North American Network Operators Group

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Re: Why do we use facilities with EPO's?

  • From: David Lesher
  • Date: Wed Jul 25 20:24:48 2007

Speaking on Deep Background, the Press Secretary whispered:
> Many years ago, the safety department for my employer made a big stink
> over the fact that the EPO hadn't been tested in a couple of years.  We
> scheduled an outage window, shut everything down.  The facilities guy
> pressed the magic big RED button and NOTHING!  Tracing the problem back,
> there was a blown fuse in the EPO circuit because a wire had shorted.  A
> real safe design!

I've never designed or looked into a EPO installation; but I'm
astonished such does not use a Normally-Closed pushbutton in a
fail-to-off circuit.


If you have electric locks on your exit doors; every installation
I have seen has a couple of such aspects:

a) You must have an exit override. If an electric strike, an
interior knob is good. If a [Locknetics-style] mag-lock, you
need an exit button.  That button SHALL be a NC pushbutton in
series with the magnet. [In other words... No, you can't have
the pushbutton connected back to some controller box on the 3rd
floor where it generates an interupt that will drop the lock
power...  or it's supposed to...]

b) When the building fire drop is pulled, you SHALL drop the lock
power to the mag locks.

And while local fire codes vary widely; given those were in the
rules for a USG SCIF I worked in; I somehow doubt you'll be able
to get more lenient treatment based on the import of the data
center's operation.

A host is a host from coast to [email protected]
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433