Foreword?This guide is the introduction to the IEEE C62.92 series of five guides on neutral grounding in electrical utility systems. In this series of guides@ individual considerations and practices are given to the grounding of synchronous generator systems@ generator-station auxiliary systems@ distribution systems@ and transmission and subtransmission systems.In the entire IEEE C62.92 series@ emphasis is on power-system grounding practices as contrasted with the grounding@ e.g.@ of industrial systems@ which are covered in other guides and standards. Those guides and standards should be referenced@ when appropriate@ to gain a full picture of other grounding practices.Besides updating the format of the guide@ this revision expands the bibliography@ adds a new annex to clarify the effects of grounding resistances and grounded conductors@ and attempts to clarify areas that elicited questions or comments in IEEE Std C62.92-1987.Scope?This guide is intended for application to three-phase electrical utility systems. This is Part I of the five-part IEEE C62.92 series. This part provides definitions and considerations that are general to all types of electrical utility systems. The remaining four parts provide specific guidance on synchronous generator systems (IEEE Std C62.92.2-1989)@ generating station auxiliary systems (IEEE Std C62.92.3-1993)@ distribution systems (IEEE Std C62.92.4-1991)@ and transmission and subtransmission systems (IEEE Std C62.92.5-1992).