Build my own cabin - DIY projects

What Does 12-2 Mean?

This is the naming convention used to describe the size and quantity of conductors in a cable (commonly seen on Romex cable). The first number specifies the gauge. The second the number of current carrying conductors in the wire - but remember there's usually an extra ground wire. "12-2" means 12 gauge, two insulated current carrying wires, plus a bare ground. 12-2 wire usually has a black, white and bare ground wire. Sometimes the white is red instead for 220V circuits without neutral. In the latter case, the sheath is usually red too. 12-3 wire usually has a black, red, white and bare ground wire. 12-3 wire is used for 220V with neutral or in three-way switch applications as the traveler between the switches where you need an extra wire.


Wiring a House