I see stuff on the Internet saying the “cone of protection” is a myth, but empirically it has worked for me.
If an omni antenna is the highest thing on a tower or grain elevator, it’s gonna get hit. Lots. Ouch. If there is even just a plain metal pipe that sticks up higher than any antennas so they are under the “cone of protection”, the probability of damage is greatly reduced or eliminated. I assume it’s a combination of bleeding off charge to avoid strikes, and giving it something else to strike rather than your equipment. From: AF <[email protected]> On Behalf Of Lewis Bergman Sent: Thursday, May 23, 2019 9:00 AM To: AnimalFarm Microwave Users Group <[email protected]> Subject: Re: [AFMUG] Fw: Active Lightning Suppressor - Snake Oil, or Science? R56 is a standard developed by Motorola for critical communications sites. Chuck can likely point you to a similiar standard developed by NEC or some Telco consortium that defines grounding standards for telco facilities. Half the standards are usually about human safety and the other half are about equipment safety. The bottom line is, if you can get your site to less than 5 Ohms earth resistance to ground you are about as good as you can hope for. Lower is better but below 5 Ohms the return on investment diminshes rapidly. I think the lowest I have seen is 0.5 Ohms on a brand new site. We put a lot of grounding, enhancemnet material, etc. But it is like good insurance and it does work. We had an old tower that had poor grounding. We retrofitted it with a modern system and lowered the number of strikes from an average of 15 or so a year to 1 in 3 years. You can use a device like this: Clamp on ground tester <http://www.testequipmentdepot.com/AEMC/ground-resistance-testers/clamp-on/clamp-on-ground-resistance-tester-6416.htm?ref=gbase&gclid=CjwKCAjwiZnnBRBQEiwAcWKfYi9_sp7BYOU7SUh8oCsy0VRd-Sm9Kx05ShpV-11tT_xAboQ4UAY5GxoClmgQAvD_BwE> to easily measure the resistance of a whole site. You do have to know where and how to use it. To accurately measure parts of a grounding system accurately you have to know how it is designed. Most of the time a zer resistance reading means you are measuring a loop of copper. I laugh every time I go to a cell site and they have a ground test pound that is basically a loop on top of a ground rod. Yaeh, no wonder they passed the test. On Wed, May 22, 2019 at 9:32 PM Chuck McCown <[email protected] <mailto:[email protected]> > wrote: Google “Air Terminal Lightning” and then click on images. Or just check out some of these: <https://www.erico.com/category.asp?category=R2438> https://www.erico.com/category.asp?category=R2438 <https://www.jjengineersindia.com/lightning-protection-system.html> https://www.jjengineersindia.com/lightning-protection-system.html <https://www.jmvearthing.com/early-streamer-emmission.html> https://www.jmvearthing.com/early-streamer-emmission.html This one has some snake oil type of hype too: <http://www.lps-pacifica.com/Ellips.html> http://www.lps-pacifica.com/Ellips.html Ever read “Something Wicked This Way Comes”? From: Matt Hoppes Sent: Wednesday, May 22, 2019 7:16 PM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] Fw: Active Lightning Suppressor - Snake Oil, or Science? So if this is all snake oil - why do some commercial towers have some variation of this at the top? That’s what I’m trying to understand. An engineer for clear channel told me he’s seen a corona develop around one of his towers that had a similar item on it when storms are coming through the area. On May 22, 2019, at 2:56 PM, Bill Prince <[email protected] <mailto:[email protected]> > wrote: My SO is unusually wary of lightning and lightning strikes. If there is the slightest hint of lightning or thunder, she reverts to the air gap method of lightning protection. If there are no wires connected to a piece of electronics, then it is most safe. Doesn't help a lot in our business, but that is what she does. bp <part15sbs{at}gmail{dot}com> On 5/22/2019 11:51 AM, Matt Hoppes wrote: Are you suggesting that if you power off the equipment during a lightning strike it won’t take damage? Why would that be? On May 22, 2019, at 2:42 PM, dave <[email protected] <mailto:[email protected]> > wrote: I have been working with this AS3935 franklin lightning sensor for about 6 months now and learned so much more about lighting and its projected energies and possible frequencies its amazing how this little sensor can detect distance and the amount of energy BEFORE it strikes. So,armed with this ability I am solely working on a design along with IR sensing to help mitigate damage to a site during a storm. I am still working on the timing to be able to shut down power to the gear outside for a time period at which if lightning is still present remain off till storm passes. End of Run sites are the worst but knock on wood after a year or 2 of planning and cleaning up the existing grounds everything seems well. <Vcard.jpg> On 5/22/19 9:23 AM, [email protected] <mailto:[email protected]> wrote: This is from the executive director of the lightning protection institute. -----Original Message----- From: Bud VanSickle Sent: Wednesday, May 22, 2019 7:41 AM To: 'Chuck McCown' Subject: RE: [AFMUG] Active Lightning Suppressor - Snake Oil, or Science? Snake oil for sure. You can't stop lightning strikes because of the volume of energy and short time period. If you put one of these devices on a fully grounded metallic tower, it would most likely take a strike to ground. Of course, if you ground your metallic tower properly, it is like a giant lightning rod, so you are out the money for this "topper". By the way, on tall towers, lightning doesn't necessarily strike the top anyway - it is almost never straight vertical and may be at a 45 degree angle to the side. But let me ask you this - if all the pine needles in a forest can release ions (which they can and do) or all the blades of grass on the prairie, why does lightning still strike there? Bud VanSickle -----Original Message----- From: Chuck McCown [mailto:[email protected]] Sent: Wednesday, May 22, 2019 7:51 AM To: [email protected] <mailto:[email protected]> Subject: Fw: [AFMUG] Active Lightning Suppressor - Snake Oil, or Science? I think snake oil. You? -- AF mailing list [email protected] <mailto:[email protected]> http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] <mailto:[email protected]> http://af.afmug.com/mailman/listinfo/af_af.afmug.com _____ -- AF mailing list [email protected] <mailto:[email protected]> http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] <mailto:[email protected]> http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- Lewis Bergman 325-439-0533 Cell
-- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com
