Arc-Fault Circuit Interrupter
2007 California Electrical Code
Section 210-12
(a) Definition: An arc-fault circuit interrupter is a device intended to provide protection
from the effects of arc faults by recognizing characteristics unique to arching and by
functioning to de-energize the circuit when an arc fault is detected.
(b) Dwelling Unit Bedrooms: All branch circuits that supply 125-volt, single-phase, 1520 ampere outlets installed in dwelling unit bedrooms shall be protected by combination
arc-fault circuit interrupter(s). This requirement shall be become effective January 11,
2008.
What is an arc fault?
An arc-fault is an unintentional discharge of electricity in a circuit. Arcing exists in two
basic varieties:
•
•
Natural, or normal occurring arcing
Occurs when a light is switched on or a vacuum cleaner or any motor driven
appliance is turned on
Unsafe arc-faults
Occurs either as series or parallel faults in wire, electrical devices or connected
loads.
What causes an arc fault?
Arc faults may occur anywhere in the home's electrical system in several ways:
•
•
•
Line-to-Neutral Arcs
- Damaged power supply cord
- Pushing furniture against cords plugged into outlets
Line-to-Ground Arcs
- Accidently piercing electrical cable behind drywalls with drill bit, nail, or screw
- Hammering electrical cable staples too tightly into studs during rough wiring
Series Arcs
- Screw terminal where a wire is connected to a receptacle may become loose as it
is pushed back into the work box
(The above instructions do not pertain to every type of AFCI breaker; refer to the exact type of manufacture instructions
for the correct installation for the AFCI breaker installed.)