I just recently bought a clamp on ground impedance tester. I found one system that was less than an ohm, worst one was almost 800 ohms. Only a few were below 25 ohms. You're absolutely right: good lightning protection starts with a good ground. The impedance tester takes the guess work out of just how good (or bad) the grounding is. My theory is that in a poorly grounded system with everything tied together, that the strike (or induced surge) just oscillates back and forth through the system dissipating itself through the components of the system.
R. Walters r...@solarray.com Solar Engineer On Apr 17, 2010, at 9:18 AM, Darryl Thayer wrote: > This last week I spoke with a cell phone tower installer. He said, Nothing > beats the ground! he said the most important thing is the tower grounding, > The idea of 25 Ohms to Ground is way to high. Ground rods are useless, and > lightning arresters do no good without a good ground, in fact people who > worry about the lightning arrestor putting power back into there system have > something to worry about if the ground is not good. > > So that is what he said and was very adimit about it. > Darryl > > --- On Fri, 4/16/10, Marco Mangelsdorf <ma...@pvthawaii.com> wrote: > > From: Marco Mangelsdorf <ma...@pvthawaii.com> > Subject: [RE-wrenches] DC lightning arrestors > To: "'RE-wrenches'" <re-wrenches@lists.re-wrenches.org> > Date: Friday, April 16, 2010, 5:31 PM > > Is the best one can do as far as high DC array voltage the Delta LA602? > > > Didn’t they used to have a high voltage version of the LA302DC? > > > Thanks, > > marco > > > <image001.jpg> > > Marco Mangelsdorf, President > 69 Railroad Avenue, A-7 > Hilo, Hawai'i 96720 > (808) 969-3281, 934-7462 facsimile > www.provision-solar.com > > > > -----Inline Attachment Follows----- > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org >
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