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Copyright © 1992, 1995, 2004 National Retail Hardware Association
ELECTRICAL
Supplies
CHAPTER FOUR:
• LIGHTING FIXTURES
• ELECTRIC MOTORS
• LIGHT BULBS
• WIRE AND CABLE
• CORDS
• WIRING DEVICES
• BATTERIES
• TELEPHONES & ACCESSORIES
ELECTRICAL SUPPLIES
ELECTRICAL
Supplies
■ The consumer trend in the electrical category is shifting toward
higher-end products that have
model variety and energy-saving
features. Energy-efficient lighting
products are finally beginning to
catch on with consumers, long after the 1992 passage of the National
Energy Policy Act, which required lighting manufacturers to replace
outdated lamps with brighter, more energy-efficient models.
The National Electrical Manufacturers Association, using money
from manufacturers, has boosted demand by conducting a national promotional campaign to inform consumers about the benefits
of energy efficiency.
The Environmental Protection Agency (EPA) further helped matters
in 1997 by creating its Energy Star® label, which manufacturers may
voluntarily display on energy-efficient lighting fixtures if they meet
program guidelines. Fixtures carrying this label can trim the cost of
lighting high-use areas, such as bathrooms and kitchens, by 50 percent to 60 percent. In addition, bulbs and lamps for these fixtures last
three times longer than incandescent bulbs.
Another key trend in the category is increased demand for lowvoltage outdoor lighting. Motion-sensor lights are popular with
consumers concerned about home security.
Many consumers are scared of electrical projects, and for valid
reasons. Retailers should remind consumers of the dangers posed
by household electrical systems. For example, tell consumers to
shut off electrical power at the fuse or circuit breaker box before
beginning any wiring project. And make sure they consult local
building codes before embarking on an electrical project.
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ELECTRICAL SUPPLIES
LIGHTING
FIXTURES
■ INTERIOR LIGHTING
because of the heat produced. Maximum
wattage limitations are indicated on all fixtures and should be followed. Recessed lighting is good for rooms with low ceilings and
can be used to supplement existing light in
kitchens and bathrooms.
No-glare lighting is also available in overhead fixtures, undercabinet lights and desk
lamps. No-glare lighting fixtures are
designed with a louver that cuts off highangle light to provide glare-free, true-color
lighting. No-glare lighting works well to prevent eye fatigue in home offices where computers are used. For more information, click
halogen, floor-mounted directional fixture
under a large plant to create an artistic pattern on the ceiling.
A room larger than 225 sq. ft. will require
separately controlled wall lights along two
walls or multiple ceiling fixtures rather than
a single light source.
Interior lighting must satisfy two requirements: function and design. A customer
replacing an existing fixture will be concerned mainly with the design, whereas a
Bedrooms
person remodeling or adding a room may be
Bedrooms under 150 sq. ft. use a total of
concerned with both function and design.
120 to 200 watts in a ceiling fixture, 4' to 9'
Along with design and function, many cusof wall lighting or one 150-watt recessed fixtomers are becoming more concerned about
ture. Over 150 sq. ft. use 120 to 200 watts in
conserving energy. Lighting takes only 12
a ceiling fixture, 12' to 16' of wall lighting,
percent to 15 percent of the electricity used
(Installing Wall or Ceiling Fixtures)
or five to eight 20- to 75-watt reflector bulbs.
in a home. Customers are finding ways to
The following guidelines suggest lighting
For closets, use a 40- to 60-watt fixture
reduce this expense by using more efficient
standards for various rooms.
and 60 to 100 watts in walk-in closets. These
lighting and advanced lighting controls.
should be ceiling mounted at least 18" from
Task lighting gives localized light for specifLiving Areas
clothing or stored items, or use a 20-watt
ic activities such as reading, writing, sewing
Permanent lighting fixtures are not a
fluorescent above the door header.
and food preparation. The light should cover
major consideration here because so many
the entire task area and be located so shadows
homes depend on table or floor lamps. Wall
Bathrooms
are reduced to a minimum. Under-cabinet
lighting (fluorescent tubes shielded by a corOverall lighting should consist of at least
lighting is a popular form of task lighting in
nice or valance) and recessed down lights
one recessed 75-watt unit for each curtained
kitchens or under shelves.
are frequently used permanent fixtures.
tub or shower area. If the lavatory counter is
General or ambient lighting provides
Track lighting is also applicable.
wider than 3', overhead fluorescent tubes
comfortable background brightness in a
Place light sources at various heights withshould be installed along the entire length
room. Light reflected from walls and ceilings
in the room to add visual interest. Use
of the counter in a soffit extending at least
or from large sources overhead reduces lighttranslucent shades on table lamps to con18" from the wall. Smaller lavatory areas
ing contrasts and contributes to the comfort
tribute to the ambient light level. Use a
need 20-watt fluorescent tubes mounted on
of the environment.
either side of the mirror and cenGENERAL LIGHTING SUGGESTIONS
Accent or specialty lighting cretered 60" from the floor.
ates a mood and adds interest to a
A ceiling fixture over the lavatoHere are a few general guidelines to help consumers begin their planning.
room. This kind of lighting is priry mirror can provide extra light.
The light sources, lighting fixtures and construction of the home, as well as
the materials and colors of the furnishings, will affect the lighting plan.
marily for decorative effects and
should be used in conjunction
Kitchens
INCANDESCENT BULBS
with task and general lighting.
Every 50 sq. ft. of floor space
14, 15 watts—Use in multiple-socket hallway fixtures, small decorative
Track lights, a system of movable
needs about 150 watts of incanwall and table lamps, recessed aisle or step lights.
lights wired to a metal track, make
descent or 50 watts of fluorescent
40, 55, 60 watts—Wall fixtures and sconces, multiple-socket ceiling
a great accent lighting choice for
light from a ceiling fixture.
fixtures and floor or table lamps, pole and tree lamps, recessed shower
living rooms, bedrooms and dinAdditional fixtures should be
lights, single- and multiple-socket bathroom mirror fixtures.
ing rooms. Track lighting is availinstalled over sinks, work areas,
70, 75, 95, 100 watts—Ceiling, wall and pendant fixtures.
able in many colors, sizes and
etc. A 20-watt fluorescent tube,
150, 200 watts—Single-socket ceiling fixtures; floor, table and desk
lamps where three-way flexibility is not desired.
shapes, is easy to install and fleximounted under cabinets above
170, 250 watts—Portable table, floor and desk lamps with singleble since the lights can be moved
the countertop, is considered adesetting sockets.
around and repositioned.
quate for every 3' of counter space
Recessed can lighting and surto be lighted. Light the sink area
THREE-WAY BULBS
face-mounted fixtures are one way
using recessed halogen or fluores30, 70, 100 watts—Portable dresser, table and hanging wall lamps.
to provide ambient lighting.
cent valance lighting. Fluorescent
50, 100, 150 watts—Floor, desk, table, double-dresser portable lamps.
Increased amounts of light are
strip lights can be concealed
100, 200, 300 watts—Large floor lamps with mogul (large) sockets.
achieved using additional fixtures.
above cabinets to provide soft,
This should be strictly observed
indirect illumination. Suspend
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ELECTRICAL SUPPLIES
decorative pendant lighting with compact
fluorescent globes over the table or island
for visual interest and energy savings.
Dining Areas
A single ceiling fixture or hanging lamp
with at least 150 watts of incandescent lighting will usually suffice for an average dining
area. However, layering with light from a
variety of sources will provide flexibility for
creating different moods. The best choice is
to install a dimmer switch to control light
levels. Chandeliers with open sockets should
contain decorative bulbs. When using down
lighting over the dining room table, be careful not to create dark shadows that might be
unbecoming to guests. Halogen directional
bulbs can be used in adjustable accent lights
to highlight plants, artwork or special furnishings. In addition, china cabinets can be
lighted from within with small halogen or
miniature fluorescent bulbs.
Recreation Areas
Relatively even lighting throughout the
room can be accomplished with one
recessed incandescent box, with a 100-watt
bulb for every 40 sq. ft. The number of fixtures can be reduced by using fluorescent
tubes, which produce as much as four times
the light of incandescents.
Hallways
Use ceiling-mounted fixtures with 75 to
100 watts for every 10' of hall or one
recessed fixture with 75 to 100 watts for
every 8'. Locate fixtures near closets or powder rooms. For halls that need light all day,
recommend fluorescent fixtures; this saves
energy and reduces bulb replacement. Wall
sconces can add a warm, welcoming touch
to a foyer. Place wall or ceiling-mounted
lights and switches at the top and bottom of
stairs for safety.
Laundry Areas
Center a diffusing fixture with 60 to 80
watts of fluorescent or 120 to 150 watts of
incandescent light over appliances.
■ OUTDOOR LIGHTING
Outdoor lighting primarily serves a securi-
ty function. There are four basic types of
outdoor lighting: area, motion, landscape
and entrance/exit lighting.
There are a wide variety of systems for
outdoor lighting, including: high–intensity
discharge (HID) systems for mercury, metal
halide and high–pressure sodium light
sources; incandescent and tungsten halogen
fixtures; low-voltage lighting systems; and
incandescent or halogen PAR spotlights and
floodlights.
HID lighting provides considerably greater
illumination than other lighting commonly
available. Its cost is also higher, although
operating costs for lumens output is generally less. Lumens are the measurement of light
output. Locate fixtures at both ends of the
house for better spread of light over the
entire yard. Many outdoor lighting units are
equipped with a photoelectric cell to turn
the fixture on at sunset and off at sunrise.
Timers are also available for outdoor units.
Fixtures to be used outdoors must seal
moisture and dust from wiring and switches.
Photocells provide automatic activation
from dusk to dawn.
Brass, aluminum, copper and baked-finish
metals as well as non-metallic products will
withstand extremes of outdoor exposure best
and offer long product life.
Outdoor lighting options have expanded
with the advent of low-voltage lighting. A
low-voltage system of six fixtures, for example, usually uses less electricity than a 60watt bulb. It makes maximum use of electricity by splitting the light source.
A power pack is the heart of the lowvoltage system and should be located outdoors by installing a weatherproof outlet
cover to keep snow and rain out. Because
of the low voltage, users will not receive
an electric shock even if they touch the
bare wires or cut a buried cable with a
garden tool. Consequently, these systems
are harmless to children and pets and do
not require cables to be buried. Power
packs typically range from 88-watt capacity up to 900-watt capacity.
To determine which transformer you will
need, add up the wattage of all the lamps
you plan to use—otherwise known as the
total nominal wattage (TNW). The total load
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wattage of the lamps should not be less than
half of the transformer’s TNW or voltamperes (VA) rating, nor should it exceed
the transformer’s maximum capacity. If the
TNW is too high, divide the electrical load
between two transformers, or use a more
powerful one.
The first fixture should be installed at
least 1' above the ground and at least 10'
from the power pack. Low-voltage cable
transmits the electricity through a weatherresistant, self-sealing stranded copper wire
between 12-gauge and 18-gauge. On runs
over 150' or when 10 or more lamps are connected to one line, consider using heavier
cable (12- or 14-gauge), which reduces voltage drop and produces greater efficiency
from the lamps. A cable connector is used to
quickly join separate cable lengths or to split
cables going different directions.
The low-voltage lamp can be one of several types. Bayonet base lamps feature a copper base that twists into the fixture socket,
while the wedge base lamp plugs into the
socket. Halogen lamps provide the most
energy efficiency. Remote photo control
automatically turns lights on at dark and off
during daylight hours. For more information, click (Installing Outdoor
Wiring/Lighting).
Area Lighting
Spot and floodlights, along with traditional yard and security lighting, are used as
decorative lighting for landscaping, architecture or holiday decorations. Colored lenses
can enhance different features; a green lens,
for example, will brighten foliage while
detracting from reddish objects.
Weatherproof sockets are essential here
because the fixture is often mounted near
the ground and pointed upward, exposing
the socket opening to rain and dirt. Most
outdoor lighting fixtures should be installed
only when the ground is completely dry,
although low-voltage systems can often be
installed anytime. Always consult the manufacturer’s instructions.
Well lights are designed to be buried,
and they cast light upward to create special effects—for example, highlighting
landscaping.
