All the experience allows the author to state that the global metal-oxide surge arrester (MOA) industry is in dire need of simple MOA application methods, but, instead it, is developing endless editions of IEC 60099, adding details to an already complex document that contains dozens of MOA characteristics.

At the same time, IEC 60099 does not divide the characteristics of MOA into main and secondary ones, but considers all the numerous characteristics as equally important, which confuses a huge number of people who have to look at many factors simultaneously, not understanding how to select MOA properly. As a result – damages to the MOA and equipment being protected.

It would be useful for the industry if MOA manufacturers stopped immersing customers in the details of a long list of various MOA tests, but simply said that, as all manufacturers have the same composition of nonlinear elements (varistors) and MOA assembly technology, only the height of the varistor column and its diameter are important, that is, the maximum continuous operating voltage of the MOA and its specific energy absorption capability. Most of the other characteristics are secondary and can, if necessary, almost certainly be derived from these two listed ones.

You will find these and other thoughts in the new 65-page brochure on Surge Arresters.