Re: Re: Lightning

["Richard Challis" <richard@xxxxxxxxxxxxxxxxxx>]

----- Original Message -----
From: "Andy Whitfield" <andywhitfield2002@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Monday, August 28, 2006 11:30 AM
Subject: [ukha_d] Re: Lightning


> Do you reckon a lightning conductor attracts lightning?
> For example: If a house had a lightning conductor and the
> neighbouring houses & buildings did not, then the house with the
> conductor is more likely to be hit?  (assuming all the
> houses/buildings are of similar height).
>

If a strike was going to happen in that near area, then yes. It would have
a
higher probability of striking that house as it would present a lower
impedance to earth.

We have a quite extensive grid of lighting conductors at work. It is taken
very seriously as we present a lot of steel structures to the sky and have
lots of computers and electronics running the production line. I use fibre
between all major parts of the controlling process to isolate the various
areas.

In the nearly two years of working for my current employer, We have had
three strikes. The most violent was about a week back. It caused damage to
(copper) comms link to the mine and damaged a single computer on the end of
this. Everything else was isolated by fibre and happy. Ironically the link
to the mine is being currently replaced by fibre, only half in so far.


> And have UPSs protecting your most valuable equipment.

I use a load of UPS units at home and they have proved invaluable. Most of
which were supplied by Andy. (of which I have no connection other than
being
a happy customer!)

At work we use a load (10plus) of 5000va units in both the computer rooms
and a generator to kick in after a minuite. All 28 of the comms cabinets
are
protected with baby industrial units. 750va to just help ride the switches
through the glitches. At about 60 secs to boot a layer 3 switch, it means
that a small 2 sec glitch can cause the network to have great difficulties
comming back up.

Regards

Richard