Spacing of vertical section supports for cable trays

Vertical cable tray supports should generally be spaced at intervals of less than 2 meters, with cables secured at the top and every 1.5 meters to ensure stability and safety.Recommended Support IntervalsFor vertical cable tray runs, supports should be fixed to the building structure at intervals preferably less than 2 meters. This ensures the tray remains stable under the weight of the cables and prevents sagging or mechanical strain on the system . Cables within the tray should be secured at the top and at every 1.5 meters along the vertical run . In long vertical runs exceeding 32 meters, strain relief sections should be incorporated. This typically involves offsetting the cable by at least 2 cable diameters or including a short horizontal section of at least 1 meter to relieve tension and prevent excessive mechanical stress . For extremely long vertical runs (over 100 meters), additional measures may be required, including detailed mechanical calculations to account for static and dynamic loads, thermal expansion, and potential seismic forces .Factors Affecting Support SpacingCable Type and Load: Heavier or armored cables may require closer support spacing. Manufacturer recommendations should always be consulted for special cable types such as shielded, coaxial, or fire-resistant cables .Tray Material and Depth: Steel trays, especially those with smaller depths (e.g., 6 inches), may be self-supporting for short vertical sections but require wall or column fastenings to resist horizontal forces .Environmental Conditions: Exposure to heat, vibration, or corrosive environments may necessitate closer support intervals to maintain structural integrity .Compliance with Standards: NEC, BS 7671, and IEEE standards provide guidance on securing cables and trays, emphasizing that vertical runs must be supported to prevent undue mechanical strain and ensure fire safety .Practical Installation TipsUse hanging rod supports with a minimum diameter of 8 mm for vertical runs to maintain stability .At bends or corners, install one hanger on each side symmetrically to prevent stress on the tray and cables .Ensure cables are laid straight and orderly within the tray, avoiding overlaps or protrusions, and secure them with ties spaced no more than 1.5 meters apart .For very long vertical risers, consider mechanical calculations to account for the combined weight of cables, thermal expansion, and potential dynamic forces such as seismic activity . By following these guidelines, vertical cable tray installations will maintain structural integrity, reduce mechanical strain on cables, and comply with safety standards.