Design and Installation Requirements for Steel Cable Trays in Structural Layout
 (1)Steel cable trays shall have a load design safety factor not less than 1.5. The relative deflection of the bracket under additional uniformly distributed load shall not exceed 1/200. When the bracket width is ≤2.5 mm, the additional uniformly distributed load is 200 kg/m; when the additional uniformly distributed load is 250 kg/m, the minimum limit for the distance between hangers for steel cable trays shall not exceed 0.5 cm. For load and deflection test reports of steel cable trays, refer to the steel cable tray inspection report and the uniformly distributed load diagram of steel cable trays.
      (2) The plate thickness of ladder-type trays and non-perforated trays in steel cable trays, as well as the design and fabrication of cable shafts, shall meet the requirements specified in the tender document.
      (3) The thickness of the anti-corrosion coating on the galvanized surface of cable trays shall be ≥65 μm (460 g/m2). For detailed data, refer to the supplier's hot-dip galvanizing inspection report.
      (4) Various types of supports and hangers shall be capable of bearing the corresponding standard uniformly distributed loads and their own weight for the trays and layers. The maximum deflection ratio of the hanger crossbar or side arm fixed bracket under the rated load of the tray shall not exceed 1/200 relative to its length.
      (5) The maximum spacing between ladder-type tray crossbars shall be 250 mm. The minimum cable-bearing cross-section dimension of the crossbar shall be 44 mm to 50 mm, with a crossbar height of 20 mm to 30 mm. The crossbar cross-section shall be smooth and free of burrs.
      (6) The steel cable tray system shall have reliable electrical connections and grounding. When the tray system forms a grounding loop, the connection resistance between tray ends shall not exceed 0.00033 Ω. Grounding holes shall have the insulation coating removed. Braided steel wires shall be used for connections at hinged plate joints. The connection holes at tray ends shall adopt an extended contraction method. A connection resistance test report shall be provided.
      (7) For steel cable trays used in partial upward or downward transitions between floors, adjustments shall be made based on actual site conditions and included in the total quantity.
      (8) Steel cable trays shall comply with the latest national standards (GB), International Electrotechnical Commission (IEC) standards, and the International System of Units (SI) standards.