When transitioning cables from a tray to equipment or another raceway, the unsupported span cannot exceed 6 feet. This spacing is crucial for adequate maintenance access, ease of inspection, and ensuring proper airflow for effective heat dissipation. It also helps reduce the risk of. The NEC requires that cable trays must be supported by members at an interval specified by the cable tray manufacturer, but not more than 5 feet for horizontal runs to support the weight of the cables and other loads. The NEC has a requirement for ladder-type cable trays. Industrial electrical standards like NEC Article 392 and NEMA VE 2 rely on these strict trigonometric. 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. Although BS 7671 touches on the subject of cable supports, it does not detail specifically what these support distances should be.
