What Type of Cable Actually Carries Electricity?

Understanding Electrical Wires in Your Home

When you think of electricity, you might imagine sparks, outlets, or even power poles — but behind it all is one key player: the electrical cable. Whether you’re a homeowner trying to understand your home’s wiring, or just curious, knowing what cable represents electricity is a great way to stay informed and safe.

🔌 So, What Cable Does Carry Electricity?

In homes and buildings, electrical cables are the main highways for electricity. These are typically made of copper or aluminum conductors, wrapped in insulation to keep the current controlled and safe. But not all cables are created equal — here are the most common types you might see:

🏠 1. Romex (NM Cable)

Best known for: Residential indoor wiring

“NM” stands for Non-Metallic sheath.

Found in walls, ceilings, and basements.

Comes with multiple wires inside (hot, neutral, ground).

You’ve likely seen it: a flat white or yellow sheathed cable.

🧱 2. UF Cable (Underground Feeder)

Used for: Outdoor or underground installations

Similar to Romex but with tougher, water-resistant insulation.

Ideal for wiring to sheds, garages, or landscape lighting.

🔧 3. THHN/THWN Wires

Used in: Conduits, commercial, and industrial work

Single, color-coded wires — often run inside metal or PVC conduits.

Very common in new construction and panel wiring.

THHN = Thermoplastic High Heat-resistant Nylon-coated

🧠 Cable Color Code Breakdown

Wires inside these cables are color-coded for safety and function:

Black or Red: “Hot” wires – carry electricity from the source.

White: Neutral – completes the circuit.

Green or Bare Copper: Ground – for safety, routes excess energy.

Knowing this can help you recognize potential hazards if you ever open an outlet or see exposed wiring.

⚠️ Important Note: Don’t DIY If You’re Not Sure

Even if you understand cable types, handling live wires can be dangerous. Always turn off power at the breaker and use a voltage tester — or better yet, call a licensed electrician for anything beyond changing a light fixture.

🧯 Bonus: What Cable Should Never Be Used Indoors?

Extension cords and outdoor-rated wires like SE cable are not made for in-wall installations. Using the wrong type of cable can cause overheating, fires, or code violations.

Final Thoughts

Cables are the silent workers behind every outlet, light switch, and appliance. Knowing which cable types carry electricity helps you understand your home better, speak clearly with your electrician, and avoid costly mistakes.