AFCI Requirements Checker

Determine if AFCI (Arc Fault Circuit Interrupter) protection is required for your room per NEC 210.12.

Results

Visualization

How It Works

An AFCI (Arc Fault Circuit Interrupter) detects dangerous electrical arcs caused by damaged, worn, or improperly installed wiring. Arcing is a leading cause of residential electrical fires. AFCI breakers monitor the circuit waveform and trip when they detect an arc signature.

The Formula

AFCI detects: parallel arcs (hot-to-neutral/ground) and series arcs (broken conductor) by analyzing current waveform patterns.

Variables

  • AFCI — Arc Fault Circuit Interrupter -- detects arcing conditions that can start fires
  • Combination AFCI — Detects both parallel and series arcs (most protective type, currently required)
  • NEC 210.12 — National Electrical Code section covering AFCI requirements
  • 2023 NEC — Requires AFCI in all 120V 15A/20A circuits in dwelling unit habitable rooms

Example

A new bedroom in new construction: AFCI is required per NEC 210.12(A). Install a combination AFCI breaker at the panel. Cost is about $35-50 per breaker versus $5 for a standard breaker.

Tips

  • AFCI breakers can trip from normal arcing events like vacuum motor brushes -- this is called nuisance tripping and is annoying but not dangerous.
  • Combination AFCI/GFCI breakers are available and provide both types of protection in a single device.
  • Bedrooms have required AFCI since the 2002 NEC -- it has expanded to nearly all rooms by the 2023 cycle.
  • If an AFCI breaker keeps tripping, it may be detecting a real problem -- have an electrician inspect the wiring before bypassing.
  • AFCI protects against fire; GFCI protects against shock. Different hazards, both important.