Example of protectors for short duration transients:
http://www.keison.co.uk/furse/furse06.htm
http://www.keison.co.uk/furse/pdf/ma...lies/m2_m4.pdf
In each case, a short and dedicated earthing connection is essential
for proper operation. A dedicated earthing wire that must be even
separated from other wires so as to not induce transients onto those
other wires.

Overvoltage protectors, such as a UPS, only provide that function if
specifically stated. Most plug-in UPSes do not. Numerical
specifications must state, specifically, an operational voltage well
above 265 VAC. Most UPSes simply connect AC mains directly to the
computer; for example, would not protect from 280 volts. Any 230 volt
appliance will work just fine if voltage rises as high as 265.
Overvoltage protector state, with numbers, operation at even much
higher voltages. Else it does not provide overvoltage protection.

James Salisbury wrote:
I am looking for a supplier of good transient suppression equipment and a
overvoltage protection unit. My parents are living out in a rural part of
spain and are having problems with the mains killing electronic equipment.
Yes I do know of Farnell, but I was wondering if there was anywhere
cheaper?