Manhattan blackout caused by fault in substation relay protection system

A fault in relay protection equipment at a substation in New York City led to a cascading blackout that left 72,000 customers without power.

NEW YORK (WABC) -- Con Edison has issued its preliminary findings on Saturday night's power outage in Manhattan, saying "the relay protection system at our West 65th Street substation did not operate as designed."

The utility said the finding followed an inspection of equipment and preliminary review of system data.

Con Ed said the relay protection system detects electrical faults and directs circuit breakers to isolate and de-energize those faults.