On January 22, 2015, the Commission issued Order No. 803, approving a new version of Reliability Standard PRC-005 (“PRC-005-3”) that requires applicable entities (Transmission Owners, Generator Owners, and Distribution Providers) to test and maintain certain autoreclosing relays as part of their protection system maintenance program. Autoreclosing relays are devices that automatically restore transmission elements to operational service following an automatic circuit breaker trip on a transmission system. Going forward, the Commission further directed NERC to modify PRC-005 to also require the maintenance and testing of “supervisory relays,” which help monitor the actions of an autoreclosing scheme, allowing for autoreclosing under certain desirable conditions, and preventing autoreclosing under other, undesirable conditions.
NERC submitted its proposed modifications to PRC-005 in response to Order No. 758, which the Commission issued on February 3, 2012. In that order, the Commission approved NERC’s proposed interpretation of Requirement 1 of the then-current version of PRC-005. Specifically, NERC’s interpretation of Requirement 1 identified the kinds of protection system equipment that are subject to the Reliability Standard. The Commission also directed NERC to develop modifications to PRC-005 to address certain gaps in the Reliability Standard that were highlighted by analysis of NERC’s proposed interpretation of Requirement 1. One of these gaps was a need to address autoreclosing relays that may affect the reliability of the Bulk Electric System, which led to NERC’s proposed modifications to PRC-005, filed with the Commission on February 14, 2014.
On July 17, 2014, the Commission issued a Notice of Proposed Rulemaking (“NOPR”) in which it proposed to approve PRC-005-3. In the NOPR, the Commission, among other things, noted that while PRC-005-3 made certain autoreclosing relays subject to a mandatory maintenance and testing program, NERC had failed to adequately explain in its petition why such a program should not also be required for supervisory relays.
In approving the proposed modifications this week, the Commission found that PRC-005-3 adequately addressed the directive articulated in Order No. 758 regarding the inclusion of autoreclosing relays in an adequate protection system maintenance program. However, the Commission, echoing the concerns it expressed in the PRC-005-3 NOPR, directed NERC to develop modifications to PRC-005-3 to include a requirement for the maintenance and testing of supervisory devices associated with the autoreclosing relay schemes that are covered under PRC-005-3. Specifically, the Commission found that the scope of the supervisory devices to be covered by the Reliability Standard should include: (i) those devises providing voltage supervision; (ii) supervisory inputs associated with selective autoclosing; and (iii) sync-check relays that are part of a reclosing scheme covered by PRC-005-3.
A copy of Order No. 803 may be found here.