[time-nuts] Daft idea with the National Grid

[Magnus Danielson]

Hi,

On 2021-02-08 18:37, John Moran, Scawby Design wrote:
> On Sun, 7 Feb 2021 20:45:57 -0800
> Jim Lux said -
>
>
> "If you happen to own something like a steel mill running electric
>
> furnaces or an aluminum refinery, so you can manipulate the load..."
>
> Sometime in the late '80s, my first decent sized computer system came on line at a telecom factory in England. It ran fine for a few days then crashed. Rebooting made it run fine for another 7 days then it crashed again, and then every 7 days at almost the same time - like a very poor clock. Monitoring the mains voltage with an expensive hired monitor showed a huge drop in voltage lasting about ten seconds at the relevant time.
>
> It turned out that the biggest steel rolling mill in Europe was only 5 miles away and they were testing new motors on the rolls. We had some interesting visits and talks with them and persuaded them to turn the motors on one by one instead of in batches and, in conjunction with some hefty mains filtering, the problem went away.
>
> That sort of load step must have been noticed by the electricity suppliers, and half the computers in the city!

So, when I was at school we had to take coarses on electricity, complete
with three-phase motors and starting them. They required step-wise start
or things go very wrong. As this was students, thing did go wrong. When
things go wrong the right way, the neighbor mainframe computer crashed,
which was not popular. Well, they did not like it, but being able to
down the national tax computer (this was the Swedish IRS), it was
actually seen as somewhat of an achievement, even if we students really
did not see much tax because we where not doing much money. That was
fun. I ended not mess things up to badly as I recall it.

It is however interesting to see modern computers where the new feed to
the house is rated in MW, parallel UPSes, another diesel engine, more
cooling and redundancy on cooling not to burn to many cores as things go
bad etc.

Cheers,
Magnus