Wire & Cable Terminology & Applications

As one of the most fundamental components in electric projects, understanding wire and cable terminology, their uses, and differences is essential when selecting the right product for your specific application or project. With a wide range to choose from, knowing which wire or cable to choose can be a daunting task. We’ll break it down and look at the main categories of single-conductor wire, the differences between wires and cables, the basic parts of an electric cable, and more. 

Read on to better understand these two components so you can get started on your wire and cable project. 

What is the Difference Between a Wire and A Cable? 

There are key differences between wire and cable.

Wire:

• Usually smaller in diameter than cable
• Used for simpler applications, such as hooking up a light fixture or electrical outlet
• Single conductor made of a conductive material, such as copper or aluminum. 

Cable:

• Consists of multiple wires (or conductors) that are wrapped or bundled together. They are insulated and may contain other protective layers. 
• Used in more complex applications, such as transmitting high-speed data. 
• Many configurations of cable, including coaxial, multi-conductor, twisted pair.

What are the Main Categories of Single-Conductor Wire?

Two main categories of single-conductor wire are solid and stranded or braided. 

Solid: 

• Made of a single conductive wire such as aluminum or copper. 
• It is rigid and is used in applications where the wire will not be flexed. 
• Solid wire is highly efficient in conducting electricity. 

Stranded or Braided:

• Made of multiple thin wires that are twisted or braided together.
• Much more flexible and able to bend and flex repeatedly.
• Increased surface area can improve conductivity.

How Many Wires Are in a Cable?

The number of wires in a cable can vary depending on what application it is used for. For ease of classification, the number of wires in a cable is denoted by a number, such as “4-conductor,” to indicate the number of wires within the cable. Cables generally will have at least these three types of wires:

Ground Wire:

• A safety wire that directs the electrical current to the ground. It protects people and any equipment from damage due to shock or short circuits.
• This wire, in normal conditions, does not contain any current.
• Often times green or neutral/bare in color. 

Hot/Live Wire:

• The wire carries electrical current from a power source to an outlet or device.
• It can be extremely dangerous and lethal if touched or handled improperly.
• Usually colored black, red, or any other color than green or white. 

Neutral Wire:

• A wire that completes the electrical circuit and returns current to the power source. 
• Often colored white or gray. 

What Are the Basic Parts of an Electrical Cable?

The four basic parts of an electrical cable include: 

Conductor:

• The conductor carries the electrical current. 
• The two most common types of materials used in the cable are aluminum and copper.
• Copper is highly efficient at electrical conductivity. Aluminum is affordable and lighter. 

Insulation:

• Insulation covers the conductor and provides protection. It is made of a non-conductive material, such as PVC, rubber, or Teflon.

Metal Protection:

• This refers to metal armor, shielding cables to protect as well as insulate from damage. A metal shield (or screen) can increase the durability and reliability of the electrical system.
• Not all cables will have metal protection. 

Outer Sheath:

• Also known as a jacket, the outer sheath is the outermost layer of the cable that provides additional protection, insulation, and resistance to environmental concerns. 
• Generally made from polymer or plastic material. 

Common Types of Wire & Cable 

Understanding the most common types of wire and cable will help in selecting the right wire for your specific electrical project. 

Low Voltage Wire: 

• Requires less than 50 volts.
• Often used in landscape lighting, doorbells, thermostats, and other low-voltage items. 
• Low-voltage wire usually has a smaller diameter for easier installation and handling. 

Non-Metallic Cable:

• Known as NM cable, it is often found in residential and light commercial construction. 
• Used for wiring outlets, switches, and lighting circuits. 
• Easy to install and can be run through walls, ceilings, and floors without the need for conduit or other protective measures. 
• Affordable, popular, and reliable option. 

THHN/THWN Wire: 

• THHN stands for Thermoplastic High Heat-resistant Nylon-Coated.
• THWN stands for Thermoplastic Heat and Water-resistant Nylon-coated.
• THHN/THWN wire has a single conductor with different color coding and is available in a variety of gauge sizes. 
• Rated for use in dry or wet locations. 
• Commonly used in residential and commercial construction.

Underground Feeder (UF):

• A type of non-metallic cable enclosed in a moisture-resistant jacket. 
• Designed for underground applications, such as outdoor lighting, irrigation systems, and other uses that require durability within underground conditions. 
• Available in a variety of gauge sizes. 

Category Cable:

• Also known as Ethernet cable, it is a typo of twisted-pair cable used frequently in computer networking.)
• Used to connect devices to a network, such as computers, printers, routers, etc. 

Fiber Optic:

• A type of cable that uses light to transmit information. 
• Consists of thin strands of glass or plastic fibers enclosed in a protective jacket.
• Has a high bandwidth and faster data transfer than copper cable.
• Used in high-speed data communications and internet applications. 

Armored Cable:

• Also known as a metal-clad cable or MC cable, it has a metal layer or sheath covering the insulation and conductor. 
• The metal layer is made from aluminum, copper, or steel.
• Used in tunnels and other underground wiring situations, HVAC, commercial and residential applications, and situations where wiring is exposed to outdoor or harsh conditions. 
• Provides a grounding protection.

Metal-Clad Cable:

• Metal-clad (MC) cable is a type of versatile electrical cable and is used in industrial, residential, and commercial projects
• MC Cable is rated for use in dry or wet locations and is suitable for use in exposed or concealed applications. 
• MC Cable is available in a variety of conductor sizes and configurations. 

Find All Your Electric Supplies at Mars Electric

At Mars Electric we can help you with any cable or wire needs, questions or concerns. Find all your electric supplies, including specialty wiring and more here at Mars Electric. For over 70 years we’ve been your full-service electrical supply distributor and we can help with any project, big or small. Contact us today!