Dave,
I am not a registered electrician. That said, I did this type of setup with my phase converter in the garage. Basically, the converter has a pigtail with a female Hubbel twist lock plug that my lathe and mill can plug in to. I found several mating pairs of plugs at a ham radio swap meet or engine show swap meet. These have at least four conductors for the three hot legs and one ground. Dont need the neutral. If you buy the plugs from an electrical supply store they are expensive (maybe 70 dollars a pair based on amp rating). The issue is there are so many configurations of these twist locks you need to have the mate to really test them. There are sets with 4 conductors in the big box stores but the amp ratings are much lower. Depends how much power your equipment would draw. This would be something to keep an eye on.
John
