Improvement in service reliability is a factor in power transmission and distribution which has received considerable emphasis in recent years. Several means for obtaining improvement in service reliability are in general use. These include ground-fault neutralizers, immediate reclosing of circuit breakers, overhead and buried ground wires, arresters and expulsion protector tubes. All have demonstrated an ability to limit outages on transmission and distribution systems. None of these means considered, however, has shown a perfect record in all cases of application.

This application guide summarizes usual methods of grounding of generator systems, and discusses considerations in applying each grounding method to various types of generator systems. The guide applies to generator systems operating at 11 kv and above, but in general, it is also applicable to generator systems operating at voltages below 11 kv. In preparing the guide, the Committee recognized that some suggestions and recommendations are in conflict with the grounding practices utilized successfully by some operating companies. It should be borne in mind, however, that the report is intended solely as a guide and its recommendations and suggestions are necessarily of a general nature and cannot take into account the special requirements of any specific situation