I just bought a 220v air compressor that says it runs at 22 amps.
I am hoping that someone with electrical experience can tell me if Anything is wrong with my plan for wiring it up. I wan't to make sure I do this safely.

The breaker box I'm going into has an unused 40 amp breaker already installed. I read somewhere that you can use a breaker rated up to 350% higher than your device draws. Can someone confirm this? Since I already have this breaker installed, I would like to use it if it will be safe.

I am thinking that I will use 8/2 grounded wire. I have to run it about 40'. Is this optimal gauge?

For safety I was going to add a 30 amp, 2 pole disconnect switch near the compressor.

Please give me some input/suggestions. Is there anything else I'm missing?

 

Sounds good. Links to competent answers:

http://electrical.about.com/od/wirin...twiresizes.htm

http://www.buildmyowncabin.com/elect...nd-sizing.html

Between the two, you should be golden!

Mike

 

You need to know if your breaker is wired for delta or wye. Then test to see how much voltage the wire your going to use is giving out. It could just be 120V!

 

Most breaker boxes use 2 bars of 120 VAC each, but out of phase. Tie into one and neutral and you have 120 volts. Tie into both bars (no neutral) and you have 220/240 volts. The 220 breakers jump between both bars and have 2 terminals.

Mike