DIY Frequently Asked Questions

Electrical & Lighting Terms

Weatherproof Box

  • Also known as an outdoor box.
  • Used for exterior switches or receptacles.
  • Thicker than interior boxes and has a rubber gasket between the cover and the box to keep out water.
  • Covers are screw-on or snap-on.

Wall Plates

  • Also known as faceplates or covers.
  • A flat metal, plastic or wooden piece that covers the openings in the wall made by receptacles and switches.
  • The openings in the cover match the type and number or receptacles or switches being covered. Blank covers are also available.

Alkaline Battery

  • Longest lasting all-purpose battery.
  • Used for high and continuous current drain applications.
  • Disposable and operates well in low temperatures.
  • Voltages range from 1.5V to 9V.
  • Lasts as many as five years on the shelf.

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. Vacuum filled.
  • Use for general and task lighting around the house.
  • Wattage indicates the amount of electric power used by a bulb to produce light. Generally, the greater the wattage, the greater the light output. Some bulbs produce more light per watt than others.
  • Standard household bulbs have an average life of 750 to 1,000 hours, which can be lengthened or shortened by the treatment 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.
  • Underwriters Laboratories (UL) tags on fixtures designate the maximum allowable wattage. A mercury or fluorescent system is typically limited to a single bulb size.
  • Long-life bulbs may last longer than ordinary bulbs, because they 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.
  • 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.

Lithium Battery

  • Holds power for eight to 10 years on the shelf.
  • Available in 9V.
  • Used for cameras, watches and other items used repeatedly over a long period of time.

Drill Press

  • Used for boring holes in precise, repetitive cuts. With the appropriate accessories, the drill press can also shape, carve, sand, grind, buff and polish.
  • Consists of a base and a column rising upward to a head holding the motor and drill. A radial arm holds a worktable that adjusts vertically. A feed handle enables the user to direct the drill chuck up and down.
  • On a radial drill press, the head rotates 360º around the column and can drill at an angle or horizontally.

Halogen Bulbs

  • Like incandescent bulbs, halogen bulbs produce light by passing current through a coiled tungsten wire. 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 incandescent bulbs, 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.
  • More energy-efficient than standard incandescent bulbs. They generate up to 30 percent more light for the same electricity.
  • Halogen bulbs blacken much less than incandescent bulbs and stay brighter as they age. Because of their brilliant white light, they are excellent for use in displays.
  • Be careful not to touch the glass on halogen bulbs. This can degrade their lifespan and they can also be extremely hot within seconds of being turned on.

Heavy-Duty Battery

  • Short life and best used for low-drain applications such as remote controls and wall clocks.

Incandescent Fixture

  • Styles vary widely, but the basic purpose is to hold an incandescent light bulb. Fixtures can be mounted on a stand, on the wall or on the ceiling.
  • The basic wall or ceiling fixture mounts onto an electrical box. The most common type of box contains a threaded stud (or threaded rod) that attaches to the fixture with a part called a hickey. Or, instead of a threaded stud, the fixture may use a crossbar hanger.
  • Various styles of lights can be used for four basic purposes: task lighting (to illuminate specific areas for activities such as reading or preparing food), ambient lighting (for general illumination of a room), accent lighting (focused, directional light generally on artwork or architectural features), and utility lighting (used to flood an area with light, often outdoors or in work areas).

Fluorescent Bulbs

  • 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 low-wattage twin tube designs. The largest is 2-1/8″ used for some high-wattage, non-residential installations.
  • Produce up to 105 lumens per watt, compared with a 100-watt, type A incandescent, which produces around 18 lumens per watt.
  • Features include a 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.
  • Available in many shades of white and colors. Color is determined by the type of phosphor used in the bulb. Soft white fluorescent bulbs are recommended for living areas, baths and kitchens since they offer good color rendering. Warm white bulbs are good for living areas, although not in areas where color discrimination is important. Cool white bulbs are used for work areas.
  • Use a ballast. Dim 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. Often noise made by fluorescent fixtures can be reduced by replacing the ballast.
  • 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. Single-pin bases are used for instant start bulbs, and recessed double contact bases are used on rapid–start bulbs longer than 48″.

Rechargeable Battery

  • A commonly used type is the nickel-cadmium (NiCd) battery.
  • Nickel-metal hydride (NiMH) batteries are another alternative, and they outlast NiCd batteries by up to 40 percent.
  • Rechargeable batteries will lose their charge if not used for an extended period of time (30 to 60 days).

