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Electrical Outlet Safety:
GFCIs And 3-Prong Plugs
How does a three-prong plug work?
What's the benefit of using it?
The third prong on a three-wire cord set
provides a path to ground for electricity that is
straying or leaking from a product. This helps
protect the equipment and can help prevent
electric shock.
How does a polarized plug work?
What's the benefit of using it?
A polarized plug is a plug with one large or
wide prong and one narrow one. It ensures that
the plug is inserted correctly in a socket and
reduces the risk of electrical shock.
Do all GFCIs work in the same
manner?
All GFCIs work in the same manner to protect
people against ground faults.
However, unlike the receptacle GFCI, the circuit
breaker-type GFCI also provides overload
protection for the electrical branch circuit.
If the appliance has a built-in shock
protector, is an additional GFCI
necessary?
Appliances that have built-in shock protectors,
as now required for hair dryers, may not need
additional GFCI protection. However, other
unprotected appliances still need GFCI protection.
What is a GFCI?
A GFCI is an electronic device for protecting
people from serious injury due to electric shock.
How does the GFCI work?
GFCIs constantly monitor electricity flowing in
a circuit. If the electricity flowing into the circuit
differs by even a slight amount from that returning,
the GFCI will quickly shut off the current flowing
through that circuit. The advantage of using GFCIs
is that they can detect even small variations in
the amount of leakage current, even amounts too
small to activate a fuse or circuit breaker. GFCIs
work quickly, so they can help protect consumers
from severe electric shocks and electrocution.
If the GFCI is working, is there any
danger of electric shock?
Even if the GFCI is working properly, people
can still be shocked. However, the GFCI can act
quickly to prevent electrocution.
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Can consumers install GFCIs?
Consumers are encouraged to use a qualified
and certified electrician to install circuit breakertype GFCIs. Individuals familiar with electrical
wiring practices, who can follow the instructions
accompanying the device, may be able to install
receptacle-type GFCIs. The portable GFCI requires
no special knowledge or equipment to install.
What is the big plug now found on
such appliances as hair dryers?
The large box-like device found on the ends of
some appliance cords can be an appliance leakage
circuit interrupter (ALCI), an immersion detection
circuit interrupter (IDCI), or a ground fault circuit
interrupter (GFCI).
They work in different ways, but they are all
intended to shut off the power to an appliance
under an abnormal condition such as immersion
of the appliance in liquid. Just because you have
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an appliance with one of these devices, it doesn't
mean that it is okay to drop the appliance in water
and retrieve it while it's plugged in. The rule that
"electricity and water don't mix" still applies.
If the product has a three-prong
grounding type plug, is a GFCI still
necessary?
GFCIs are necessary even if the product has a
third wire to ground it. GFCIs provide very sensitive
protection to consumers against electric shock
hazards. Under some conditions, a shock hazard
could still exist even if a product has a grounding
wire.
Using Outlets And Appliances Safely
Once upon a time you could buy a small
appliance, take it home, plug it in and be done.
Of course, that was before the advent of polarized
and grounded plugs. But don’t make the mistake
of thinking of these safety advances as problems
for you to solve. They exist to protect you and
your family -- and your equipment, too -- from
electric shock, and using them inappropriately
can cause serious injury or death.
For instance, many types of electronic
equipment and some extension cords come with
a third prong on the plug. That wasn’t put there
to make it hard to use, but rather to make it safe!
That third prong is a ground, which provides a
safe path for stray or leaking power to go to
ground, and it can prevent equipment damage
and shock. If your outlets are ungrounded -- and
you don't have a place to plug in that third prong
-- NEVER cut off the third, or ground prong, so
that you can plug the item in.
Consult with a licensed electrician about
upgrading your home’s electrical system and
outlets. How much work will be required, and
what it will cost, will vary; but the price will be
worth the safety you gain.
Newer appliances that don’t require a grounded
plug will almost always have a polarized plug -one in which one prong is wider and longer than
the other. This simply ensures that the plug is
inserted correctly in a socket and reduces the risk
of electrical shock. These seldom present a
problem for users, even with older homes and
outlets. But don’t try to force a plug into an outlet
if it doesn’t fit. Check with an electrician. Don’t
short-circuit these safety measures!
Do you have questions about electrical safety
in your home? Call us here at Kotzebue Electric
for assistance. We’re always glad to help our
consumers.
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