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Science Forum Index » Electronics - Design Forum » power and tiebreakers...
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| David Williams... |
 Posted: Tue May 06, 2008 4:48 pm |
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Guest
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Hello,
Can anyone give me information on the purpose of a tiebreaker
that is found in switchgear power distribution?
This is more of an electrical than electronic question but
I could not find an electricicity newsgroup.
Meaning, in a typical building, you have power that comes
from the street and goes into switchgear, then a transformer, then
a feeder panel that has a tiebreaker switch there.
As I understand it, if you have two feeders into a system,
and one feeder fails, the tiebreaker switch opens up so that
bad/faulty electricity from the bad feed cannot flow through the sysem
until it is safe. That is about all I know.
Anybody have any resources I can read on this?
Thanks,
David |
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| legg... |
| Posted: Wed May 07, 2008 10:59 pm |
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On Wed, 7 May 2008 12:23:58 -0700 (PDT), mpm <mpmillard at (no spam) aol.com>
wrote:
Quote:
Ch-4 (TV) in Miami went off the air for about an hour once because
someone had the bright idea to tie the UPS in separate from the
generator.
Utility power goes out, runs on UPS. (20 minutes run time reserve)
Generator won't start. UPS dies.
Generator finally started (after some effort), BUT the UPS would not
release the tie until it recharged.
Long story short: Main, UPS and Generator - and there the station was
sitting in the dark.
Unbelievable.
If you've got a dead syatem, there has to be a manual procedure and
hardware present to allow manual over-ride of the dead hardware.
When a UPS is configured, it's important to determine who's on first.
RL |
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| Paul Hovnanian P.E.... |
| Posted: Fri May 09, 2008 10:00 pm |
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Guest
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mpm wrote:
Quote: Ch-4 (TV) in Miami went off the air for about an hour once because
someone had the bright idea to tie the UPS in separate from the
generator.
Utility power goes out, runs on UPS. (20 minutes run time reserve)
Generator won't start. UPS dies.
Generator finally started (after some effort), BUT the UPS would not
release the tie until it recharged.
Long story short: Main, UPS and Generator - and there the station was
sitting in the dark.
Unbelievable.
Not really. I was involved in the repairs to a (supposedly) redundant
power system in a companies critical data center. Someone had installed
some bolts in panelboard buses incorrectly and they were in danger of
overheating.
It turned out that these bolts (and the associated panelboards) were
single point failure locations that could take the entire data center
down. Nobody could figure out how to de-energize even one source and
panel at a time to perform the repairs. The whole data center had to be
shut down for several days.
--
Paul Hovnanian mailto:Paul at (no spam) Hovnanian.com
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