Fluorescent Fixture

  • Used to house fluorescent lamps, and can be rectangular or round.
  • The rapid start type has a starter (a small aluminum barrel that is a type of automatic switch) and ballast in one piece and turns on the instant the switch is flipped.
  • The starter type has a small ballast and a starter and will flicker for a moment before turning fully on.
  • The instant type turns on after a momentary pause.
  • Fluorescent lights are less expensive to operate than incandescent, and most of the parts are replaceable.


  • Some models are battery operated and are wireless. They are easiest to install.
  • If not battery operated, they require AC step-down transformers to reduce household voltage to the proper operating voltage.
  • Standard doorbells operate at 10V or 16V.


  • Provides localized light for specific activities such as reading, writing, sewing and food preparation.
  • The light should cover the entire task area and be located so shadows are reduced to a minimum.
  • Available in a wide variety of styles.

Lamp Holder

  • Used to hold light sockets where design is not a concern. Often used in garages or basements, or as a temporary fixture.
  • One type has a pull chain to turn it on. The other, a keyless lampholder, does not have a chain. Another type has a socket, two receptacles and a pull chain that turns off the lamp but not the receptacles.
  • Typically is a round porcelain fixture with a socket with prewired leads ready for connecting to a circuit. It also has screw holes for mounting it to a box.
  • Another type is the Pigtail. It is merely a socket with wire leads and without a fixture. It is also used for temporary lighting or for testing.

Compact Fluorescent Bulbs

  • CFL BulbCompact fluorescent bulbs offer different style and performance from standard fluorescent bulbs. Their color nearly equals that of Soft White incandescents, and they offer superior energy efficiency and long life.
  • 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.
  • Cannot be dimmed. Their life will be maximized if they are used in locations where a light stays on for hours at a time.
  • 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” bulbs in portable lamps.
  • Twist-shaped compact fluorescents can replace standard Type “A” bulbs in virtually any application.
  • 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 1600 lumens with a 25-watt compact fluorescent lamp that also produces 1600 lumens.

Track Lighting

  • A system of movable lights wired to a metal track that makes a great accent lighting choice for living rooms, bedrooms and dining rooms.
  • Available in many colors, sizes and shapes, is easy to install and flexible since the lights can be moved around and repositioned.

High Intensity Discharge Bulb

  • HID BulbProduces light when current flows through a conducting gas. Uses ballasts 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.
  • Used primarily 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.
  • One type is the mercury vapor lamp. These are 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.
  • 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.
  • 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, you must replace it with exactly the same type of bulb.


Voltage Tester

  • Also known as a test lamp, a circuit tester, a neon tester or a test light.
  • Consists of two insulated wire probes and a small neon light.
  • Designs vary widely.
  • Used to determine if there is electricity running through a circuit or if it is properly grounded.
  • Recommend as a basic tool for every toolbox.

Can Light

  • Also known as recessed lights.
  • Provides ambient lighting.
  • Ideal for rooms with low ceilings and can be used to supplement existing light in kitchens and bathrooms.

Continuity Tester

  • Used to determine if a wire or circuit can carry electricity from one end to the other.
  • Generally consists of two probes (one of them being an alligator clip) and an indicator light powered by a battery.
  • Can also be used to test cartridge fuses.

Landscape Fixtures

  • Designed to accent or light steps and pathways. It also serves a decorative function and is relatively easy to install. Don’t install 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 can be recessed into steps or planters to directly illuminate pathways.
  • Landscape boulders blend naturally into the environment and glow from within, casting illumination for pathways. The faux boulders contain low-voltage 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.

Receptacle Analyzer

  • Analyzes a receptacle to determine whether or not the wiring is sound, if it is grounded and if the receptacle is receiving power.

Outdoor Fixtures

  • Primarily serve a security function, but there are a wide variety of systems, 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.
  • Fixtures to be used outdoors must seal moisture and dust from wiring and switches. Fixtures with photocells provide automatic activation from dusk to dawn.
  • Spotlights or floodlights are used for security. They can also be used with a colored lend as decorative lighting. Weatherproof sockets are essential because the fixture is often mounted on the ground and pointed upward. Only install when the ground is completely dry.
  • Motion lights use sensors that activate the light when they detect heat and motion up to 40 feet away. They can attach to a power pack and mount on walls or fences 6 to 8 feet above the ground.

