Facility Ratings Methodology (FAC-008 & FAC-009)

The NERC alert identified possible ratings discrepancies between design and actual field conditions of transmission facilities, and stated that by December 15th entities must report a plan to NERC that identifies and corrects line ratings.

NERC recommends that entities verify their ratings methodology based on actual field conditions - rather than solely on design documents - and take corrective action, if necessary. The alert requires entities to develop a plan to identify and implement any necessary actions to correct their ratings, and report that plan to NERC and regional entities by December 15th. There are more than 450,000 miles of transmission lines greater than 100 kV in North America - many of them are decades old, and many of these lines are in hard-to-access places.

“Fortunately, new technologies, such as LiDAR and PLS-CADD™ allow entities to more easily assess their lines” NERC—10/07/10