How to find the right Electrical Wire AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Electrical Wire
- Gauge vs. breaker
- Copper: 14 AWG on 15A, 12 AWG on 20A, 10 AWG on 30A circuits Undersized wire on a larger breaker can overheat before the breaker trips.
- Cable type for location
- NM-B for dry interior walls; UF-B for direct burial or wet locations; THHN/THWN individual conductors inside conduit NM-B jacketing is not rated for wet locations or burial.
- Conductor count
- '/2' means two insulated conductors plus ground; '/3' adds a red conductor for 3-way switches or 120/240V circuits Buying /2 when you need /3 means pulling the run again.
- Conductor material
- Solid copper for branch circuits Small-gauge aluminum and copper-clad aluminum have termination and heat problems in standard devices.
- Long runs
- Upsize one gauge on very long runs to limit voltage drop Voltage drop dims lights and stresses motors at the far end.
Brands that matter
- Southwire: Makes Romex, the most common NM-B cable.
- Cerrowire: A major NM-B and UF-B maker with wide availability.
- Encore Wire: A large US maker of building wire and THHN.
- Coleman Cable: Southwire-owned, also strong in cords.
What to avoid
- Copper-clad aluminum (CCA) sold as building wire
- Lamp cord, speaker wire or extension cords used as permanent wiring
- NM-B run outdoors, underground or in conduit in wet locations
- Using 14 AWG on a 20A circuit
Questions
Is 'Romex' a type of wire?
It's Southwire's brand name for NM-B cable. Any listed NM-B of the same gauge and conductor count is equivalent.