Playing with two-lug 220v current today. (Wiring in an RV receptacle.)
This kind of thing makes me nervous as hell. It doesn't help that the last time I did this a pair of actual certified electricians (my daughter and a friend) helped me – and they were nervous as hell.
And this time I'm doing it on my own…
Update: Finished the job today, without killing myself or burning down the garage.
Still was nervous as hell doing it, especially given it's pouring down rain today. But I have 50 amp 200v to the RV and everything works. On to the next project.