I have a metal pole barn that I use as my woodworking space, along with parking the mower and a trailer I have. I currently only have one 220 outlet. I have added machines over the years and now have 4 machines that require 220, dust collector, table saw, jointer, and lathe. I only have a 100 amp box in the barn and I don't want to use all of the available spaces in the box because I would like to to maybe add some kind of air conditioning. So I would like to do the work by using only 2 or 3 circuits. I'm thinking of putting the dust collector on a circuit by itself, then adding multiple 20 amp circuits on one or two additional circuits. Only one machine would be used aside from the dust collector because its just me. Is there any reason I can't use a 20 amp circuit and string 3 or so outlets of the same circuit as long as only one 20 machine would ever be used at one time on the circuit? I bought an electrical wiring book at Lowes, but it does not address this question. Seems to me it would work fine just like multiple standard outlets. Is there a better way to do this? The barn is not insulated yet, so its wide open and easy to wire, so I want to do it myself.