Fish Tape

  • Also known as a snake.
  • Used for pulling the electrical cable or wire through the wall or through electrical conduit.
  • Often comes in lengths of 25 or 50 feet, 1/2” or 3/4” wide with a hook on one end. Also comes coiled in a case.
  • Also used to probe wall cavities to determine the best path for routing a cable.

Low Voltage Lights

  • Safe for many outdoor lighting applications. 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.
  • A power pack is the heart of the low-voltage system and should be located outdoors by installing a weatherproof outlet cover to keep snow and rain out. Power packs typically range from 88-watt capacity up to 900-watt capacity.
  • May 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.

Electrical Tape

  • Most common type is plastic, usually 3/4” wide.
  • Handy for many uses. In electrical work, it is used to cover bare wires after they have been exposed.

Trouble Lights

  • Have a strict standard for safety. All lamps with metal guards must be permanently grounded to the guard. Some lamps have plastic guards that solve the grounding problem, reduce heat build-up and prevent scratching of painted surfaces.
  • Some models do not have built-in cords. These models attach to a user’s extension cord and are easy to store and convenient to use.
  • In all cases, handles must be tightly fitted to the cage and meet crush-resistance testing and heat-factor requirements.

Wire Nuts

  • Used to connect the bare ends of two wires inside a box. At least two are required at every circuit connection.
  • Available in a variety of sizes and colors.
  • Connects wires with a twisting action.


  • Available in a variety of sizes and styles. Popular features include high-intensity, adjustable spot-to-flood beams with a simple twist of the wrist.
  • Mini-flashlights operate with AA or AAA cell batteries. Standard flashlights use two 6D cell batteries.
  • Flashlights with LEDs (light emitting diodes) will last much longer than standard incandescent bulbs. LEDs do not have a filament that will burn out. Instead, they use a semiconductor material. They’ve long been used in the electronic industry, and manufacturers are new using them in consumer flashlights.

Fuse Puller

  • Used to remove cartridge-type fuses.


  • Fluorescent lamps 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.
  • Instant-start ballasts provide sufficient voltage to start fluorescent lamps without preheating and are commonly used with single-pin lamps and some special lamp types.
  • Rapid-start ballasts heat the cathodes continuously from a low-voltage transformer 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.


  • A small silver-colored cylinder found mostly in older fluorescent lamps.
  • Allows the electrodes to heat up prior to the lamp starting.
  • 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.


  • Different than cable. Cable refers to two or more wires or conductors grouped together in a jacket.
  • Copper or tinned copper is the most common conductor in home wiring because it has minimum resistance at reasonable cost.
  • Wire is grouped by gauge number, running from 0000 to No. 40. The smaller the number, the thicker the wire. For home use, the most common gauges are between 10 and 20.
  • Larger wire carries more current. Forcing too much current through a wire will cause it to overheat and trip a breaker.
  • Wire is also characterized by letters that correspond to the insulation type and electrical capacity.
  • Grounding wire provides a path of least resistance from the frame or case of an appliance to the ground to guard against electric shocks. Both two- and three-conductor cables can carry grounding wires.


  • Refers to a collection of two or more strands of wire or conductors.
  • Basically, cable has a “hot” line to carry the current and a “neutral” line to complete the loop. They often have a third wire as that acts as a grounding wire.
  • Classified according to the number of wires it contains and their size or gauge.
  • All cables are marked with a series of letters followed by a number, a dash and another number. The letters indicate the type of insulation (cord, wire and insulation). The first number indicates the resistance of the wires in the cable, and the number following the dash indicates the number of individual conductors in the cable.
  • If the designator “G” follows the series it means that the cable is also equipped with a non-current-carrying ground wire. Hence, the designator USE 12-3/G indicates an underground cable containing three separately insulated wires capable of carrying 20 amps of current plus a grounding wire.
  • The most common jackets are NM-B (Non-Metallic Building Indoor), UF-B (Underground Feed) and BX, which is flexible metallic cable.
  • Two-conductor cable contains 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 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. This three-wire circuit is increasingly common in home wiring; it accommodates major 220V appliances, such as ranges and air conditioners.
  • BX cable is armored metallic cable. It consists of two or three insulated wires individually wrapped in spiral layers of paper. The steel casing acts as a ground wire. There is also a bond wire included in the casing that acts as a ground if the casing breaks.
  • Romex® cable is a flat, beige thermoplastic jacket surrounding two or three wires. Each wire is wrapped in insulation and a spiral paper tape. Type NM means it can be used indoors. Type NMC means it can be used indoors or outdoors. Type UF means it is suitable for use underground outdoors.

