Updated January 18, 2024

In the modern world, we rely heavily on electricity. At home, we run computers, TVs, washers, dryers, refrigerators, and other appliances every day. All these things are possible because of the many wires and cables that are going through our walls. These wires and cables carry the electricity to where we need it and help us live our daily lives. In this guide, we will be going over the eight main types of electrical wires and cables commonly found in residential homes. It is important to allow a trained electrician to do the wiring in your home to prevent injury and fires from occurring.

What Are Electrical Wires and Cables?

Before we get into the different types of wiring, we must know what they consist of and what they do. Electrical wires are usually made from either copper or aluminum, both of which conduct electricity. Nonconductive plastic coatings insulate these. A cable consists of more than one wire housed together in a plastic coating/sheath, whereas a wire is a single unit. There are several types commonly found in your home.

Nonmetallic (NM) Cables

Nonmetallic, or NM, cables are the most commonly found cables in modern homes, especially in drier locations. They are made up of three different types of wiring held together in a single sheath: one or more current-carrying wires, a neutral wire, and a ground wire. You can use these for all your outlets, fixtures, and light switches. They are often color-coded to tell the difference between gauges and amps used. They are usually flat and tubular in shape and run all through your walls.

Armored Cables

Armored cables (AC), also called BX wiring, are sometimes used when local codes prevent the use of NM cables. Flexible metal sheathes these wires, providing better protection, and they have been used since the early 1900s. However, buildings higher than three floors cannot use them, and they are also more expensive.

Metal-Clad Cables

A common type of wiring found in the basement and other exposed or unfinished places in your home is the metal-clad cable or MC cable. These are also housed in metal and are sturdier than NM cables.


THHN or THWN wires are some of the most common insulated wires found inside your home. They are often used for shorter circuits, such as for your water heater or garbage disposal. They are also found in your basement as well as your garage. The letters stand for “thermoplastic heat-resistant nylon-coated.” And the “W” means it is safe to use in wet locations. The nylon-coating offers the wire extra protection. There are three wires that work together: a hot wire, which is black, orange, or red; a neutral wire, which is white or brown; and a ground wire, which is green or yellow-green. Since these wires are part of a circuit, when the circuit is turned on, touching these wires is dangerous.

Underground Feeder Cables

Underground feeder cables, or UF cables, are often used to bring electricity outside to garages or sheds that are not attached to your house. They are also used for outdoor lighting, such as lampposts. These cables are also sheathed in plastic like the NM cables; however, they also have a plastic coating on each of the three individual wires within the cable as well. This helps add extra protection from moisture and sunlight and being underground. The outer sheath is usually gray. These cables are also often used for major circuit wiring, so they are very dangerous to touch when the circuit is on because of their high voltage.

Low-Voltage Wires

Low-voltage wires are often used for smaller circuits that only require up to 50 volts. You will often find them in things like doorbells, landscape lighting, thermostats, speaker systems, and sprinkler systems. These wires are often insulated or twisted together in pairs, like a lamp cord. Since they do have a lower voltage, it is less likely to cause a shock, but it is still a good idea to shut them off before working on them.

Landline Phones and Data Wires

If you still have a landline phone, chances are it has a Cat 5 cable. These are also used for your wired internet service. These cables generally have eight wires housed in them, combined into four pairs, which provides great capacity and quality for data transmission. These are also low-voltage; however, it is good to not touch bare wires regardless of voltage.

Coaxial Cables

Coaxial used to be more common, but nowadays things like HDMI are slowly replacing them. They are, however, still sometimes used for hooking up your television to your cable or satellite service and internet. They are round and consist of a copper conductor wire surrounded by a tubular insulated layer and a conducting shield comprised of braided wire, which is sheathed, or jacketed, in a cable.

Wire and Cable Identification

You can identify different wires and cables by size and color. The gauge measures the size of a wire and tells you how much electricity it conducts. The most common gauges you will find in your home range from two-gauge to 14-gauge. Bigger wires have smaller gauges and can conduct more electricity. Wires are often color-coded to help you and your electrician more easily identify them. Black and red are usually “hot” wires that conduct electricity to your outlets and switches. Blue and yellow are “travel wires” that control things like fans, appliances, lights, and switches. White and gray are often neutral wires that help the electrical current circulate. Green or copper wires are grounding wires, making an electrical fire less likely to occur.

Electrical Safety in Your Home

If you look at an outlet in your bathroom or kitchen, you will often find red and black buttons in between the two plug-ins. These are GFCI, which stands for “ground fault circuit interrupter.” These help prevent severe electrical shocks and burns by shutting off your power before they can give off fatal doses of electricity. They can also help prevent and mitigate electrical fires. Your electrician can install these on your outlets or on a power cord.

Always check to make sure your exposed cords, wires, and cables are not damaged. If you notice any fraying or cracks, call us, and we will send an expert electrician to inspect them. Scheduling routine maintenance is an important way to prevent fires and other damage from occurring.

Your Trusted Electricians in Grimes, Iowa

At Golden Rule, we have been serving our customers in Grimes, Iowa for over 20 years. Besides electrical services, we also offer HVAC and plumbing services. We have over 50 vehicles and many licensed and highly trained electricians, HVAC technicians, and plumbers at your service. We are family-owned and offer all our customers a 100% satisfaction guarantee. We strive to treat you the way we want to be treated and provide fast, personal, and efficient service. Contact Golden Rule for more information about electrical wiring in Des Moines, IA today!

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