CABLE

Underground Cable Laying

  • Excavation for ground – loose soil (1 mtr to 1.5 mtr)
  • Sand bed
  • HDPE pipe
  • Cable laying
  • Sand bed
  • Waring sticker
  • Bricks
  • Backfilling of loose soil
  • Cable route marker installation every (30 to 50 mtr)

Cable tray / trunking installation

  • To make sure that the entire installation is in conformance and in accordance with the design intent of the project for the Electrical and Low Voltage System in addition to the specification and as per approved shop drawings and comply with Local and International Standards.
  • hanger rods together with nuts and locking washers, supports channel hold down clips all of which shall have a galvanized finish. Any cut ends support’s, rods, etc, must be corrosion protected by use of galvanized or equal. No extended rods to be left.
  • Additional support shall be provided where the Cable Tray / Trunking changes direction or cables drop out of the cable tray. Dome headed bolts, nuts and washers of finish suitable to the tray shall be used between trays.
  • able tray shall be installed with a 40mm minimum space between the structure and the tray.
  • All cable shall be securely fixed to the tray, work and the complete installation must be carried out in a neat and workmanlike manner without crossovers.
  • If cables are bunched or single cables greater than 25sq mm are installed, cleats or metal straps shall be used.
  • Earth continuity conductors shall be provided across gaps in all Cable Tray / Trunking runs and bolted connections.
  • Accessories: – Vertical elbow -up, Reducer, Horizontal tee, Support cantilever Arm, Horizontal
  • cross piece, Horizontal elbow, Straight ladder, Vertical elbow down.

Cable tray and Trunking wall mounted installation

  • Install cable tray support using a pre-fabricated flange or GI channel. The size, length and intervals of the support to be as per the specification, standards, number of cables, and size of the cable.
  • Fix the cable tray
  • Lay the cable keeping the distance as per calculation
  • Tie the cable using cable tie and tagging the cables as required
  • Earth continuity conductors shall be provided across gaps in all Cable Tray

CONDUIT WIRING AND INSTALLATION

  • Conduit wiring is a system of wiring using tubes (pipes) either steel or PVC, to provide good mechanical protection for its conductors drawn inside the tubes. It also gives high degree of protection from fire hazards to its conductors. Conduit pipes will be installed on the surface of walls or roofs by means of saddles or hooks or concealed inside the wall or roof or floor.
  • Modern building construction adopts conduit wiring (PVC conduit or GI conduit both in various mechanical strength depending on site requirement and project specification) and found mainly in two types: 1) Surface or Open type conduit installation, and 2) Concealed type conduit installation.
  • Steel Conduits and Fittings are made out of heavy / medium / light gauge steel. It uses different technologies. In general interior and exterior wires ways shall be Electrical Metallic Tubing (EMT). Coupling and connector used with tubing shall be made up tight.

WIRING MATERIALS AND INSTALLATION

The scope of electrical wiring shall cover supply, installation, testing and commissioning of all conduits and accessories, wiring, switches, socket outlets, spur outlets, junction boxes / pull boxes, GI pull wires, ceiling roses making connections etc.

  • Lighting system.
  • Power outlets.
  • Emergency light.
  • Telephone system.
  • Fire alarm system.
  • Sound / public address system.
  • Network system.
  • Panel wiring (Control/Network/Electrical).

Base frame installation or wall mounted

Located the base frame based an approved drawing, and match the holes, fixed with anchor bolt, connect the base frame body connected with grounding.

Anchors it to the wall with screws or anchors driven through the back of the panel and into the wall. If the holes don’t align with studs behind the panel, they may drill additional drill holes in the back of the panel to accommodate the installation, panel will be carefully positioned

Open Knockouts in Box: as well as for each branch circuit that will enter the breaker box. Yet another knockout may need to be opened for the main grounding wire. The knockouts are the round metal discs visible in the top, bottom, sides, and back of the box—of various sizes to match different-sized conduits that may need to connect to the box. the branch circuits later, as individual circuit wires are run.

Install the Main cable with neutral: The main service cable is secured laying- Plenty of excess wire is pulled into the panel to allow for connections to be made anywhere in the panel., Cable glands used for armored cables are to be of brass compression type, complying with BS 6121 and BS EN 50262: Part I, with earth tag and PVC shroud. and termination, the bus bars shall be mounted on non-hygroscopic insulators and shall withstand the rated short circuit level. The neutral bar shall be provided with a separate terminal for each incoming and outgoing feeders. A separate earth terminal block shall be provided which shall have a separate terminal for each feeders. All phases shall be identified and separate circuits shall be labeled

Connect the Main Ground Wire: This main ground wire is usually connected to a grounding rod.

Pull wire/cable for Branch Circuits: Pull the wires for the various branch circuits into the panel. If they arrive at the panel through a metal conduit/trays/trunking,

Connect Branch Circuit Ground Wires: To connects all of the yellow-green and bare copper wires for the branch circuits to the ground bus bar inside the panel.

Connect the Branch Circuit Breakers: The circuit breaker for each branch circuit is now connected, one at a time. The breakers have been carefully chosen to match the required amperage and voltage of the circuits and to meet code requirements.