Re: Lightning

["Andy Whitfield" <andywhitfield2002@xxxxxxxxxxx>]

--- In ukha_d@xxxxxxx, "Richard Challis" <richard@...>
wrote:
> ----- Original Message -----
> From: "Andy Whitfield" <andywhitfield2002@...>
> 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.

I have to admit I was being a bit rhetorical in my question.  Also I
was ignoring quite a few other factors such as the topology of the
land.  If the house was on the side of a hill, then neighbouring
buildings may be the same height but on higher ground.  I guess
older houses may have metal guttering and drainpipes which could
attract the lightning.  No doubt other factors come in to it as well.

> 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.

What kind of mine?   gold mine?   ;-)

> > 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!)

You had a lightning strike a while back didn't you?  And the UPSs
protected your equipment.

> 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

Are you looking for any more 5000s for work?   I've just got quite a
few in stock.
Regards
Andy the UPS Man