ELECTRICAL SUPPLIES
Motion Lighting
Motion sensors are popular accessories
to low-voltage outdoor lighting. They
attach to a power pack and mount on
walls or fences 6’ to 8' above the ground.
By detecting heat and motion up to 40'
away, they can cover 600 sq. ft. of property to guard against intrusion.
Motion sensors are used with incandescent, halogen and fluorescent bulbs.
When used in combination with a switch,
the user can manually switch on the
motion detector light.
Indoor motion sensors are also available
that automatically turn on a light when
someone enters a room.
Landscape Lighting
Landscape lighting is designed to accent
or light steps and pathways. It also serves a
decorative function and is relatively easy to
install. Advise customers not to hook up
landscape lighting with extension cords,
which are for temporary use only.
Mushroom lights, named for their sloped
shades, are commonly used along pathways
or in gardens. The bulb ranges from 5 watts
to 60 watts, and light is reflected downward
to give a soft illumination to the immediate
area near the fixture. Opaque, tiered lens
attachments shield light from the eyes and
direct it downward.
Bollard lights are cylindrical in shape,
with the faceted lens being part of that
cylinder. The lens diffuses light in a 360°
pattern to create a soft glow. Lens shields
can limit lighting to a 180° range.
Globe lights have spherical lenses, so they
cast light in all directions, providing subtle
illumination that can cover a large area
without glare. They are often used around
outdoor living areas.
Deck lights are designed to fit under
steps, benches and railings. They can be
mounted in many other ways as well.
Many other kinds of fixtures are also
made to be recessed into steps or planters
to directly illuminate pathways.
What follows are some common lighting
techniques used in landscape lighting.
Down lighting—shines light down from
large trees or eaves onto surfaces below
WHERE TO USE BULBS
SPECIAL-PURPOSE BULBS
TYPE AND WATTAGE
WHERE TO USE
Reflector Bulbs (2-1/2" dia.)
Pole and tree lamps. Track lighting and recessed downlights
(cans).
Reflector Floods (3-3/4" dia.)
Track lighting and recessed downlights (cans).
Reflector Spots (3-3/4" dia.)
Track lighting and recessed downlighting (cans).
Reflector Floods (5" dia.)
Track lighting and recessed downlights (cans).
Reflector Spots (5" dia.)
Track lighting and recessed downlighting (cans).
Floodlight Bulbs (4-3/4" dia.)
Exposed weatherproof sockets under eaves, on garages,
porches and other outdoor locations. Bullet-shaped outdoor
floodlight fixtures.
Bug Lights (yellow coating)
In fixtures on patios, porches and entrances to houses.
Post Light Bulbs
For post lights and coach lanterns.
Plant Lights
Special color bulb finish enhances plant appearance,
helps growth.
Rough Service
Workshop, utility area, garage. Usually used on “trouble
light” extension cord.
High-Intensity Bulbs
Replacement bulbs for high-intensity portable lamps, they
provide supplementary lighting for sewing, manicuring,
hobby work and other close-up tasks.
Night Lights
Use in plug-in fixtures in bedrooms, bathrooms and hallways.
Garage Door Opener Bulb
Built to take shock and vibration.
Appliance Bulbs
For ovens, refrigerators, freezers, microwaves, saunas and
range hoods.
Showcase Tubular Bulbs
Approximately 6” long, frosted and clear. Use for picture
lights, piano lights, aquariums, range hoods. Regular (medium) base.
Always check the fixture for required diameter and wattage limitations before recommending any of
these bulbs. In general, floods are used for wide area lighting, spots are used for accent lighting.
FLUORESCENT BULBS
TYPE AND WATTAGE
WHERE TO USE
Cool White
Use for work areas only.
Warm White
Good for living areas. Will harmonize with incandescent lighting. Not for use where color discrimination is important.
Soft White
The recommended fluorescent for living areas, baths,
kitchens. Good color rendering. Harmonizes with incandescent lighting.
Different wattage tubes are different lengths. It is important to purchase the right length tube to fit
the desired fixture. Fluorescent tubes come in a variety of “white” colors. Use these guidelines to select
the correct “white” tube for your use.
SOURCE: GE LIGHTING
the light source to create safer passageways at night. Down lighting is used to
outline driveways and walkways, mark
garden paths and flowerbeds, and to
accent patios and decks.
Uplighting—places fixtures in the ground
and directs light upward to create a dramatic
focal point that accentuates the detail in a
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trellis or archway, illuminates fountains and
statuary or highlights small trees and shrubs.
Front lighting—positions light sources in
front of an object to highlight important
features and details.
Back lighting—illuminates objects or
plants from the back to highlight architectural features and eliminates darkened areas
ELECTRICAL SUPPLIES
CHECKLIST FOR
OSHA STANDARDS
OSHA (Occupational Safety and Health
Administration) standards affect the physical
facilities of retail stores, but some of the rules
make good safety sense for customers who
are embarking on do-it-yourself electrical
projects. Following are 10 OSHA rules that
can be adapted as safety tips for consumers.
1.
Be sure all electrical installations are
in accordance with the National
Electrical Code.
2.
All live parts of electrical equipment
operating at 50V or more must be
guarded against accidental contact.
3.
Protect all equipment against overcurrent.
4.
Overcurrent devices in damp and
wet locations must be of the type
approved for this use.
5.
Fuses and circuit breakers must be
located and shielded to prevent
burns or injuries.
6.
All fixed electrical equipment must
be grounded.
7.
All electrical equipment—air conditioners, sump pumps, portable
tools, others—must be effectively
grounded.
8.
All boxes and fittings in wet locations
must be waterproof.
9.
All electrical outlet boxes must be
durably and legibly marked with the
manufacturer’s name and/or trademark. They must be rigidly and
securely fastened to the surface to
which they are mounted. All outlet
boxes must have a cover.
10. Flexible cords must be in a continuous length when used-without
splices. They cannot be worn,
frayed or taped. They must be connected so that tension will not be
transmitted to joints or terminal
screws. Flexible cords cannot be
used where fixed wiring is required.
blend naturally into the environment and
glow from within, casting illumination for
pathways. The faux boulders contain lowvoltage lamps and UL-listed components
that are easy to wire, can be installed on
their own system or added to an existing
low-voltage system.
Entrance/Exit Lighting
Light each entrance to illuminate the door
and to identify callers clearly. Recommend
wall lanterns, 25 watts to 60 watts, on each
side of the front door, centered 66" above
standing level.
For secondary entrances, recommend a
single fixture on the latch side of the
door. Lanterns with concealed downlights
light up wall-mounted house numbers as
well as the lock.
Suspended or over-door lanterns should
allow the light to flow downward. Wallmounted lanterns above doors should
accommodate 75 watts to 100 watts;
lanterns suspended from a ceiling 100
watts to 150 watts. With shallow, close-toceiling fixtures for a porch, recommend
60 watts to 100 watts.
Exit or emergency signs are used to
identify exit areas in commercial buildings. Internally lighted models are the
most common.
LIGHT
BULBS
There are three main types of light bulbs:
incandescent, fluorescent and high-intensity
discharge (HID). Generally, the higher the
wattage, the greater the light output.
Bulb Finishes
behind large bushes and around doors and
windows for security purposes.
Area lighting—uses a floodlight or another source of wide light to illuminate large
areas for evening entertaining.
Safety lighting—provides light for certain
areas, such as paths or steps, so people can
navigate safely.
Also available are landscape boulders that
Originally, only clear glass was used to
make incandescent bulbs, which left the
bright filament exposed and resulted in a
harsh, glaring light. To remedy this, special
finishes are used to reduce the glare by diffusing the light.
Clear glass is still used in applications
where accurate light control is desired and
in decorative lighting.
A frosted finish used to be the most com-
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mon. Light loss averages less than 0.5 percent due to the frosted finish.
Today, light diffusion is usually accomplished by applying a coating of fine powder
to the inside surface of the bulb. This coating provides a softer, more even distribution
of light and reduces glare. Inside-coated
bulbs are made in colors as well as white. A
variety of colors are available in outsidecoated bulbs which can be either transparent
or translucent.
Bulbs can be made to direct the light by
applying a reflecting material to the inside
surface of the bulb, or in the case of R, PAR
and sealed beam, light can also be directed
by beveled cuts on the surface of the bulb.
General Classes of Light Bulbs
Bulbs come in a variety of shapes, sizes
and designs, each with a different purpose.
Bulb shapes have letter codes that correspond to a general guideline. For example,
"C" refers to cone-shaped bulbs and "T" to
tubular bulbs.
General service is the Type A (arbitrary)
bulb used for lower-wattage bulbs from
about 15 watts to 200 watts. This type is
normally used for home lighting.
Vibration service is used on machinery or
where continuous vibration could cause
early failure of the filament. These bulbs
have lower lighting efficiency.
Rough service bulbs withstand shocks and
bumps. The relatively long filament is securely
mounted with many supports but has a lower
efficiency than general and vibration service
bulbs. They are used in workshops and
garages and with trouble lights.
Appliance bulbs are for ovens, refrigerators,
freezers, microwave ovens and range hoods.
Special coated bulbs are covered with a
Teflon™ or silicon protective material to
prevent shattering and to resist breakage
upon contact with water. They are recommended for use in trouble lights and outdoor fixtures.
Decorative bulbs with clear or coated flameshaped glass, smooth B-type glass, C-line glass
with bent tip bulbs and globe-shaped bulbs
are useful in chandeliers and wall bracket fixtures where fashion is important.
Reflector® bulbs are usually made of “soft”
ELECTRICAL SUPPLIES
glass for indoor service as a directional light
source with a built-in reflector. These are
available as spot or floodlights.
Projector (PAR) bulbs are made of hard
heat-resistant glass molded into a reflector
and lens that are sealed together. Most are
weather-resistant.
Elliptical reflector bulbs are shaped differently than the parabolic reflector bulbs,
bringing light to a focus a couple of inches
in front of the bulb. Less light is wasted in
LIGHT BULB BASES
1
2
3
6
5
7
9
12
4
8
10
13
11
14
deep-baffle fixtures, and glare is reduced in
downlight fixtures.
LAMP TYPE
Light Bulb Bases
15
2. Candelabra Incandescent Base
GLASS BULB
Filament
3. Double-Contact Bayonet Incandescent Base
4. Intermediate Incandescent Base
5. Medium Incandescent Base
Support
Wires
Filling
Glass
Button
6. Medium Skirted Incandescent Base
7. Three-Contact Medium Incandescent Base
8. Mogul Incandescent Base
9. Three-Contact Mogul Incandescent Base
10. Circline Florescent Base
Lead-in
Wires
Heat Deflecting
Disc
Stem Press
11. Medium Bi-Pin Fluorescent Base
12. Four-Pin Fluorescent Base
Exhaust
Tube
Fuse
13. Recessed D.C. Fluorescent Base
Base
14. Two-Pin Single-End Fluorescent Base
15. Four-Pin Single-End Fluorescent Base
7
LUMENS PER WATT
Incandescent . . . . . . . . . . . . . . .18
Light bulbs come with a variety of bases
for use in different fixtures. The following
are the most commonly used base types:
Candelabra is a screw base used for specialty chandeliers and decorative lighting. It
is the smallest base for 120V lamps.
Intermediate is a screw base with applications similar to the candelabra bulb.
Medium is a screw base, standard on most
general-service bulbs of 300 watts and under.
It has a high degree of interchangeability in
bulb applications.
Mogul bases are used for larger, heavyduty bulbs rated at 300 watts and higher.
Skirted screw base is used on bulbs where
the neck is too large to fit into the desired
size base or where additional space between
filament and bulb terminals is desired.
Three-contact bases are used for threeway bulbs that contain two separate filaments in one bulb. They are similar to other
screw bases, but use an extra ring contact to
light wattage filaments separately or in combination for three light levels.
Bayonet bases are used on specialty lamps
such as vacuum cleaners, sewing machines
and low-voltage bulbs. It provides a more
secure contact by using two small protruding pins on the sides of the base that fit into
1. Single-Contact Bayonet Incandescent Base
COMPARING LAMP EFFICIENCIES
Halogen . . . . . . . . . . . . . . . . . . .25
Mercury Vapor . . . . . . . . . . . . . .63
Fluorescent . . . . . . . . . . . . . . . .100
Metal Halide . . . . . . . . . . . . . . .125
High Pressure Sodium . . . . . . . .140
Low Pressure Sodium . . . . . . . .200
slots in the socket.
