This AutoCAD DWG file provides a comprehensive cable tray installation plan, featuring detailed support rod, duct, and expansion joint specifications. This document details the Cable Tray and Trunking System Installation : 1. Installation of the. Cable tray systems are designed for easy installation and to accommodate power, communications, and signal cabling across a variety of applications. Tool Required: On receipt of the cable tray, trunking, cable ladder and accessories at site necessary precautions shall. The purpose of this article is to define the sequence and methodology for the installation of electrical cable trays, cable trunking, cable raceways and boxes, junction and pull boxes.