Thank you, CathyO! Since I do not want my WorkCentre to go to waste in the U.S., would it be possible to convert it, for example by changing built-in power supply unit?
This is not recommended. You would need a proper power converter and I am not sure if that would even work.
I would like to use my EU-spec WorkCentre in the US by hooking it up to the 240 V dryer outlet. Is this safe given the AC frequency difference (EU: 50 Hz, US: 60 Hz)?