Thermostat Cable

  • 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.
  • Although thermostat cable is low voltage, it carries an 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.
  • 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.

TV Wire and Accessories

  • Television lead-in wire connects the receiving set to the antenna. Good quality 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, you should be aware 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

  • Home networks connect multiple computers in the home, satellite dishes, cable TV, sophisticated audio systems and home.
  • 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, fiber-optic lines, Category 3 cables and coaxial lines.
  • Jacks are used to terminate the cable. 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.

Extension Cord

  • Indoor extension cords come in two-wire cords in lengths from 6′ to 15′. 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.
  • 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 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.
  • 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.

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 to 50 amps for dryers and 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.

Thin-Wall Conduit

  • Also known as EMT (electric metallic tubing).
  • Steel pipe used to carry house wiring in places where it is exposed.
  • Comes in inside diameters of 1/2” to 4”. 1/2” is most common.
  • Do not use underground.

Range Hood

  • Comes in many styles and is used to draw grease, heat, steam, smoke, odor and hazardous gasses away from the stove and out of the kitchen.
  • A complete system consists of a hood, a blower system and ducting.
  • Downdraft models are built into the stove of surrounding counter and are less efficient than updraft hoods.
  • Updraft hoods hang above the cooktop and easily vent air outdoors.
  • An island range hood is used for stoves that are part of cabinet islands. They are suspended from the ceiling.

Heavy-Wall Conduit

  • Also known as rigid conduit.
  • Comes in the same sizes as EMT but has thicker walls.
  • Has threaded ends for connections.
  • Use for carrying wire outdoors and underground.

Appliance Receptical

  • Used for heavy-duty plugs and appliances.
  • Contains vertical and slanted slots in various configurations.
  • Configurations are different, so make sure to bring the plug with you if you don’t know the exact configuration you need.

Plastic Conduit

  • Easy to use.
  • Use inside and outside.
  • Best for burying underground as it will not corrode with water.

Greenfield Conduit

  • Also known as flex conduit.
  • A hollow spiral metal jacket that resembles BX cable.
  • Use for installing wiring in the home.

Conduit Connectors

  • Used to connect lengths of conduit.
  • Can make straight or bent connections.
  • Conduit can also be bent to a 90º curve using a conduit bender.

LB Fitting

  • Connects at a 90º angle.
  • Has thick gaskets to make it impervious to moisture.
  • Generally, an LB fitting is placed outside at the point where the conduit leaves the house.
  • This fitting should not be used to make wire connections.

Conduit Fasteners

  • Use to fasten conduit to a wall or other framing member.
  • Staples can be used to fasten conduit or bare cable.
  • Straps are another type. They can be either one-hole or two-hole.
  • Generally, staples are best used inside the house, straps are best used outside.

Wire Channels

  • Use to fasten conduit to a wall or other framing member.
  • Staples can be used to fasten conduit or bare cable.
  • Straps are another type. They can be either one-hole or two-hole.
  • Generally, staples are best used inside the house, straps are best used outside.

Plug Fuse

  • Also known as Edison base fuse, plug-in fuse or glass fuse.
  • A safety device that breaks an electrical circuit when it is overloaded.
  • The most commonly used fuse. Available in 5- to 30-amp sizes.
  • It has a threaded base like a light bulb and a small window to view a metal linkage. Electricity flows through the linkage. When the circuit is overloaded, the linkage melts and turns black, cutting off the flow of electricity through it. The fuse then must be replaced.

Type S Fuse

  • Also known as Fustats® or Nontamperable
  • Similar in design and use to a plug fuse. However, it prevents anyone from replacing a lower-rated fuse with a higher one.
  • Has two parts: the fuse and the adapter. The adapter has a different diameter for each fuse ampere rating. Once the adapter of a particular size fuse has been inserted into the fuse socket, it cannot be removed. Only fuses with the same rating can be used in that socket.

Cartridge Fuse

  • Cartridges fuses for circuits above 60 amps are also known as knife-blade cartridges. They look like rifle cartridges with metal caps and blades sticking out of each end.
  • Cartridges fuses for circuits 60 amps or less are also known as ferrule contact or round cartridge fuses. They look like rifle cartridges with plain, capped ends.
  • Used in high-current applications, such as in the main service box and in clamp- or bar-type fuse boxes that serve electric ranges, water heaters, clothes dryers and air conditioners.
  • Unlike plug fuses, you cannot tell if the fuse is blown by merely looking at it.
  • Use a special pair of pliers known as fuse pullers to remove these fuses.