Medium bi-post base is used for highercurrent bulbs.
■ INCANDESCENT BULBS
Incandescent bulbs produce light by passing current through a thin coil of wire called
a filament. As the wire heats, it becomes
white hot and emits visible light.
Incandescent bulbs come in two types:
vacuum filled and halogen gas filled.
They are mainly used for general and task
lighting around the house.
Incandescent bulbs offer many advantages: a concentrated light source that is easy
to direct; instant lighting; a wide assortment
of sizes, shapes and colors; easy maintenance; and low initial cost.
Moreover, incandescent lighting is flexible, particularly since light levels (proportional to wattage) for a given bulb-holder
can be changed simply by using the desired
wattage bulb. However, users should be careful not to exceed bulb wattage recommendations for a fixture. Underwriters Laboratories
(UL) tags on fixtures designate the maximum allowable wattage. A mercury or fluorescent system is typically limited to a single
bulb size.
An incandescent bulb can operate on
either direct current (DC) or alternating current (AC). Wattage indicates the amount of
electric power used by a bulb to produce
light. Roughly speaking, the higher the
wattage, the greater the light output. Some
bulbs, however, produce more light output
per watt than others do.
Standard household bulbs have an average life of 750 to 1,000 hours, which can
be lengthened or shortened by the treat-
ELECTRICAL SUPPLIES
LIGHT BULB SHAPES
INCANDESCENT SHAPES
“A” Type
R-40
Reflector
Flame
Tubular
PAR-30
Reflector
(indoor)
PAR-30
Reflector
(outdoor)
Bulge Tube
(LT-10)
COMPACT FLUORESCENT SHAPES
Bulb designations denote size and shape.
The figure following the bulb shape letter
designation is the bulb’s maximum diameter
in eighths of an inch. Thus, A-19 would
mean an A-shaped bulb with a diameter of
19 x 1/8", or 2-3/8".
Most standard bulb envelopes are made of
lime glass, but bulbs that must withstand
greater heat are made of harder, heat-resistant glass. Hard-glass envelopes are used in
many high-wattage bulbs and in bulbs recommended for outdoor use where there is
danger of thermal shock from condensation.
Incandescent bulbs turn black as they
near the end of their lifetimes. Customers
should consider replacing darkened bulbs, as
they use the same amount of electricity to
produce less light.
■ HALOGEN BULBS
Screw Base
Circular Tube
Screw Base
Lamp
Screw Base
Bulb
HID SHAPES
BT
E
ment they receive. For example, a 120V
bulb operating on a 125V circuit may produce more light but won’t last as long as
one on a 120V circuit.
Long-life bulbs, which may last up to
twice as long as ordinary bulbs, have heavier
filaments that do not burn out as quickly.
However, these bulbs do not produce as
much light as standard bulbs.
Manufacturers disclose average light output (in lumens) and average bulb life (in
hours) on package labeling.
The filament vaporizes as a result of current flowing through it, and generally, the
bulb “burns out.” Three-way bulbs lose two
light levels when one filament burns out
because two filaments are used in the bulb
separately for two of the levels and together
for the third.
Halogen bulbs are technologically
advanced incandescent bulbs used in residential and commercial applications. As
with incandescent bulbs, light is produced
by passing current through a coiled tungsten
wire, but the tungsten wire is enclosed in a
small quartz or high-temperature glass tube,
which is then filled with gases, including a
halogen gas.
The advantages of tungsten halogen bulbs
compared with standard incandescent bulbs
include less loss of light over lamp life;
smaller physical size for better directional
light control; whiter, brighter light; more
light per watt; and longer life. Like incandescents, halogen lights have the advantage of
instant-on light. They are easy to use with
dimmers for energy savings.
Typical halogen lamps last 2,000 to 4,000
hours compared to 750 to 1,000 hours for
incandescent lamps. Wattage levels for home
use run from 5 watts to 500 watts.
Halogen bulbs are more energy-efficient
than standard incandescent bulbs. They generate up to 30 percent more light for the
same electricity. In addition, because their
bulbs blacken much less than incandescents,
they stay brighter as they age.
Halogen bulbs are available for accent and
task lighting and for general lighting applications. Since their brilliant, white light registers true colors, they are excellent for dis-
8
plays. Shading is important because of halogen’s intense brightness. They are available
in A-type equivalent bulbs, PAR spotlights
and floodlights in a variety of sizes, as well
as low-voltage spotlights and floodlights.
Advise customers not to touch the glass
on halogen bulbs.
■ FLUORESCENT BULBS
The two main types of fluorescent bulbs
are tubular and compact fluorescent.
Fluorescent bulbs are used in commercial,
institutional, industrial and residential lighting. The popularity of the fluorescent bulb is
due to its high efficiency in producing light,
resulting in low lighting energy costs.
Fluorescent bulbs produce up to 105 lumens
per watt, compared with a 100-watt, type A
incandescent, which produces around 18
lumens per watt.
A fluorescent also has long lamp life,
relatively low brightness and low heat
content and glare compared with incandescent lamps. Fluorescents work well for
area lighting, especially in kitchen, bath
and task areas.
In a fluorescent bulb, current flows
through an atmosphere of inert gas and
mercury vapor, producing ultraviolet energy that is invisible to the human eye. A
phosphor coating on the inside of the
tube transforms the ultraviolet energy
into visible light.
Fluorescent bulbs can vary from straight
tubes 6" to 96" long to U-shaped tubes and
circular tubes. Wattages for home use range
from 4 to 75 watts.
Tubes also come in a variety of diameters.
Several common types are available in
reduced-wattage versions that consume 15
percent to 20 percent less energy.
The most common tube is the 1-1/2" used
in most bulbs from 15" to 96" long. The
smallest diameter is 1/2", used in lowwattage twin tube designs. The largest is 21/8" used for some high-wattage, non-residential installations.
Fluorescent bulbs are available in many
shades of white, as well as colors determined
by the type of phosphor used in the bulb.
These colors are indicated by the color rendering index number printed on the bulb.
ELECTRICAL SUPPLIES
GLOSSARY OF ELECTRICAL STANDARDS
UL—Underwriters Laboratories Inc. is a not-for-profit independent testing laboratory.
Manufacturers submit products to UL for testing. “UL-listed” means that the merchandise meets
minimum safety standards and is suitable and safe if used for the purpose for which it was
intended by the manufacturer.
ANSI—American National Standards Institute is a non-profit organization that coordinates the
voluntary development of national standards by industry, establishes national consensus standards and represents United States’ interests in international technical standardization. Its standards are developed and used voluntarily, becoming mandatory only when adopted by government bodies, such as the Consumer Product Safety Commission.
NEMA—National Electrical Manufacturers Association writes performance standards for products. These standards are formed by committees that reach a consensus on individual matters. A
typical committee consists of manufacturers, industries that will use the product, Underwriters
Laboratories and other standard-setting groups. Consumer organizations are also on the committee where matters that apply to them are considered.
NEC—National Electrical Code is based on safe, functional wiring methods and is updated every
three years. Many cities and states require that wiring conform to NEC specifications. Local and
state codes and ordinances also supplement the NEC.
CSA—Canadian Standards Association is an independent, not-for-profit Canadian organization
that is similar to UL of the United States.
The higher the number, the more accurate
the color produced. Soft white fluorescent
bulbs are recommended for living areas,
baths and kitchens since they offer good
color rendering. Warm white bulbs, 3000K
and lower, emphasize reds and yellows and
are good for living areas, although not in
areas where color discrimination is important. Cool white bulbs, 4000K and higher,
emphasize blues and greens and are used for
work areas.
There are a few important limits to the
use of fluorescent lamps. Because they use a
ballast, they can be dimmed only with special equipment that is relatively expensive.
Standard household fluorescents are also
sensitive to temperature and therefore work
best indoors. High-output fluorescents are
for outdoor use and commercial application.
Ballasts have sound ratings— “A” is the
quietest; “C” is the loudest. If a customer is
complaining about the noise made by fluorescent bulbs, suggest replacing the ballast.
The main objection to fluorescents in the
past has been their unflattering color. New,
color-corrected tubes overcome this drawback with recent developments in phosphor
technology. Premium types use rare-earth
phosphors to offer superior color that blends
beautifully with incandescents.
Electrical connections to the bulbs are
made to the bases at each end. The most
common is the two-pin base, designated
miniature bi-pin for small diameter bulbs,
medium bi-pin for average-size bulbs and
the mogul bi-pin for industrial bulbs. Singlepin bases are used for instant-start bulbs,
and recessed double-contact bases are used
on rapid–start bulbs longer than 48".
Ballast Operation
Because fluorescent lamps are arc discharge devices, they require special auxiliary
equipment to provide reliable starting and
to assure proper electrical operation. The
principle function of the ballast is to hold
operating current within proper limits and
to provide enough voltage to start the lamp.
Initially, all fluorescent lamps used a
“starter” or time-delay switch, which
allowed the electrodes to heat up prior to
the lamp starting. The starter is a small silver-colored cylinder found mostly in older
fluorescent lamps. When the lamp in an
older fluorescent begins to flicker, both the
tube and the starter should be replaced.
Starterless operation is achieved with
instant-start and rapid-start ballast designs.
Instant-start ballasts provide sufficient voltage to start fluorescent lamps without preheating and are commonly used with singlepin lamps and some special lamp types.
Rapid-start ballasts heat the cathodes continuously from a low-voltage transformer
9
within the ballast. This is the most common
type of ballast in use today for 40-watt
lamps and for all lamps that use recessed
double-contact bases.
Reduced-wattage lamps operate on most
existing ballasts, which can reduce wattage
14 to 20 percent. In addition, new ballasts
developed to minimize the wattage consumed by the ballast itself further reduce
electrical consumption.
Compact Fluorescents
Compact fluorescent bulbs offer different
style and performance from standard fluorescent bulbs. Their color nearly equals Soft
White incandescents, and they offer superior
energy efficiency and long life.
The new compacts can be used in many
household fixtures. Circular units are
already familiar in ceiling fixtures and
artists’ lamps; new applications are wall
sconces, table lamps, lanterns, desk lights
and outdoor fixtures. Compact fluorescents feature sizes and shapes to match
most incandescent bulbs including one
that resembles a standard household bulb.
They can be as small as 4.5" long, and
some are the same size as their incandescent counterparts. Not all fixtures
designed for incandescents may have
enough room inside the shade or glass for
the bulb.
Compact fluorescents cannot be
dimmed. Their life will be maximized if
they are used in locations where a light
stays on for hours at a time.
Compact fluorescent lamps typically last
7,000 to 10,000 hours, which is nine to 13
times longer than comparable incandescent
lamps. Energy efficiency can go up to 105
lumens per watt. Wattages for home use
range from 7 to 27 watts.
Reflector-shaped compact fluorescents can
replace standard R30 and R40 shaped incandescent reflector bulbs. Globe-shaped compact fluorescents can replace standard G25
bath and vanity globes or G30 decorative
globes that are used in pendants. Decorator
or flame-shaped bulbs can replace similar
incandescent bulbs in chandeliers, sconces
and outdoor fixtures. Stick-shaped compact
fluorescents can replace standard Type “A”
ELECTRICAL SUPPLIES
bulbs in portable lamps, while twist-shaped
compact fluorescents can replace standard
Type “A” bulbs in virtually any application.
There are also household-shaped compact
fluorescents that make ideal replacements
where the bulbs are visible in the fixture.
When choosing a compact fluorescent
bulb to replace an incandescent bulb,
compare the lumen output of the two
bulbs. For maximum energy efficiency,
select a bulb with the highest lumens and
lowest wattage combination. For example,
replace a 100-watt incandescent household lamp that produces 1,600 lumens
with a 25-watt compact fluorescent lamp
that also produces 1,600 lumens.
■ HIGH-INTENSITY
DISCHARGE LIGHTING
High-intensity discharge (HID) bulbs produce light in a manner often described as
“lightning in a bottle.” As in fluorescent
bulbs, current flows through a conducting
gas and ballasts are required to start the
bulb and to control its operation. Unlike
fluorescent, most of the light comes from
the arc itself rather than through the
work of the phosphor.
