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. Below are the key principles to guide the layout of E&I cable trays, focusing on practical, safety, and efficiency aspects. Separation of Electrical and Instrumentation Cables Electrical on Top, Instrumentation Below: Typically, electrical trays are positioned above instrumentation trays. This is a guide for installation. Question 4: Does the NEC apply to telecommunication cabling installations? Answer: Yes, in the following articles: 645 Information Technology Equipment 725. maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. 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. Cable tray barriers can be used to separate conductors operating over 600 volts from other conductors in the same tray operating at 600 volts or less. Code Change Summary: A clarification was made regarding separation of conductors in cable trays when conductors operate at different voltage levels. Cable tray is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or. Drop-Outs: Allow cables to exit the tray vertically to connect to equipment below.