Hmm. And as anybody old enough to have grown up on "Emergency!" (and to
remember a rescue involving a worker caught in a vinyl record press), if
you reverse any two of the three hot wires on a 3-phase motor, you
reverse the direction of rotation.
Which caused a rather amusing malfunction at the International Printing
Museum, where I spend my Saturdays docenting: our Heidelberg cylinder
press was not feeding paper, and we eventually realized it was running
backwards, because somebody working on the wiring had gotten two wires
switched. Thank God it wasn't the Heidelberg Windmill: you run those
backwards more than 1 or 2 degrees, and they shred themselves.
--
James H. H. Lampert
