Everything You Need To Know To Find The Best household distribution wire

Family Handyman

We all have a few items on our electrical to-do lists. Whether you’re putting in a light fixture, adding a ceiling fan or cutting in a receptacle, you’re going to need electrical wire. Unfortunately, the wire and cable aisle at your home center can be a pretty confusing place. If you don’t know stranded from solid or a gauge from a Romex, we’ve got you covered.

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Ahead, we’ll teach you how to identify different electrical wire types and their uses, and how to determine the size of individual wires in your home and on the store shelf. Learn about color codes and gauges, and if you’re looking for low-voltage electronics wire, we’ve got info on that too. You’ll be able to cut through the confusion, get exactly what you need and ensure that your wiring is safe.

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Electrical Wire vs. Electrical Cable

People often use these electrical terms interchangeably, but there’s a difference:

• A cable assembles two or more wires in a single jacket.
• Wires are the individual insulated or bare conductors inside the jacket.

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Wire Gauge

Wires come in different sizes/gauges to work with the amperage of the circuit in which they’re used. It’s counterintuitive, but the larger the number, the smaller the wire.

The most common work gauge sizes you’ll find in residential work are 14-gauge and 12-gauge. Larger appliances such as electric stoves, electric water heaters, electric dryers and central air units will often use 10-, 8- or even 6-gauge wire.

If you’re adding an outlet, you need to use wire that’s the same gauge as the existing wiring. How do you tell your old wiring gauge? Here’s a simple visual using your pocket change.

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Cable by the Numbers

An electrical cable is classified by two numbers separated by a hyphen, such as 14-2. The first number denotes the conductor’s gauge; the second denotes the number of conductors inside the cable.

For instance, 14-2 has two 14-gauge conductors: a hot and a neutral. This cable also contains a bare copper wire as the ground. Individual conductors are also color-coded, which tells you their purpose in the circuit.

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Outer Sheath Color Coding

The color of a cable’s outer sheath tells you the gauge of the wire inside the sheath as well as the amperage rating for the circuit.

WHITE = 14-gauge wire, 15-amp circuit

YELLOW = 12-gauge wire, 20-amp circuit

ORANGE = 10-gauge wire, 30-amp circuit

BLACK = 8- or 6-gauge wire, 45- or 60-amp circuits. Check sheath labeling for gauge and circuit specifics.

GRAY = Underground cable. Since all UF (underground feeder) cable is gray, check the sheath labeling for gauge and circuit specifics.

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Not All Cable Is Color-Coded

Cable-sheath color coding started in and is still voluntary. If you have older wiring, don’t assume it complies with the current color coding. However, most manufacturers now follow the standard color code.

Wiring problems and mistakes are all too common, and if left uncorrected have the potential to cause short circuits, shocks and even fires. Planning to buy smart devices? Here’s what you need to know about smart home wiring.

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Wire Color Coding

This code is standard for all conductors. The colors you’re most likely to find in your home are the following:

BLACK (OR RED) = HOT. Hot wires carry current from the panel to the device, which could be a switch, receptacle, light fixture or appliance. There are other colors for hot wires, but they’re much less common.

WHITE = NEUTRAL. Neutral wires carry the current back to the panel, completing the circuit.

BARE (OR GREEN) = GROUND. In the event of a ground fault, the equipment grounding conductor, aka ground wire, provides a path for the fault current to return to the panel, opening the breaker or blowing the fuse and cutting off the flow of electricity.

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NM-B – Nonmetallic Cable

This is the most common type of electrical cable in homes built since the mid-’60s. “Nonmetallic” simply means that the outer jacket is not metal. It’s often referred to as Romex, which is a brand name. Typically, NM-B cable has either two conductors and a ground, or three conductors and a ground. The conductors are individually insulated, wrapped in paper and sheathed in plastic. Ground wires are either bare copper or insulated in green.

14-2 Used for general lighting and receptacle circuits. 15-amp circuit maximum.

