In m, David Nebenzahl
wrote:

The other night our power went out here in Oakland. Was watching teevee
when the lights went out all of a sudden. Then they came back on. Then
they flickered a bit and went out again. Came on again, there was a
muffled "BOOM!", whereupon they went out, this time for good.

It was the first power outage we'd had here in a long time. And I
noticed some really strange things.

First of all, the "BOOM!" turned out to be a transformer which exploded
rather spectacularly right outside the building I'm in. Some neighbors
down the street said they actually saw the thing go, sparks and all.

Turns out there were several other transformers all over town that blew
at (about) the same time. Power was out to 4,500 customers at the peak
of the outage, in an area covering many square miles. But walking
around, I'd see blocks on end without power and with no streetlights.
Then there'd be a block with power. And some of the blacked-out areas
had working streetlights. The local power grid must be a crazy quilt of
wiring.

Regarding the cause of the outage, when I got ahold of PG&E (Pure Greed
and Extortion), the guy said it was due to "equipment failure". Talking
with my neighbor, though, he said he though it was human error: someone
threw the wrong switch or something.

And really, how else could a transformer fail spectacularly, other than
an overload, except by there being some kind of massive overvoltage
surge (what people incorrectly call a "power surge")?

OK, so for the rest of the evening we were without lights. Sort of.

Sort of? I though power outages were pretty much black and white: either
the power is on or it's off.

Not so, grasshopper. I stuck my VOM into an outlet and monitored the
line voltage. The reason I did this was that after the power had been
off for a good long time, I heard my microwave squealing a high-pitched
whine. And there was noise coming from the fridge motor. At that point,
I could see that there was about 60 volts on the line, enough so that
when I turned the lights on, they came on, sorta dimly.

After that, the line voltage fluctuated wildly, going from a low of
about 45 volts all the way above 80.

SNIP

I do remember one power outage (of many) at my workplace where some
strange noises emanated, and the only incandescent light at the workplace
glowed to an extent typical of about 16 volts. I had a voltmeter handy
and it indicated about 40 volts. So I suspect a bunch of noise from UPS
units and a few generators, plus maybe a bit of RF pickup from the many
nearby radio transmitters. This was in the University City section of
Philadelphia, in an urban zip code (19144) having 4 hospitals for people
and 1 for animals.

That power outage did not damage anything.

A few or several months before that was the power "outage" where for the
first 45 minutes or hour or so (I disclaim accurate memory of amount of
time of the following stressful condition), the voltage was about 45
volts. I did not have a voltmeter handy. The only incandescent lamp at
the shop glowed to an extent that I consider typical of about 45 volts.
The fluorescent fixtures (with electronic ballasts) gave an eerie very dim
glow. Two refrigeration devices had compressor motors being burnt out.
Someone I know suggests that a transformer upstream from my shop
could have a 13,200 volt primary with a 4,600 volt tap, and the 4,600 volt
feeding power got switched to the 13,200 volt primary connection as a
result of an overload.
The overload could be from rich college kids having 42 inch plasma TVs
and refrigerators for beer in most bedrooms and most living rooms and 300
watt halogen torchiere lamps almost everywhere and computers running in
most bedrooms. I say "have the flashlights handy" when the weather gets
warm enough to need air conditioning during the "school year" to remove
the heat produced by all those beer cooling refrigerators, 42 inch plasma
TVs and 300 watt halogen lamps that my workplace's neighbors have!

Also turned off the fridge because I didn't like the sounds I heard
coming from the compressor.

- Don Klipstein )