The standard NEMA lengths for cable tray are 12, 20, 24 and 30-feet, although some manufacturers like Eaton offer cable tray in lengths up to 40 feet. Selecting a cable tray length is based on several criteria, including: The required load that the cable tray . In practice, cable tray dimensions are a system of interrelated measurements —width, depth, length, and material thickness—that directly affect cable fill compliance, heat dissipation, structural loading, and long-term expandability. This includes both the. Hubbell's NEXTFRAME® Ladder Tray is the effective and widely used cable runway that supports and delivers bundles of cable between cabinets, racks, and closets, along walls, and suspended from ceilings. It is designed for. cable trays are equivalent. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. Cable trays vary in size in order to accommodate varying numbers of wires. International projects are most often made in widths of between 50mm and 900mm and depths of between 50mm and 150mm.