Arc-Fault Circuit Interrupter (AFCI) | CEC § 210.12


This section focuses on the rules and regulations for Arc-Fault Circuit Interrupter (AFCI) protection in residential properties. To make sure we're all on the same page, let's first break down what some of these technical terms mean:

  1. Arc-Fault Circuit Interrupter (AFCI): This is a device that provides protection against electrical fires that can be caused by dangerous electrical arcs in a home's wiring. These arcs can happen when electricity jumps from one wire to another, which can cause extreme heat and potentially spark a fire. It is defined in the CEC as "A device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc fault is detected."
  2. Branch Circuit: This is a portion of a wiring system extending beyond the final overcurrent device (such as a breaker or a fuse) protecting the circuit. This circuit is what carries electricity from your main electrical panel to the outlets, lights, and appliances in your home. It is defined in the CEC as "The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s)."
  3. Voltage, Ampere: These are units used to measure electricity. In this context, a 120-volt, single-phase, 15- and 20-ampere circuit refers to the standard electrical circuit found in most U.S. homes.


AFCI protection shall be provided as required in California Electric Code (CEC) 210.12(A), (B), (C), and (D). The arc-fault circuit interrupter shall be installed in a readily accessible location.

Dwelling Units

All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be AFCI protected.

Branch Circuit Extensions or Modifications

AFCI protection shall not be required where the extension of the existing branch circuit conductors is not more than 6ft (1.8m) and does not include any additional outlets or devices, other than splicing devices. This measurement shall not include the conductors inside an enclosure, cabinet, or junction box.