power hit stories...

Mon Sep 9 00:21:26 UTC 1996

Reminds me of the power hit at MIT one summer Saturday in 1988.  Ask
Jeff Schiller about it some time...

Short version:

MIT had just installed a 5ESS as its new PBX; they put in the usual
batteries for backup, and opted to not include a generator just for
the switch, because MIT had its own generator.

All the multi-line phone sets were ISDN sets, powered from the phone
closets.  The phone closets supposedly had emergency power (from the
generator) and (small) backup batteries.

Anyhow, something bad happened somewhere in Cambridge (transformer
explosion or some such), with the result that most of town lost power.
For a long time.

One might expect the generators to come on.

Nope.  They were off-line for maintainance.

Phys plant had brought in portable generators on trailers.

They didn't work either.

oops.

So, there were now three grades of power at MIT, and two of them
weren't working.

 - normal power (from the local power grid, now dead)
 - emergency power (from the generator, now dead)
 - switch power (from the switch's batteries, still working)

Unfortunately, the main phys plant emergency number was on one of the
ISDN phones.  As one might expect, that phone got a lot of calls after
the lights went out, and the phone went dead when its phone closet's
batteries went out..

Jeff was summoned to fix the switch so that the emergency number would
work again.. I happened to be nearby at the time and wound up getting
an impromptu tour of the switch.

We noticed, on arrival, that the lights in the nearby room housing the
modem pool were evidently on switch power.. which was clearly a wiring
mistake.

Jeff tried to get into the switch room with his key card, but some
part of the card reader/electronic lock setup which controlled access
to the door to the switch room was not on switch power, and it
wouldn't let us in.

Our ears soon verified that the switch's burglar alarm, on the other
hand, *was* on switch power.  

Once we shut up the alarm, we discovered that switch console terminal
was *not* on switch power...

Things went on like this for a while..

Moral:

If there are multiple grades of power available, make *darn* sure that
nothing plugged into the highest grade depends on anything plugged
into a lower grade..

					- Bill