Well Lightning can't cause EMP but it's very similar both of them result in an electrical pulse threat that can be addressed with similar circuit protection techniques. There is a good white paper here http://www.blackmagic.com/ses/bruceg/EMC/EMP-Light.html
So don't underestimate the power of CHEESE!! ohh wait sorry that was supposed to be lightning ;) Best regards, Eje Gustafsson mailto:[EMAIL PROTECTED] The Family Entertainment Network http://www.fament.com Phone : 620-231-7777 Fax : 620-231-4066 - Your Full Time Professionals - Online Store http://www.fament.com/catalo/ --- wp1o> I thought we all had a long conversation not too long ago and was determined wp1o> that Lightning CAN NOT cause E.M.P. wp1o> Michael wp1o> ----- Original Message ----- wp1o> From: "Nish Park" <[EMAIL PROTECTED]> wp1o> To: <[EMAIL PROTECTED]> wp1o> Sent: Sunday, June 29, 2003 9:45 AM wp1o> Subject: RE: [smartBridges] Grounding?! >> Wow. This are nice tips John. We will make sure to include them in our >> product documentation to help others. Thanks. >> >> Nish >> >> >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of John Hokenson >> Sent: Sunday, June 29, 2003 3:01 PM >> To: '[EMAIL PROTECTED]' >> Subject: Re: [smartBridges] Grounding?! >> >> I've been involved with designing and installing communications systems >> for >> over thirty years, are here is my take on the proper installlation and >> grounding of the SmartBridge units (and WISP equipment in general).... >> >> TOWER TOP ACCESS POINTS/BRIDGES >> >> 1. In any area that is prone to lightning, grounding and protection >> of >> the antenna port is a must. With the units that are fed from the ground >> with PoE (power over ethernet) and an antenna jack, first--screw a high >> quality lightning supressor on the N-female jack on the radio--the >> Polyphaser PSX-ME is what I prefer. It has a male connector to screw >> onto >> the radio and a female for attachment of the antenna cable. Since the >> case >> of the radio is plastic and does not ground to the tower (not really a >> good >> idea in my opinion but we're stuck with it), use a grounding kit to >> securely >> bond the body of the protector to the metal leg of the tower. >> 2. I am suspecting that many of the radio failures are due to induced >> emp >> from nearby lightning strikes on the ethernet cable itself which is >> acting >> as an antenna to pick up the pulse. For this reason I suggest the use >> of >> outdoor shielded cat5--the kind with icky pick embedded in the inner >> layer >> among the pairs, a first pvc insulation layer, an aluminum jacket with >> additional icky pick and finally an outer PVC jacket. At the radio end, >> terminate the connection as close as you can get it to the radio--the >> new >> style radios I would terminate it in the weatherproof splice box. You >> will >> need a bonding kit to attach a ground wire to the aluminuum >> jacket--these >> are commonly made by 3M and available from Graybar. Using a #10 or >> larger >> wire attached to the stud on the grounding kit, bond the shield to the >> leg >> of the tower, keeping the ground wire as short as possible. The best >> way I >> have found to do this is to assemble the grounding kit to the shield >> about >> 6" from the end of the cable where the pairs will be attached, then >> slide >> some Panduit DB shrink with hot glue sealant inside over the splice and >> shrink it down to weather seal the bond. Since you also need the ground >> for >> the antenna protector, you can clamp a phospher bronze ground clamp to >> the >> leg of the tower directly below the radio and attach both the ground >> from >> the antenna protector and the cat5 ground to the same point. Graybar >> has >> the Panduit shrink and ground clamps as well. >> 3. Install another bonding kit on the cat5 where it leaves the tower, >> again you can seal it with Panduit DB shrink. >> 4. If the run up the tower is more than 150' (50M) or so, I would >> probably bond the shield in the middle of the run as well. >> 5. Where the cat5 terminates, again bond the shield to a ground....#8 >> or >> larger copper wire back to the tower ground is preferable, lacking that >> the >> building ground....and make sure someone has bonded that to the tower >> ground >> with #6 or larger copper. >> 6. Lastly, between the end of the shielded cat5 and the PoE injector, >> install a good quality PoE surge suppressor--Motorola makes a nice one >> for >> their Canopy products and is available from Tessco for about $40. Make >> sure >> the ground stud on it is tied to the same ground feeding the end of the >> cat5 >> shield. >> 7. Code generally requires that the protector beinstalled where the >> cat5 >> enters the building, so the place to terminate the shielded cat5 and >> install >> the Motorola cat5 protector is on the outside of the wall, and >> transition >> there to normal cat5 in to your power injector. >> >> ROOFTOP ACCESS POINTS/BRIDGES >> >> 1. Many times either an access point or cpe radio will be installed >> on >> the top of a commercial building or home. The same rules apply with >> some >> modifications because of the installation. >> 