Today’s LiveWire Spotlight looks at three NERC Lessons Learned; “teachable moments” where Protection System Misoperations threatened electric system reliability.  Each had a very different root cause – ranging from a defective relay circuit board, improperly wired Current Transformer circuits, and subtle timing miscoordinations between mixed-technology relays used in directional comparison blocking schemes.

Protection System Misoperations continue to be a leading cause of BES service loss and are 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.