Calculate the minimum cable tray bend radius required for LV, MV, HV, fiber optic, and control cables. Instantly estimate centerline fitting curves to ensure compliance with IEC 60364 and NEC Article 392 standards, preventing physical cable jacket damage. What Is Cable Bending Radius? 1. Solid Bottom / Perforated Tray 3. These limits should not be used for cables subj olerate a sharper bend than a shielded cable. When bent too sharply, helical metal tapes can eparate. The bending radius expresses the smallest possible bend with which one can safely bend a cable without kinking it, damaging it or shortening its life span. The bending radius is usually expressed as a multiple of the outer diameter of.