Cable Tray Installation Guide

The correct installation of cable trays is crucial for establishing a reliable and efficient cable system. It ensures that cables are properly supported and protected, reduces the risk of cable damage, and facilitates maintenance and management. Proper installation is not just about placing the cable tray in the right position; it also involves correct selection and layout, ensuring structural safety, maintaining appropriate spacing and safety distances, and adopting the correct installation techniques and methods to ensure the installation process meets regulatory requirements. We have summarized some precautions for cable tray installation for your reference.

Cable tray installation display
  • The overall layout of the cable tray should be short distances, economic feasibility, safe operation, and meet the requirements for construction, maintenance, and cable laying.
  • The cable tray should have sufficient rigidity and strength to provide reliable support for the cables.
  • After cable laying, the deflection of the cable tray should not exceed 1/200 of the span of the cable tray. When the span of the cable tray is ≥ 6000 mm, its deflection should not exceed 1/150 of the span of the cable tray. (Deflection refers to the degree of bending of the cable tray caused by the weight of the cables and other loads after cable laying.)
  • Cable trays should be installed on buildings and structures (such as walls, columns, beams, floors, etc.) as much as possible, in close coordination with civil construction.
  • When cable trays are installed together with process pipe racks, the cable trays should be arranged on one side of the pipe rack.
  • When cable trays are installed parallel to various pipelines, the clear distance should meet the following requirements:
    • When cable trays are installed parallel to general process pipelines (such as compressed air pipelines), the clear distance should be no less than 400 mm.
    • When cable trays are installed parallel to pipelines carrying corrosive liquids, the clear distance should be no less than 500 mm.
    • Cable trays should not be installed parallel below pipelines transporting corrosive liquids or above pipelines transporting corrosive gases. If unavoidable, the distance should be no less than 500 mm, and a corrosion-resistant partition should be used.
    • When cable trays are installed parallel to thermal pipelines, the distance should be no less than 500 mm if the thermal pipeline has insulation, and no less than 1000 mm if it does not.
    • Cable trays should not be installed parallel above thermal pipelines. If unavoidable, the distance should be no less than 1000 mm, and effective thermal insulation measures should be taken.
  • When cable trays intersect with various pipelines, the net distance should meet the following requirements:
    • When cable trays intersect with general process pipelines, the distance should not be less than 300 mm.
    • When cable trays intersect below pipelines carrying corrosive liquids or above pipelines carrying corrosive gases, the distance should not be less than 500 mm. Additionally, at the intersection, the cable tray should be protected with a corrosion-resistant cover plate, and the length of the cover plate should not be less than d + 2000 mm (where d is the outer diameter of the pipeline).
    • When cable trays intersect with thermal pipelines, if the thermal pipeline has an insulation layer, the distance should not be less than 500 mm; if there is no insulation layer, the distance should not be less than 1000 mm. Additionally, at the intersection, the cable tray should be protected with a thermal insulation board (such as an asbestos board), and the length of the insulation board should not be less than d + 2000 mm (where d is the outer diameter of the thermal pipeline's insulation layer).
  • When installing cable trays through walls, they should be set up according to environmental conditions:
    • When cable trays pass through walls from a normal environment into a fireproof or explosion-proof environment, appropriate sealing devices should be installed on the wall.
    • When cable trays pass through walls from indoors to outdoors, rainproof measures should be taken on the outside of the wall.
    • When cable trays are installed at a higher position from indoors to outdoors, the cable tray should first be extended downward at an appropriate distance before being set up upward to prevent rainwater from flowing into the interior along the cable tray.
    • When the cable tray passes through expansion and settlement joints, the cable tray should be disconnected, with a separation distance of about 100 mm.
  • When two sets of cable trays are installed on the same beam, the net distance between the two sets of cable trays should not be less than 50 mm.
  • When multi-layer installation of cable trays for laying cables of 10 kV and above, the spacing between layers is generally not less than 300 mm.
  • The distance from the cable tray to the bottom of the floor, beam, or other obstacles should not be less than 300 mm.
  • Under normal circumstances, the distance between the support arms of the cable tray should be about 1.5 m – 3 m, and should be verified according to specific conditions.
  • When installing the cable tray horizontally, its direct plate connection should not be placed at the midpoint of the span or on the support point.
  • The cantilever section that appears during the installation of the cable tray should generally not exceed 1000 mm.
  • The cable tray should not be used as a pedestrian walkway.
  • In any of the following situations, the cable tray should be equipped with a protective cover:
    • When the cable tray is installed outdoors, the cable tray should be equipped with a protective cover at its upper layer or each layer.
    • When the cable tray is installed vertically, the cable tray within 2 meters from the ground should be equipped with a protective cover.
    • When the cable tray is installed in places prone to mechanical damage.
    • Cable trays installed in dusty environments.
    • Special requirement locations.
  • Cables laid inside the cable tray should be fixed with nylon straps, binding wires, or metal clips. The fixing points are as follows:
    • When laid horizontally, at both ends of the cable, at bends, and at both ends of cable joints.