I don't care to get into it other than to say just because you call a frog a duck does not make him a duck....
JH ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, June 29, 2003 8:01 AM Subject: Re: [smartBridges] Grounding?! > 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 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
