Electrical wiring in your home comprises different types of wires and cables. Understanding these differences can help you complete DIY home electrical projects safely and accurately. A wire is a conductor that moves electricity, and most of the cables in your house are insulated. The exception is ground wires, typically solid copper, either insulated with green sheathing or uninsulated (bare).
Single Conductor Wire
Most low-voltage wiring in your home — doorbells, thermostats, landscape lighting, and telephone and internet connections – is wire with a plastic insulation or cable sheath. This type of wiring can range in size from 12 to 22-gauge. Nonmetallic, or NM, wiring is the most common type of electrical wire in homes today. It contains three or more conductors (hot, neutral, and ground) wrapped in a flexible plastic sheathing. NM cable is typically labeled with its circuit information and the size of each conductor. It comes in both solid and stranded versions. Stranded wire can be routed through pipes and walls more easily and flexibly. Understanding these different types of electrical wires and cables can help you diagnose problems, make repairs, plan renovations, and stay up to code. In addition to knowing the basics, such as how wire gauge relates to amperage and cable-sheath color coding, you should also know when to hire an electrician in Salem OR.
Armored Cable
Armored cable is used where electrical wires may be exposed to mechanical hazards like rodent infestation, water ingress, or abrasion. It also protects the line from fire, a significant threat in any setting. The core, insulation, and metal sheath are the main components of a wire-armored cable. An outer protective sheath safeguards the line from UV, water ingress, and differing soil compositions. The sheath may be made of polyethylene, LSZH, PTFE, or rubber. If you are working with an armored cable, make sure that you use proper tools to avoid nicking the inner wires. For example, you should make sure to use cable cutters that are specifically designed for cutting across armored wires. To further prevent the conductors from coming into contact with one another and resulting in a short circuit, slide a plastic anti-short bushing onto them. You should also choose a sheath material that works well with the cable connectors you plan to use.
Metal-Clad Cable
It’s important to understand how each type of electrical wire works in your house, including its gauge and color (to identify a hot, neutral, and grounding wire). It will help you diagnose problems, complete repairs, plan renovations, and keep your home wiring up to code. Nonmetallic sheathed cable, commonly called NM or Romex, is the most common wire used for residential wiring today. It consists of individual wires within a sheathing designed to be installed in wall cavities. It is rated to 600 volts, with individual conductors labeled in terms of their gauge. These wires are also stranded rather than solid, which makes them easier to move through conduits.
NM Cable
If your house was built (or rewired) after about 1965, most of its electrical wiring uses a nonmetallic sheathed cable or NM. Also known as Romex, this house electrical wire has an outer plastic sheathing that protects two or three insulated conductors and a bare copper ground wire. NM comes in dual-wire and three-wire versions. The insulated wires carry electricity to and from the circuit breaker box, light fixture, or switch. In contrast, the grounding wire minimizes the fire risk by creating an easy path for the current to return to the panel during a power outage. Depending on the store, a 250-foot roll of NM cable costs about $100 at your local hardware or home improvement center.
