I would doubt if they cared but you definitely would have to take it up with them. On second thought, CC can be pretty stupid so maybe they would. If they don't let you, doing as you described would be as good as you could hope for.
On the bonding all part, I would wonder what all these ground systems tie to. They call it a ground because that is where it goes of course. does this tower have a bunch of different unconnected ground systems at ground level? Meaning, don't all the cell companies and so forth all tie into the same ground ring or ground system? If so it really doesn't matter as they should all stay pretty close with the exception of some ever so slight timing differences in the rise and fall. What you do to get to the ground doesn't matter nearly as much as what you do to get there. Ohhh... a long time ago...at one of the first..the first...I don't remember... AF I did a talk on grounding. This tower i am building now came back with a ground resistance of 10 Ohms using the greenfield method. You can use 3 stakes but I like 4. Anyway, you use that figure to determine what you are going to have to do to get the tower to ground resistance down to 5 Ohms. If you have a single ground rod with an earth resistance of 50 ohms you could take a 500 Mil copper line to it and it still wouldn't do you as much good as sinking a bunch more ground rods tied together to lower the resistance value. Having said all that, if some on the tower have an issue and some don't it would seem to me it isn't the ground system in the dirt that is the issue. It is really hard to argue with something that is working and I would duplicate the working setup. On Tue, Jul 25, 2017 at 12:38 PM Paul McCall <[email protected]> wrote: > Lewis, > > > > On option 2, if you are just leasing space on a tower such as Crown > Castle, etc., I have doubts that they would allow me to install the 8’ rod > at the top and run the 2/0 down the tower. So, would you, just do a 2/0 > starting at your equipment area, bond to the tower at that height, and go > down from there? > > > > On the “bonding everything together” scenario, if the tower ground is not > as good as the other grounds going down the tower (mine, the cellular > companies, etc.) won’t the differential in impedance cause the lightning to > 1) likely take the lesser impedance path down and/or 2) have the voltage > not rise and fall together and bad things happen from that? > > > > Paul > > *From:* Af [mailto:[email protected]] *On Behalf Of *Lewis Bergman > *Sent:* Monday, July 24, 2017 1:47 PM > > > *To:* [email protected] > *Subject:* Re: [AFMUG] Tower Top Grounding discussion > > > > On 1. it will be really difficult to completely isolate a piece of > equipment unless it is designed to float but good luck. If you are truly > going to isolate everything from ground then you won't need to worry about > #2 as all will float. You should check that the antenna you are using don't > require a ground plane. > > On 2. I Cadweld a 2/0 jacketed to an 8' rod at the top of the tower, not > isolated. I then bond (15 ton Hydraulic Crimp) it to a bus bar 5' below the > top for equipment grounds. Anywhere else there is a cluster of equipment I > also put a bus bar. I then take that 2/0 to the bottom to the last bus bar > and then into the ground ring. > > > > 1. *Wondering what materials people are using to isolate their mounts?* > What is sufficient? Would the rubber from a thick radiator hose be enough > to keep the lightning from coming through? Double thicknesses? > > > > One consultant recommended starboard, but I am not sure how I will craft > that into a work piece that would mold around a tower leg and be able to > grip it. > > > > 1. *What size wire should be going down the tower to bond to my tower > / electrical ground? * > > I am assuming it should be insulated but is normal THHN jacketing enough > to have it truly isolate from something jumping over or does it have be in > conduit. > > > > Paul > > > > Paul McCall, President > > PDMNet, Inc. / Florida Broadband, Inc. > > 658 Old Dixie Highway > > Vero Beach, FL 32962 > > 772-564-6800 <(772)%20564-6800> > > [email protected] > > www.pdmnet.com > > www.floridabroadband.com > > > > > >
