What it is

Blog post answering common NEC code questions for electricians working with LED lighting installations. Covers Class 2 and Class 3 power-limited circuits under Article 725, and introduces Class 4 as a newer category specifically created for fault managed power systems.

Why it matters

The distinction between Class 2/3 and the new Class 4 category affects electrical contractors’ installation practices, wire/conduit sizing, and AHJ approval workflows. Understanding which article governs fault managed power systems versus traditional power-limited circuits is critical for code compliance and avoiding rework on LED and low-voltage power projects.

Evidence from source:

  • Class 2 and Class 3 circuits remain in Article 725 and are power limited
  • Class 4 is a newer category introduced for fault managed power systems

Open questions

  • What specific installation requirements differentiate Class 4 from Class 2/3 under Article 725?
  • How are AHJs interpreting Class 4 provisions for fault managed power in field installations?