Thanks, Phil -- I'm familiar with all this info - I guess I should have
made it clear I was only really asking about the grounding of the entry panel.
73, Pete
At 09:31 AM 8/2/2005, Phil Camera wrote:
>I'll take a stabe at this. First off, go to the Polyphaser and ICE
>websites and thoroughly read up on what they recommend for second floor
>shack grounding.
>
>
>You've grounded the shields but you've not grounded the center
>conductor. The only way to do that is to install lightning arrestors
>which will protect both sides of the coax. Also, the long run from the
>existing shield ground up to the shack entrance may be long enough for
>energy to be induced in that section alone. I'd say that Poly and ICE
>will recommend that you install arrestors up at the shack entrance panel
>and then run a very low resistance/impedance ground wire (wide copper
>strap) down to the house perimeter ground. You didn't say how the
>existing shield ground is bonded to the AC entrance ground. If that is
>not low resistance/impedance then it may be useless. You may want to beef
>up that connection wire and/or add ground rods along it's length. Finally
>depending on if your house wiring is in conduit or not you'll want to
>install either whole house surge protection (former) or surge protectors
>at the shack equipment (latt er) to protect against energy induced into
>the house wiring. All of this also applies to CATV, network, rotator
>control, and other wiring that connects to the equipment. Finally if the
>tower ground system is not too far away, connect it to the house perimeter
>ground system. How is the tower ground constructed? Phil KB9CRY
>
>-------------- Original message --------------
>
> > At 05:43 AM 8/2/2005, Tom Rauch wrote:
> > >....You not only had a very poor tower ground, it sounds like
> > >the entrance panel was never bonded to the power mains
> > >entrance ground! If we don't bond the entrance panel to the
> > >utility ground it is a big problem (and goes against the
> > >national electric code).
> > >
> > >As you painfully found out, ground rods do next to nothing
> > >for establishing a good ground. A poorly grounded radio
> > >entrance panel that isn't bonded to the utility entrance is
> > >also a big problem.
> >
> >
> > OK - Question. My aluminum entrance panel is in a second-floor
> > window. The hardline (CATV) comes out of the ground (conduit) alongside
> > the house, and flexible coax runs from there across a porch roof, maybe 50
> > feet to the shack window. Where the hardline comes out of the conduit, I
> > have grounded the shield to the same ground rod as the AC service.
> >
> > I disconnect everything at the entry panel but don't usually disconnect
> > equipment from the house AC. With close hits I have had three instances
> > when I have had arcs from the center conductor of the barrels in the entry
> > panel to the shell, and thence to ground -- it's pretty startling, but
> > aside from a little soot, no visible damage.
> >
> > Two years ago I took a hit on the top of my tower, about 200 feet from the
> > house. No radio gear was damaged. I lost 2 computers and a phone
> > answering machine due (I think) to induced voltage on the house Ethernet
> > wiring, and of course everything electrical on the tower proper (2
> > rotators, an RCS-4V and a Stackmatch).
> >
> > Have I done ab out all I can, given my compromise shack location? Would it
> > make sense to plug grounding plugs into the barrel connectors, to "assist"
> > the strike voltage in finding its way to ground?
> >
> > 73, Pete N4ZR
> >
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather
> > Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
> questions
> > and ask for Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>--
>Phil - KB9CRY
>Lockport, IL
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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