Common Types of Electrical Wiring Used In Homes

Your home is wired with different types of wire. Each has its specific use to accommodate the load and conditions it is exposed to. Let’s examine what each type is and how it is used in the home’s electrical system.

1. Triplex Wire

Triplex is an aerial cable that the utility company uses to feed the power pole. This wire ties to the wires sticking out of the weather head.

2. Main Feeder Wires
These wires are usually type THHN wire and are rated for 125% of the load required. These are usually black insulated wires coming out of the service weather head.




3. Panel Feed Wires
These wires are also type THHN, like the main feeders. A typical 100-amp service would have a #2 THHN set of wires. They would then be rated at 125 amps. This would protect the wires if the amperage was a full 100 amps.




4. Non-Metallic Sheathed Wire (NM)

This wire, commonly called Romex, is a plastic coated wire that has either two or three conductors and a bare ground wire. This is the typical wiring used in most homes. The rating for this wire is either 15 amps, 20 amps, or 30 amps, depending on the installation.

5. Single Strand Wire

When you home is piped, you’ll have to have another type of wire. Single strand wire is insulated and many of these can be pulled into the same pipe. Normally, you’ll be using THHN wire for this installation.