Classification of Surge Arrestor

What standards are you referring to as "known"? I am familiar with type I, II and III of IEC 61643 which is built parallel to the German VDE classes B,C and D, thought they are far more stringent than IEC per class. I am unfamiliar with types 4 and 5, so I assume you mean some other standard.

I have found that whereas the European community has specific sections to a building (Lightning protection zones) and these sections have some bearing on using type I, II, or III, the American IEEE 62.41 does not delineate the zones specifically with regards to inherent grounded farady cages, specifying only areas A, B, and C that are pretty arbitrary.

I am curious to know more about the types of arresters in the standard you refer to.

A general answer to your question would be to define the requirements of a surge arrester. See my web site http://www.lightning.co.il/lightning.html (sorry, link no longer available) where I write English, though specifically to my country, and download the Lightning Primer. This document is written for the layman, but reading it will save writing here.

As explained there, there are three distinct types of overvoltage and at least two types of application: power supply and communication.

To oversimplify, a surge arrester is rated regarding the modes of protection (from what incoming lines it takes the overvoltage to ground) the amplitude of the impulse and the type of wave form.

The above classification for Class 1 to 5 is given in IEC 60099-4 page no. 49 onwards

hi Ambrish Gandhi

your surge arrester for high or medium rated voltages?