Calculate cable tray bend dimensions, centerline arc lengths, setback distances, and offset configurations. Ensure compliance with NEC, IEC, and NEMA bend-radius standards for safe cable routing. 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. The Cable Tray ng standards, performance standards, test standards and application in this document have been tested extens ompetent professional en completely installed, without damage either to conductors or.