I've looked through many threads related to installing a 220V, 50A circuit for an arc welder but I haven't found the answer to my question so I decided to start a new thread.

The welder instructions refer to two black and one green wire. The outlet I purchased refers to two black and one green wire. Regardless of the wire gage I choose, I don't see readily available cable with two black and one green wire.

I'm planning to run cable with the extra neutral (white) wire to allow for future upgrade of the circuit if needed. With that in mind I find myself looking for two black, one white and one green.

The typical cable I find available in home centers and hardware stores contains various colors depending on the brand but none of them seem to have a green wire.

Is it okay to use the bare copper wire that is commonly found in these cables rather than a coated green wire? For example, one cable that's available to me consists of red/black/white/bare. Based on the information I've seen in other threads I believe the answer is yes I can use that cable.

In my case I'll leave the white disconnected on both ends for now and use it later if I change the circuit.

Thanks.