Please check my plan for Air Compressor wiring

[misterfixit]

I just want to make sure before I do this, that I'm doing it right. I will be wiring a 5hp compressor. My plan is to run 8/2 nm-b from breaker panel to compressor on a 40amp breaker. The 8/2 will terminate in a box, but not a disconnect since I am less than 20 ft from the panel. From the compressor control box I plan to use a 10awg whip.

I think this is ok, it just seems that the 10 gauge whip should be the same size.

 

[wyliesdiesels]

If the compressor is in sight of the panel then youre good to go with no disconnect. if its not within sight of the panel, then disconnect is required.

the 8/2 NM-b is required because 10/x NM-b is NOT rated for more than 30a. The wire in the whip is THWN and thus is rated for 35a...