Commercial AC power outage - restore Voltage ?

[Mike O'Dell]

the magic device is called a "sectionalizing relay"
(or sectionalizing switch if a guy with a long fiberglass
pole does the deed)

the first big NYC blackout too much much longer to recover
precisely because of the lack of sectionalizing relays
which caused the recovery areas to be far larger than 
could be handled easily without whacking the crap out of
the transmission grid.

now, whne recovery starts, all the sectionalizing relays
are opened and then the power to the distribution tree
core is restored. then, section by section is re-energized
for the reasons Mr. Seastrom implied.  these days, there
are overvolt and undervolt cutouts which would open up
and dump an area to prevent upstream damage. the big
transmission grids are living, breathing beasts and
will snap and bite *hard*. the generation assets are
also protected by those cutouts, so the generators are
less likely to tear down the powerhouses or throw
turbine buckets through several inches of steel housing
and lots of concrete.

    -mo