Today’s LiveWire Spotlight examines FERC Order 799, which approves without modification two NERC standards that establish load-responsive relay settings for generator and transmission systems.

  • PRC-025-1: Provides the settings criteria for relays that protect generators, step-up transformers, and auxiliary transformers.
  • PRC-023-3: Outlines the corresponding transmission system criteria – although modified to eliminate overlap with load relays used in generation systems.

PRC-023-3 and PRC-025-1 take effect in the U.S. on October 1, 2014. After that point, Clients who own newly applicable relay systems will have 60 months to verify their settings comply with the standards – 84 months if replacement is necessary.