Is using a 125VAC Kill-A-Watt (Power meter) on a 220VAC network possible?
The kill-a-watt unfortunately does it's own RMS conversion, and does not use a off-the-shelf power monitoring IC or anything.

Also, the controller IC is unfortunately, a epoxy-blob device, so it's not possible to easily reverse engineer it, or even determine what it is. The only IC I could look find the data sheet for in the kill-a-watt I took apart a while ago was a simple quad-op-amp (a LM2902).

Overall, I think it would probably be easier to build your own, rather then try to convert a existing kill-a-watt.

Anyways, no matter what you do, there is really no way to make the voltage readout work properly without a firmware change, so I can't see how useful even swapping some parts would be.





Note the high-quality soldering job. It was like that from the factory.









I did this tear-down a few years ago, and I've been just too lazy to actually post it anywhere.