The highest-efficiency light sources (the
most light per watt) are members of HID
families. The four basic HID types are
mercury vapor, metal halide, high-pressure sodium and low-pressure sodium.
HID bulbs are primarily used for area
and security lighting. They feature a lifespan of 20,000 to 24,000 hours. They come
in a variety of shapes and in medium and
mogul bases.
Mercury vapor lighting is used for exterior area and security lighting, such as
dusk-to-dawn residential lighting.
Mercury vapor lamps provide twice the
light output per watt as incandescent
lamps. Along with the higher output, they
also have a longer lamp life, in some cases
up to 30 times as long. They are also more
expensive than incandescent or fluorescent. Mercury vapor bulbs produce a
bluish white color.
Self-ballasted mercury lamps can be
used with a ballast in incandescent fixtures and are available for 120V systems
in the lower wattages (up to 250 watts)
and for 240V systems in both lower and
higher wattages. These lamps deliver
slightly more light output per watt as the
incandescent lamps but have the long life
of mercury lamps.
Lighting systems that provide three to
six times the light output per watt of
SELLING TIPS FOR ELECTRICAL PROJECTS
You can further both your sales and your “know-how” image by making sure the customer has everything needed for the job. Here is a checklist of items to go over in the store.
CABLE—Are they buying enough to reach the distance of the circuit? Allow at least 10 percent
excess to accommodate bends. Also, make sure the wire will handle the amount of amperage it
will be expected to draw. Explain that lower resistance wire, while more expensive initially, will
save money by reducing power loss or blown fuses and will increase safety.
BOXES—Go over the proposed circuit with the customer. They will need a box for every outlet,
fixture, splice or other break in the cable.
WIRE CONNECTORS—At least two of these are required at every cable splice. Most light fixtures
are pre-wired and must be spliced onto the circuit cable. Sockets and switches do not require
connectors since cable is usually mounted directly to the device.
INSULATED STAPLES—These will be needed to mount the cable to the studs. Make sure they
are the right size for the type of cable being used.
INSULATED TAPE—Necessary for wrapping splices or taping any electrical wires.
TOOLS—Wire cutters, strippers stapler and screwdrivers are all part of the electrician's toolbox.
WALL PLATES—Does the customer have the right number and configuration of wall plates to
match the fixtures being installed?
LIGHT BULBS—Most lighting fixtures are sold without bulbs. Does the customer have the proper size and number for the fixtures being purchased?
10
incandescent lamps can replace incandescent, mercury and self-ballasted mercury
systems. These metal halide and
high–pressure sodium (HPS) lamps require
specific ballasts, but offer major energy
savings to users.
The metal halide lamps feature medium
efficiency, with 50 to 110 lumens per
watt. They provide good color characteristics (similar to cool white fluorescent
lamps) along with higher light output.
The high-pressure sodium lamps provide even higher light output per watt
than metal halide (50 to 150 lumens per
watt), with a golden yellow light.
Residential applications include security
and landscape lighting.
Low-pressure sodium bulbs feature the
highest efficiency, with 100 to 180 lumens per
watt. They produce an orange light.
When replacing HID bulbs, it is necessary to use the exact bulb.
Energy-Saving Bulbs
Compact fluorescent bulbs can be
screwed into a standard incandescent
base. In addition to energy savings, their
main advantage is longevity. The lamps
give as much or more light as an incandescent bulb, with about 1/4 the wattage.
The bulb’s life is approximately 7,000 to
10,000 hours.
Energy-saving incandescent bulbs generally provide nearly the same amount of light
output as conventional 60- and 100-watt
bulbs but use fewer watts.
Energy-saving PAR spot and floodlights
combine a special reflector design with
lower wattage to provide almost the same
amount of useful light, using considerably
less electrical energy.
Lighting takes approximately 12 percent
to 15 percent of the electricity used in a
home. However, the following will help customers economize on the lighting portion of
an electricity bill:
o Turn off lights when you do not need
them.
o Use dimmers, when desirable.
o Use photoelectric cells or timers to turn
outdoor lights on and off automatically.
o Use reflector bulbs, especially for task and
ELECTRICAL SUPPLIES
USE COMMON SENSE TO AVOID ELECTRICAL HAZARDS
Stress to your customers that they use common sense when working with electricity. Before
proceeding with any electrical work, make sure the main disconnect on the service entrance
panel is at the “off” position or pull the main fuses if the panel is the cartridge fuse type.
When working on individual receptacles or light switches, turn off the circuit breaker for the circuit being worked on, and test with a test light before handling bare wires.
Other tips:
• Never stand on wet or damp floors when working at the service entrance on any electrical
device. Wear rubber gloves and stand on a rubber mat for added safety.
• To avoid overloaded circuits, never use a fuse which has a higher amperage rating than the
rating on the wire for the circuit.
• Never run more appliances from one receptacle than the amperage rating for that outlet.
• Never use a penny or tinfoil in a service panel instead of a fuse.
Two-Conductor Cable
Two-conductor cable has one black wire
and one white wire. The black wire is always
the “hot” wire and must be fused. The white
is always neutral and must never be fused.
When current bridges the gap from the
110V hot wire to the neutral, it results in a
110V input to the appliance.
Three-Conductor Cable
Three-conductor cable contains a red
wire in addition to black and white. The
black and red wires are “hot,” carrying
110V each, and both must be fused. The
white remains neutral.
Bridging either 110V wire to the neutral
wire produces 110V. Bridging both 110V
wires results in 220V. This three-wire circuit
is increasingly common in home wiring; it
accommodates major 220V appliances, such
as ranges and air conditioners.
Grounding Wires
Both two- and three-conductor cables can
carry grounding wires, which provide a path
of least resistance from the frame or case of
an appliance to the ground to guard against
electric shocks.
The electric motor in a refrigerator, for
instance, might develop a current leak to the
frame of the appliance. A person touching
the refrigerator could create a path for the
current to pass to the ground. Consequently,
he would receive a shock.
A grounding wire, attached to the frame
of the refrigerator and directly to the
ground, would provide a lower resistance
path than the person. The electricity could
then pass safely to the ground.
The National Electrical Code (NEC) was
changed in 1996 to require a separate
ground wire for certain appliances to ground
their frames. If your customers are wiring for
120/240V or 120/208V ranges, wall-mounted ovens, counter-mounted stoves or clothes
dryers, they need the separate ground wire.
Thermostat Cables
Thermostat cables are used in low-voltage
control, alarm and communication systems.
Most common types are braided, twisted
and plastic-jacketed types.
All three use solid copper conductors and
are twisted and insulated with plastic.
Twisted cable, which has no outer braid,
is used in doorbells, burglar alarms, intercom
telephones and public address systems.
Braided cable is covered with cotton
braid and is used primarily in thermostat
controls and other low-voltage, remote
control circuits.
Plastic-jacketed cable is also used in similar low-voltage applications.
Although thermostat cable is low voltage,
it carries a UL-listing for being flame-retardant since it is installed in the wall. Wiring
used in security alarm and smoke detection
systems must be UL-listed.
TV Wire and Accessories
Television lead-in wire connects the
receiving set to the antenna. Good quality
12
300-ohm wire is used for both VHF and
UHF receivers.
A TV set coupler is a loss-producing device
for connecting two or more TV receivers to
the same antenna. The loss introduced into
the circuit is small, but can be critical in
“fringe area” reception. In such areas, customers should be told of this small loss and
to expect a slight reduction in signal
strength at the receiver.
A lightning arrestor mounts on the outside of the house as close to the TV receiver
as possible to protect the receiver against
lightning damage. The lead-in wire is
attached to proper contacts and the ground
rod to ground connector. Lightning will
jump the gap inside the arrestor and flow
into the earth if the circuit is properly
installed.
Home Networking
Multiple computers in the home, satellite
dishes, cable TV, sophisticated audio systems
and home theaters have given rise to the
desire for home networks.
The heart of these systems is the networking hub. Usually thought of in conjunction
with computers, the home network hub differs in that it provides central control of
computers, peripherals, phones, TVs and
audio components. This is the unit where
most of the wiring from different locations
comes together to meet.
Most home networks use coaxial,
Category 3 and Category 5 cable. Coaxial
cable is used for TVs, VCRs and satellite
equipment. Category 3 cable is used for
telephones while Category 5 is used for
telephone, fax and computer systems.
Some cables combine different functions
into one cable.
“Structured” wiring refers to a bundle of
cables that runs from the networking hub to
meet a home’s future information-carrying
needs. This wire bundle may consist of some
combination of Category 5 cables, fiberoptic lines, Category 3 cables and coaxial
lines. New home construction and renovation jobs should try to accommodate wiring
in this fashion to meet the bandwidth needs
of digital transmissions.
Jacks are used to terminate the cable.
ELECTRICAL SUPPLIES
There are different jacks for telephones,
computers, satellite, audio and video equipment. Many of these jacks and cable connectors require special tools for installation.
Patch cords are used to connect different
computer and audio/video devices with one
another or with a central networking device
such as a hub.
Binding posts are used to connect bare
speaker wire, while F-Connectors are used
with coaxial cable.
AMPERAGE RATINGS FOR CORD
AWG WIRE #
TYPES OF CABLE AND CORD
MINIMUM AMPERAGE
0 . . . . . . . . . . . . . . . . . . . . . . . . .125
2 . . . . . . . . . . . . . . . . . . . . . . . . . .95
4 . . . . . . . . . . . . . . . . . . . . . . . . . .70
Non-Metallic Sheath Cable
6 . . . . . . . . . . . . . . . . . . . . . . . . . .55
8 . . . . . . . . . . . . . . . . . . . . . . . . . .40
10 . . . . . . . . . . . . . . . . . . . . . . . . .30
Armored Cable
12 . . . . . . . . . . . . . . . . . . . . . . . . .25
14 . . . . . . . . . . . . . . . . . . . . . . . . .18
Home Wiring Testers
16 . . . . . . . . . . . . . . . . . . . . . . . . .13
New tools and testers are making the job
of installing and maintaining household
wiring and home networks easier and safer.
Non-contact voltage testers allow you
to see if a line is carrying current without
touching the line. Features include audible and visual alarms, battery-checking
circuitry and a size that is small enough
to fit into a pocket.
Circuit analyzers and receptacle testers
are designed to determine if circuits are
wired properly. They plug into any grounded
electrical receptacle and test receptacle
wiring and grounding in standard and GFCI
outlets. A convenient chart and lights tell
you if the circuit is wired properly, if the
wiring is reversed, the ground is not working
or if there is an open line.
A ground fault receptacle tester and analyzer performs the same functions for GFCI
receptacles plus it also tests the ground fault
feature. Similar tools are available for telephone and computer lines.
Circuit trackers easily locate circuits without turning off breakers or fuses. They feature a transmitter that is plugged into a live
outlet. A receiver is used at the service panel
to identify the circuit into which the transmitter is plugged. Some models incorporate
a visual and an audio indicator. Adapter kits
allow you to identify light switches and light
bulb sockets.
An in-wall pipe and wire detector
locates metal objects and live unshielded
conductors behind drywall, paneling and
plaster walls.
18 . . . . . . . . . . . . . . . . . . . . . . . . .10
■ CORDS
Electrical cords provide a path for current
to travel from a fixed outlet to an appliance.
The type of cord needed for a given job
is determined by the amperage drawn by
the appliance, whether the appliance is
grounded and the degree of physical protection required.
Type SPT Cord
Type S and SJ Cord
Type HPD Cord
Extension Cords
Extension cords are for temporary power
only. Make sure the customer uses the right
size for the application. Outdoor and
indoor/household types are available, as well
as commercial cords with heavier gauges,
higher amp ratings and extra flexibility.
Indoor extension cords come in twowire and three-wire cords in lengths from
6' to 15' with 6' and 9' being the most
popular lengths. White and brown are the
basic colors.
Outdoor extension cords are used for outdoor power tools and exterior lighting. They
come in 16/3, 14/3 and 12/3 wire, and the
most common lengths are from 25' to 100'.
Heavy-duty extension cords should be used
with high-wattage appliances. Be sure to
match the construction of the cable to the
job. SJT round cord is better able to withstand the constant flexing of use with power
tools than SPT2.
