Cable tray fill capacity is governed by electrical codes (typically NEC Article 392) which limit cable fill to 40-50% of tray cross-sectional area for safety and heat dissipation. The tray area is the product of width and depth in millimeters. The flexibility and scalability of cable trays make them an ideal choice for environments where cable density and organization can significantly impact operational efficiency. This compliance is not. 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. The primary rulebook used in the safe use of cable trays is NEC Article 392. 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. NEC Article 392 outlines the key rules for installing and maintaining industrial cable tray systems. For multiconductor cables rated 2000V or less in ladder or ventilated trays, the total.