[Gllug] Power outages in NW London?

[Chris Bell]

On Wed 27 Mar, Rev Simon Rumble wrote:
> We've just had three very short (1/2 second) power outages here in NW
> London.  Enough to make all the desktops reboot and have everyone ask
> the "why aren't our servers UPSed" question.
> 
> Anyone else?
> 
   I know about brown-outs and surges, low and high frequency mains, and
simple power cuts, so I assume that a power outage occurs when the customer
starts feeding power back into the grid.
   A split second drop often occurs when there is a fault in a neighbouring
area, and the area fuse takes a short time to blow. I have not seen it done,
but I am told that the standard technique for changing one of these fuses
(perhaps normal carrying capacity of 400 amps or more) is to take aim, close
your eyes and look away, then bang the fuse in at arms length. You have to
hope that one of your supply of spare fuses will survive the enormous
initial surge.
   I used to live next door to a local area switching station, and one
evening a few years ago a couple of engineers operated an oil-filled switch
to re-connect a local main feeder after maintenance. Unfortunately they had
forgotten to remove a massive protective earth they had fitted during
installation work at a local factory. The switch exploded, and the flame
that came out through the window went over 50 feet into the air.

-- 
Chris Bell



-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug