Construction of cable trays under the wall

Cable trays under walls are fabricated using metal support structures, mounted at regular intervals, and isolated to ensure safe and durable cable routing.Materials and Support StructuresCable trays are typically fabricated from Mild Steel (MS) or Galvanized Iron (GI), with perforated or solid designs depending on ventilation and load requirements . Wall-mounted supports are commonly made from MS angles (e.g., 50 x 50 mm, 6 mm thick), spaced at 1-meter intervals along the wall . For longer spans, bridge supports using MS C-channels (e.g., 150 x 75 mm, 5.7 mm thick) can be welded to the existing structure to maintain stability .Mounting and FasteningSupports are fastened to the wall using high-strength bolts, such as Hilti nut bolts of at least 75 mm length . Cable trays are then mounted on these supports using high-tensile bolts, washers, and nuts, with coupler plates connecting tray sections securely . Proper alignment and leveling are essential to maintain the tray's horizontal run and prevent sagging.Isolation and ProtectionTo prevent electrical conduction or corrosion, G-10 or FRP sheets (e.g., 400 x 100 mm, 10 mm thick) are placed between the tray and the support at each mounting point . This ensures electrical isolation and reduces mechanical wear. Additionally, bends, T-pieces, and other fittings are fabricated with adequate radius to maintain the minimum bend radius for cables and avoid damage .FinishingAfter fabrication and welding, the MS support structure should be primed with red oxide and finished with enamel paint (e.g., Siemens grey) to protect against corrosion and provide a smooth surface .Standards and Safety ConsiderationsCable trays and supports should comply with BS EN 61537 or equivalent standards for mechanical and electrical performance . They are designed to support cables, not personnel, and must withstand imposed loads such as cable weight and short-circuit forces . Proper installation ensures safe cable routing, prevents overheating, and maintains structural integrity.SummaryFabricate wall-mounted MS angle supports at 1-meter intervals.Use bridge supports for longer spans with welded MS C-channels.Fasten supports with high-strength bolts and mount trays with coupler plates.Isolate trays using G-10 or FRP sheets at each support.Apply primer and enamel paint for corrosion protection.Ensure bends and fittings maintain minimum cable bend radius.Follow relevant standards for safety and mechanical performance. This approach ensures a durable, safe, and compliant cable tray installation under walls, suitable for HV, control, and fiber optic cabling applications .