Small trays (50mm) are utilized in a small number of data lines, whereas wide trays (900mm) are used in large factories. The depth or the height of the side wall ensures that the cables remain held in a safe shape. The trays are available in 3-meter (10-foot) segments made by. association representing the major electrical equipment manufac-turers in the U. The Cable Tray ng standards, performance standards, test standards and application in this document have been tested extens ompetent professional en completely installed, without damage either to conductors or. us-trations without notice. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. Cable tray (or cable ladder) systems are a popular alternative to electrical conduit systems, as they have an outstanding record for dependable service, design flexibility and cost savings in commercial and industrial applications. A properly designed and installed cable tray system will provide. 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.