Cable tray systems are recognized as a wiring method by many national and international electrical codes. Typical requirements address: Tray construction, load ratings, and materials. Support spacing, mechanical strength, and. en completely installed, without damage either to conductors or structural system use 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 International Electrotechnical Commission (IEC) provides detailed guidelines for cable tray systems under IEC 61537. Whether you're designing a new. This standard specifies the requirements for nonmetallic cable trays and associated fittings designed for use in accordance with the rules of the Canadian Electrical Code (CEC) Part 1, and the National Electrical Code® (NEC). 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. This publication is intended as a practical guide for the proper and safe* installation of cable ladder systems, cable tray systems, channel support systems and associated supports.