210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Dwelling Units. All 120-volt, single phase, 15- and
20-ampere branch circuits supplying outlets installed in
dwelling unit family rooms, dining rooms, living rooms,
parlors, libraries, dens, bedrooms, sunrooms, recreation
rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter,
combination-type, installed to provide protection of the
branch circuit.
Informational Note No. 1: For information on types of
arc-fault circuit interrupters, see UL 1699-1999, Standard
for Arc-Fault Circuit Interrupters.
Informational Note No. 2: See 11.6.3(5) of NFPA 72-
2010, National Fire Alarm and Signaling Code, for information
related to secondary power supply requirements for
smoke alarms installed in dwelling units.
Informational Note No. 3: See 760.41(B) and 760.121(B)
for power-supply requirements for fire alarm systems.
Exception No. 1: If RMC, IMC, EMT, Type MC, or steel
armored Type AC cables meeting the requirements of
250.118 and metal outlet and junction boxes are installed
for the portion of the branch circuit between the branchcircuit
overcurrent device and the first outlet, it shall be
permitted to install an outlet branch-circuit type AFCI at
the first outlet to provide protection for the remaining portion
of the branch circuit.
Exception No. 2: Where a listed metal or nonmetallic conduit
or tubing is encased in not less than 50 mm (2 in.) of
concrete for the portion of the branch circuit between the
branch-circuit overcurrent device and the first outlet, it
shall be permitted to install an outlet branch-circuit type
AFCI at the first outlet to provide protection for the remaining
portion of the branch circuit.
Exception No. 3: Where an individual branch circuit to a
fire alarm system installed in accordance with 760.41(B) or
760.121(B) is installed in RMC, IMC, EMT, or steelsheathed
cable, Type AC or Type MC, meeting the requirements
of 250.118, with metal outlet and junction boxes,
AFCI protection shall be permitted to be omitted.
(B) Branch Circuit Extensions or Modifications ? Dwelling
Units. In any of the areas specified in 210.12(A), where
branch-circuit wiring is modified, replaced, or extended, the
branch circuit shall be protected by one of the following:
(1) A listed combination-type AFCI located at the origin of
the branch circuit
(2) A listed outlet branch-circuit type AFCI located at the
first receptacle outlet of the existing branch circuit