Width is set by total cable area plus spare factor; depth helps maintain side containment and segregation. Eaton's B-Line series wide cable trays use stronger rungs to safely bear the loads published (only our 42 and 48-inch widths require load reductions). When supporting small diameter multi-conductor control and instrumentation cables, 6, 9, or 12-inch rung spacings should be specified. Quality Type. 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. Armoured cables. In this guide, you will learn how to calculate cable tray size step by step using a practical formula, tray selection rules, and a real example. Selecting the appropriate cable tray dimensions and size is essential for many kinds of reasons: The size of the cable tray has to be suitable on account. 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. International projects are most often made in widths of between 50mm and 900mm and depths of between 50mm and 150mm. The majority of the sections have a length of 3 meters, as this is easy to transport and can be compactly.