Code Change Summary: A new Part IV was added to Article 400.

In the 2023 NEC^®, Part IV was added to Article 400 to address portable power feeder cables over 2000 volts. Before this change, Article 400 contained part III, titled “Portable Cables Over 600 Volts, Nominal” but contained no requirements specific to portable cables rated more than 2000 Volts.

There are cranes, hoists, mobile equipment, and machinery in existence that operate above 2000 Volts and yet, until now, the NEC^® has not addressed them in Article 400.

This new part of Article 400 adds the necessary information to properly apply portable cables rated above 2000 Volts. The ampacity and construction requirements referenced in new part IV of Article 400 align with ANSI/NEMA WC 58-2017/ ICEA No. S-75-381-2017, Standard for “Portable and Power Feeder Cables for Use in Mines and Similar Applications”.

Highlights from new Part IV include:

• New Section 400.44 requires conductors of portable power feeder cables to employ flexible stranding and be no smaller than 6 AWG copper.
• New Section 400.47 requires the minimum bending radius for portable power feeder cables from 2000 volts to 5000 volts to be no more than six times the overall cable outer diameter. The minimum bending radius for portable cables from 5001 volts to 25,000 volts shall not exceed eight times the overall cable outer diameter.
• New Section 400.50 requires portable power feeder cable types G, SHD-PCG, and SHD-CGC to be used only from 2000 volts to 5000 volts. Types SH, SHD, and SHD-GC must be used from 2000 volts to 25,000 volts.