Both width and the height of tray are functions of the number, size, spacing and weight of the cables in the tray. Load rating is independent of width. Even though a 900 mm wide tray has six (6) times the volume of a 150 mm wide tray, it cannot carry any more. Cable tray systems are engineered support structures designed to route, support, and protect insulated electrical cables used for power distribution, control, instrumentation, and communication. Unlike conduit systems, cable trays allow cables to be laid in bundles, improving accessibility, heat. 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 the cable tray cont d for instrumentation and control applications that require additional protec eferred to support and protect numerous small. 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. A cable support system consists of cable support lengths and system components, such as cable support fittings, support elements, mounting elements and system acces-sories. A properly designed and installed cable tray system will provide. 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.