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Re: Summary: Bay Area Power (2000-06-14)
From: John Hall <j.hall () f5 com>
Date: Fri, 16 Jun 2000 12:40:11 -0700

When you lose a part of a multi-phase circuit, you usually get bleed
through enduser devices that are still getting power through the other
phases.  Your 27VAC was probably bleen through a (or more likely several)
three-phase motors that did not have phase-outage protection circuit
breakers.  They probably had stopped spinning and were slowly cooking
themselves.  A building I once worked at lost one of their phases and
after an hour the fire alarm went off and we had to evacuate the whole
10 stories.  A "temporary" compressor in a design model shop did'nt have
adequate protection and cooked all it's lubrication, filling the shop
with smoke.  Apparently, phase-outage protection is not required in
many installations where it should be.  One data-center in the same
building still had some three phase powered mini-computers (mini in
name only) and they lost almost half their hardware.


Jim Browne wrote:
Downtown Sunnyvale around Carroll Street (including PacBell SNVCA01
and us) lost power (on one phase only) yesterday at 12:35 PDT.  PG&E
brought it back at 15:35.  PG&E said that our area is using too much
power and we blew the breaker on that phase.  The odd thing was we
were still getting about 27 VAC on that phase with the breaker

John Hall <j.hall () f5 com>                                     F5 Networks, Inc.
Senior Test Engineer                                          206-505-0800

One of the large consolations for experiencing anything unpleasant is
the knowledge that one can communicate it.
                -- Joyce Carol Oates

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