Each year the Bellingham Fire
Department responds to a significant number of fires and medical emergencies
caused by electrical malfunction. Every year in the United States, more than
1,000 people are killed and thousands more injured in electrical fire or
shock incidents. It is important to know how to use electrical appliances
safely and how to recognize electrical hazards.
The Nature of Electricity
Most homes have two incoming voltages: 120 volts for lighting and
appliance circuits and 240 volts for larger air conditioning and electric
When an appliance switch is turned on, electrical current flows through
the wire, completing the electrical "circuit" and causing the appliance to
operate. The amount of flowing current is called "amperage." Most lighting
circuits in the home are 15 amp circuits. Most electric dryers and air
conditioners require larger 30 amp circuits.
The amount of electrical power needed to make an appliance operate is
called "wattage" and is a function of the amount of current flowing through
the wire (amperage), and the pressure in the system (voltage).
Mathematically speaking, volts x amps = watts. So, if we have a 120 volt
system and a 15 amp current, we can flow a maximum of 120 x 15 or 1,800
watts on a typical lighting or appliance circuit. When too many lights or
appliances are attached to the electrical system, it will overload and
overheat. This can cause the wire insulation to melt and ignite, resulting
in an electrical fire. The amount of electrical current flowing through wire
is affected by resistance. This is known as "ohms." Resistance causes
increased heat in the wire. Heat is the byproduct that makes some appliances
work, such as an iron, toaster, stove or furnace. Large current faces high
resistance when moving through a small wire. This generates lots of heat.
That's how an incandescent light bulb works. Resistance through the light
filament causes it to heat up which gives off a bright light. Electrical
resistance also is affected by the length of a wire. Operating an electrical
hedge clipper with a long extension cord increases resistance and might
cause the cord to overheat, melt or ignite. The same occurs if too many
strands of Christmas lights are connected together.
The size of electrical wire is dependent upon the amount of current
required to operate a particular appliance. Wiring to the air conditioner,
electric stove and electric dryer is much larger to handle the increased
voltage (240) volts) and amperage (30 amps). Wiring is covered with a
protective material called "insulation."
Electrical circuits in homes are designed so that all components are
compatible. The size of the wire, outlets and circuit breakers are designed
for an anticipated electrical load. A circuit is said to be overloaded when
too much current flows causing heat build up or wiring to break down. When
two bare wires touch, a "short circuit" is said to occur. This can lead to
sparks and fire. Deteriorated insulation is one of the most frequent causes
of short circuits.
A "circuit breaker" or "fuse" is a safety device designed to prevent
accidental overloading of electrical circuits. They are set at a specific
amperage. When that amperage is exceeded, it trips and shuts off the flow of
electricity, stopping the circuit from continued overheating. When a fuse or
circuit breaker trips, it is important to find the cause and correct it.
Often, people will just reset the breaker or put in larger fuse. NEVER USE
OVERSIZED FUSES ON CIRCUIT BREAKERS. NEVER SUBSTITUTE A PENNY OR
FOIL-WRAPPED FUSE. This could cause a fire!
General Electrical Safety
When a house is under construction, city inspectors visit to make sure
the electrical system is in compliance with the City Building Code and the
National Electrical Code. Only licensed electricians are permitted to
install electrical systems. During home remodeling, when electrical circuits
are added or changed, make sure to use a licensed electrician whose work
complies with the electrical code. Add enough outlets in every room to avoid
using multiple plugs or extension cords. Use a ground fault interrupter
(G.F.I.) on circuits in the bathroom, or outdoors where water or moisture is
When choosing an electrical appliance, be sure it is approved by a
safety-testing laboratory. This insures that it has been constructed in
accordance with nationally-accepted electrical standards and has been
evaluated for safety. Use the appliance only according to manufacturer's
If you touch an electrical appliance, wall switch or electrical cord
while you are wet or standing in water, it will increase the chance of
When using an extension cord, be sure it is designed to carry the
intended load. Most cannot carry as much current as permanent wiring and
tend to overheat. Do not use an extension cord in place of permanent wiring,
especially if a tripping hazard exists or where there is high physical
abuse, such as under a carpet. Keep electrical cords away from infants and
toddlers and use tamperproof inserts on wall outlets to prevent them from
sticking objects into the outlets. The cord must be protected from damage.
Do not run it around objects or hang on a nail. Inspect it periodically for
worn insulation and overall condition.
Safety with Electrical Appliances
The potential for electrical shock or fire from an electrical appliance
is very real, especially when safety recommendations are not followed.
Before buying an appliance, look for the label of a recognized testing
laboratory such as Underwriters Laboratory or Factory Mutual.
Keep space heaters, stoves, irons and other heat-producing appliances
away from furniture, curtains, bedding or towels. Also, give televisions,
stereos and computers plenty of air-space so they won't overheat.
Never use an appliance with a damaged cord, and be sure to use
three-pronged electrical devices in three-pronged outlets. These outlets may
not be available in older homes, so use a three-pronged adapter, and screw
the tab onto the grounded outlet box cover. Never cut off or bend the
grounding pin of the plug. If you have a polarized plug (with one side wider
than the other), never file it down or try to make it reversible.
Keep electrical cords out of the path of traffic. If you put cords under
carpets or rugs, wires can be damaged and might result in fire.
An electrical cord should never be wrapped around an appliance until the
appliance has cooled. Because hair care equipment is often used in bathrooms
near sinks and bathtubs, it is extremely important to be especially careful
that the appliances do not come in contact with water. If one drops into
water, do not touch it until you have pulled the wall plug.
Protect young children by putting plastic inserts in receptacle outlets
not in use to keep them from putting anything into outlets.
Never put a kitchen knife or other metal object in a toaster to remove
stuck bread or bagels unless it is unplugged and cooled. Install television
and radio antennas where they cannot fall across power lines. Use caution
when operating a tree-pruning device or using a metal ladder around power
Inspect appliances regularly to make sure they operate properly. If an
appliance smells funny when in use, makes unusual sounds or the cord feels
warm to touch, repair or replace the unit. Don't repair it yourself unless
you are qualified. Keep appliances in a cool, dry place to prevent rusting.
When an electrical emergency occurs, there are several survival actions
that can be taken. You should know how to trip the main circuit breaker at
the electrical panel to turn off all power to the house.
If an appliance smells funny or operates improperly, pull the plug if it
can be done safely. If arcing, burning or smoking from an appliance occurs,
turn off the power at the circuit breaker and call 911.
Winds accompanying thunderstorms may knock down power lines or utility
poles. Keep people away from the area, and call 911. If power lines come in
contact with a vehicle, do not touch it or the vehicle. If people are
inside, tell them to stay inside. If they try to exit, they may complete a
grounded electrical circuit and be instantly killed. They must stay inside
until the power is shut by the utility company.
If a serious electrical malfunction occurs in your home, school or
workplace, it is the same as a fire. Notify others, activate the fire alarm
and exit promptly. If you are familiar with the operation of a fire
extinguisher, you can use only a "Class C" Fire Extinguisher on an