Relay protection system failure caused New York City blackout

Con Edison blamed their relay protection system Monday for the weekend power outage in New York City, saying the system didn’t operate as designed, according to preliminary findings from the company.

“That system detects electrical faults and directs circuit breakers to isolate and de-energize those faults,” the company said in a statement. “The relay protection system is designed with redundancies to provide high levels of reliability. In this case, primary and backup relay systems did not isolate a faulted 13,000-volt distribution cable at West 64th Street and West End Avenue.”

“Our analysis of data and testing of the relay protection equipment is continuing, and will provide more insight into why the system, and its multiple redundancies, did not operate as designed,” the company added.

CNN