Design information for the methods historically and typically applied by substation designers to minimize direct lightning strokes to equipment and buswork within substations is provided. Two approaches, the classical empirical method and the electrogeometric model, are presented in detail. A third approach involving the use of active lightning terminals is also briefly reviewed.

The scope of this guide is the identication and discussion of design procedures to provide direct stroke shielding ofoutdoor distribution, transmission, and generating plant substations. All known methods of shielding from directstrokes were investigated during the preparation of this guide, and information is provided on two methods found to bewidely used:a) The classical empirical methodb) The electrogeometric modelA third approach, which involves the use of active lightning terminals, is briey reviewed in clause 6.This guide does not purport to include all shielding methods that may have been developed. The guide also does notaddress protection from surge...

The intent of this guide is to provide design information for the methods historically and typically applied bysubstation designers to minimize direct lightning strokes to equipment and buswork within substations. The generalnature of lightning is discussed in clause 2 and the problems associated with providing protection from direct strikesare described in clause 3. The methods reviewed in this guide for designing a system of protection are explained inclauses 4 and 5, and sample calculations are given in annex B to illustrate use of the methods. Clause 7 contains anextensive bibliography for further study of the subject.