2. If it is a customer radio that is not as critical as an access >> point, >> you may choose to dispense with the lightning supressor on the >> antenna--but >> DO at the minimum bond the shield of the coax to the galvanized metal >> support mast or support structure or DSS mount. One option for this >> would >> be to loosen the lock nut for the N female connector on the radio and >> install a piece of sheet metal under the nut to attach a ground >> wire--we've >> done this and it works well. >> 3. You still need to use shielded cat5 and bond the shield to the >> common >> antenna ground point as described in the previous section on tower >> grounding. >> 4. Since the antenna support is most likely not grounded in this >> instance, you need to attach a #6 copper wire to the support stucture >> (the >> 5/16 bolts securing the tripod to the mast is a good spot) and bring it >> down >> along with the cat 5 to where things enter the building. >> 5. Attach the #6 wire to the ground lug on the cat5 protector, along >> with >> the cat5 shield, then continue to the closest attachment point to the >> building system ground. >> >> INDOOR ACCESS POINTS AND BRIDGES >> >> 1. In those cases where the installation is using an indoor unit with >> coax out to an outdoor antenna, I would direct you to a typical >> installation >> of a certified SmartBridge CPE: >> http://www.vircom.net/pictures/res-install/res-install.htm >> 2. In the case of an indoor access point, the only change I would >> suggest >> is installation of a Polyphaser PSX instead of simply a bulkhead ground >> at >> the entrance point. >> >> Hope this helps a few of you out there avoid unnecessary failures. >> >> ========================================== >> John Hokenson, Operations Manager >> VIRCOM.NET >> reply to: [EMAIL PROTECTED] >> 425-558-0674 bellevue >> 425-432-8172 king county >> 206-341-9421 seattle >> 800-806-7446 toll-free >> 425-432-8173 fax >> WWW.VIRCOM.NET >> giving you the world since 1994 >> ========================================== >> ----- Original Message ----- >> From: "David Berndt" <[EMAIL PROTECTED]> >> To: <[EMAIL PROTECTED]> >> Sent: Saturday, June 28, 2003 9:50 PM >> Subject: [smartBridges] Grounding?! >> >> >> > A bit of a mid-night rant here. >> > >> > I've been thinking on a lot of the failures we hear talked about here >> on >> > the list, the quesitons about lightning, potential lightning strikes, >> > lightning striking near by. Alot of the answers seem to be a >> combination >> of >> > finger crossing and some black magic. >> > >> > So what I'd like to see to rectify some of these issues is smartbridge >> > publish a document about proper grounding. Where do we need >> grounds/surge >> > protectors/lightning arrestors, the differences between them, etc. >> > >> > I know these things are all dictated by the local building code and >> the >> > like wherever you happen to be using the product. But how about some >> sort >> > of a document that is intended as a bare minimum/recommended practices >> > document to get all the installs to be put together in a fairly >> similar >> way >> > and help correct some of the new newbie mistakes and take a bit of the >> > black magic out of this. >> > >> > This could be a fairly simple diagram of a few different sample setups >> of >> > the outdoor equipment. I am especially interested in the total >> equipment, >> > is there a polyphaser in there? Should the cat5 be grounded when using >> > sheilded cat5, otherwise? Surge protector on the cat5? before/after >> the >> POE >> > device? etc etc. >> > >> > A recommended parts list wouldnt be horrible either. I do not want to >> see >> > this enforced, but more documentation and standardization would make >> things >> > clearer for everyone, provide a quick way to answer peoples questions >> and >> > maybe make everyones systems a bit more stable. >> > >> > Hope that made some degree of sense. >> > >> > Dave >> > >> > The PART-15.ORG smartBridges Discussion List >> > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe >> smartBridges <yournickname> >> > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe >> smartBridges) >> > Archives: http://archives.part-15.org >> >> The PART-15.ORG smartBridges Discussion List >> To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe >> smartBridges <yournickname> >> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe >> smartBridges) >> Archives: http://archives.part-15.org >> >> >> The PART-15.ORG smartBridges Discussion List >> To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe wp1o> smartBridges <yournickname> >> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe wp1o> smartBridges) >> Archives: http://archives.part-15.org >> >> wp1o> The PART-15.ORG smartBridges Discussion List wp1o> To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> wp1o> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) wp1o> Archives: http://archives.part-15.org wp1o> --- wp1o> [This E-mail scanned for viruses by Declude Virus] --- [This E-mail scanned for viruses by Declude Virus] The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://archives.part-15.org
