Guide for the Application of Neutral Grounding in Electrical Utility Systems | August 23
This part of the guide is concerned with the neutral grounding of single- and three-phase ac electric-utility primary distribution systems with nominal voltages in the range of 2.4 kV to 34.5 kV. For the purpose of this guide, the term “distribution” includes the substation providing power to distribution feeders, the distribution feeders, and the distribution transformers providing service at utilization voltages. The scope of this guide does not include the grounding of the low-voltage secondary systems supplied by distribution transformers or consumer-owned facilities that are covered by other documents such as the National Electrical Code(R) (NEC(R)) (NFPA 70, 2011 Edition)