14-3 Used for three-way switches and split receptacle circuits. 15-amp circuit maximum.

12-2 Used for 20-amp kitchen, bathroom, laundry and garage receptacles; 230-volt heating circuits up to 3,700 watts; and 115-volt circuits up to 1,800 watts. Can be used anywhere in place of 14-2.

12-3 Same uses as 12-2, with the addition of three-way switches and split receptacle circuits.

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UF – Underground Feeder Cable

UF is used primarily to bring power to detached garages, outbuildings or outdoor lighting. The insulated conductors are molded into the sheathing. Depending on the situation, UF is either direct-buried or run in conduit. It must be protected from physical damage by conduit where it exits the ground and is exposed. Understand wiring color codes so you can finish the job safely.

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MC – Metal-Clad Cable

MC cable is common in unfinished areas where the cable would otherwise be exposed and subject to physical damage. It’s also sometimes used inside walls. A bare aluminum wire is in continuous contact with the metal sheathing. The combination of aluminum wire, sheathing and metal boxes grounds the circuit.

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Stranded Wire vs. Solid

Stranded wire is more flexible than solid. If you’re pulling wire through conduit, stranded wire makes it easier to get around corners and bends in the conduit. However, if the situation requires pushing wires through a conduit, you’ll want to use solid wire.

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Common Specialty Cables for Low-Voltage Wiring 9

• Landscape lighting cable
  • This is used for low-voltage outdoor lighting for landscaping, accent or security lighting. It’s approved for outdoor use, suitable for direct burial and is sunlight resistant.

• Thermostat cable
  • This is used for thermostat wiring and other similar types of control wiring. It’s available in lots of sizes and configurations. It’s also used for doorbell wiring. This cable is approved for in-wall use. It will often be labeled as Type CL2 (Class 2 Circuits).

• Audio cable
  • This is a power-limited circuit and communications cable for whole-house audio systems. It’s approved for in-wall use. It will often be labeled as Type CL2 (Class 2 Circuits) or CM (Communication Circuits).

• Security system cable
  • Similar to an audio cable, it’s a power-limited circuit cable intended for whole-house security systems. It’s approved for in-wall use. It will often be labeled as Type CL2 (Class 2 Circuits), Type CL3 (Class 3 Circuits), CMR (Communication Riser), or Type FPLR (Fire Power Limited Riser). It’s a multipurpose low-voltage cable.

Family Handyman

• Speaker wire

• • This is the transparent wire we use for connecting speakers and woofers to our audio equipment or audio system wall jacks. Beware: This type of speaker wire is NOT approved for in-wall use.

• Computer network cable
  • CAT 5E and CAT 6 computer network cables are used for high-speed data transmission for computers, modems, routers, printers and similar equipment connected to a data network. These ethernet cables are approved for in-wall use. They do not come from the factory with pre-installed connectors. This type of cable needs to be terminated at wall jacks or crimped connectors. These cables contain the familiar grouping of four twisted pairs of wires. They will often be labeled as Type CM (Communication), Type CMR (Communication Riser), or CMP (Communication Plenum). Lots of types and configurations are available. Beware: Ethernet cables with pre-assembled, factory-installed connectors are usually not rated for in-wall use. They’re intended for interconnecting computer equipment in a room, not permanently installed inside walls, floors, and ceilings.

• Coaxial cable
  • This is often referred to as “RG6″ cable. It’s used for video signals, closed-circuit TV and broadband internet access. Approved for in-wall use, this cable usually has several layers of shielding to eliminate electronic interference from nearby electrical sources. It’s often labeled as Type CM (Communication), CL2 (Class 2 Circuits) or Type CATV.

• cable
  • Yes, in the modern era of cellphones you can still buy cable for installing landline phones. This type of cable is approved for in-wall use. The round cable consists of four 24 AWG wires. It’s typically labeled as Type CM (Communication) and is not a substitute for ethernet cable.

FAQ

Is it safe to work on electrical wiring in my home?

