New York Blackout July 13, 1977
- 8:30 pm Con Edison (a utility which supplies energy to New York City) is importing 2860 MegaWatts of electricity to meet a service load of 5868 MW.
- 8:37 pm An electrical storm begins, with a destructive lightning strike.
- 8:39 pm A protective relay malfunctions and six (of eight) high capacity electrical feeders goes offline.
The remaining two relays become overloaded (trying to supply the demand) and automatically go offline.
The power frequency fell to 57.5 Hertz. The generating units are not designed to operate with stability at this frequency. They start to shut themselves down.
- 8:55 pm A second lightning strike and power stations elsewhere (which were offline) were ordered by a Con Ed system operator to come online to provide the additional power.
- 8:58 pm Another power station goes offline (automatically), unable to handle the increased load.
- 9:13 pm The Con Ed system operator reduces voltage by 5% ... then 8%, in order to respond to the demand.
- 9:20 pm All ties to northern power supplies tripped out and NYC is now left with only a tie to a New Jersey generator.
- 9:29 pm The New Jersey station, not able to meet the demand, starts to shut itself down.
- 9:34 pm New York City is now in total darkness.
And in 2003?