Any UL-listed cord will carry a UL label
near the female end. Many companies are
now using an alternative method of labeling allowed by UL, which permits the UL
markings to be molded into the cord
ends. This ensures a permanent marking
that cannot be provided with a label. It is
13
important to check for this UL insignia,
whether it is a label or a permanent marking. Non-listed cords can be similar in
appearance to listed ones.
To be UL-listed for outdoor use, three-wire
round cords must have connector and cap
molded to the cord and a lip on the end of
the connector to prevent misuse. Beginning
in 1998, UL-listed outdoor cords began
appearing with the “SJTW” marking on the
cord, not “SJTW-A” as was previously used.
For a period of time, either marking will be
acceptable for outdoor use.
Grounding cords are available in both
heavyweight and heavy-duty construction
differing from standard cords, because they
have three conductors instead of two and
are equipped with a three-prong grounding
plug and connector.
An assortment of specialty extension
cords includes:
Step-saver cords—have built-in pendant
switches to control appliances and lamps
across the room.
Wind-up reels—keep tangled, foot-catching cords off the floor.
In recommending a proper extension cord,
pass along these buying and safety tips:
ELECTRICAL SUPPLIES
CORD, WIRE AND INSULATION
DESIGNATOR
TYPE OF INSULATION
GENERAL USE
WIRE
R
Rubber
All-purpose building wire, 600V, 60°C.
RH
Rubber & cotton braid
Same as R with heat resistance to 75°C.
RW
Rubber
Same as R with moisture resistance.
RHH
Rubber & cotton braid
Same as R with heat resistance to 90°C.
RHW
Rubber & cotton braid
Same as R with heat and moisture resistance to 75°C wet or dry.
RH/RW
Rubber & cotton braid
Same as R but 75°C dry and 60°C wet.
T
Thermoplastic vinyl
All-purpose building wire, 60°C.
THW
Thermoplastic vinyl
Same capacity as RHW.
TW
Thermoplastic vinyl
Same as RW.
WP
Cotton braid
Weatherproof for suspended outdoor use.
NM
Paper overlaid with cotton
For dry use only, 60°C. Braid or plastic
NMC
Plastic or neoprene coating
Wet or dry use, 60°C. Only cable approved for barns.
USE
Rubber & neoprene
Underground service entrance. Fusing or additional covering not required.
UF
Thermoplastic
Underground feeder and branch cable. Can be buried but must be fused.
ACT
Armored cable on plastic
Branch circuits and feeders. Insulated wires.
ACU
Armored cable on rubber
Same as ACT. Insulated wires.
C
Rubber & cotton braid
Lamps and portable appliances in dry areas, 300V and 600V, 60°C.
HPN
Neoprene
Same as HPD with moisture resistance.
SP-1
Rubber
Lightweight for lamps, clocks, etc., 300V.
NONMETALLIC CABLE
ARMORED CABLE
CORDS
SP-2
Rubber
Same as SP-1 with heavier construction for more general use, 300V.
SP-3
Rubber
Heavier construction than SP-2 for use with refrigerators, air conditioners, etc., 300V.
SPT-1, SPT-2, SPT-3
Thermoplastic
Correspond to SP-1, SP-2 and SP-3.
S
Rubber and jute twine
Heavy duty for power tools, battery chargers, etc., 600V.
SJ
Rubber and jute twine
Same as S but only 300V.
SJO
Rubber and jute twine
Same as SJ but oil resistant, 300V.
AWG
0
2
4
6
8
10
12
14
16
18
125
95
70
55
40
30
25
18
13
10
Actual Size
Maximum
amperage
Actual size of copper wires and maximum amperage allowed in permanent installation.
14
ELECTRICAL SUPPLIES
o Advise customers to follow manufacturer
recommendations for outdoor use and to
not use a household extension cord outdoors.
o Damaged or worn extension cords should
be replaced, not repaired. Replace older
cords that are non-polarized and don’t
have safety closures.
o Know the length of cord needed and electrical load it can carry. Cord should reach
easily from wall outlet to appliance. Never
put two short cords together to obtain
needed length.
o Only use an extension cord that has been
tested by a nationally recognized testing
laboratory such as UL, CSA or ITS.
o Keep cords out of the reach of children
and out of high-traffic areas where people
might trip over them.
o Never remove the third prong or cut
down the blade of a plug to fit a nonpolarized receptacle.
o Do not cover cords with carpet, furniture
or appliances.
o Cord should be permanently bonded
to the plug and the connector to
ensure a good connection and no
exposed wiring.
Appliance Cords
Appliance cords combine cord and connector. The difference between cord sets can
be in type of connector and/or cord used.
Free-end attachment cord sets without
connectors are used in re-wiring direct
attachment irons, toasters and similar small
appliances. They have pre-tinned ends to
speed up wiring.
Range and Dryer Cords
Range and dryer cords are free-end types,
commonly called “pigtails,” attached directly to the appliance. Free ends are fitted with
cable terminals that connect to screw terminals of the appliance to assure positive connections. A metal clamp attached to the
cable serves as a strain relief at the point
where the cable enters an appliance and a
cord protector.
Heavy-duty attachment plugs for
ranges and dryers are much larger than
standard attachment plugs. Most are “L”
shaped with a power cord feeding out
the side of the plug.
Sizes range from 30 amps for dryers and
small ranges to 50 amps for larger ranges.
The different amperage attachment plugs are
not interchangeable because of a difference
in their configuration.
A recent change in the National
Electrical Code requires new range and
dryer receptacle installations to be 3-pole,
4-wire grounding receptacles. The neutral
(grounded circuit conductor) can no
longer be used to ground the frames of
electrical ranges and dryers.
Heating Tapes
The primary function of heating tape is
to protect pipes from freezing. Today
there are heating tapes to warm the soil
for growing plants as well as tapes for preventing water damage caused by snow
and ice buildup. They are all designed for
quick and easy installation.
Tapes are automatic, constant-heat or selfregulating. A thermostat controls an automatic tape. Constant-heat tape must be
manually turned on and off as the temperature changes. A self-regulating tape is made
of semi-conductive plastic that adjusts to
outside temperatures.
Other Cords
Plastic parallel cord can be sold off the roll
for use with lamps, radios and other small
appliances. Plastic bell wire is used for bells,
buzzers, chimes, toy electric trains and other
similar systems and hook-ups.
■ WIRING DEVICES
Wires and cable form circuits to carry
electricity through a building. Wiring
devices described here are used to control
current flow and provide access points so
electricity can be used to power appliances and lights.
Switches
A switch controls power to lights and
devices by turning off the hot side of the circuit. Selection depends on design and load
capacity. For more information, click
(Installing or Replacing Electric
Switches).
15
Conventional Switches
A conventional switch makes or breaks
contact when a mechanically connected
tumbler or toggle bridges or breaks the line
contacts in the switch.
A single-pole switch is simplest and most
frequently used in the home, controlling
current on one circuit from one point. It features two terminal screws.
Double-pole switches have four terminal screws.
A three-way switch controls one circuit
from two separate points, such as a garage
light that can be turned on or off from the
house or the garage.
Four-way switches are used in connection
with three-way switches to control one circuit from three or more points.
Single-pole and three-way switches are
available with lighted handles that glow in
the dark.
Dimmer Switches
Dimmer switches control the amount of
current in a lighting circuit, allowing the
user to control the degree of light from off
to full capacity.
Some dimmers control the amount of
voltage going to the lamp, increasing or
reducing the amount of light given off.
Other dimmers control a portion of each
alternating current cycle applied to the
lamp. This means a solid state dimmer turns
the light off and on approximately 120
times per second. The on-off rate has no
noticeable effect on the life of the bulb or
on the eyes of persons in the room.
One undesirable side effect of this on-off
cycle is interference on AM radios. Some
dimmers have radio/TV filters and printed
circuitry. There are table lamp dimmers and
dimmers that wire parallel into the lamp
cord. In addition, use of a dimmer will cause
some light bulbs to “hum.” The sound is created from the turning on and off of the A.C.
sine wave. The rapid switching causes the
tungsten filament to resonate. Filament hum
is typical with inexpensive lamps that are
commonly installed in new construction.
The hum can be greatly reduced by upgrading to a lamp with a heavier filament.
It is also normal for a dimmer to get warm
ELECTRICAL SUPPLIES
OUTLETS AND SOCKETS
Grounding
Outlet
Single Pole
Switch
Two Switches
during operation, which is why dimmers are
built with a heat sink. If the load is not over
the wattage rating of the dimmer and is a
proper load for which the dimmer is
designed to control, the dimmer does not
need to be replaced.
There are several styles of wall dimmer
switches available. The most popular include
a push on-off/dial-to-dim type, a rotary fullrange type, a slide type and a toggle type
that offers full-range control but uses toggle
motion instead of a dial.
Dimmers also come in single-pole or
three-way construction. If two, three-way
switches are involved, only one of them can
be a dimmer. Otherwise, the setting will not
work, although some toggle dimmers allow
two three-way switches to be used.
Double Outlet
Pull Chain Ceiling Pull Chain
Lampholder
Socket
Keyless Ceiling
Lampholder
An air gap switch is built into all dimmers as a safety feature to ensure that
power can be removed to the output—this
is a UL requirement.
Specialty Switches
Rocker switch—used in place of a standard wall switch, it is activated with a pushbutton mechanism. Useful near a doorway
or area where hands might be full or for
appearance and for range hood and appliances.
Delayed-action switch—circuit remains
active for a few minutes after switch is
thrown. Useful in garage or breezeway,
allowing individual to get into the house
before light goes out.
Programmable memory switch—set to go
SWITCHES
RIP #
ST
KE
Y
RIP #
ST
WIRE
14
WIRE
12
KE
Y
LOOP HOLE
OFF
6A 125V AC, 3A 25 0V
3A
AC,
VT
125
ELOH POOL
IR
# P TS
12
WIRE
WIRE
RIP
ST
4 WIR
#1
#12
IP
Cord switch
STR
Duplex receptacle
2-pole, 3-wire
grounding
Weather
protective cover for
single receptacle
Single-pole
grounding switch
IW 41
ER
E
ST
RIP #
Three-way lighted
toggle grounding
switch
4 WIR
#1
STRIP
RIP #
ST
WIRE
12
E
TOP
2 single-pole switches
3 single-pole
switches
TOP
Single-pole AC
quiet switch
Three-way AC
quiet switch
16
3-way
Socket
Push-Through Weatherproof
Socket
Pigtail Socket
on and off at specific times for security or
safety purposes.
Photoelectric switch—operates by light
striking cell. Usually used on yard lights.
Daylight turns circuit off; it goes back on at
dusk. Circuit usually has a delay device to
prevent passing headlights from turning
light off.
Motion switch—turns the light on as you
enter the room. Used for both convenience
and security. Can be used to replace existing
wall switches.
Illuminated switch—is available in two
types. One has a small light that is on when
the switch is off so it can be easily found;
these are usually used at entrances to rooms
and in hallways. Pilot light switches are on
when the light is off and usually used for
out-of-sight lights such as those in the basement, garage and attic.
Outdoor switch—enables electrical power
to be used for outside applications. They feature a turning lever inside a weatherproof
box cover with a toggle switch.
A second type of tamper-resistant outlet
utilizes an overlapping shutter system
that limits improper access to its energized contacts.
Voice-activated switch—offers a handsfree approach to illuminating dark areas
quickly and safely. Voice-activated switches incorporate the latest technology in
speech recognition to enable homeowners
to control the brightness of the lights.
Used in place of any standard wall switch,
they can be programmed with any command or language.
Silent switch—provides the same operation
as many of the other switches with little or
no noise. Silent switches are either mechanical or solid state. The mechanical switch is
almost identical to the regular switch except
ELECTRICAL SUPPLIES
for an extra bumper to reduce the noise. Prior
to 1991, silent switches contained mercury
and used no springs or mechanical devices.
This resulted in smooth, silent operation and
long life. Due to health concerns they were
removed from the market.
Receptacles
The wall receptacle, or outlet, taps the circuit to provide electrical power at a given
location. The slots in the outlet are designed
to match the plug blades of the appliance or
extension cord. Building codes specify number and spacing of outlets.