It depends. If you work safely, and don’t overestimate your skill level, DIY electrical work can be very rewarding. It can also save you money. Putting in a light fixture or swapping out a receptacle are good places to start, but assess your comfort level before moving on to more extensive projects. Always call a licensed electrician if you need help.

What steps should I always take before attempting any electrical work?

Turn off the power at the breaker. Use a non-contact voltage tester or multimeter to verify the power is off to all conductors in the electrical box. If your project needs a permit, get the necessary approvals and inspections.

Armor-Clad (AC) Cable: AC cable includes THHN-insulated conductors with 16-gauge aluminum bond wire placed inside the armor to act as a grounding conductor.

Automotive Cable: This is a general-purpose thermoplastic (GPT) wire, also referred to as primary wire. Normal applications are within motor vehicles with limited exposure to fluids, physical wear and abuse.

Want more information on household distribution wire? Feel free to contact us.

Bayonet Neill-Concelman (BNC) Cable: BNC cables are small, quick-connect/disconnect radio frequency connectors used for coaxial cables.

Category Cable: This is used for systems and data networking systems. Cat 5e is the most common variety of category cable that’s used for computer networking on internet service installations. The conductor pairs are twisted together to prevent cross-talk and interference from other paired conductors in the cable, as well as external interference. The higher the megahertz (MHz) capability, the more twists per foot.

Coaxial Cable: This is a metallic cable that carries television and video signals. It connects to video equipment and features a central conductor with a dielectric insulator, metallic shield and plastic jacket.

Doorbell Wire: Doorbell wire is used to connect a wired doorbell or video doorbell to a home’s electrical system. 18-gauge wire is the variety most often used.

Dual Armored Cable: This is a durable cable that offers protection without employing electrical conduit, elbows, offsets (which can be expensive) or conduit couplings. For areas where the cable may be exposed to moisture, metal-clad armor prevents corrosion. 

Flexible Cord: Typically used for industrial machinery, washing machines and large appliances, portable tools, equipment, and extension or power cords, flexible/power cord has its own naming convention based on a letter code, with a common option being SJEOOW.

• S: service cord (when not followed by a J, V or P; also indicates a rating of 600 volts)
• J: junior service cord, 300 volts
• T: thermoplastic
• E: elastomer, thermoplastic that looks and feels like rubber
• O: oil-resistant outer jacket
• OO: oil-resistant outer jacket and oil-resistant insulation
• P: parallel cord (light duty, flat)
• V: vacuum cleaner cord (light duty, round)
• W: sunlight- and moisture-resistant

Lamp Cord: Used with lamps, small appliances, radios and other similar products that don’t exceed 300 volts, lamp cord is available between 18- and 12-gauge sizes in a variety of colors. 

Landscape Lighting Low-Voltage (LV) Cable: This underground cable is suitable for outdoor accent lighting, landscape lighting and security lighting. Applications shouldn’t exceed 150 volts. It’s used for direct burial, is suitable for sunlight and is available between 16- and 8-gauge sizes.

Metal-Clad (MC) Cable: MC cable is used heavily in commercial electrical work, for running through concrete or in other commercial environments. Individual THHN wire conductors are run through an aluminum interlocked armor. It includes a grounding wire.

Mobile Home Feeder: This connects a mobile home to a supply of electricity where permanent wiring is required, and it’s suitable for direct burial and underground service entrance cable. It includes four RHH or RHW-2 conductors, with a white stripe for neutral and a green ground conductor. It’s sunlight-resistant.

Network and Data Cable: This comes in three types — fiber-optic, twisted-pair and coaxial cable — and is used to connect multiple networking devices or computers in a network.

NM-B: This is a non-metallic sheathed cable that’s used as a residential building wire for branch circuits for outlets, lighting and other residential applications. NM-B is available between 14 AWG and 6 AWG with two or three conductors.

Preassembled Whips: These are pre-cut lengths of armored cable designed to increase jobsite productivity. Assembly comes with pre-stripped THHN conductors and pre-installed zinc die-cast, snap-in fittings.