Time Delay Fuse

  • Similar in appearance to a plug fuse.
  • Provides a minimum time delay for small household motors that cause an electrical surge when started. That surge would cause a regular fuse to blow needlessly.

Extension Ladder

  • A non-self supporting type of ladder with two similar sections that are linked with internal guides on the bottom of base section and external guides on the top.
  • Sections are pulled apart to increase length.
  • Used for working in high areas and primarily for exterior applications.
  • Available in heights ranging from 16’ to 40’.
  • Smaller extension ladders are extended manually and secured with gravity spring lock brackets
  • that rest on the selected rung.
  • Larger extension ladders are extended by means of a rope and pulley running down the side of the ladder and secured with a cleat.
  • Generally available in all aluminum and fiberglass with aluminum rungs.
  • Rungs can be round or flat and are usually serrated for enhanced slip resistance.
  • Ladder shoes pivot to allow full contact with ground. Shoes can also be turned up to penetrate soft ground for extra stability.
  • Quality classifications include consumer (household), commercial (mechanic) and industrial grades.

Circuit Breaker

  • Two styles are available: Push button (less common) and toggle.
  • Breakers can be single, double or thin.
  • Contains a bi-metal strip that breaks the circuit when a current exceeds a predetermined rating.
  • A breaker indicates a broken circuit when the switch is in the mid-point, or tripped, position.
  • Reset the circuit breaker after correcting the overload problem. Switch it to the off position, then to the on position.
  • Another type of circuit breaker is a screw-in type that looks similar to a fuse, but has a button on the top. The button pops out when the circuit is broken.

Arc Fault Circuit Interrupter

  • An arc fault occurs when the insulation surrounding wire and cable is damaged or deteriorates. The arc fault can flare at temperatures in excess of 10,000ºF and ignite surrounding combustible material.
  • Standard circuit breakers do not respond quickly enough to arc faults. An arc fault circuit interrupter (AFCI) recognizes an arcing fault and acts instantly.
  • The National Electrical Code® (NEC) requires AFCIs be used in new construction on all bedroom circuits, family rooms, dining rooms, closets and hallways.

Circuit Breaker Box

  • Also called the electrical house panel or service panel.
  • A metal cabinet used to hold a series of circuit breakers.
  • Usually found near the main service entrance of the house.

Single-Pole Switch

  • Controls power to lights and devices by turning off the hot side of the circuit.
  • Mounted in an electrical box.
  • Has two brass terminal screws.
  • Controls current from one circuit from one point.

Double-Pole Switch

  • Controls power to lights and devices by turning off the hot side of the circuit.
  • Mounted in an electrical box.
  • Has four brass terminal screws

Three-Way Switch

  • Controls power to lights and devices by turning off the hot side of the circuit.
  • Mounted in an electrical box.
  • Has three brass terminal screws.
  • Controls one circuit from two separate points. For example, a light that can be turned on in either the house or garage.
  • It may also include a green grounding screw.

Four-Way Switch

  • Controls power to lights and devices by turning off the hot side of the circuit.
  • Mounted in an electrical box.
  • Has four brass terminal screws.
  • It may also include a green grounding screw.
  • Used in connection with three-way switches to control one circuit from three or more points.

Specialty Switches

  • Rocker Switch operates the same as a standard switch, but instead of a toggle, it operates with a rocker action.
  • Delayed Action Switch keeps the circuit open for a few minutesafter the switch is turned off. A good use is in a garage where, after the user turns off the switch, it allows the light to remain on in time exit.
  • Photoelectric Switch operates with a photoelectric cell. It turns off during the day and turns on during the night.
  • Motion Switch turns on the light as you enter the room. Good for both convenience and security.
  • An Illuminated Switch 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. Another version is the Pilot Light Switch.
  • An Outdoor Switch features a turning lever inside a weatherproof box cover with a toggle switch.
  • Voice-Activated Switch operates with a voice command.

Dimmer Switch

  • Controls the amount of current in a light circuit and allows for varying levels of light.
  • Usually may be installed in place of standard switches.
  • They are available in a variety of types, including rotary, toggle and slide.
  • Dimmers may also interfere with radios and TVs and cause the light bulb to hum. Some dimmers are manufactured with a filter that eases this problem.

