Fixing Spacing of Cable Trays in Vertical Shafts

For vertical cable tray installations, secure trays at the top and every 1.5 meters, maintain proper tie spacing, and ensure adequate clearance for airflow and maintenance.Vertical Tray Support and SpacingFor vertical runs inside shafts, cable trays should be supported at the top and at intervals of approximately 1.5 meters to prevent sagging and maintain stability of the cables . Hanging rod supports should be at least 8 mm in diameter to ensure structural integrity . Proper support prevents mechanical strain on cables and reduces the risk of displacement or damage due to the weight of the cables themselves .Cable Binding and OrganizationCables within vertical trays should be laid straight and orderly, avoiding overlaps or crossings. When binding cables, the distance between ties should not exceed 1.5 meters, ensuring even tension and preventing undue stress on terminations . For troughs or wireways, binding may not always be necessary, but in vertical shafts, securing cables is critical for stability and safety.Clearance and AirflowMaintain a minimum top clearance of 0.3 meters from ceilings or obstructions and ensure the tray is installed at least 2.2 meters above the ground for accessibility . The cross-sectional fill rate of cables should not exceed 50% to allow proper airflow, heat dissipation, and future expansion . This is particularly important in vertical shafts where heat can accumulate.Mechanical and Fire Safety ConsiderationsAll cable supports must be fire-resistant to prevent premature failure in case of fire . Flexible systems, such as J-hanger installations, require calculations to determine support spacing based on cable stiffness, weight, and deflection (typically 2% sag) to avoid expansion issues . Using the Heinhold method or similar calculations ensures that support intervals are appropriate for the cable type and material.Summary RecommendationsSupport vertical trays at the top and every 1.5 meters.Use hanging rods ≥8 mm in diameter.Bind cables every 1.5 meters to maintain order and prevent strain.Maintain at least 0.3 meters clearance from ceilings and 2.2 meters above ground.Limit tray fill to 50% for airflow and heat dissipation.Use fire-resistant supports and calculate spacing for flexible cable systems. Following these guidelines ensures structural stability, safety, and compliance with cable management standards in vertical shaft installations .