Hi all,
What do you guys understand when in the datasheet of a certain 1 phase electric product it reads something like overvoltage protection when Vin >265Vac.
Apparently it would suggest that the product will shut off or will be protected in some ways whenever the input voltage is greater than 265Vac.
But obviously if I apply a voltage in the range of kV or more at the input, the protection circuit/IC itself will blow up, hence no protection at all.
So what should I interpret such information? What is the maximum values for those overvoltage protections?
Thanks in advance.

 

The overvoltage protection is fairly commonly an MOV across the power input which becomes very low resistance when a certain voltage is exceeded and so blows the fuse.

 

Thanks but I am actually not interested in the technique, what I meant was what should be the maximum voltage protect-able when we see a certain spec about overvoltage protection. When a product has overvoltage protection whenever the input voltage goes beyond 265Vac, it doesn't mean it can protect itself from a 5kV input voltage (prolonged period), right?
Another example, when a 24Vdc power supply has output overvoltage protection of 30Vdc, it can only protect the power supply from 30Vdc to the maximum voltage rating of the output capacitor, say 40V. Am I missing something?