Receptacles come in flush- and surfacemounted designs. Flush-mounted (recessed)
is the style most commonly used for permanent installations.
Configuration of a receptacle refers to the
arrangement of slots or openings on the face
of the outlet. These arrangements vary
according to voltage and current rating of
the receptacle.
The most common configuration is threewire grounded. The most common outlets
used in homes are standard 15-amp, 125V,
three-wire designs. All outlets must be
grounded (three prongs).
A single- or double-wipe contact refers to
the area of the inserted prong on which contact is made. In the case of a double wipe
contact, contact is made on both sides of
each blade.
All outlets should have a faceplate to help
prevent exposure to “live” wiring.
There are three basic ways to terminate
wiring in wall receptacles. First is the conventional binding-screw method where
wires are stripped, looped and placed under
binding screws and then secured by tightening down screws.
Second is the pressure-lock method,
which eliminates binding screws. In this
method, connection is made by inserting a
stripped conductor, which pushes the conductor into and against the terminal channel for a strong connection. Release slots
permit easy removal of conductors.
A third method involves clamp-type terminals. Stripped wire is inserted into an
open clamp beneath a screw that is then
turned down to lock connection.
Some receptacles have small “pilot” or
guide lights. Appliance receptacles consist of
one vertical slot and two slanted slots and
are designed to be surface-mounted.
Specialty receptacles include twist lock,
childproof, surge suppressor, isolated ground
and RV.
Any flush-mounted receptacle may be
installed outdoors if covered by a protective
plate. These weatherproof covers have
hinged or threaded caps that cover the outlet face. A self-sealing gasket fits between
the plates and the wall surface to add further protection.
Safety outlets have spring-loaded caps to
prevent children from inserting objects into
them. To insert an attachment plug, its
prongs must be placed into the slots of the
protective cap, then turned 90 degrees or
until the slots of the outlet are exposed.
When the plug is withdrawn, the cover
automatically returns to its original protective position. A slight variation of this uses
an overlapping shutter system.
A second type of safety outlet utilizes a
cam to make an internal electrical connection only when both blades are properly inserted.
Ground Fault Circuit
Interrupters
Even with proper wiring and fusing or circuit breaking equipment, danger exists from
ground faults, which are the most common
cause of electrical shock.
Ground fault occurs when a person comes
into contact with a live
electrical wire. This can
happen by touching an
exposed wire, or by operating a faulty appliance or
power tool. Worn insulation, hidden damage or
Ground fault
circuit interrupter
faulty connections can
make the metal housing of an appliance a
hot electrical conductor. Technically, this
happens when a wire develops a small leak
that will flow to the ground through any
path, including a human body. This can
cause serious shock, even death. Ground
faults can also cause electrical fires.
This hazard is so serious that the National
17
Electrical Code requires all new homes to be
equipped with ground fault circuit interrupters (GFCI) in bathroom, kitchen, workroom, outdoor, basement and crawl space,
garage and swimming pool receptacles. It is
a good idea to suggest that homeowners
install such a device in older homes. The
GFCI interrupts power quickly enough to
help prevent someone from receiving a
lethal dose of electricity.
GFCIs are available in receptacles, modules, breakers and extension cords.
Receptacles work for 15- or 20-amp circuits.
GFCIs should be tested monthly to ensure
they are working properly.
For convenience, a portable GFCI can
be plugged into any existing outlets,
either two-wire or three-wire, without
rewiring. Circuit breaker GFCIs can be
added in electrical panels to replace ordinary circuit breakers. They should be
installed by a qualified electrician.
Surge Suppressors
With increasing use of home computers
and other sensitive electronic home entertainment equipment, there is a growing
need for protection from voltage surges,
often called spikes or transients. Surge protection is also needed because of the sheer
number of
potentially
destructive
Surge protector power strip
spikes and
surges that occur in the home every day.
Surges can cause equipment to malfunction
and in severe cases cause catastrophic damage or fire.
A surge is a transient increase of current,
voltage or power on an electrical system.
The larger, more destructive surges, generally
caused by lighting, can reach thousands of
volts. Surges can also come from utility
transformer switching, air conditioner operation, inductive and power switching, distant
lightning strikes and static discharges. They
put extreme stress on solid-state components. Unchecked, such surges can quickly
destroy wiring, appliances, telephones and
other electrical devices.
Transient voltage surge suppressors (TVSS)
help protect sensitive electronic equipment.
2
2
1
1
1
5
5
3
4
3
2
4
3
ELECTRICAL SUPPLIES
Surge protectors limit surge voltages by
the unit must be replaced. Look for audia cord enters through the top. Side outlet
discharging surge currents to ground.
ble or visual indicators.
fits cords coming through the side. Nozzle
Proper grounding is the strongest prereqWhen selling surge protection devices,
caps are used on table lamps where cord
uisite for proper surge protection.
stress the low cost of these products comfeeds through the bottom.
The key component in almost all surge
pared to the high cost of repairing or
The shell is the body of the socket. It can
protectors is metal oxide varisters (MOVs).
replacing branch wiring and electrical
be brass, brass-finished, nickel-finished aluUnder normal conditions, MOVs offer
appliances and equipment. However, a
minum or plastic. Shell liner, interior and
high resistance to currents, preventing
surge protector will not protect against a
cap may be disassembled for wiring.
normal currents from discharging to the
direct lightning strike.
Other sockets include pigtail weatherground. Under surge conditions—typically
proof, which comes with two short leads
115 percent or more of a normal curTransfer Switches
for splicing into a power source.
rent—the MOV’s resistance drops within
Transfer switches have become more
Similar to the pigtail is the pin type,
nanoseconds, creating a path with far less
popular for new construction and afterbut tightening down the top and forcing
resistance than the facility’s wiring for the
market installations due to weather
contact pins into wire makes contact.
current to flow to the ground.
storms or accidental power outages.
The most common size sold is medium
Basically, there are two types of supTransfer switches are wired up to specific
base (such as on 60- and 100-watt bulbs).
pressors. One—also known as a surge
load center circuits that will be utilized
Other principal sizes are large-base mogul,
strip—is similar to a grounding adapter,
when there is an emergency power outused on three-way floor lamps; and interand the appliance plugs into it at the wall
age. A portable generator is then plugged
mediate, which is used on outdoor
outlet. Surge strips are not capable of supinto it and the switch transfers generator
Christmas tree bulbs, candelabra and
pressing a powerful surge. The other type,
power through the home’s existing electrisome night lights.
designed primarily to prevent lightning
cal circuits. There is no backfeed when
damage, is mounted at the service panel
power is restored. Transfer switches elimiAppliance and Heater
and protects the home where the electric,
nate unnecessary extension cords and are
Connectors
telephone and cable lines enter. The
easy to install. Available in choice of
Connectors are used to connect older
Institute of Electronics and Electrical
watts and number of circuits, plus optionstyle, heat-generating, small household
Engineers recommend whole-house surge
al accessories.
appliances with heat-resistant neoprenesuppression as the most effective way to
type HPN cords.
protect against damage in the home.
Lampholders
The connectors are molded of strong,
Some of these suppressors also feature
Lampholders are devices with a screw
heat-resistant materials and come in a varifilters that reduce or eliminate line noise
base that hold light bulbs. Some have
ety of styles, such as switchless, armored (or
distortion that is picked up on radios, telswitches to turn them on and off.
heavily protected), side outlet and monopevisions and tape recorders. These filters
Lampholder sockets come in two basic
ull. All have spring cord protectors.
also help guard against accidental data
styles: single and multiple holders. The
There are two standard sizes: 11/16"
loss in home computers triggered by
most popular styles are twin light,
and the miniature 1/2". Standard 11/16"
spikes or line noise.
adapter, keyless, pull-chain tap socket,
connectors generally fit on irons and
A whole-house surge protector mountpush switch and turnkey.
toasters. The 1/2" connectors are for cofed at the service panel also protects secA socket has three principal parts: shell,
feemakers, corn poppers, some electric
ondary distribution wiring and electrical
cap and interior. The cap has three basic
skillets and other similar appliances.
appliances such as ovens, air conditionstyles: pendant, nozzle and side outlet. A
ers, dishwashers and refrigerators from
pendant is used with a suspended socket;
Bulb Life Extenders
most sudden power surges. To
Extenders have different
LAMP HOLDERS
increase the protection of elecdesigns. One screws into a regtronic equipment, it is also recular socket like a socket
ommended that a plug-in surge
adapter; the other is a small
suppressor be installed at the
disc placed in the base of the
point of use to supplement a secsocket before the bulb is insertondary surge arrester.
ed. Bulbs last up to 30 times
Surge protectors are rated in
longer than in standard sockJoules and clamping voltages.
ets; extenders should be recomKeyless lampholder
Lampholder with
Fluorescent
Once surge protection has been
mended for use where the bulb
pull cord
lampholder
provided at the maximum levels,
burns continuously.
18
ELECTRICAL SUPPLIES
BOXES AND COVERS
Boxes, Fittings and Conduit
According to the National Electrical
Code, every break or termination in an
electric cable must be enclosed in an
appropriate box. This rule applies to
switches and fixture connections as well
as to splices and junctions.
Wall boxes, ceiling boxes (junction
boxes) and weatherproof (outdoor) boxes
are the main types of electrical boxes.
The three types of boxes are switch and
outlet, ceiling and utility boxes. Some are
made of galvanized steel with knockouts
to bring cable into the box. Non-metallic
(plastic) boxes are also available. Clamps
are included in some boxes to hold cables
in place.
Switch boxes are 2" x 3" in size and can be
used to house receptacles (outlets) as well as
wall switches. Switch boxes are designed so
that two or more may be fastened together
to form a larger box. The side walls must be
removed where the boxes join.
Octagonal ceiling boxes are used primarily
in ceilings to hold overhead light fixtures
and splices.
Utility boxes are used for the same purpose as switch boxes, but their rounded corners make them suitable for surface wiring.
All boxes require covers. Box covers can
be made of metal or plastic and come in several different shapes. The box covers may be
solid or feature knockouts for receptacles.
Electrical fittings are used to couple, connect, fasten or ground conduit or cable.
Refer to local codes for requirements.
Cable is sometimes held in place by straps
or staples that are designed to handle different sizes and is terminated by the use of
cable connectors. A number of other fittings
are available for service entrance installations, for grounding purposes or for hazardous locations. Fittings can be installed
easily with a screwdriver, hammer or pliers.
Conduit is a raceway in which wires are
installed and protected. Types of conduit
include metal, non-metallic and flex. Each
conduit and size requires its own family
of fittings.
Metal conduit can be electrical metallic
tube (EMT); intermediate metallic conduit
(IMC); rigid or surface raceway.
WET LOCATION ONLY
WHEN COVER CLOSED
Weather protective cover for
duplex receptacle
4-hole outlet box
Non-metallic conduit can be surface raceway or polyvinyl chloride (PVC).
Flex conduit types include flexible
(steel and aluminum); electrical nonmetallic tube (ENT); and liquid tight
(metallic and non-metallic).
Conduit can be held in place by a variety
of straps and hangers that are designed to fit
a specific size diameter. The diameter of rigid
and EMT conduit differs, so the correct strap
or hanger must be specified. Lengths of conduit are joined together by couplings (either
rigid or EMT) and terminated by connectors.
Couplings and connectors generally are
either a set-screw type, threaded for rigid
conduit or rain-tight compression type for
damp locations.
PVC, EMT with rain tight fittings, liquid
tight, rigid and IMC conduit can be used
outdoors. For underground applications,
only PVC and rigid conduit can be used.
Surface Wiring Devices
Surface wiring switches, receptacles, lampholders, etc., are installed entirely on the
surface of the wall as opposed to a normal
flush-mounted installation.
The device includes a box, cover and electrical device in one unit. The unit is molded
of an attractive and sturdy plastic insulating
material, which makes it suitable for use in
the home as well as in barns, garages and
basements.
On-the-wall wiring systems created for
do-it-yourselfers allow the consumer to
run electrical wires to the point of use in
the home without breaking into the wall
or ceiling.
