CSLB C-10 Electrical ContractorEquipment and InstallationHard

An electrician needs to extend an existing 120-volt, 15-ampere bedroom branch circuit by 4 feet to relocate a single receptacle outlet, with no additional outlets added. The existing circuit is not currently AFCI protected. Per NEC 210.12(B) Exception, is AFCI protection required for this extension?

  1. AYes, but only combination-type AFCI breakers may be used.
  2. BNo, because AFCI protection only applies to new construction, not existing dwellings.
  3. CNo, because extensions of not more than 6 feet from an existing outlet, with no additional outlets, are exempt from the AFCI requirement.
  4. DYes, AFCI protection is always required for any modification to a dwelling bedroom circuit.
Show answer & explanation

Correct answer: C. No, because extensions of not more than 6 feet from an existing outlet, with no additional outlets, are exempt from the AFCI requirement.

The Exception to NEC 210.12(B) permits extending an existing branch circuit up to 6 feet without adding outlets without requiring AFCI protection, recognizing the impracticality of retrofitting AFCI protection for minor extensions. Since the extension here is 4 feet with no new outlets, it qualifies for the exception.

Why the other options are wrong

  • A. Combination-type AFCI is the general requirement when protection IS required, not applicable to this exempted extension.
  • B. AFCI can apply to existing dwellings when circuits are modified, but this specific short extension is exempted.
  • D. This overstates the requirement; the code provides a specific exception for short extensions.

AFCI Extension Exception (210.12(B))

An exception to AFCI requirements allows extending an existing unprotected branch circuit up to 6 feet without adding outlets, without requiring AFCI protection.

  • Extension must be 6 feet or less
  • No additional outlets may be added
  • Recognizes impracticality of retrofitting AFCI on minor extensions

Memory trick: 'Six feet, no more outlets, no AFCI required.'

More Equipment and Installation questions