POWER CABLE INSTALLATION AND TERMINATION

POWER CABLE INSTALLATION AND TERMINATION

REFERENCES AND INTERNATIONAL STANDARDS FOR POWER CABLE INSTALLATION

M7.12.12      Wire and Cable Specification

IEC 60050    International Electro-Technical Vocabulary

IEC 60055    Paper Insulated Metal Sheath Cables For Rated 1KV to 30KV

IEC 60173    Colours of the Cores of Flexible Cables and Cords

IEC 60183    Guide to the Selection of HV Cables

IEC 60228    Conductor of Insulated Cables

IEC 60287    Calculation of the Continuous Current Rating of Cables

IEC 60331    Fire Resisting Characteristics of Electrical Cables

IEC 60332    Tests on Electrical Cables under Fire Conditions

IEC 60364    Electrical Installation in Buildings

IEC 60446    Colour Identification-Insulated & Non-Insulated Core

IEC 60502    Extruded Sold Dielectric Insulated Power Cables for Voltages from 1KV to 30KV

IEC 60540    Test Methods for the Insulation & Sheaths of Electrical Cables & Cord (Elastometric & Thermoplastic Compounds)

IEC 60754    Tests on Gas Evolved During Combustion of Electric Cables

IEC 60811    Common Tests Methods for Insulating & Sheathing Materials of Electric Cables

IEC 60851    Methods of Test for Winding Wires

IEC 61034    Measurement of Smoke Density of Electric Cables Burning Under Defined Conditions, Test Procedures & Requirement

IEC 61158-2   H1 Field bus cables

PROCEDURE POWER CABLE INSTALLATION

• • Cable installation shall comply with reference codes and design documents.
  • All cable drum shall be checked with packing list and confirmed no mechanical damage.
  • During cable drum shifting; check mechanical damage, nameplate with cable schedule & drum list and phase rotation of the cable.
  • Assure necessary PPE, tools and equipment for cable pulling. Check the latest cable drum list and cable schedule. Prior for cable pulling, QA/QC inspector shall check if all the cable supports are installed and fixed.
  • All wire and cable shall be megohm meter tested after it is pulled, but prior to termination.
  • High voltage cable shall be given a hi-pot test after it is pulled and stress relief is installed, but prior to termination.
  • Electrical cables shall be oil & sunlight resistance and flame retardant shall be used as per IEC 60332.
  • Cables used for buried or external installation shall be steel wired armoured. Noted that armouring cables are not required within the building, e.g. from control room to control building rack room
  • Cables shall be installed direct buried on the ground or in formed concrete trenches with backfill, fastened to cable ladder rack or tray and in underground ducts.
  • Make check for the following during wire and cable installation;

1. 1. 1. The proper type, size, colour and number of wires & cables are being installed.
      2. For long pulls, the pull is performed as per required pulling tension.
      3. Cable is not pulled around too many bends.
      4. Ambient temperature is above the minimum allowed for the cable insulation.
      5. Proper pulling compound is being used.
      6. For long pulls, allowable pulling tensions are not exceeded.
      7. Cables are not bent on too tight a radius.
      8. Wire and cable is protected and kept clean throughout the pulling operation.
      9. Cable fill does not exceed NEC requirements.

 

1. • Except for special application for control, power & lighting cables the minimum cross-section shall be 1.5mm². For high voltage, the cross section shall not exceed 185mm² for three core armoured cable and 400mm² for single core cable. For low voltage, the limits shall be 240mm² for a cable whether armoured or not, up to a maximum of three conductors and 400mm² for single core cable.
   • Minimum curve radius for cables, where D is the overall diameter, shall be 6xD for un-armoured cables and 8xD for armoured cables.
   • Conductors shall be circular, stranded, annealed copper type, class 2 for the cables for fixed installation and class 5 for the flexible cables feeding mobile equipment, as per IEC 60228.
   • Junctions/splices, when not removable, shall be made using sleeves, crimped or welded, restoring the integrity of the line by appropriate heat-shrinkable sleeves. Cable splicing shall be prohibited except in case of cable length exceeding the normally manufactured length.
   • Cables shall be drummed in maximum continues length, protected against damage during transit and storage. Cable ends shall be sealed and protected.
   • Earthing cable conductor shall be stranded annealed copper conductor and tinned in area containing H2S. Insulation shall be PVC, with green/yellow outer sheath.
   • Cables used for buried or external installation shall be steel wire armoured. Armouring cables are not required within the building.