At 04:24 AM 3/20/2007, Robert G. Brown wrote:
On Mon, 19 Mar 2007, Jim Lux wrote:
At 03:19 PM 3/19/2007, Robert G. Brown wrote:
On Mon, 19 Mar 2007, David Mathog wrote:
After looking at the specs I believe that at least 4 of the 5
can be wired to shut down instantly. (Not sure about the one
desktop size APC unit in the room, as it isn't mine so I don't
have the manual). However it seems that turning off the
tripp-lite UPS requires a positive voltage (12V) on the
inverter shutdown line. Which means, that even after the
power has been killed (overtemp, red kill button,
or building power shut down) the fireman entering this room would
still need to smack another (not yet extant) red kill button, and
that button is going to need DC power in order to work.
OK, this and David's replies are well worth preserving in marble and
bronze somewhere. I will dutifully spec out and assemble one as per the
instructions below, and let my electrician friend do that last itty bit
of wiring it in (or at least, wiring in the 120 line to drive the power
supply).
So, if the same kill switch controls the supply breakers, is this
accomplished by just replacing the box breakers with special ones that
can be tripped by the control lines? Sort of like a GFCI breaker with
an extra wire where you can feed in a deliberate imbalance high enough
to trip it?
That's called a breaker with a "shunt trip"
Another way is just to wire a contactor in series and power it
through a NC set of contacts on your EPO.
So with the resources you included I'll even try to answer this
myself...
rgb
--
Robert G. Brown http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567 Fax: 919-660-2525 email:[EMAIL PROTECTED]
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James Lux, P.E.
Spacecraft Radio Frequency Subsystems Group
Flight Communications Systems Section
Jet Propulsion Laboratory, Mail Stop 161-213
4800 Oak Grove Drive
Pasadena CA 91109
tel: (818)354-2075
fax: (818)393-6875
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