scope:

Purpose and Scope.

The intent of this guide is to provide guidance and information pertinent to safe grounding practices in ac substation design. This guide is primarily concerned with outdoor substations, either conventional or gas insulated. These include distribution, transmission, and generating plant substations. With proper caution, the methods described herein are also applicable to indoor portions of such substations, or to substations that are wholly indoors.¹

The specific purposes of this guide are:

(1) To establish, as a basis for design, the safe limits of potential differences that can exist in a substation under fault conditions between points that can be contacted by the human body

(2) To review substation grounding practices with special reference to safety, and develop criteria for a safe design

(3) To provide a procedure for the design of practical grounding systems, based on these criteria

(4) To develop analytical methods as an aid in the understanding and solution of typical gradient problems

( 5 ) To provide a bibliography of pertinent literature on grounding, and English translations of some of the more valuable foreign language articles