I feel kinda stupid asking this question, but the labeling on the outlet threw me for a loop. Its a 50 Amp 3 wire plug, the particular one I have is the Pass and Seymour 3890-CC6. This will be wired up for a temporary use on a stove that I currently do not have access to. Normally i'd wire it up with Red Black and Green since a 240volt 3 wire plug would have a ground and no neutral. I don't know if the stove has any 120volt parts on it (I am going to assume not). The back of the outlet marks the center pin as "white". I will be wiring this up with a 3 wire cable into a sub panel that has the neutral and ground separated on it, and when I do get to the point of using this next weekend I could change the bus bar the center pin connects to pretty easily. I would think that if the stove does not have any 120volt parts, that center pin should be Ground, not Neutral.
One thing I just thought of, with the center pin being flat (not U or round shaped) it should be connected to the neutral bus verses the ground bus. Would that make sense?
Below is an image of the outlet I am working with: