Does the RH450/ RH750 have an auto switching power supply? What should I do when connecting in another country with different voltage?
Yes. the RH450 / RH750 has an auto-sensing switch-mode power-supply which accepts any mains voltage from 100 to 240 volts – you do not have to change settings, fuses or anything else. You just need to get the right AC plug for the country you're in.