I have the same concern as the original poster. I'd like to use my Mac Mini, bought in the US, in Germany.
The Mac Mini is marked as accepting voltages up to 240V. I would happily use a plug adapter with the original US cord, but I hesitate because the electrical cord is labeled as being rated for 120V. I'm not sure if this rating refers simply to the US-style plug, or whether it has implications for the wire gauge of the cable.
Am I right in thinking that the Mac Mini will draw the same amount of current whether it is connected to 120V or 220V (the German standard)? Or does applying a higher voltage mean that the cable will have to carry a greater current?
A cable that is designed to carry more current would have a thicker wire gauge spec in order to avoid overheating from the resistance in the wire. The required gauge in a given case is also related to the length of the cable.
I'm pretty sure that I can use the US cable with a plug adapter without any worries because the computer will draw the same amount of current regardless of voltage. The power supply inside the Mini regulates this. I think. But I'm not 100% sure. If anyone has any thoughts about this, I'd be grateful to hear.