scope:

This document specifies standard service conditions, standard ratings, environmental performance requirements, and testing requirements for communications networking devices installed in electric power substations. It does not cover such equipment designed for operation in other environments, such as office locations. It does not cover such equipment used in protective relaying applications, for which IEEE Std C37.90™-1989 [B6]¹, IEEE Std C37.90.1™-2002 [B7], IEEE Std C37.90.2™-1995 [B8], and IEEE Std C37.90.3™-2001 [B9] apply.

¹ The numbers in brackets correspond to the numbers of the bibliography in Annex B.