Arc Faults and Electrical Safety

Arc Faults and Electrical Safety
W H AT I S T H E D I F F E R E N C E B E T W E E N A
G R O U N D FA U LT A N D A N A R C FA U LT ?
There is a major difference between the
functioning of an AFCI as compared to a GFCI
(Ground Fault Circuit Interrupter). The function
of the GFCI is to protect people from the
deadly effect of electric shock that could
occur if parts of an electrical appliance or tool
become energized due to a ground fault. The
function of the AFCI is to protect the branch
circuit wiring from dangerous arcing faults that
could initiate an electrical fire.
AFCI and GFCI
technologies can co-exist
with each other and are a
great complement for the
most complete protection
that can be provided on a
circuit.
IT’S ALL ABOUT SAFETY
N E M A A N D E L E CT R I C A L S A F ET Y
For more than 80 years, manufacturers of low
voltage distribution equipment have been
working to ensure public safety by standards
writing efforts and the dissemination of
important industry information through the
National Electrical Manufacturers Association
(NEMA), one of the most respected standards
development organizations in the world.
Headquartered in Rosslyn, Virginia, NEMA has
approximately 400 electroindustry companies,
including large, medium and small businesses.
To learn more about NEMA visit
www.nema.org.
To learn more about AFCIs, visit our AFCI web
site at www.afcisafety.org.
arc faults and
electrical safety
Smoke alarms, fire
extinguishers and escape
ladders are all examples of
emergency equipment
used in homes to take
action when a fire occurs.
AFCIs are products designed to detect a wide
range of arcing electrical faults to help reduce
the electrical system from being an ignition
source of a fire. Conventional overcurrent
protective devices do not detect low level
hazardous arcing currents that have the
potential to initiate electrical fires.
AFCIs are the next generation product in
electrical circuit protection. As you evaluate
your new home’s construction or consider
upgrading or remodeling your current
electrical system, consider enhancing the
protection of your electrical system
with AFCI.
P R OT E CT I N G H O M E S & FA M I L I E S
F R O M E L E CT R I C A L F I R E S
W I T H A D VA N C E D T E C H N O LO GY
NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION
Low Voltage Distribution Equipment Section
1300 North 17th Street, Suite 1752 • Rosslyn, Virginia 22209
(703) 841-3200 Fax: (703) 841-5900
www.nema.org
NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION
Low Voltage Distribution Equipment Section
E L E CT R I C A L F I R E S K I L L
T H O U S A N D S E V E RY Y E A R
According to the U.S. Fire Administration*, home
electrical problems accounted for an estimated
67,800 fires and $868 million in
property losses in 2003. Electrical
fires also cause an estimated 485
deaths annually and injure almost
2,300 more individuals.
Electrical fires can be caused by a
number of failures. Appliance
defects or misuse, incorrectly
installed wiring, or misapplied
extension cords can lead to electrical hazards.
In 1992, the Consumer Product Safety
Commission (CPSC) contracted with
Underwriters Laboratories (UL) to provide
research and evaluation of products and
technology that could reduce the likelihood of
residential fires. A result of the research, UL
identified an electrical hazard called “arcing
faults” that could eventually lead to the ignition
of a fire as one possible cause of residential fires.
W H AT I S A N A R C FA U LT ?
Most people are familiar with the
term arcing. Arcing may be
intended, such as with an arc
welder or unintended, such as
when a tree falls on a power line
during a storm creating a current
discharge between conductors or
to ground.
An arc fault is an unintended arc created by
current flowing through an unplanned path.
Arcing creates high intensity heating at the
point of the arc resulting in burning particles
that may easily ignite surrounding material,
such as wood framing or insulation. The
temperatures of these arcs can exceed 10,000
degrees Fahrenheit.
*USFA. 2006. “On the Safety Circuit: A Factsheet on Home Electrical
Fire Prevention.” U.S. Fire Administration.
H O W A R E A R C I N G FA U LTS D ET E CT E D ?
Traditional overcurrent protective devices
cannot detect these types of arcs. The
capability now exists to detect many of these
arcing conditions and disconnect the problem
circuit through the use of Arc Fault Circuit
Interrupters (AFCIs).
H O W D O E S A N A R C FA U LT C I R C U I T
I N T E R R U P T E R ( A F C I ) WO R K ?
In essence, the detection is accomplished by
the use of advanced electronic technology to
monitor the circuit for
the presence of
“normal” and
“dangerous” arcing
conditions. Some
equipment in the
home, such as a
motor driven vacuum
cleaner or furnace
motor, naturally create
arcs. This is considered to be a normal arcing
condition. Another normal arcing condition that
can sometimes be seen is when a light switch
is turned off and the opening of the contacts
creates an arc.
W H Y I S I T I M P O RTA N T TO H AV E A N A F C I
B R E A K E R I N STA L L E D I N MY H O M E ?
AFCIs were developed in response to an
identified electrical problem causing fires in the
home as noted by the Consumer Product
Safety Commission and other prominent
organizations.
An AFCI provides a higher level of protection
than a standard circuit breaker by detecting
and removing the hazardous arcing condition
before it becomes a fire hazard.
W H E R E A R E T H EY R E Q U I R E D TO B E
I N STA L L E D BY T H E N AT I O N A L
E L E CT R I C A L C O D E ?
The 2005 National Electrical Code states that
AFCIs must be placed on bedroom power and
lighting circuits. The 2008 NEC
may expand this requirement to
other areas in the home. As with
all property protection and life
saving devices, the ultimate use,
beyond the Code, rests with the
homeowner. Whether new
construction or retrofit, NEMA
supports that
you utilize the
maximum
electrical
protection level
available to
reduce the
chance of an
electrical fire.
C A N I H AV E
AFCIs
I N STA L L E D E V E N I F MY STAT E
O R M U N I C I PA L I T Y D O E S N ’ T
REQU I RE TH EM?
Absolutely, do you only place locks on the front
door of the house? Just like placing locks on all
external doors and windows for security
reason, it is logical to request AFCI protection
on all 15 and 20A branch circuits, not just
those in the bedroom, to protect the entire
home from an electrical arcing ignition hazard.
AFCIs are available through electrical
distributors and in many home centers and
hardware stores nationally. The only major
physical requirement is that the AFCI requires
directly wired hot and neutral wires on the
circuit you’re going to protect.
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