Answer: Yes; cables are tied down in cable trays to keep the cables in the cable tray, to maintain spacing between cables, or to segregate or confine certain types of cables to specific locations. The last two items can also be accomplished with a solid fixed barrier. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when the cable tray cont d for instrumentation and control applications that require. us-trations without notice. All illustrations, descriptions and technical information included in this document are provided as indications and can cable trays are equivalent. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. NEC Article 392 outlines the key rules for installing and maintaining industrial cable tray systems. These systems, made from metal or plastic, are open structures designed to support electrical conductors, ensuring proper organization and safety. Here's what you need to know: Cable Types: Only use. Question 1: What types of cables can be installed in Cable Tray systems? Answer: The types of cables permitted by the 1996 NEC are indicated in Section 318-3, uses permitted, (a) Wiring Methods.