EMP is generated by a atomic bomb. Electro Magnetic Pulse. Lightning has similar charaistics as EMP generated from a atomic bomb but still different in many aspects. Both over generate a electrical pulse threat that can be addressed in similar fashion to protect your equipment.
Great white paper that introduces you to EMP and Lightning theat can be found here. http://www.blackmagic.com/ses/bruceg/EMC/EMP-Light.html 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 - eBay UserID : macahan --- searchable smartBridges mailing list archive. http://www.mail-archive.com/smartbridges40part-15.org/ -- DP> You are kidding right? DP> The simplest and easiest way to prove this is to listen to AM radio during DP> an electrical storm. The static you hear every time lightning strikes is DP> the result of the E.M. P. (ElectroMagnetic Pulse) from a massive electrical DP> burst. Lightning will produce radio waves across a huge portion of the DP> electromagnetic spectrum. DP> Dan Petermann DP> Wyoming.com DP> At 10:01 AM 6/29/2003 -0500, you wrote: >>I thought we all had a long conversation not too long ago and was determined >>that Lightning CAN NOT cause E.M.P. >> >>Michael >> >>----- Original Message ----- >>From: "Nish Park" <[EMAIL PROTECTED]> >>To: <[EMAIL PROTECTED]> >>Sent: Sunday, June 29, 2003 9:45 AM >>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 >>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 DP> The PART-15.ORG smartBridges Discussion List DP> To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> DP> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) DP> Archives: http://archives.part-15.org DP> --- DP> [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
