Dual voltage surge protection

Discussion in 'General Electronics Chat' started by Fuzzy54, Mar 24, 2011.

  1. Fuzzy54

    Thread Starter Member

    Jun 9, 2006
    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.
  2. saikat36


    Jan 28, 2009
    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.
  3. ifixit

    Well-Known Member

    Nov 20, 2008
    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?