TIA Proposed for 2023 NEC Regarding Conductor Bending Radius

The National Fire Protection Association (NFPA) recently released a proposed Tentative Interim Amendment (TIA) to the 2023 Edition of the National Electrical Code (NEC). The TIA was submitted by Joseph Cross, Eastman Chemical Company, and has a comment closing date of July 13, 2023.

TIA Log No.: 1731

Reference: 400.47

1. Revise section 400.47 to read as follows: 

400.47. Minimum Conductor Bending Radii Radius. The minimum bending radii for Pportable power feeder cables rated from 2000 volts to 5000 volts shall not exceed be bent to a radius less than six times the overall cable outer diameter. The minimum bending radii for Pportable power feeder cables rated from 5001 volts to 25,000 volts shall not exceed be bent to a radius less than eight times the overall cable outer diameter.     

Substantiation: The purpose is to clarify and be uniform with other Code language. The original verbiage contradicted the title. (Title was concerning the “minimum” and verbiage was in conjunction with a “maximum” bending radius. The language was not consistent. (using “shall not exceed”). Radii is plural and should have been singular since we are speaking of a particular bend. Language was also corrected to correlate with 305.5.

Emergency Nature: The standard contains an error or an omission that was overlooked during the regular revision process.

This TIA proposed action will clarify a bending radius of the conductor which is vital to the integrity of the conductor.     

For more information or to read the full proposed TIA, visit NFPA's website.