These systems have adapters that alter
existing outlet boxes, so consumers can tap
wires off them and snap together vinyl
19
3-hole outlet box
5-hole outlet box
BOXES AND ACCESSORIES
Switch Box
Utility Box Cover
Octagon Box
Utility Box
channels that carry the wires to the new
outlet or switch. The channels hide unsightly wiring and can be painted to blend into
any decor. Quick and easy installation and
economy are its major advantages.
Fuses and Circuit Breakers
A fuse or circuit breaker box, commonly
called a main service entrance panel or load
center, is located between incoming power
lines and house wiring. It divides the main
power line into branch circuits. Load center
applications vary, depending on local codes.
Fuses and circuit breakers are safety
devices that break an electrical circuit
when it is overloaded. The fuse or circuit
breaker is sized to protect the branch circuit wiring between the breaker and the
outlet and does not protect anything
plugged into the outlet.
Circuit breakers come in three main types:
single, double and thin.
You can generally tell if a fuse is blown
by looking at it. If the fuse is blackened,
that indicates a short circuit has occurred;
if the metal is melted, then an overload
has occurred.
ELECTRICAL SUPPLIES
There are several types of fuses. Plug fuses
are available in 5- to 30-amp sizes and are
the most commonly used fuse.
Another fuse is the Type S, which provides a minimum time delay for the starting
of small household motors. Type S fuses prevent anyone from replacing a lower-rated
fuse with a higher one. It consists of two
parts: the fuse and the adapter, which has a
different diameter for each fuse ampere rating. Once an adapter of a particular size has
been inserted into the fuse socket, it cannot
be removed and only the same rating fuses
can be used in that socket.
Cartridge fuses are used in high-current
applications, such as the main service box
and in clamp- or bar-type fuse boxes that
serve electric ranges, water heaters, clothes
dryers and air conditioners. Round cartridge
fuses have ratings to 60 amps; greater capacity (to 600 amps) requires a cartridge fuse
with knife-edge contacts.
A screw-in breaker can replace a fuse.
When a circuit malfunctions, a button on
this device pops out; it must be pushed in
to reset.
A circuit breaker contains a bi-metal strip
that breaks the circuit when current exceeds
a predetermined rating. A broken circuit is
indicated by the breaker’s switch being in
the mid-point position. This is commonly
referred to as a “tripped” breaker.
After the overload has been corrected, reset
the circuit breaker by switching it to the “off”
position and then to the “on” position.
Arc-Fault Circuit Interrupters
Existing circuit breaker technology does
not protect against an occurrence known as
an arc fault. Arc faults are believed to cause a
significant percentage of the more than
43,000 electrical home fires, 330 deaths and
1,800 injuries annually.
An arc fault can occur when insulation
around cords, wires or cables is damaged or
deteriorates. In many cases, arc faults are the
results of aging wire. Arc faults can flare at
temperatures in excess of 10,000°F, igniting
surrounding combustible material.
In many cases, conventional circuit breakers do not respond quickly enough to arc
fault situations. By the time a circuit breaker
responds, a fire may have begun to smolder.
An arc-fault circuit interrupter (AFCI) is
a device that recognizes the unique characteristics of many types of arcing faults
and acts instantly to interrupt the circuit.
In some devices, the arc-fault circuit interrupter is integrated into state-of-the-art
circuit breaker design.
In 1999, the National Electrical Code
mandated that arc-fault interrupters be
installed on all 15- and 20-amp circuits in
bedroom outlets in new home construction starting in 2002. Some states mandated the change earlier.
Now available is a combination
AFCI/GFCI circuit breaker that is certified
by Underwriter’s Laboratories. The breaker
protects against electrical fires and dangerous electrical shock hazards, enhancing
electrical safety in the home. It also simplifies the installation process for electrical contractors since there is no need to
wire two separate devices.
Wall Plates
Wall plates include all plates used to finish or cover switches, receptacles or combination devices. Standard plastic wall plates
are constructed with durable, smooth surfaces. Builders in new homes often install
inexpensive ones. There are also designer
and decorator plates, switches and receptacles with smooth plastic faces in contemporary colors.
Chrome-plated wall plates are made of
steel and brightly finished for lasting appearance and durability.
WALL PLATES
Decorative wall plates come in many
styles and materials such as ceramic, aluminum, brass, wrought iron, stainless steel,
copper, wood and die-cast metals. Die-cast
products include switch and receptacle
plates made in finishes and designs to match
other functional hardware items such as
door handles, cabinetware and bath fixtures.
Timers
Timers turn on lights and appliances at
specified intervals and times, making them a
useful security product. They are available
for outdoor or indoor applications and can
be electronic or mechanical. Spring-wound
timers for bath fans and spas have a manual
on-off switch.
Doorbell Equipment
If not battery operated, doorbells require
AC step-down transformers to reduce household voltage to the proper operating voltage.
Standard doorbells operate at 10V or 16V.
Some doorbells may require other voltages,
depending on the design. Step-down transformers should be UL-listed. The doorbells
themselves are safe, low-voltage devices that
do not require UL inspection.
Single or multiple-stranded bell wire is
used between the doorbell, the transformer
and the push buttons.
Push buttons are easily installed and
replaced. Bulb life for lighted push buttons is
approximately three to five years, and
replacement bulbs are available. Push buttons are available in lighted or unlighted,
recessed or surface-mounted styles.
Non-electric chimes are also available.
Wireless doorbells are all on the same frequency, although some offer adjustable frequencies. For more information, click
(Installing Doorbells).
Plugs, Adapters and Taps
Toggle Switch Plate
Combination Wall Plate
Weatherproof Outlet Plate
20
Double Outlet Plate
Plugs connect devices to the power supply through a receptacle. The typical plug
includes two blades or prongs, a molded
plastic body holding the two blades apart
and a blade/cord connection within the
plug body. When inserted into an outlet,
the blades become energized. Electricity
flows through the blades, through the
ELECTRICAL SUPPLIES
blade/cord connection and through the
cord, thus energizing the appliance.
Plugs come in polarized and non-polarized varieties. Polarization helps reduce
the potential for shock. With polarized
plugs, one blade is wider than the other.
Three-conductor plugs are automatically
polarized because they can only be inserted one way. Two-prong plugs do not have
a grounding pin.
Older homes may not have polarized
receptacle outlets. If not, the receptacles
will not accept polarized plugs. A qualified electrician should replace the old
receptacles and put in wiring consistent
with polarization.
Choose the plug based on the gauge of
wire on the appliance or tool. Male plugs
have prongs while female connectors
have slots.
There are plugs for different applications, such as exterior, interior and
marine. A twist lock prevents accidental
disconnection.
Attachment plugs fit on the ends of
cords of portable appliances and permit
them to be connected to wall receptacles
or extension cords. Plugs and connectors
are used to build extension cords or for
replacement on extension cords.
The arrangements of slots and blades
on connectors, receptacles and plugs must
match the configuration of the devices
with which they will be used. The number
of slots or prongs on these devices must
be the same as the number of wires in
associated cords.
Socket adapters screw into the socket,
while taps plug into the outlet.
Adapters are generally used for temporary application to provide two outlets
where a light socket is in use.
Taps are used to increase the number of
attachment plugs that can be used on a
single receptacle face.
Caution must be exercised when tapping additional attachment plugs into the
same line. If the power rating of the circuit is exceeded, fuses will blow (if the circuit is properly fused).
Multiple taps plug into existing outlets
and can accommodate four to six plugs.
PLUGS AND TAPS
Straight plug
Grounding adapter
3-outlet
4402 tap
6-outlet tap
C t N
Some come with built-in surge protectors.
Other types of taps are table and cube.
Plug-in strips feature multiple outlets
placed at regular intervals. If used in a
workshop, it should have grounded outlets and be attached to a grounded circuit.
Quick-Clamp Devices
Quick-clamp devices do away with
screw terminals and the necessity of stripping wire. If a plug needs replacing, insert
the cord into the clamping mechanism as
shown on the instructions. The clamp
forces the cord into the proper position
and onto sharp contact points that pierce
the insulation and make contact with the
conductors.
Clamp devices include both attachment
plugs and cord connectors of various
styles. They are used with portable lamps
and small appliances. They cannot be
used on kitchen or large appliances
because of their low amperage rating.
Wire Nuts/Connectors
Insulated wire nuts or connectors are
used to connect wire ends that have been
twisted together inside a lighting fixture
or box. The size of the wire nut or connector must correspond to the size wire
being used. Connectors are used to connect heat-generating, small household
appliances with heat-resistant neoprenetype HPN cords.
The connectors are molded of strong,
21
heat-resistant materials and come in a
variety of styles, such as switchless,
armored (or heavily protected), side outlet
and monopull. All have spring cord protectors. An offset wing design on some
models provides increased torque with
reduced wear on fingers. A hex head
enables nut driver and automated use.
There are two standard sizes: 11/16"
and the miniature 1/2". Standard 11/16"
connectors generally fit on irons and
toasters. The 1/2" connectors are for coffee makers, corn poppers, some electric
skillets and other similar appliances.
TELEPHONES AND
ACCESSORIES
■ TELEPHONES
Consumers look at telephone purchases
much the same way as they look at other
home electronics purchases. They want a
quality product sold by a reputable retailer. Service backup is important because
telephone owners are responsible for their
own repairs, just as they are for any other
kind of equipment they own. If the telephone breaks, they take it back to the
store that sold it.
Telephones contain microprocessors
and other electronic parts. New and more
sophisticated features are being added.
As telephones become more complicated, they require more sales attention.
Consumers need to be shown how to use
the additional features. If they will be
installing, replacing or rewiring, they may
need instruction in these areas, too. To
stock the telephones and accessories most
needed in your market, study the demographics of the area. Cordless phones may
work well in suburban and rural homes,
but are sometimes subject to interference
in urban areas.
Affluent areas may be a good market for
accessories such as telephone-answering
devices, while low-cost compact electronic
“disposable” phones may appeal more to
a middle-class market.
Beyond the basics, consumers can buy cordless phones, automatic redialing phones and
ELECTRICAL SUPPLIES
combination clock-radio phones.
Here are important points to keep in mind
when selling phones and accessories.
Telephone companies require consumers to report their ringer equivalency
number (REN). This REN is published on
the instruction sheet or phone unit housing. Standard AT&T phones have REN ratings of one. Compact, low-cost models may
have as low as .7 REN or as high as 1.3 REN.
If the REN on one line exceeds 4.0, the
phones will not ring.
There are two basic types of phones:
pushbutton tone and dial pulse. The dialpulse phone looks like a pushbutton tone,
but its pushbuttons technically dial the
phone. It doesn't process a call as fast as
the pushbutton tone.
Dial pulse gives the convenience of the
pushbutton-tone type of dialing without
higher monthly costs. It should be noted
too that pushbutton-tone phones are
required to access long-distance services.
Consumers should also be aware that
installing a pushbutton-tone phone
means they must also be receiving this
type of service from the phone company.
Cordless telephone systems incorporate
a base station connected to the telephone
line and a wireless handset. The distance
a cordless phone will work away from the
base station varies. It may be as little as
50' or phones with antennas may work as
far away as 1,000'.
Elevating the base station and placing it
away from other reception barriers can
improve cordless phone performance. One
word of warning: In most cordless
phones, ringers are located in the earpiece. The ring registers nearly 130 decibels, and if the phone is picked up and
the switch not turned from “standby” to
“talk” position, a phone ring could damage hearing.
Cordless phones are powered by
rechargeable nickel-cadmium or nickelmetal hydride batteries. The length of
time required to recharge and the length
of time between rechargings will vary.
Therefore, it is necessary to read the
instructions with the individual product
to see how long to charge and how sensi-
ENVIRONMENATL
CONCERN ALERT
Many states are enacting legislation concerning dry-cell and rechargeable batteries.
Current legislative topics include mercury in
batteries, batteries for cordless tools and
appliances and battery recycling.
Mercury will have to be eliminated from
batteries. This will probably reduce the performance and increase the cost. Batteries
in cordless power tools and appliances will
have to be removable. And nickel-cadmium
batteries will have to be recycled through
battery retailers.
Be sure you know the laws regarding these
topics in your area.
tive the battery is to frequent rechargings.
Some nickel-cadmium batteries will
“remember” how much time elapsed
between chargings and if they are
recharged too often, will shorten the
length of time they hold a charge.
