Related Files
Status
Board Adopted: May 24, 2011
Filed with FERC: June 15, 2011
Order Effective
Purpose/Industry Need:
The expansion of this project is necessary to address a directive from Order 693 that was not addressed in FAC-008-2 – Facility Ratings. There were three directives in Order 693 relative to FAC-008-1 – Facility Ratings:
(1) document underlying assumptions and methods used to determine normal and emergency facility ratings;
(2) develop facility ratings consistent with industry standards developed through an open process such as IEEE or CIGRE and
(3) identify the limiting component(s) and define the increase in rating based on the next limiting component(s) for all critical facilities.
The version of FAC-008-2 that was approved in 2010 only addressed the first two of the three directives. FERC’s September 16, 2010 Order Denying Rehearing, Denying Clarification, Denying Reconsideration, and Denying Request for a Stay on its March 18 Order included the following clarification regarding the third directive: "In order to determine facility ratings, entities must identify the most limiting component that comprises the facility, based on a validated methodology that considers the specific characteristics and ratings of all of the components to determine their limits for a range of ambient conditions, including if and for what duration these limits can be exceeded. This is, in part, because the limiting element upon which a facility rating is based can change under different operating conditions. For example, an underground high voltage cable may be the limiting element for continuous ratings, but a disconnect switch may be the limiting element for a four-hour emergency rating. With heavy power flows from generators through critical facilities to load, contingency conditions could reveal a thermal overload above the normal rating of the first limiting component of one of these facilities. However, that component also likely has a documented short time rating that could sustain the overload. If the second-most limiting component does not afford much increase in rating above the first, and its overload can result in the unintended removal of the facility from service (i.e., a relay or other protection system component that trips a facility out of service due to the overload), the prior identification of this second limiting component could alter the mitigation plans and avoid relay operations that trip facilities out-of-service, and thus potentially prevent a cascading event."
With this additional clarity, the drafting team has developed a new requirement to address the reliability intent of the third directive. NERC received a final order on March 17, 2011 granting the ERO 90 days to file a version of FAC-008 that addresses all three of the directives from Order 693, making the filing due on June 15, 2011.
