Types of Wiring

The Types of Wiring

There are different types of wires and each type has a different purpose. Some people think that the terms cable and wire are the same thing. However, cable refers to a bunch of wires wrapped in a sheath whereas wire is a single entity.

NM Cable

NM Cable is used inside houses in dry areas. Most of the cable in modern houses is NM cable.

UF Cable

UF stands for underground feeder. These cables are nonmetallic and used in wet locations. They can be buried in the ground.


These two wires are insulated wires and commonly used inside conduit. They’re often used in areas such as basements and garages, as well as hot water heaters and garbage disposals.

Low-Voltage Wire

Low-voltage wire is exactly what it sounds like – it is used for things requiring low voltage. For example, it is used for doorbells and thermostat wiring.

Phone/Data Wire

Again, self-explanatory. Phone and data wires are used for internet and landline connections.


T: thermoplastic
H: heat-resistant (HH is highly heat-resistant)
W: wet location
N: nylon-coated


Different color wires have different purposes. Below are the meanings:
Black: Hot wire
Blue and yellow: Hot wire
Green and copper: Grounding
Red: Hot wire
White: Neutral

Cable Size

Cable size is the size of the individual wires inside the cable. The smaller the size, the bigger the number. If ground wire is present, it is not shown in this number. It is instead written in as the letter G. The larger the wire, the greater the wire’s capacity to carry current is.

When doing work on your home, it’s important to know what type of electrical wire you’re working with. In older homes, it’s typical to see single conductor wires. Nowadays, use of multi-conductor wires is more convenient. However, you can use a combination.

Solid-core wires have the best connections but are difficult to work with when routing through conduits. Stranded wires are much easier to route.

You have to remember to check whether the wire is for indoor or outdoor use as well as how much temperature it can stand.

Purchasing wire is fairly simple. Wire comes in spools. You can purchase 50 feet or up to 500 feet, depending on your need.

Made from metal or plastic, the multi-conductor wire comes with a hot wire – or two – a grounding wire, and a neutral wire. While the hot and neutral wires are insulated, the grounding wire may or may not be. Each wire is color-coded, as explained above.

When working with wires, be sure to do your research. Ensure that you understand what you are working with and how to do it. Improperly installed wiring can not only wreak havoc, but can be dangerous. Fires start from improper use of wiring all the time. Keep in mind that electricity is no joke. You need to know your stuff before jumping into a project. There is nothing worse than putting time and effort into something and having it, literally, blow up in your face.