@hrnieto, thanks for reaching out. We have a handful of users in countries across the world. Many of them had to source local power adaptors/convertors that satisfied the electric requirements of the Iro, however I haven't heard of any issues related to the clock running fast. I'd assume this is due to 1) the power adaptor limiting the voltage/Hz going into the Iro to 50Hz, and 2) the Iro's logic is clouded based -- therefore the clock in the Iro is only used if the controller looses WiFi connectivity and needs to run the backup schedule saved on the hardware.
I hope this helps. Maybe some other international users can confirm their experience using the Iro with a local power adaptors/convertors.