With the new house construction progressing, I had my heating contractor install central air as well. The one thing that i noticed when he was done is that he wired the AC with 12-2 but tagged the wire for me to install a "20A Double Pole" breaker for my final connection. Is this right? How do I double pole a 2 conductor cable? Shouldn't it be a 12-3 instead? I'm guessing that he's trying to double up the ground to act as neutral/ground?
My electrical rough-in won't happen for at least 3 weeks and I would want him to change it now rather than have this one thing fail my rough-in later.