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. NEC section 300-8 does not permit any tube, pipe, or equal for water, air gas, drainage, steam, or any service other than electrical in raceways or cable trays containing. Article Summary: A compliant cable tray installation requires a thorough understanding of NEC Article 392, proper structural support, and precise installation techniques. The cable tray helix fittings from Thomas & Betts (T&B) ease transitions between horizontal and vertical cable tray runs, especially. Construction Experience: It is recommended that the work described be performed by qualified persons familiar with Standard electrical construction practices, electrical equipment, and safety of electrical wiring systems. The following pages address the 2014 National Electrical Code® requirements for cable tray systems as well as design solutions from practical experience. It includes the general requirements for all wiring methods included in the NEC, but does not apply to twisted-pair cable and coaxial cable (covered in Chapters 7 and 8) unless Article.