This AutoCAD DWG file provides a comprehensive cable tray installation plan, featuring detailed support rod, duct, and expansion joint specifications. A Cable Tray System is defined as a continuous, rigid structural system for supporting cables, composed of straight sections, bends, and fittings (trays/channels or ladders), supported by brackets, hangers, or supports. General Technical Requirements 1. For licensed electricians, mastering these principles is essential. 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.