> You will need 12/2 for a 240 - volt receptacle. > 12/2 cable means it contains 3 wires - hot (black), > neutral (white) and > ground (bare or green). Read what's stamped on the cable > covering. I just looked. All my 12-2 cable with a ground says 12/2 G I have some 16-2 (no G) that does not have a ground, but it is old wiring we removed.