Explore various cable tray types and sizes for electrical installations. Solid-Bottom. 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. The selection of material and finish is a function of the environment in wh tant in a wide range. Is your cable tray system optimized for safety, dependability, space and cost savings? 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. When choosing the size of cable tray, it is a tradeoff between the existing volume of cable and the future volume of cable. A tray that is too small will overheat and physically damage, and too large tray will drain the project budget. All illustrations, descriptions and technical information included in this document are provided as indications and can cable trays are equivalent.