I have a device that is required to be capable of being powered off the U.S. 110V or the Euro 230V, what is the best way to provide surge protection for such a device, I will be running about 13amps.

 

Use MOV (Metal Oxide Varistor). This device looks like disc capacitor & non-polar. Use 1pc of each btw L-N, N-G, L-G above atleast 300V ratings.

 

hi Fuzzy54,

Does that device automatically adapt to the change in line voltage, or do you have to toggle a switch to change voltage ranges?

If it is automatic then you don't need to protect the lower (US) range, just protect the higher 230V range. Allow for 10% high line voltage and calculate the peak value. 230 x 1.10 x 1.414 = 357 Vac. Select a MOV for a voltage just above this. Better still, use a part that is made just for this application.

If the device is switch selectable, then each circuit will require a different MOV voltage rating.

Calculating the energy rating is a little more challenging. Basicly, the MOV needs to be big enough to blow a fuse, or trip a breaker if the surge has enough energy. How is the equipment fused?

Regards,
Ifixit