How to ground a compressor?
I'm setting up a 80 gallon compressor with a Baldor 5 hp motor. I'm setting it up on a dryer type plug so that I can use my welder on the same outlet. Since it's a true 220 application (ie the coil on the mag starter is 220 not 110), my understanding is that I dont need a neutral (the middle, L shaped prong on the dryer plug), just 2 hots and neutral. What's the best, safest way to ground this thing? I think a lot of guys permanently hardwire their compressor so they run their ground from the fuse box. Since I'm making mine a plug in, I have no way to ground this through the plug. Should I just drive a long rod into the ground and run a ground wire that connects the tank, motor, mag starter?
Also, since I don't need the neutral wire that comes through my plug, cord, what should I do with it?
I've heard three options: 1. since you don't need it, but a wire nut on it to cap it off. 2. Connect the neutral to the "com" tab in the magnetic starter 3. Heard one guy who simply connected it to the metal case of his magnetic starter as your would with a ground. Since the neutral is not equal to ground, I'm not sure this is right. I've heard that you shouldn't connect the neutral to ground although they are connected at the breaker box I think.