Installing a 220 volt circuit/outlet

[s55808]

I'm working on putting in a new 220 volt circuit to feed a single outlet in my workshop. As I understand it, I'm supposed to use 4 lead (black/white/red/bare) 10 or 12 ga wire (20 amp breaker). In the circuit panel I'm supposed to wire both black and red leads to the two pole 20 amp circuit breaker, and white and bare leads to the common grounding strip.

My question is, where does the fourth wire go in the outlet box? According to the installation instructions on the outlet (Eagle Electric 20 amp 250 volt locking connector with three leads) I'm supposed to connect the bare wire to one (green fitting), the white wire to another ("W" fitting) and the black or red wire to the third (X fitting). Where does the remaining black/red wire connect?

Can anybody give me a hand on this one?

[kliot]

The black and red wires are the 110 hot legs that connect to the breakers, the white wire is the neutral that connects to the isolated grounding strip on the sub panel and the bare or green wire is the ground that connects to the box itself. The neutral and ground wire only share the same bar in the main panel after that they must be kept separate.

Hope this helps.

Perrin