We had an HVAC technician come out and look at our central air outdoor unit because it was not blowing cold air. He said the wiring to the unit is black from overheating, and that we'd need to have it re-wired. I've done quite a bit of re-wiring in the house, already and consider myself at least knowledgable enough about code requirements to make safe connections. Therefore, I should be able to at least run the wire myself (even if I need to call out an electrician to make the actual connections). What I'm not sure of is what gauge wire is required for a central air unit? I could probably tell by looking at the existing wire, but I'd like to pick the appropriate wire up on my way home from work tonight. Thank you in advance for your assistance.

I was wondering if it matters putting a single 20 amp outlet on a 15 amp circuit? The outlet is for a microwave hood above our stove. I had to put an outlet in the cabinet above. The circuit is tied to our kitchen/dining room lighting/outlets. The microwave will work on a 15 or 20 amp circuit. I bought a 20 amp outlet just in case and found that the circuit is 15 amps.