WHAT IS A GFCI?
A ground fault circuit interrupter, called a GFCI or GFI, is an inexpensive electrical
device that can either be installed in your electrical system or built into a power cord to
protect you from severe electrical shocks. GFCIs have played a key role in reducing
electrocutions. Greater use of GFCIs could further reduce electrocutions and mitigate
thousands of electrical burn and shock injuries still occurring in and around the home
each year.
Ground fault protection is integrated into GFCI receptacles and GFCI circuit
breakers for installation into your electrical system, especially for circuit outlets in
particularly vulnerable areas such as where electrical equipment is near water.
Portable GFCIs are also available to provide on-the-spot ground fault protection
even if a GFCI is not installed on the circuit.
The GFCI is designed to protect people from severe or fatal electric shocks but
because a GFCI detects ground faults, it can also prevent some electrical fires and
reduce the severity of other fires by interrupting the flow of electric current.
What Is A Ground Fault?
A ground fault is an unintentional electrical path between a power source and a
grounded surface. Ground faults most often occur when equipment is damaged
or defective, such that live electrical parts are no longer adequately protected
from unintended contact. If your body provides a path to the ground for this
current, you could be burned, severely shocked or electrocuted.
How Do They Work? Where to Install/Use
The circuits that require GFCI protection are designated by the National
A GFCI constantly monitors current
Electrical Code (NEC).1 The NEC typically only applies to new
flowing through a circuit. If the current
construction/major renovations. The coverage of GFCI protection has gradually
flowing into the circuit differs by a very
increased over the years.
small amount (as little as 0.006 amperes)
from the returning current, the GFCI
NEC GFCI requirements (and effective date):
interrupts power faster than a blink of an
eye to prevent a lethal dose of electricity. Underwater pool lighting (since 1968)
GFCIs are designed to operate before the Receptacles:
electricity can affect your heartbeat. A o Outdoors (since 1973)
GFCI works even on two-slot receptacles. o Bathrooms (since 1975)
o Garages (since 1978)
Here's an example: A bare wire inside an o Kitchens (since 1987)
appliance touches its metal case. The o Crawl spaces and unfinished basements (since 1990)
case is then charged with electricity. If you o Wet bar sinks (since 1993)
touch the appliance with one hand while o Laundry and utility sinks (since 2005)
another part of your body is touching a
grounded metal object, such as a water Also consider portable GFCI protection:
faucet, you will get shocked. If the Whenever operating electrically-powered garden equipment (mower,
appliance is plugged into an outlet hedge trimmer, edger, etc.)
protected by a GFCI, the power will be With electric tools (drills, saws, sanders, etc.) for do-it-yourself work in and
shut off before a fatal shock can occur. around the house
U.S. Consumer Product Safety Commission, Bethesda, MD 20814 ● (800) 638-2772 ● www.cpsc.gov ● www.recalls.gov
How to Install
Circuit breaker and receptacle-type GFCIs may be installed in
your home by a qualified electrician. Receptacle-type GFCIs RECEPTACLE
may be installed by consumers with adequate knowledge and
skills to conform to proper electrical wiring practices and the Used in place of the standard duplex
instructions accompanying the device. When in doubt about receptacle.
the proper procedure, contact a qualified electrician; do not
attempt to install it yourself. Fits into a standard outlet box and protects
against ground-faults for whatever is
A portable GFCI gets plugged into a receptacle just like any plugged into the outlet and other electrical
other cord-and-plug-connected device. outlets further "down stream" in the branch
circuit.
Can even replace older ungrounded, two-
How to Test slot receptacles with new GFCI receptacles.
Test every GFCI: Must use supplied label “NO EQUIPMENT
After installation GROUND GFCI PROTECTED” to identify
that the receptacle is not grounded.
At least once a month
After a power failure2
According to the manufacturer’s instructions.
If you do not have the instructions follow this procedure: RESET
o Plug a lamp into the outlet and turn the lamp on.
o Press the GFCI’s test button. Did the light go out? If TEST
not, the GFCI is not working or has not been correctly
installed. Contact a qualified electrician to correct the
wiring and/or replace the defective GFCI.
o Press the reset button. Did the light come back on? If PORTABLE
not, replace the GFCI.
Used where installed GFCIs are not
practical.
Types of GFCIs
CIRCUIT BREAKER One type contains the GFCI circuitry in a
plastic enclosure with plug blades in the
A circuit breaker with a built-in GFCI may back and receptacle slots in the front. It
be installed in a panel box to add protection can be plugged into a receptacle, then the
to the circuits it supplies. electrical product is plugged into the GFCI.
Protects against both a ground fault and a Another type of portable GFCI is an
circuit overload extension cord combined with a GFCI. It
adds flexibility in using receptacles that are
Protects the wiring and every outlet, lighting not protected by GFCIs.
fixture, or appliance on the branch circuit
that it supplies.
1
The NEC is published by the National Fire Portection Association (NFPA 70). It is the most widely adopted building code for requirements for electrical system installations in the U.S.
It may be adopted into law by states, counties or local jurisdictions for enforcement by inspection authorities and is currently revised every three years.
2
Blackouts and other power disturbances can sometimes damage a GFCIs ability to function properly.
092010 Pub. 099
U.S. Consumer Product Safety Commission, Bethesda, MD 20814 ● (800) 638-2772 ● www.cpsc.gov ● www.recalls.gov
