Method for Installation of Cable Tray:(Part-1)

Purpose:

This method explains the Procedures or sequence of activity for safely installation and Testing of

cable tray,

and it’s accessories as per the quality Practice.

General Equipment & Tools:

The equipment which will be engaged for Installation of Cable Tray are going to be:

Tool Box with Screwdriver, Pliers, Spanner , Hammer

Drilling Machine with various Bits , Grinding & Cutting Machine

Electrical Tester , Continuity Tester ,MultiMeter

Cutter , Blower

Knockout punch and Flat File

Galvanizing paint

Marker, Measuring tape, Level gauge / level.

Ladder / Scaffolding / Mobile scaffold

Chain Block and Pipe Wrench

Portable Lights

Removable Barricades

Storage & Material Handling:

The cargo area must be free from dust and Water leakages / seepages.

Manufacturer recommendation shall always be followed in loading/unloading and storing of fabric

Material and its accessories shall be unloaded and handled with care in designated areas of the Store (Do not directly drop to Ground) to avoid      any damages.

Materials shall be stored during a dry place which is free from water or from weather effects and protection should tend to the fabric by means of      covering the material with Tarpaulin sheet.

The Material will be stacked / unload in the site store on a proper stand on a wooden loft on a flat surface at a sufficient height from Ground.

If materials are dispatched 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 Material should be visually inspected for damage, which can have occurred during transport.

When bringing down materials, they ought to be handled with care and lowered carefully to the bottom . They should not be dropped.

To prevent damage to cable tray, never pull cable tray from a truck trailer by chaining to rock bottom rung and dragging cable tray out of the      trailer

If the fabric is found defective it shall not be installed and therefore the cable shall be returned to the supplier for replacement.

Cable Tray and its accessories (pre-galvanized, hot dipped galvanized) shall be stored during a dry place, fully enclosed / ventilated store.

Inspection of Materials:

Check the fabric consistent with its Type, Size, Make

Visual inspection:

Type of Cable Tray

Type of Cable Tray Material

Type of Cable Tray Coating

Standard width of Cable Tray

Standard length of Cable tray

Cable Tray thickness

Flange height of Cable Trays

Proper painting / Galvanization and identification numbers of the cable trays

Physical Damages Inspection:

Damage on trays and ladders

Damage on galvanizing

Flange height of Cable Trays

Fittings and accessories are of proprietary type

Testing of galvanizing:

Uniformity of coating Thickness Test

Electrical continuity of connection

TRs not more than five year old from the date of purchase order shall be reviewed for acceptance. Otherwise the test shall be carried out.

Fittings and accessories are of proprietary type

Sequence of Cable Tray Installation Works:

Installation of Cable Tray:

1. Shifting of Cable Tray on Site
• Cable Tray shall be carefully unloaded or shifted to the location by using Crane/Hydra or by sufficient manpower and moved to an outlined installation location.
• Remove the packing and make sure that the Cable Tray is free from transportation damages
• Check and ensure that approved drawings, the correct size and type of cable trays, trunking & accessories are ready for installation.
• Ensure that cable trays/trunking and accessories received from site store for the installation are freed from rusty parts and damages.


2. Marking the Route:
• Mark the route of Cable Tray and Trunking as per approved drawings with marking threads. The route of Cable Tray and Trunking got to be coordinated with other services and shall be confirmed by the location Engineer.
• Minimum space from the building structure and other services to be maintained (200 mm from the closest point) to facilitate easy handling and maintenance of cables.
• If Possible, Do not install Cable trays below water/sewage pipes.



iii. Hanging Support:

• The location of hangers and supports should be carefully marked as per the approved specifications and Drawings.
• Required sizes of holes should be marked and drilled by employing a drilling machine.
• The threaded rod (M12 steel) or Specified rod should be fixed carefully into the anchor using clamping tools for a balanced smooth twist. The threaded rod should be necessary thickness and length. Sizes should be as approved within the drawing. It should be wiped out to avoid damage to the threaded rod.
• Mark the route of Cable Tray and Trunking as per approved drawings with marking threads. The route of Cable Tray and Trunking got to be coordinated with other services and shall be confirmed by the location Engineer.
• When the thread is done, a washer should be inserted into it. The washer should even be the specified size and of quality. It should be fixed properly and the nut fastened tight to ensure that the threaded rod is strong and able to bear load.
• Trays and ladders shall be securely anchored to supports. They shall be secured such that the tray or ladder system won't move during cable installation.
• Ensure that the rod is properly vertical under operating conditions.
• Tighten hanger load nut securely to make sure proper hanger performance. Tighten upper nut after adjustment.
• The distance between supports is called SPAN. The support span shouldn't be greater than the length of the tray. This will prevent two connecting points from being located within one support span.
• The support span shouldn't be greater than the straight section length, or as recommended by the

  cable tray manufacturer

  , to make sure that no quite one splice is found between supports.
• Cable Tray and Trunking joints are to be positioned as on the brink of the supports as possible, less than 300 mm from either side.
• Splice joints fall between the support and therefore the quarter point. When installing a 12-foot long section, for instance , a support spacing of three .7 m (12 foot) causes the splice joints to fall at an equivalent position whenever .
• The maximum tray overhang past the last support shouldn't exceed 600 mm (2 ft).
• At every maximum of 1200 mm horizontally and 1500 vertically supports should be installed.

• Horizontal cable trays

  and

  ladder cable tray

  shall be supported by either wall mounted support bracket or a hanger rod system. The intervals between supports shall be as recommended by the manufacturer but this shall not exceed 1 meter for wall mounted support brackets, and 2 meters for the hanger rod system.
• The hanger, hanging support, cable tray bracket and therefore the ladder should be trimmed to required size and galvanizing paint should be applied on the sides .
• Group parallel runs of trunking should be supported together where it's possible.
• For shaft cable trays and ladders that are vertical, all supports and fixings should be done as approved.
• Do not cut or drill structural building members (e.g., I-beams) without approval by the most contractor.
• Warning: don't use a cable tray as a walkway, ladder, or support for people; cable tray may be a mechanical network for cables and raceways. Using cable trays as walkways can cause personal injury and may damage cable trays and installed cables.



iv. Horizon Fitting Support:

• Supports for horizontal fittings should be located at a distance, no greater than 610 mm (24″) from each end of the fitting on the attached ladder.
• Fitting must even be supported at the radius center point on each side of the fitting as per below:
• At the midpoint (45°) of the arc for a 90° elbow.
• At the midpoint (30°) of the arc for a 60° elbow.
• At the midpoint (22.5°) of the arc for a 45° elbow, excluded are 305 mm (12″) radius fittings.
• At the midpoint (15°) of the arc for a 30° elbow, excluded are 305 mm (12″) radius fittings.