Photography http://bit.ly/2PUeBwI xnxx Operators must assess the worst case scenario, usually theloss of the largest generator or transmission line on thesystem, and plan how to meet it (the "N-1 criterion"). If ithappens, they must be able to bring the system back into a safeoperating condition within no more than 30 minutes, and startplanning to meet the next worst-case scenario.