Estimate Copper Conductor Bending Radius
When installing wire or cable on curved surfaces around building, in
ducts or cable tray, how far can you bend it?
NEC (National Electric Code) and the Insulated Cable Engineers Association (ICEA) have provided bending radius information as listed in the table below.
Simply multiply the cable diameter by the factor on the right side of the table.
| Cable Type | Bending Radius as a Multiple of Cable Overall Diameter |
|---|---|
| Single or multi-conductor cable without metallic shielding | x 8 the overall cable diameter |
| Single or multi-conductor cables with tape shielding | x 12 the overall cable diameter |
| Multi-conductor cables with individually shielded conductors. |
x 12 the individual cable diameter (pairs, triads, etc.) or 7 times the overall cable diameter. Whichever is greater. |
For more accurate information, see NEC Articles 300-34, 334-11 & 336-16, and Appendix H of ICEA S-66-524 and ICEA S-68-516.