Today’s LiveWire Spotlight assesses the Commission’s recent approval of TPL-001-5, the updated Transmission Planning Performance Standard addressing Protection System single points of failure.  Going forward, planners must treat simultaneous single-phase Faults and Protection System failures as a single contingency event, not a multiple contingency.

TPL-001-5 will take partial effect in the U.S. beginning on April 1, 2023.  At that time, the first annual planning assessments for single points of failure must be complete.  Planners are not required to create Corrective Action Plans for revised P5 until 24 months later.