[Fellow Traveler]

Just wanted to back up what null and void said. It can take months/years to repair a generator after an accident. I was a generator and excitation specialist for six years with GE. I have worked on two complete stator rewinds of large steam generators. Both jobs took three to four months working six or seven days a week and ten to twelve hours a day two shifts. Of course we had the advantage of having the parts already ordered. From the time you fry the generator to restart could easily be a year.

One thing to keep in mind is that the relaying system is designed to protect a particular peice of equipment. Each piece of equipment be it a generator, transformer, transmission line, or circuit breaker has relays associated with it. The relays will trip that peice of equipment if certain operating parameters are exceeded. People keep talking about computer control of the grid. It is true that large SCADA sytstems run much of the grid. These systems are used to operate the grid, they do not protect it. Protection is provided by relays on each individual peice of equipment. Some effort is made to "coordinate" relay settings but no one models an entire system in a state of flux. Nor would they try to adjust relay settings to take into account a system wide problem, the relays would simple trip the equipment off-line, hopefully isolating the problem. The system should be robust enough to withstand isolated outtages.

Keep in mind also that the entire grid crash probably happened in a matter of seconds. The 65 blackout took only 10 seconds to propagate across the northeast and eastern Canada.

[ThirdMate]

Could you tell me what SCADA stands for?

[fatima]

Fellow Traveler,Thank you.

[Calpernia]

>>>Keep in mind also that the entire grid crash probably happened in a matter of seconds. The 65 blackout took only 10 seconds to propagate across the northeast and eastern Canada.

Explain this? This means something to you...but I don't have the background knowledge.

[null and void]

Thanks.