Background:
Project 2007-17.3 (PRC-005-X) will address a directive from FERC Order No. 758, which accepted NERC’s proposal to develop a technical document, in lieu of a prescriptive FERC directive, that will provide the following information:
(1) describe the devices and functions (to include sudden pressure relays which trip for fault conditions) that should address FERC’s concern; and
(2) propose minimum maintenance activities for such devices and maximum maintenance intervals, including the technical basis for each.
In Order No. 758, the Commission accepted NERC’s proposal, by stating as follows:
NERC states that these technical documents will address those protective relays that are necessary for the reliable operation of the Bulk-Power System and will allow for differentiation between protective relays that detect faults from other devices that monitor the health of the individual equipment and are advisory in nature (e.g., oil temperature). Following development of the above-referenced document(s), NERC states that it will "propose a new or revised standard (e.g. PRC-005) using the NERC Reliability Standards development process to include maintenance of such devices, including establishment of minimum maintenance activities and maximum maintenance intervals." Accordingly, NERC proposes to "add this issue to the Reliability Standards issues database for inclusion in the list of issues to address the next time the PRC-005 standard is revised."
The Commission accepts NERC's proposal, and directs NERC to file, within sixty days of publication of this Final Rule, a schedule for informational purposes regarding the development of the technical documents referenced above, including the identification of devices that are designed to sense or take action against any abnormal system condition that will affect reliable operation. NERC shall include in the informational filing a schedule for the development of the changes to the standard that NERC stated it would propose as a result of the above-referenced documents. NERC should update its schedule when it files its annual work plan.
As a follow-up to this Commission ruling, the Planning Committee studied sudden pressure relays and issued the attached report, which recommends moving ahead with a Standard. Specifically, the System Protection and Control Subcommittee (SPCS) completed a technical report recommending that a standard drafting team modify PRC‐005 to explicitly address maintenance and testing of the actuator device of the sudden pressure relay when applied as a protective device that trips a facility described in the applicability section of the Reliability Standard. Additionally, the standard drafting team (SDT) intends to consider changes to the standard that provide consistency and alignment with other Reliability Standards. Lastly, the standards drafting team intends to modify the standard to address any directives issued by FERC related to the approval of PRC-005-3, which is pending filing with FERC.
