Any electricians on the board?

I have an electrician question that hopefully someone can help with. I installed the 220v outlet pictured below. I wired the red and black to the sides. Does the white or the bare copper go to the ground?
Four wires and three screws on the back.
Below are pictures of the outlet and the sub panel. I’m referring to the 20a side.

 

paging @Sixthelement

 

White = neutral = not connected
You did not need a 4 conductor bundle for that outlet

Full disclosure: engineer not electrician

 

The above post is correct. What did you connect the neutral to at the outlet? What gauge wire did you use? What are using the plug for?

Also not an electrician but an old guy.

 

10 gauge wire for a 5’ run from the sub panel
Connected hot/hot/ground
Looks like I got it right.

Thanks all!

 

If I remember correctly, with sub panels you need to NOT bond the neutral to the ground. Your not in there, but something to keep in mind. HVAC not electrician

 

I believe you're NEC correct - keep neutral and ground separated

 

I can't tell exactly from the photo. But the neutral bus does not seem to be bonded to the box or ground.