The fittings can be used for cable trays of widths of 100 to 600 mm and the heights 35, 60, 85 and 110 mm. 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. The Ladder Tray features light, rugged, tubular steel construction. It is designed for. en completely installed, without damage either to conductors or structural system use maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when. us-trations without notice. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. The work covered under this section consists of the furnishing of all necessary labor, supervision, materials, equipment, tests and services to install complete cable tray systems as shown on the drawings. The screw-on cable tray systems fulfil the requirements of "IEC 61537:2006 – Cable management – Cable tray systems and cable ladder systems” for the low-voltage area.