I'd use stranded wire if you can get it. Likely that is all you can get.

My charts show for #6 it has a cir. mil of 26250 and a
resistance of .395 ohms / 1000'.

E=I*R - 30a * .395 * 190/1000 = 2.2v or so at 30 amps. for
#6 at 30 amps 190 feet.

Now for the facts - double it - since you have the hot wire to and back -
even you run 220 - effective the same.

So for 30 amps you get 5v drop. for 22 - 22/30 * 5v ~ 3.5v

That assumes 68 degrees - warmer will be slightly higher voltage drop.
Martin

SteveB wrote:
FACTS:

I need to run about 190' from breaker box to my shop. I have a double pole
breaker on a 200 (+ or -) v. that says 30 on each leg.

In the shop, I will be running a SP175+ 220v MIG Lincoln welder rated at 22
amps, but that only when cranked fully open. Most of the stuff is half
that. I will be running about four shop lights, radio, and a power tool or
two at any given time. My electrician buddy has suggested IIRC a #6 wire.

Does this sound adequate? Do I get the bundled wire, or use the separate
strands? How much voltage drop on that far? Is #6 marginal, or should I
slightly oversize?

Mike (my electrician) will put the right thing, but I just wanted to start
shopping and getting prices together. BTW, does anyone know what #6 copper
solid strand goes for now? There would be just about a 200' run.

I did get about 800' of 2.5" underground conduit for free, so that helped.

Steve