This guide establishes criteria and requirements for application of Rogowski coils (RCs) (air-core current sensors) used for protective relaying in electric power systems. The selection and application of RCs for the more common protection schemes are addressed. Purpose This document provides a guide for application of Rogowski coils used for protective relaying in electric power systems. It is intended to assist the relay application engineer in the correct selection and application of RCs for protective relaying purposes. It provides requirements relevant to the performance@ operation@ testing@ and maintenance of Rogowski coil-based current sensors. This guide applies to all types of Rogowski coils used for protective relaying purposes.