Step-by-step on-site guide: learn how to plan, mark, support, and install cable trays correctly, from shop drawing approval to final checks. eferred to support and protect numerous small instrumentation and control cables. Because of its closed design, this type of tray should e used in applications where there is minimal risk of heat generation and buildup. When equipped with a solid cover, this type of cable tray can be used t -piece. Cable tray systems are designed for easy installation and to accommodate power, communications, and signal cabling across a variety of applications. The beginning of success is to review the Bill of Quantities (BOQ) so that. This guide breaks down the process step by step. This guide covers the critical steps, from selecting the right electrical cable tray and performing accurate cable fill calculations to managing a safe cable pull through and ensuring all bonding and grounding requirements are met. For licensed electricians, mastering these principles is essential. At its heart, Cable Tray Design, Layout means choosing and setting up cable trays to hold and protect electrical and data cables. Cable trays give cables a clear path.