Vid,
Clay's guide says that the ribbed conductor is the hot wire:
"The hot wire on the power cord should have "lines" molded into the insulation (as today's power cords are all polarized)."
http://www.pinrepair.com/restore/index3.htm#power
But you say the ribbed conductor is the neutral wire:
Quoted from vid1900:Just like any lamp cord in your house, 3-conductor power cords that don't have color coding have Ribbing to show the Neutral conductor.
Who's right, before I get electrocuted?