Due to their exposure to the open air because of the cable trays, the wires contained within need a very durable outer covering. The regulations dictate that the cables must either be Type TC (also known as Tray Rated) or must be metal-armored (Type MC). The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. 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 trays play a vital role in supporting electrical cables and wires in commercial, industrial, and utility installations. One of the most recognized frameworks globally is the IEC standard for. The primary rulebook of cable tray systems is called NEC Article 392. These regulations ensure that the metal or plastic frames that contain the wires are robust enough to ensure. The National Electrical Code (NEC) provides comprehensive safety standards for electrical installations, including requirements for electrical panels (main service panels and subpanels or breaker box). NEC Article 408 covers switchboards, switchgear, and Panelboards installation and applications.