust and Water leakages / seepages. * Manufacturer recommendation shall always be followed in loading/unloading and storing of Material. * Material and its accessories shall be unloaded handle with care in designated area of the Store (Do not directly drop to Ground) to avoid any damages. * Materials shall be stored in a dry place which is free from water or from weather effects and protection should be given to the material by means of covering the material with Tarpaulin sheet. * The Material will be stacked / unload in the site store on a proper stand on wooden loft on a flat surface at a sufficient height from Ground. * If Material are dispatch in packs or pallets, each pack or pallet shall be lifted individually with suitable lifting equipment. * The material shall be transported / Shifted in their original packing to Site location. * The cable drums shall be off-loaded at the site locations.

  • The cable drum should be visually inspected for damage, which may have occurred during transport. * During storage periodical rolling of drums once in 3 months done. Rolling shall be done in the direction of the arrow marked on the drum. * It should be ensured that both ends of the cable are properly sealed to prevent ingress/absorption of moisture by the insulation. * Protection from rain and sun shall be ensured. Sufficient ventilation between cable drums, should be ensured during storage. * The drums shall always be rested on the flanges and not on the flat sides. f. Damaged battens of drums etc. should be replaced, if necessary. * When cable drums have to be moved over short distances, they should be rolled in the direction of the arrow, marked on the drum * While transferring cable from one drum to another, the barrel of the new drum shall have a diameter not less than that of the original drum. * The manufacturer’s seal on the inner and outer cable ends should be examined and the condition of the sheath inspected for mechanical damage. * If the cable is found defective it shall not be installed and the cable shall be returned to the supplier for replacement.

INSPECTION OF MATERIALS:

  • Check The Material according to its Type, Size, Make * Inspection of Cable: * Type of Cable (HT /MV /LV) * Cable Operating Voltage * No of Cable Core (1 core,2core,3 core, 3.5 Core,4 core) * Type of Cable Core (Cu, Alu) * Type of Cable Material (PVC,XLPE) * Size of Cable * Length of Cable * Physical Damages Inspection: * Damage on Cable Drum * Damage on insulation of Cable * In case of any damages observed during inspection, the concern report will be issued and Material shall be returned to the supplier for replacement.

TESTING AND OF CABLE:

(1) INSULATION RESISTANCE TEST:

  • Following Insulation resistance test will be carried out by approved calibrated equipment. * At the Time of Cable drum receiving at the Store * Before Installation of Cable on Site. * After Installation of Cable on Site. * The Insulation Resistance values will be noted for Core to Core and Armor by DC High Voltage Tester (Megger) before following activities.

Voltage Class Test instrument Acceptance Value L/V Cable 1000 VDC >20 Mega ohm M/V Cable 5000 VDC >100 Mega ohm Control, Instrumentation, Communication cable 250 VDC >1 Mega ohm

  • The cables and conductors must discharged after Insulation Resistnce test.

(2) THE CONTINUITY TEST:

  • The continuity test would be carried out between * Phase to Phase, * Phase to Neutral, * Phase to earth and * Neutral to Earth. * The results would be recorded for records and future reference. * After the test, the end of the cable shall be sealed to prevent the ingress of moisture.

GENERAL STEPS FOR CABLING LAYING

  • Shifting of Cable Drum at Working Location: * If a crane is used to unload / Shift cable, a shaft through the arbor hole or a cradle supporting both reel flanges should be used. * Forklifts must lift the reel by contacting both flanges. * Check and ensure that approved drawings, the correct size and type of Cable & accessories are ready for installation. * Ensure that Cable and accessories received from site store for the installation are free of rusty parts and damages. * Installation of Cable Drum on Jacks: * Check and ensure that the Correct Size and Type of Cable Drum and accessories are transported at the Site loca…