Need help with jointer wiring problem

Hello. I have a very basic electrical question for the gurus. I recently purchased a 220V Grizzly 0593 jointer and am now setting it up. The manual recommends a 3 prong plug for the unit (Nema L6-20 amp) and the cord comes with three wires (black , white, green for ground). Unfortunately, my electrician installed a 4 prong socket in my garage (Nema L14-30 amp). As I understand it, the fourth prong is "neutral." I want to confirm that I am not messing this up before I make that fateful move and turn on the jointer. The L14-30 plug I bought to match the socket has four terminals. One is labelled ground (no problem there). One is labeled (neutral), which I assume I don't need to connect to anything and the other two are not labeled (and I must assume they are "hot").

Two questions:

(1) The two "hot" wires that are not ground (white and black)...do they need to be attached to the two "hot" prongs in some distinct order or are they interchangeable in position?

(2) Is there a problem with using a four plug system such as this but not attaching anything to the neutral prong? Do I need to get my electrician back to switch out the socket to a three prong system or can I just install my four prong plug on the jointer without attaching anything to "neutral."?

I don't want to do this and turn on the motor and burn it out....Sorry if I'm a complete newbie when it comes to electricity...

Thanks so much in advance for any help. I really want to try out this jointer.

Rick

No, you are doing everything just fine as-is. Ignore te Neutral wire, and it makes no difference which hot is which.