210.12 Arc-Fault Circuit-Interrupter (AFCI)
The word "receptacle" was deleted and the words listed
device that protects the entire branch circuit
were added. This subsection now reads:
(A) AFCI Definition.
AFCI protection device provides protection from an arcing
fault by recognizing the characteristics unique to an
arcing fault and by functioning to de-energize the circuit
when an arc fault is detected.
(B) Dwelling Unit Bedrooms.
branch circuits supplying 15 or 20A, single-phase, 125V
outlets installed in dwelling unit bedrooms must be AFCI
protected by a listed
device that protects the entire branch circuit.
Intent: The change extends AFCI protection to all branch circuit conductors
that supply 125V outlets in dwelling unit bedrooms, whereas
the 1999 NEC only required AFCI protection for all branch
circuits conductors that supply 15 or 20A, single-phase, 125V
receptacle outlets in dwelling unit bedrooms. Currently there
are three types of AFCI protection devices.
AFCI Branch/Feeder Type (AVZQ) This protection device
is typically has the AFCI protection integral with a circuit
breaker. It is designed to protect the branch circuit wiring
against the unwanted effects of arcing, with limited protection
to power supply cords connected to the receptacle.
AFCI Outlet Branch Circuit Type (UL AWBZ) This
AFCI protection device is typically a receptacle with integral
AFCI protection that is intended to protect both the power
supply cords connected to the receptacle and the upstream
branch circuit wiring.
AFCI Outlet Type (UL AWCG and AWBZ) This device
is likely to be a receptacle with integral protection that
is designed to protected cord sets plug into it, not the upstream
branch circuit wiring.
At the time a dwelling unit is wired, it is hard to tell from
looking at the bare walls whether a room will be used as a
home office or a bedroom. Also, if you are looking at an efficiency
apartment, a room may well be furnished with a foldout couch
that is used for sleeping on every night, making it look as
much like a bedroom as a living room.
If you wire bedroom branch circuits with one circuit for
lighting and receptacles, this change will have little
effect. But the practice of separating the lighting from
the receptacle circuits in dwelling unit bedrooms will
now require two AFCI circuit breakers. The 125V limitation
to the requirement means that AFCI protection would not
be required for a 240V baseboard heater or room air conditioner.