Electrical wiring is used to conduct electricity through homes and businesses to individual outlets and fixtures. There are four types of electrical wires found in most residential homes and some smaller commercial buildings:
- Triplex wire
- Main feeder wires
- Panel feed wires
- Non-metallic sheathed wire
Each type of electrical wire has a different function and consists of different materials, though most electrical wires are made of copper or aluminum (which conduct electricity) and a sheathing, or insulator which is typically made of plastic.
Triplex wire is the wire that is strung between power poles. It’s made up of three wires. Two are insulated. They carry the electricity; the third wire is a bare and acts as the neutral wire. Triplex wire is very sturdy and made to withstand foul weather conditions.
Main Feeder Wires
The main feeder wires act as connectors between the triplex wire and a house or other building. They can be strung from the power pole to the house, or might be buried underground. Main feeder wires are made of copper wire that is twisted together and insulated with a plastic coating. The wire comes in different sizes, or gauges, which determines how much electricity it can handle. Most main feeder wires are chosen to hold about 125% of the capacity expected for the building they serve.
Panel Feed Wires
These are the wires that run from the main feeder wires into a circuit breaker box or junction box inside the home or building. They are typically rated to carry 125 amps of electricity.
Non-metallic Sheathed Wires
These are the wires with which homeowners are most familiar. They run between the circuit breaker box and individual outlets and fixtures. This wiring contains two or three wires and a ground wire. The wires are sheathed in different colors of plastic, depending on their uses:
Wire encased in black sheathing conducts the electricity.
Wire encased in white sheathing acts as the neutral wire. In some cases, a white wire may be a hot wire. If so, it will be marked with black or red electrical tape to avoid confusion.
Wire encased in green sheeting is the ground wire. The ground wire may also be un-sheathed and just appear as a copper wire.
Red wire can act as a second conducting wire, or as a travellling wire for a 3-way switch