Line Switch

  • Used to interrupt the flow of electricity on cords, most often for lamps and appliances.
  • A variety of styles are available, and they can operate with a toggle, rotary or push-button action.


  • Turn on lights and appliances at specified intervals and times.
  • Available for indoor and outdoor applications.
  • Spring-wound timers for bath fans and spas have a manual on-off switch.


  • Taps the electrical circuit to provide power at a given location.
  • Available in flush- or surface-mounted designs.
  • A single- or double-wipe contact refers to the area of the inserted prong where the contact is made.

GFCI Receptacle

  • Stands for Ground Fault Circuit Interrupter.
  • Also known as a GFI or ground fault interrupter
  • Used to protect against ground faults, which occur when a person comes into contact with a live electrical wire. This may be caused by worn insulation on a wire or by operating a faulty appliance or power tool.
  • The GFCI interrupts power quickly enough to help prevent a lethal dose of electricity.
  • To turn the GFCI back on after it trips, push the reset button located in the middle of the switch.
  • They can be installed as a receptacle or at the main power panel.


  • Connects to the power supply through the receptacle.
  • Technically, it is a male receptacle.
  • Available in polarized and non-polarized versions. In the polarized version, one blade is larger than the other to help reduce the potential for shock.
  • Three conductor plugs have three blades, one of which is a grounding pin.
  • Large appliances have plugs with specific configurations.
  • Can use to build extension cords or to replace plugs on appliances or power tools or other devices requiring a plug.


  • The opposite of a plug. It has slots or openings on the inside designed to receive male receptacles or plugs.
  • Technically known as a female receptacle.
  • Larger appliances have special configurations (often called NEMA configurations). The configuration of the slots must match the configuration of the prongs on the plug.

Table Tap

  • Also known as a plug-in strip or plug-in outlet adapter.
  • Increases the number of outlets available at a single outlet.
  • One side plugs into an outlet and the other provides two to six pairs or outlets.
  • A smaller version is the cube tap, which is in the shape of a cube and provides two or three receptacles in the place of one.

Multiple Tap

  • Like the table tap, it plugs into an existing outlet to increase the number of outlets at a location.
  • It typically has four to six plugs.
  • Some models may contain circuit breakers or surge protectors, but may not be suitable for computer equipment.

Multiple Outlet Strip

  • Also known as a surge suppressor or a power strip.
  • Achieves the same purpose of a tap, but has a cord that plugs into an outlet and a strip of outlets contained in a metal or plastic box.
  • Better models have built-in surge protectors that protect electronic equipment from sudden surges of electricity.
  • A surge protector does not protect against a lightning strike.

Socket Adapter

  • Screws into light sockets to adapt them for use as two outlets while keeping the function of a light socket.
  • Also known as a current tap or socket switch.
  • Some models have a switch or pull chain that turns off the bulb without turning off the outlets.

Plug Body

  • Adapts a light socket for use as a single outlet.

Twin Light Adapter

  • Adapts a single light socket for a double light socket.
  • Y-shaped and holds bulbs at an angle from one another.


Grounding Adapter

  • It allows you to use a plug with three prongs in a receptacle that has only two slots.
  • Cube-shaped plastic or rubber.
  • Has a small U-shaped piece that is to be attached to the screw in the middle of the receptacle.

Wall Box

  • Used for housing switches and receptacles.
  • Made of metal or plastic and have the capability to be mounted to a wall or stud.
  • The holes in the side of the box where the conduit enters the box are called knockouts. In metal boxes, conduit can also be secured to the holes.
  • Four-Inch Square and Shallow boxes are other types only 1-1/2“ or 2”deep for places too shallow to mount a standard box.
  • Handy box is surface mounted and has rounded corners for safety.
  • Drywall box has expandable arms and can be mounted on drywall.
  • Plastic box is best for new installation and often has a nail built-in for quick attachment to the stud.
  • Gem box is a commonly made box, usually 2” wide, 3”high and 2-1/2” deep and made of metal. Deeper boxes are available.

Ceiling Box

  • Also known as a junction box or splice box.
  • Used to anchor ceiling fixtures and serves as a junction box where wires can meet and run to other areas of the room.
  • They are either 4” octagonal or round shaped, and either 1-1/2” or 2-1/8” deep.
  • They also may include adjustable mounting hangers that attach to rafters in the ceiling and allow the box to be placed anywhere between.
  • Hangers also provide the short nipple or threaded rod that secures lighting fixtures.