SOUTHWIRE 12/3 NM-B ROMEX WIRE WITH GROUND - 50 FTRun residential 20-amp three-conductor circuits with this 50-foot length of Southwire 12/3 NM-B non-metallic sheathed cable. The assembly carries three insulated 12 AWG solid copper conductors (black, red, white) plus a bare copper equipment ground inside a sunlight-resistant PVC outer jacket. The extra red conductor is what 3-way and 4-way switch loops need for the traveler, and what kitchen multi-wire branch circuits use to share one neutral between two 20-amp small-appliance circuits.
- 12 AWG (3 insulated conductors plus bare copper equipment ground)
- Solid annealed copper conductors per ASTM B3
- THHN/THWN-style PVC insulation on the current-carrying conductors
- Color-coded jackets: black, red, white, plus bare ground
- 20-amp ampacity at 60 deg C per NEC 334.80 / 240.4(D)
- 600V rated, sunlight-resistant PVC outer jacket
- For interior wiring in dry locations only (not for direct burial or outdoor use - see UF-B for those)
- Not approved for use inside conduit or raceway (NEC 334.15)
- UL Listed per Standard 719 for residential branch circuits per NEC Article 334
- Length: 50 Ft
Common Uses: 3-way and 4-way switch loops on 20-amp lighting circuits, kitchen and dining-area multi-wire branch circuits sharing one neutral between two 20-amp small-appliance circuits (requires handle-tied breakers per NEC 210.4), and split-receptacle outlets where top and bottom are separately switched or fed.
Install Tip: Staple within 12 inches of the box and every 4-1/2 feet thereafter (NEC 334.30). When the cable passes through a stud bore less than 1-1/4 inch from the stud face, protect it with a 1/16 inch steel nail plate so drywall screws can't pierce the jacket. 12 AWG belongs on a 20-amp breaker, never 30.