In a message written on Fri, Jun 24, 2011 at 06:29:14PM -0400, Jay Ashworth wrote:
> I believe the answer to that question is contained here:
> 
>   http://yarchive.net/car/rv/generator_synchronization.html [1]

I wouldn't use a colo that had to sync their generator to the grid.
That is a bad design.

Critical load should be on a battery or flywheel system.  When the
utility is bad (including out) the load should be on the battery or
flywheel for 5-15 seconds before the generators start.  The generators
need to sync to each other.

Essential load (think lighting, AC units) get dropped completely for
30-60 seconds until the generators are stable, and then that load gets
hooked back in.

I have never seen a generator that syncs to the utility for live, no
break transfer.  I'm sure such a thing exists, but that sounds crazy
dangerous to me.  Generators sync to each other, not the utility.

-- 
       Leo Bicknell - bicknell@ufp.org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/