NERC Files Proposed Reliability Standard Interpretations Addressing Significant Compliance Issues

The North American Electric Reliability Corporation (NERC) has proposed three Reliability Standard interpretations regarding compliance issues that have been of significant concern to the industry, and requested that the Federal Energy Regulatory Commission (FERC) approve these interpretations. If approved, these interpretations would clarify whether the failure of a Protection System must be assessed under TPL-002-0 as part of the loss of a single element, the extent of the Protection Systems that must be maintained under PRC-005-1, and what the term "ports" refers to in CIP-007-2.

TPL-002-0 - System Performance Following Loss of a Single Bulk Electric System Element (Category B) governs system planning as it relates to the performance of the system under Category B contingencies, requiring that Transmission Planners and Planning Authorities analyze the ability of the system to meet system performance requirements following the loss of a single element. The proposed interpretation of this standard states, in part, that compliance with this standard does not require an assessment of system performance because of a Protection System failure. Such an assessment would be performed under TPL-003-0 - System Performance Following the Loss of Two or More Bulk Electric System Elements (Category C).

In interpreting PRC-005-1-Transmission and Generation Protection System Maintenance and Testing, NERC addressed whether certain types of equipment would be considered part of a Protection System and thus subject to this Reliability Standard. Equipment discussed in the interpretation included battery chargers for station batteries, auxiliary relays, and associated communication systems.

The final interpretation examined CIP-007-2 - Cyber Security - Systems Security Management, and explained that the reference to "ports" that must be disabled in compliance with the standard refers to logical ports such as Transmission Control Protocol ports, "where interface with communication services occurs."

If you would like more information on any of the issues discussed in this LawFlash, please contact any of the following Morgan Lewis attorneys:

Washington, D.C.
John D. McGrane
Stephen M. Spina
J. Daniel Skees