Residential Grounding Wire: This is bare copper wire that’s available in 4-, 6- and 8-gauge solid and stranded construction. It’s used to ground the residential electrical system, usually at the meter before it enters the dwelling. It’s also used for grounding the perimeter surface around pools.

Service Entrance Cable: This includes individual conductors rated XHHW-2 or THHN/THWN and feeds power from a main breaker to a subpanel. It can be exposed to direct sunlight and used in wet or dry locations.

• SE-R: Twisted together with a bare ground, SE-R is used to bring service from the panel to other panels in multiple-unit dwellings and in SE-U purposes.
• SE-U: Bare conductor strands are helically wound about the two paralleled insulated conductors. It’s used for single-family residential buildings to convey power from the service drop to the meter base and from the meter base to the distribution panel board.

Speaker Wire: Made of copper and designed to transport a low-voltage electrical current, speaker wire has a variety of wiring uses, including doorbells, thermostats, home security sensors, landscape lighting and other low-current systems. 

Sprinkler Wire: Multi-conductor sprinkler wire is suitable for direct burial on applications up to 30 volts. It’s used in central controls for underground sprinkler systems and is available in 18-gauge construction with up to 25 conductors.

Submersible Pump Cable: This includes THWN copper conductors that are heat-, moisture-, oil- and gasoline-resistant. It’s suitable for temperatures below 75 degrees Celsius with two or three conductors. It’s used for power and circuits for submersible pump systems.

Thermostat Wire: Used in heating and air conditioning systems, along with bell and alarm systems, thermostat wire is available in 20- or 18-gauge sizes with up to 10 conductors.

Underground (UF-B) Wire: A copper wire used for underground purposes, including direct burial, it comes in a gray jacket and can be used for deck lighting, outdoor water features, landscape lighting and air conditioner compressors.

Underground Residential Distribution (URD) Cable: Used for secondary distribution and underground service applications at 600 volts or less, it’s suitable for direct burial or placement in ducts. It’s acceptable in wet locations in triplex or quadruplex. Conductors are stranded, compressed aluminum. The neutral conductor has a yellow, triple-extruded stripe.

When completing an electrical project, it’s important to have the right tools and safety equipment to get the job done. Check out some of the most common tools for an electricians tool box.

Boxes and Covers: These are used to house outlets and adapters for operating lights, ceiling fans, kitchen appliances, etc.

Circuit Breakers and Fuses: These are two devices for preventing an electrical current from causing damage by overloading or shorting a circuit. Breakers and fuses interrupt the current during an overload or short and are housed in a breaker box or fuse box. Homes built after the s typically use circuit breakers rather than fuses.

Electrical Tape: Used for repairing electrical cords or insulating a wire, electrical tape is typically black. It can be used to identify wires and should be stretched as you apply it for better adherence.

Electrical Testers: Checking a circuit to make sure it isn’t live can be a life-saving decision. An electrical tester will quickly inform you if you’re working with live cables or not.

Outlets and Adapters: When wires are connected to an outlet or adapter, it allows the electrical current to power anything plugged into it, such as a kitchen appliance.

Plugs and Connectors: These are usually run from an appliance or a power cord and are plugged into an outlet on the wall. They allow an appliance to receive power from an outlet.

Wire Connectors: These connect two wires together with a connector: The exposed end of each wire is put into the connector and twisted so that they’re connected. Check out our DIY Basics video: How Do I Connect Two Wires?

Wire/Cable Cutters: This tool is used to cut directly through wire and cable. There are a variety of cutters for different jobs, so check that you’re using the appropriate one, whether you’re cutting through copper wire or a network cable.

Wire Strippers: This device removes the plastic casing to expose the bare wire underneath. Most strippers offer multiple slots for a variety of wire sizes, while some have an adjustment dial to set the correct size. Simply insert a wire into the correct sized slot, twist and pull it through.

Contact us to discuss your requirements of Photovoltaic Wire. Our experienced sales team can help you identify the options that best suit your needs.