The blade that's keeping you from fitting it into
a USA 15A
120V outlet
should be the neutral.
Sorry I wasn't clear, my custom-made A/C line has a
box with two duplex outlets that match the line cord.
And thanks to everyone who chimed in, it turns
out my cord is wired correctly to the PSU.
And the line tester from Radio Shack says the line
is correct and not reversed and properly grounded.
Gott be something else...
-dq