This guide contains information on a number of different protective relaying practices for the utilityconsumer interconnection. It is intended to cover applications involving service to a consumer that normally requires a transformation between the utility's supply voltage and the consumer's utilization voltage. Interconnections supplied at the utilization voltage are not covered. This guide is not intended to supplant specific utility or consumer practices@ procedures@ requirements@ or any contractual agreement between the utility and consumer. The examples of interconnection protection of varying complexities that have been provided are used for illustrative purpose only and do not necessarily represent the preferred protection under all conditions. This guide addresses consumers@ with or without conventional generation@ that are connected to utility subtransmission or transmission circuits. The specific control schemes associated with generation are not addressed. It is not intended to apply to consumer generation connected to utility distribution circuits. For these interconnections@ refer to IEEE Std 1547?-2003 [B8].1 Purpose The primary purpose of this guide is to help those who are responsible for the application of protective relaying for the electrical interconnection between utility and consumer systems. It is anticipated that representatives of the utility@ the consumer@ and their consultants who are responsible for the specification@ design@ and operation of the interconnection will use this guide. Recognizing the diverse audience being addressed@ background information is included in a bibliography to direct the reader to more complete treatment of the material. 1 The numbers in brackets correspond to those of the bibliography in Annex A.