Eventually the batteries will have to be
replaced, but most phones will take several hundred chargings.
■ ACCESSORIES
Accessories are available in either “modular” or “conventional” designs.
Installation of a conventional system
requires no more than a screwdriver.
Accessories are used in conjunction with
standard telephones, using standard fourprong plug configuration, spade-tipped
wires or hard wiring.
All wiring in the phone base, handset
and wall receptacle can be replaced by
matching the colored wires. But it is
SPECIFICATIONS FOR
CYLINDRICAL BATTERIES
AA (Penlight) . . . . . . . . . .1.2**, 1.4*, 1.5
AAA . . . . . . . . . . . . . . . . .1.5
C . . . . . . . . . . . . . . . . . . .1.2**
D . . . . . . . . . . . . . . . . . .1.2**, 1.4*, 1.5
N . . . . . . . . . . . . . . . . . .1.5
*Mercury cell
**Nickel-cadmium cell
22
important that store employees know
enough to help d-i-yers with wiring information and connection procedures on the
models you stock.
Plugs and jacks provide the connection
for standard telephone and extension
cord hook-ups. They may also be attached
to existing cords, adding versatility to
existing phones.
No tools are needed for modular connections; the system was designed to
allow “snap-fit” connection of miniature
plugs with mating hardware. The following connections are available using the
snap-fit modular concept:
Coil cord—old cords can be removed by
depressing a clip and pulling the plug out of
the phone’s base and handset. The new cord
is then pushed into place until it locks.
Straight-line cords—plugs are clipped
into the base of the phone and the wall
receptacle.
Extension cords—cords are equipped
with modular plugs that snap into a wall
receptacle while a modular jack accepts
the line cord from the existing telephone.
Modular adapter—allows phones with
modular line cords to be plugged into a
four-pronged conventional plug that
matches the holes of conventional telephone jacks.
Modular plug and conventional jack—
allows connection of conventional fourpronged plug extended line cords to modular jacks so that conventional phones
can be plugged into modular connections.
Modular coupler—allows connection of
modular plug-ended cords to each other
to extend the phone system.
Duplex modular adapter—allows two
modular extensions to be run off one
modular unit. For instance, allows you to
connect a telephone and telephoneanswering device to the same phone line.
Retrofit modular adapter—allows conventional telephones with spade-tipped
conductors to be connected to modular
jack assemblies without tools.
Surface wall-mount jack assembly—
allows conversion of conventional terminal blocks to a modular jack.
Portable wall-mount jack assembly—
ELECTRICAL SUPPLIES
allows connection of modular plug-ended
line cords in any location to convert fourhole jack to a modular design.
Flush wall-mount jack assembly—allows
flush-mounted connection of plug-ended
modular line cords for initial installation
or conversion from existing wall receptacles. Can be connected in parallel when
more than one jack is required.
Wall-mount modular patio jack—weatherproof assembly accepts plug-end modular line cords.
■ ANSWERING DEVICES
The kind of telephone answering
device you recommend will depend in
large part on the kind of use the customer expects of it. Models vary by price
and optional features.
Basic digital units do not require a tape
recorder or tape to handle incoming messages. In most models, total answer time
is limited, but more sophisticated units
will allow for messages of varying lengths.
Features which differentiate models
include:
Leaving messages—some units permit
the user to leave a digital or tape-recorded
message.
Dictation—some units double as dictating machines with no time limit on
recording. A switch will stop and start the
answer tape.
Announce only—for messages that
require no response, such as announcements of when the owner will return.
Ring-response adjustment—allows
machine to wait to answer call until
phone has rung up to 10 times. An advantage since it eliminates connecting and
disconnecting unit each time owner
leaves and returns.
Remote pick-up—allows owner to pick
up messages from a distance by telephoning the answering unit.
Extended recording—allows user to
record a complete two-way conversation
without being cut off after allotted message time.
Monitor—allows user to listen, undetected, to incoming messages as callers
leave them. Listener can pick up phone
GLOSSARY OF ELECTRICAL TERMS
ALTERNATING CURRENT—Abbreviated “AC.” A current of electricity that alternates at a rate of
60 hertz (cycles per second). It flows first in one direction, then in the other. Only at very low frequencies is this charge visible to the eye through the flickering of lamps.
AMPERE—Abbreviated “amp.” A measure of the flow of electrical current through a wire.
BALLAST—A form of transformer used in fluorescent lamp circuits to control current and keep it
within specific operating limits.
CANDLEPOWER—A measure of the intensity of light produced by a source. One candlepower
corresponds approximately to the light produced in any one direction by an ordinary candle.
DIRECT CURRENT—Abbreviated “DC.” A flow of electric current continues in one direction as
long as the circuit is closed.
FOOTCANDLE—The unit used to measure how much total light is reaching a surface, such as a
wall or table. One footcandle is the amount of illumination falling on a one-square-foot surface
from a standard candle located 1 foot away.
FUSE—A replaceable safety device used to break the flow of current when a circuit becomes
overloaded.
GROUNDING—Connects the electrical system with the earth to prevent damage or shock.
Ground wires are usually bare.
HOT WIRE—A power-carrying wire (usually in red or black) as distinguished from the “neutral”
wire (usually white).
KILOWATT—1,000 watts. From “watt” and Greek word “kilo,” meaning 1,000.
KILOWATT HOURS—Abbreviated “kwh.” A 1,000-watt lamp burning one hour will use one kilowatt hour of electricity. If the rate were 3 cents per kwh, the cost would be 3 cents per hour to
operate.
LAMP—Technical word meaning light bulb or tube—the part that shines until it burns out. It
can also refer to a type of fixture, such as a desk lamp.
LUMEN—A unit that expresses the total quantity of light given off by a source regardless of
direction. A lumen is defined as the amount of light falling on a surface of one square foot, every
point of which is one foot away from a source of one candlepower.
NEUTRAL WIRE—A wire that runs from an appliance or device to make uninterrupted connection back to the power source. The opposite of a “hot” wire that carries power from the electrical source to the appliance.
NOMINAL LAMP LIFE—A rated average bulb life that is obtained through closely controlled
tests.
OHM—A unit of electrical resistance. (Electrical resistance is the opposition by a material to the
flow of electrical current.)
TRANSFORMER—Steps up or steps down amount of alternating current available from circuit to
that required by the appliance.
VOLT—Amount of pressure needed to push electricity through a wire.
WATT—The unit of measurement of electrical power. Calculated by multiplying volts times
amperes. For instance, 746 watts equal one electrical horsepower.
and interrupt recording message, if
desired, or simply let it be recorded.
Some phone companies still require an
Authorized Protective Connection
Module, if the answering device could
produce excess voltage on the telephone
line. The APCM plugs directly into the
phone jack.
■ BATTERIES
General-purpose and heavy-duty battery
systems serve a variety of functions.
23
General-purpose batteries provide 1.5V to
510V. They have good shelf life but
decreased efficiency at high-current
drains. They drop voltage gradually with
use and operate poorly in low temperatures. They are available in a variety of
shapes from small pen cells to huge emergency lighting batteries. Their uses range
from camera flashbulbs to radios and
flashlights.
General-purpose and heavy-duty batteries are designed for light moderate to
ELECTRICAL SUPPLIES
heavy-current drain equipment. They, too,
are available in a variety of sizes and
shapes providing from 1.5V to 9V. They
have a good shelf life and maintain voltage better under load than general-purpose
batteries. They are used in flashlights, calculators, motor-driven toys, electronic games
and portable compact disc players.
Alkaline batteries are the longest-lasting
all-purpose batteries. They are designed
for high- and continuous-current drain
applications. Voltage ranges from 1.5V to
9V. The average cell holds 90 percent of
its energy for two to three years on the
shelf. Alkaline batteries are disposable and
operate well in low temperatures. Uses
include tape recorders, remote controls,
portable communications systems, radios,
television sets and shavers.
Lithium batteries are more expensive but
can hold their power for eight to 10 years,
unused. They are designed for cameras,
watches and other items that use a small
amount of current repeatedly over a long
period of time. They are available in 9V.
Heavy-duty batteries have a short life
compared to alkaline batteries and work
best for low-drain applications such as
remote controls and wall clocks.
Miniature zinc air batteries are designed
to provide power to miniature hearing aids.
They can be directly substituted for silver
oxide or mercuric oxide batteries in most
hearing aid applications. They are activated
by removing the covering from the air
access hole. They are available in common
hearing aid battery sizes.
Improved cell construction and advanced
use of titanium and lithium technology
have resulted in new premium batteries that
offer long-lasting performance for use in
high-drain devices.
Nearly 80 percent of all batteries sold
are in the AA and AAA sizes. Some batteries come with a gauge-style tester so the
user knows how much power remains in
the battery.
Household batteries should be stored in
a dry place at room temperature. Make
sure not to mix battery types in the same
device and never mix new and old batteries in the same device. Do not dispose of
any battery type in a large group since
they can come into contact with one
another. Always take precautions when
handling exposed battery chemicals.
Battery chemicals should not be placed
near the eyes or ingested by any means.
Mercury Batteries
Mercury (and silver) batteries are used to
power hearing aids, electronic watches, calculators and other electronic equipment
where small size and long life are critical.
They maintain a constant voltage for the
entire life cycle.
Concern over the environment has led
manufacturers to design mercury-free batteries for household use.
Rechargeable Batteries
Although nickel-cadmium (Ni-Cd) batteries are most commonly used in
rechargeable applications, other kinds are
available, including alkaline and leadacid. The major drawback to rechargeable
alkaline batteries is fewer recharging
cycles. Nickel-metal hydride (Ni-MH) batteries have emerged as a viable alternative
to Ni-Cd batteries since they outlast Ni-Cd
batteries by up to 40 percent.
Ni-MH cells are available in AA, AAA, C,
D and 9-volt sizes. Ni-MH batteries offer
superior performance for use with highdrain applications such as flash cameras
(including digital) and camcorders.
Rechargeable batteries are not charged
before purchase and must be charged for
approximately eight to 12 hours before
using. Some rechargeable batteries are now
available with shorter charging times.
Rechargeable batteries will lose their charge
if not used for an extended period (30 to 60
days) and should be charged every month
for best performance. Some batteries can be
recharged 800 to 1,000 times and will last
up to four years.
They offer “overcharge” capability,
which means they can stay on house current for long periods without damaging
the cell. Like mercury batteries, nickelcadmium cells maintain constant voltage
for their full life span.
Nickel-cadmium batteries are perma-
24
nently built into a number of cordless
tools and appliances. In addition to the
larger batteries, nickel-cadmium batteries
are available in D, C, AA, AAA and 9V
sizes with chargers.
Battery recharging systems include the
charger and charging module. The module
is available in four sizes to hold AA, C, D or
9V batteries. The charger should be used
only with batteries specifically designated as
rechargeable. These are sometimes known as
secondary batteries. Trying to charge nonrechargeable batteries can cause leakage and
possible cell rupture.
Lead-acid batteries are built into tools.
These batteries, about the size of a D battery, won’t leak, don’t vent explosive gas or
corrosive fumes, offer lengthy shelf life and
cost about half as much as nickel-cadmium.
Life span is 200 to 500 cycles, but they will
lose power gradually with age and use.
A national program has been started to
recycle rechargeable batteries. Retailers can
participate at no cost. For more information, contact the non-profit Rechargeable
Battery Recycling Corp. at (877) 723-1297 or
visit www.rbrc.org/diy.
Electric Motors
There are two basic motors found most
frequently in household applications—split
phase and universal.
The split-phase motor is the simplest. It
contains no brushes or commutator and
comes in one-third or less horsepower. At
full speed, the split-phase motor is able to
develop as much power as any other type,
but it is not capable of starting heavy loads
such as pumps or compressors. It functions
best when maximum load is applied at full
speed, such as in sanders, grinders and light
power tools.
Universal motors do not run at a constant
speed but slow as the load increases in some
instances from 15,000 rpm without a load
to 500 rpm under heavy load.
For this reason the motor is unsuitable for
many jobs. It is used only where the load is
reasonably constant and predetermined, such
as in sewing machines, vacuum cleaners, fans,
etc. It is the only type of motor that can be
controlled by a rheostat.