RE: Lightning Protection WAS Re: Bloody Lightning!

["Keith Doxey" <ukha@xxxxxxx>]

Lightning is a real pig :-(

You can "TRY" to protect against it but nothing will stop a
direct hit.

About 20 years ago I was working up a pole repairing a dentists line and I
could tell there was a storm about 5 miles away. Then there was a flash and
almost instant bang so I got down the pole pretty damn quick. I found out
later that it had hit a pole about a mile from where I was working.

My mate and I spent the next 4 days on that housing estate going from house
to house replacing everything. We tried the doorbell at one house and it
didnt work so we knocked on the door. When the door was opened we realised
why the doorbell didnt work. The phone wire and bell wire ran along the
same
skirting board which was now laying at the opposite side of the hallway
having been blown off the wall.

At another house that had a wall mounted phone, the lightning had gone into
the phone and earthed itself through the breezeblock to the lightswitch on
the opposite side of the wall. The switch and metal box left the wall, flew
across the kitchen and bent the venitian blind.

We also went to one house where the overhead wire looked OK apart from
sagging a bit. Upon closer examination we saw that the side of the
insulation looked as if it had been slit with a razor blade and the wire
pulled out. the copper wire had completely vapourised!

That was obviously a very severe direct hit but with the advent on modern
electronic communications equipment it doesnt need a direct hit to damage
or
kill equipment. We once had a solicitor querying how we could prove that
lighting had caused his phone system to die. I pointed out that ...

a. we had 10 times the normal rate of faults
b. the symptoms were typical of a lightning induced fault.
c. that he could have the chips examined in a laboratory to determin the
probable cause of failure

.... or he could go to the shop next door and look at the black mark on the
wall where their phone system USED to be!!!!

He believed me then :-)


Keith

www.diyha.co.uk
www.kat5.tv