Con Ed Reveals Root Cause Of Manhattan Blackout

NEW YORK, NY — Con Ed has identified and fixed the root cause of a July 13 blackout where more than 73,000 customers lost power in Midtown and the Upper West Side, company officials announced this week.

The blackout occurred when a relay system — designed to trigger circuit breakers and isolate faulty equipment — at Con Ed's West 65th Street substation failed to isolate a faulty cable, according to a company statement. The utility company studied 15 years of data and took equipment out of service at the substation in order to simulate the blackout and identify the root cause.

Tests revealed that a "flawed connection between some of the sensors and protective relays" at the West 65th Street substation resulted in the relay failing to isolate the damaged cable.

"We are confident that we have identified the cause of the July 13th outage, and taken the corrective actions necessary to provide safe, reliable service for our customers," Con Ed said in a statement.

The utility company added that it has isolated similar relay systems at its other substations as a preventative measure and that it will test all equipment before it goes back into service.

More than 73,000 Con Ed customers located on Manhattan's west side from the 30s to 70s lost power during the blackout. The blackout occurred shortly before 7 p.m. and power was fully restored around midnight.

From St. Luke's Hospital, which had to switch to backup generators, to Madison Square Garden where a Jennifer Lopez concert was cut short and people evacuated, to Broadway where theaters emptied and impromptu performances broke out on the street, the effects of the outage were felt far and wide.

The MTA said that the "entire system" was affected – causing stoppages and delays not only on the West Side but also those entering Manhattan from Brooklyn, Queens, and the Bronx. Some passengers were trapped underground for nearly an hour.

Read more of Patch's blackout coverage here.