Today’s LiveWire Spotlight examines three NERC Lessons Learned where human errors made during planned work activities threatened electric system reliability. One such error triggered a Remedial Action Scheme (RAS) by jostling an unsecured card in the control unit. In the second, a work crew removed the CVT fuses for an adjacent live transmission facility instead of the one that had been isolated in preparation for planned maintenance. In the third case, the gap between a circuit breaker’s close-coil plunger and close lever was improperly set when a component in an operating control assembly was replaced.

Human error during a planned work activity continues to be a leading cause of BES service loss and is among NERC’s top reliability concerns. Severe penalties may be levied if an outage occurs, and it is found that an Operator did not act upon these Lessons Learned.