I Just want to post about the argument between the thread OP, and User friendly.

He is talking about digital ballasts... they are something new and special.

The only thing you need to convert a digital ballast from 120v to 240 or vice versa is the manufacturers 240 volt or 120volt power cord, you just swap it out.. that simple...

90% of digis have a microprossers (sorry cant spell) that knows when the power has been switched...

but you still need the different power cord sold by the manufacturer....

Check it out on most any website that sells digi ballast...

or check out lumatek.com

it is all described there, and no Opening the case to resolder anything...

GG