Where sizes of Cable Trays / Trunking are not detailed on drawing then tray shall be adequately sized to support the cables without bunching and a 25% reserve margin shall be allowed in size and weight be loaded. All routes are chosen to allow ease of access to all. This method statement covers the site installation of the cable tray & ladders and the requirements of checks to be carried out. This section will guide you through the necessary steps to ensure a successful. Article Summary: A compliant cable tray installation requires a thorough understanding of NEC Article 392, proper structural support, and precise installation techniques. Delivery and inspection upon arrival of material at site. DEFINITIONS QA/QC : Quality Assurance / Quality Control Engineer.