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Re: power-grid physics

"... And even so it takes lots of cleverness to extinguish
the bit of arc that occurs anyway."


In the basement of the original (1954) Science Bldg. at UC Santa Barbara is (was?) the manual switch for either the bldg. or all of the surrounding bldgs. It was a simple, but very big, knife switch, and transparently incased in transformer oil. I don't remember well, but I think the case was very thick lucite. I suspect the oil was PCB, so no longer there. In the same area were? a number of rather large Pb-acid cells in glass and a connection panel. My job, inter alia, as a freshman lab helper was to appropriately make connections for the next lab. and in the lab to plug in light loads so the cells would be in a more linear part of their discharge.

bc


p.s. the switch was not locked: oh for the good old days when one didn't worry about "security".



John S. Denker wrote:

On 08/22/2003 03:43 PM, Frohne, Vickie wrote:

> Edison was the DC guy, and his company actually did put generating


cut

The last is nothing to be sneezed at; the big
circuit breakers at a substation are synchronous
so as to minimize the arc when they open. These
things are a highly amusing combination of cleverness
and brute force: they have a syncrhonous motor
that stays in phase with the current. The motor
drives a disk with a dog; the dog is normally
retracted, but when it comes time to trip the
breaker the dog sticks out and knocks out the
three bars that carry the current, bing, bing,
bing. A view looking down the axis is:

Z

O----
Y X

where the dog is about to whack the X phase. And
even so it takes lots of cleverness to extinguish
the bit of arc that occurs anyway.