I just purchased a 3 1/2 ton Central Air Condition unit. I was told that I need to run an 8 gage 40 amp circuit. I will have a Electrician come over and do the final hook up, what I wanted to do is mount the disconnect box and run the wire. That way I can take my time drilling the holes for the box, and line set ensuring it comes out nice and neat. This is a brand new house and I don't trust anyone anymore.
My question is... what type of wire should I buy, the run will be about 30 - 40 feet. Should it be 8-AWG 2 wire plus a ground our 3 wire plus a ground.
The disconnect box has 4 connections along top ( 2-line and 2 load) and right below a bus with 2 screws.
Like I said I just want to run the wire, mount the disconnect box, pull the wire into the disconnect box, and leave several feet at the circuit breaker box.
I did open the panel tonight and saw what I expected. For example the 50 amp range has 3 wire and a ground. The black and red are connected to the breaker, the white and copper are connected to the bus. Is that the way this 40amp circuit should be hooked up, if so which wires would be connected to what in the disconnect box.
Sorry for the long and unclear question.
Thanks in advance.