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:
- 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.
- 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.