I did the same thing with no ill effects. Ran the set-up for years and will again at my new location very soon. My compressor is a 5 hp direct drive. I put a dryer plug on the cord in place of the original plug. It worked fine. You mentioned 12 gauge wire. If you plan on making the wire much longer than the stock one be careful not to go overboard on the length. Keep it short. Too long will increase resistance and cause heat build-up.

You probably already know that 12 gauge wire will carry 20 amps, so you are OK here. Dryer's are usually on 30 amp circuits with 10 guage so you should be OK here. Any meltdown would be in your 12 guage wire which I think should be OK as it will be visable.

Thanks for the feedback, I forgot to mention this model compressor doesnt come with any factory installed plug/wires at all. The customer service guy at Lowes said I would have to have one put on myself. Thanks again for this and any additional info.

I'm assuming you're planning to use just the 2 hot legs and the ground? The neutral would not be connected unless you needed 110V at the compressor.

My table saw uses 220V/240V and that's how it's wired. The neutral isn't used since there is no need for 110V at the saw.

"From what I gather HP doesnt matter too much when it comes to compressors,"
Horsepower does matter when it comes to compressors. TRUE HP that is. Peak HP is crock to fool the unsuspecting consumer. HP matters because you can only get X CFM from Y full load amps.
Another post says, "My compressor is a 5 hp direct drive." I suspect strongly that this is a 2 HP running compressor as I have never seen a true 5 HP (27 FLA) on any direct drive unit.
Your head cable should be fine.

green_valley , My "5hp" direct drive compressor (mentioned above) is a horizontally opposed twin cylinder with a direct drive 220 volt motor. 5hp is stated on the side of the machine but I take that with a grain of salt. (like most hp ratings) I need to check the amp rating on the motor for a more accurate idea of it's actual power. While it may not be a full 5hp it is a seriously powerful compressor although quite noisy.

I too just purchased the Kobalt 45 gallon compressor from Lowes. Upon getting it home I noticed it was missing a couple of pieces. Rather than loading it back up I called the 800 number on the tank to see if they would just send me the parts. They did but the also asked if I had it direct wired or plugged in and also if it is sitting on rubber pads and bolted down. Apparently they can deny you a warranty claim if you don't do those things. Now theoretically you could change your wiring if you have a problem and they send someone to your house but I just thought you'd like to know. If you ever call for anything they will ask you if you have done those things and they do take note as when I called back the second time they made sure I had it hard wired and bolted down.

I did wire it but it is not bolted, just sitting on cut up pieces of tire to absorb vibration which it helps a ton.

The other thing Kobalt will do is deny warranty for any of the compressors they didn't manufacture. What you may ask? It says Kobalt on the side right? Wrong, apparently they've had multiple manufactures and aren't warrantying compressors made less than 2 years ago.

It just cost me $95. to replace one valve plate.
both
kobalt & Lowes refused to repair comp. or pay for part.
where is the 3 yr warranty

last time i buy from Lowes or Kobalt.