[TowerTalk] Lightnig Arrestors at tower base or house entrance?

[Alfred Frugoli]

Dick said:

With arrestors at the tower only, a surge could be induced in the portion of
the cables leading from the tower to the house, and there would be no
protection from the surge jumping right to the equipment inside the house.

Dick also said:

I have a set of arrestors at the bulkhead entrance, and another identical
set at the tower. One reason is that I have SO2R switching equipment at the
base of the tower and I wanted to protect it. Also, the run to the house is
over 225 feet, which is a long way for a surge to travel before finding a
path to ground. Seemed like a good idea to give it a shorter path to protect
the long and very expensive cable runs.

So I'm envisioning the following (--- being coax cables)

     Tower-----arrestor at base of tower-----2x6 switch-----arrestor at
bulkhead----equipment

My question is what guarantee is there that any surge induced in the cables
between the tower and the house is going to find the ground at the house end
of the cables?  It could just as easily flow down the cable towards the
switches/tower, in which case the switches are not protected.  Or is this
one of those cases where it is very important to interconnect all your
grounds so that there is equal potential at all grounds?  It still seems
that if the induced surge were closer to the switches it would find it's
path to ground by going back towards the tower (and switches you're trying
to protect).  It would seem that the only solution is to "isolate" the
switches from all coax/control lines by putting arrestors on both the input
and output of the switches, as well as at the bulkhead.

Does this make any sense?

73 de Al, KE1FO



> 73, Dick WC1M
>
>
> > -----Original Message-----
> > From: K7LXC at aol.com [mailto:K7LXC at aol.com]
> > Sent: Monday, February 25, 2008 6:25 PM
> > To: towertalk at contesting.com; gathorne at traer.net
> > Subject: Re: [TowerTalk] Lightnig Arrestors at tower base or house
> > entrance?
> >
> >
> > In a message dated 2/25/2008 12:42:59 P.M. Pacific Standard Time,
> > towertalk-request at contesting.com writes:
> >
> > >  I've seen descriptions and pictures of installations where
> > lightning
> > arrestors were installed in a weather proof box at the tower base  and
> > others
> > where they are at the house entrance.  Which is  better?
> >
> >
> >         Well, the whole idea is to  keep the transients out of the
> > house so
> > that's where your Single Point Ground  System should be and all of the
> > transient arrestors.
> >
> > Cheers,
> > Steve     K7LXC
> > TOWER TECH
> >
> >
> >
> > **************Ideas to please picky eaters. Watch video on AOL Living.
> > (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-
> > campos-duffy/
> > 2050827?NCID=aolcmp00300000002598)
>
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