Ok, I "acquired" a 70w Mh security light to use for my mom cab, but the wires aren't color-coded, so I'm not sure how to wire it...it has 4 wires...3 wires have white insulation, one (ground) isn't insulated...of the 3 with white insulation, one says 120v, one 277v, the other says COM...now, I would assume that this light is able to be used with European current, and I should use the 120v for positive, the "com" for negative, but I just wanted to make sure I'm right...I don't wanna blow the ballast by switching the polarity by accident...
Here's the schematics printed on the ballast & a few pics of it to give you an idea of what I'm talking about.

Schematics:


This one, the wires are, from top to bottom, COM, 120v, 277v.


A shot of the whole setup, once extracted from the case.