[142449] in North American Network Operators' Group
Re: Wacky Weekend: NERC to relax power grid frequency strictures
daemon@ATHENA.MIT.EDU (Jay Ashworth)
Sun Jun 26 12:08:21 2011
Date: Sun, 26 Jun 2011 12:07:08 -0400 (EDT)
From: Jay Ashworth <jra@baylink.com>
To: NANOG <nanog@nanog.org>
In-Reply-To: <4F3FF32B-AC21-4505-91E1-3EEA21374994@deman.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
----- Original Message -----
> From: "Michael DeMan" <nanog@deman.com>
> It is my understanding also that most commercial grade gensets have
> built into the ATS logic that when utility power comesback online,
> that the transfer back to utility power is coordinated with the ATS
> driving the generator until both frequency and phases are within a
> user specified range?
I don't believe that's actually true, Mike. In a *load transfer*
configuration, it's really not all that critical if the power presented
to the load skips phase a touch on the transfer; there's a 50-500ms gap
in the power anyway, since such transfer switches are required by the
NEC to be non-shorting, so they don't electrocute power workers.
Cheers,
-- jra
--
Jay R. Ashworth Baylink jra@baylink.com
Designer The Things I Think RFC 2100
Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII
St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274
